1
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Chiu PL, Orjuela JD, de Groot BL, Aponte Santamaría C, Walz T. Structure and dynamics of cholesterol-mediated aquaporin-0 arrays and implications for lipid rafts. eLife 2024; 12:RP90851. [PMID: 39222068 PMCID: PMC11368405 DOI: 10.7554/elife.90851] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/04/2024] Open
Abstract
Aquaporin-0 (AQP0) tetramers form square arrays in lens membranes through a yet unknown mechanism, but lens membranes are enriched in sphingomyelin and cholesterol. Here, we determined electron crystallographic structures of AQP0 in sphingomyelin/cholesterol membranes and performed molecular dynamics (MD) simulations to establish that the observed cholesterol positions represent those seen around an isolated AQP0 tetramer and that the AQP0 tetramer largely defines the location and orientation of most of its associated cholesterol molecules. At a high concentration, cholesterol increases the hydrophobic thickness of the annular lipid shell around AQP0 tetramers, which may thus cluster to mitigate the resulting hydrophobic mismatch. Moreover, neighboring AQP0 tetramers sandwich a cholesterol deep in the center of the membrane. MD simulations show that the association of two AQP0 tetramers is necessary to maintain the deep cholesterol in its position and that the deep cholesterol increases the force required to laterally detach two AQP0 tetramers, not only due to protein-protein contacts but also due to increased lipid-protein complementarity. Since each tetramer interacts with four such 'glue' cholesterols, avidity effects may stabilize larger arrays. The principles proposed to drive AQP0 array formation could also underlie protein clustering in lipid rafts.
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Affiliation(s)
- Po-Lin Chiu
- Department of Cell Biology, Harvard Medical SchoolBostonUnited States
| | - Juan D Orjuela
- Max Planck Tandem Group in Computational Biophysics, Universidad de los AndesBogotáColombia
- Biomedical Engineering Department, Universidad de los AndesBogotáColombia
| | - Bert L de Groot
- Computational Biomolecular Dynamics Group, Max Planck Institute for Multidisciplinary SciencesGöttingenGermany
| | - Camilo Aponte Santamaría
- Max Planck Tandem Group in Computational Biophysics, Universidad de los AndesBogotáColombia
- Molecular Biomechanics Group, Heidelberg Institute for Theoretical StudiesHeidelbergGermany
| | - Thomas Walz
- Department of Cell Biology, Harvard Medical SchoolBostonUnited States
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2
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Eberle SA, Gustavsson M. Bilayer lipids modulate ligand binding to atypical chemokine receptor 3. Structure 2024; 32:1174-1183.e5. [PMID: 38776922 DOI: 10.1016/j.str.2024.04.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Revised: 02/28/2024] [Accepted: 04/25/2024] [Indexed: 05/25/2024]
Abstract
Chemokine receptors belong to the large class of G protein-coupled receptors (GPCRs) and are involved in a number of (patho)physiological processes. Previous studies highlighted the importance of membrane lipids for modulating GPCR structure and function. However, the underlying mechanisms of how lipids regulate GPCRs are often poorly understood. Here, we report that anionic lipid bilayers increase the binding affinity of the chemokine CXCL12 for the atypical chemokine receptor 3 (ACKR3) by modulating the CXCL12 binding kinetics. Notably, the anionic bilayer favors CXCL12 over the more positively charged chemokine CXCL11, which we explained by bilayer interactions orienting CXCL12 but not CXCL11 for productive ACKR3 binding. Furthermore, our data suggest a stabilization of active ACKR3 conformations in anionic bilayers. Taken together, the described regulation of chemokine selectivity of ACKR3 by the lipid bilayer proposes an extended version of the classical model of chemokine binding including the lipid environment of the receptor.
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Affiliation(s)
- Stefanie Alexandra Eberle
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark
| | - Martin Gustavsson
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark.
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3
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Jeon CK, Rojas Ramirez C, Makey DM, Kurulugama RT, Ruotolo BT. CIUSuite 3: Next-Generation CCS Calibration and Automated Data Analysis Tools for Gas-Phase Protein Unfolding Data. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2024; 35:1865-1874. [PMID: 38967378 DOI: 10.1021/jasms.4c00176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/06/2024]
Abstract
Ion mobility-mass spectrometry (IM-MS) has become a technology deployed across a wide range of structural biology applications despite the challenges in characterizing closely related protein structures. Collision-induced unfolding (CIU) has emerged as a valuable technique for distinguishing closely related, iso-cross-sectional protein and protein complex ions through their distinct unfolding pathways in the gas phase. With the speed and sensitivity of CIU analyses, there has been a rapid growth of CIU-based assays, especially regarding biomolecular targets that remain challenging to assess and characterize with other structural biology tools. With information-rich CIU data, many software tools have been developed to automate laborious data analysis. However, with the recent development of new IM-MS technologies, such as cyclic IM-MS, CIU continues to evolve, necessitating improved data analysis tools to keep pace with new technologies and facilitating the automation of various data processing tasks. Here, we present CIUSuite 3, a software package that contains updated algorithms that support various IM-MS platforms and supports the automation of various data analysis tasks such as peak detection, multidimensional classification, and collision cross section (CCS) calibration. CIUSuite 3 uses local maxima searches along with peak width and prominence filters to detect peaks to automate CIU data extraction. To support both the primary CIU (CIU1) and secondary CIU (CIU2) experiments enabled by cyclic IM-MS, two-dimensional data preprocessing is deployed, which allows multidimensional classification. Our data suggest that additional dimensions in classification improve the overall accuracy of class assignments. CIUSuite 3 also supports CCS calibration for both traveling wave and drift tube IM-MS, and we demonstrate the accuracy of a new single-field CCS calibration method designed for drift tube IM-MS leveraging calibrant CIU data. Overall, CIUSuite 3 is positioned to support current and next-generation IM-MS and CIU assay development deployed in an automated format.
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Affiliation(s)
- Chae Kyung Jeon
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | | | - Devin M Makey
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | | | - Brandon T Ruotolo
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
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4
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Sokratous K, Cooper-Shepherd DA, Ujma J, Qu F, Giles K, Ben-Younis A, Hensen M, Langridge JI, Gault J, Jazayeri A, Liko I, Hopper JTS. Enhanced Declustering Enables Native Top-Down Analysis of Membrane Protein Complexes using Ion-Mobility Time-Aligned Fragmentation. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2024; 35:1891-1901. [PMID: 39007842 DOI: 10.1021/jasms.4c00190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/16/2024]
Abstract
Native mass spectrometry (MS) is proving to be a disruptive technique for studying the interactions of proteins, necessary for understanding the functional roles of these biomolecules. Recent research is expanding the application of native MS towards membrane proteins directly from isolated membrane preparations or from purified detergent micelles. The former results in complex spectra comprising several heterogeneous protein complexes; the latter enables therapeutic protein targets to be screened against multiplexed preparations of compound libraries. In both cases, the resulting spectra are increasingly complex to assign/interpret, and the key to these new directions of native MS research is the ability to perform native top-down analysis, which allows unambiguous peak assignment. To achieve this, detergent removal is necessary prior to MS analyzers, which allow selection of specific m/z values, representing the parent ion for downstream activation. Here, we describe a novel, enhanced declustering (ED) device installed into the first pumping region of a cyclic IMS-enabled mass spectrometry platform. The device enables declustering of ions prior to the quadrupole by imparting collisional activation through an oscillating electric field applied between two parallel plates. The positioning of the device enables liberation of membrane protein ions from detergent micelles. Quadrupole selection can now be utilized to isolate protein-ligand complexes, and downstream collision cells enable the dissociation and identification of binding partners. We demonstrate that ion mobility (IM) significantly aids in the assignment of top-down spectra, aligning fragments to their corresponding parent ions by means of IM drift time. Using this approach, we were able to confidently assign and identify a novel hit compound against PfMATE, obtained from multiplexed ligand libraries.
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Affiliation(s)
- Kleitos Sokratous
- OMass Therapeutics, Chancellor Court, John Smith Drive, ARC Oxford OX4 2GX, United Kingdom
| | | | - Jakub Ujma
- Waters Corporation, Stamford Avenue, Altrincham Road, Wilmslow SK9 4AX, United Kingdom
| | - Feng Qu
- OMass Therapeutics, Chancellor Court, John Smith Drive, ARC Oxford OX4 2GX, United Kingdom
| | - Kevin Giles
- Waters Corporation, Stamford Avenue, Altrincham Road, Wilmslow SK9 4AX, United Kingdom
| | - Aisha Ben-Younis
- OMass Therapeutics, Chancellor Court, John Smith Drive, ARC Oxford OX4 2GX, United Kingdom
| | - Mario Hensen
- OMass Therapeutics, Chancellor Court, John Smith Drive, ARC Oxford OX4 2GX, United Kingdom
| | - James I Langridge
- Waters Corporation, Stamford Avenue, Altrincham Road, Wilmslow SK9 4AX, United Kingdom
| | - Joseph Gault
- OMass Therapeutics, Chancellor Court, John Smith Drive, ARC Oxford OX4 2GX, United Kingdom
| | - Ali Jazayeri
- OMass Therapeutics, Chancellor Court, John Smith Drive, ARC Oxford OX4 2GX, United Kingdom
| | - Idlir Liko
- OMass Therapeutics, Chancellor Court, John Smith Drive, ARC Oxford OX4 2GX, United Kingdom
| | - Jonathan T S Hopper
- OMass Therapeutics, Chancellor Court, John Smith Drive, ARC Oxford OX4 2GX, United Kingdom
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5
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James VK, Voss BJ, Helms A, Trent MS, Brodbelt JS. Investigating Lipid Transporter Protein and Lipid Interactions Using Variable Temperature Electrospray Ionization, Ultraviolet Photodissociation Mass Spectrometry, and Collision Cross Section Analysis. Anal Chem 2024; 96:12676-12683. [PMID: 39038171 DOI: 10.1021/acs.analchem.4c01392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/24/2024]
Abstract
Gram-negative bacteria develop and exhibit resistance to antibiotics, owing to their highly asymmetric outer membrane maintained by a group of six proteins comprising the Mla (maintenance of lipid asymmetry) pathway. Here, we investigate the lipid binding preferences of one Mla protein, MlaC, which transports lipids through the periplasm. We used ultraviolet photodissociation (UVPD) to identify and characterize modifications of lipids endogenously bound to MlaC expressed in three different bacteria strains. UVPD was also used to localize lipid binding to MlaC residues 130-140, consistent with the crystal structure reported for lipid-bound MlaC. The impact of removing the bound lipid from MlaC on its structure was monitored based on collision cross section measurements, revealing that the protein unfolded prior to release of the lipid. The lipid selectivity of MlaC was evaluated based on titrimetric experiments, indicating that MlaC-bound lipids in various classes (sphingolipids, glycerophospholipids, and fatty acids) as long as they possessed no more than two acyl chains.
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Affiliation(s)
- Virginia K James
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Bradley J Voss
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, Georgia 30602, United States
| | - Amanda Helms
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
| | - M Stephen Trent
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, Georgia 30602, United States
- Department of Microbiology, College of Arts and Sciences, University of Georgia, Athens, Georgia 30602, United States
| | - Jennifer S Brodbelt
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
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6
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Jaillais Y, Bayer E, Bergmann DC, Botella MA, Boutté Y, Bozkurt TO, Caillaud MC, Germain V, Grossmann G, Heilmann I, Hemsley PA, Kirchhelle C, Martinière A, Miao Y, Mongrand S, Müller S, Noack LC, Oda Y, Ott T, Pan X, Pleskot R, Potocky M, Robert S, Rodriguez CS, Simon-Plas F, Russinova E, Van Damme D, Van Norman JM, Weijers D, Yalovsky S, Yang Z, Zelazny E, Gronnier J. Guidelines for naming and studying plasma membrane domains in plants. NATURE PLANTS 2024; 10:1172-1183. [PMID: 39134664 DOI: 10.1038/s41477-024-01742-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Accepted: 06/14/2024] [Indexed: 08/22/2024]
Abstract
Biological membranes play a crucial role in actively hosting, modulating and coordinating a wide range of molecular events essential for cellular function. Membranes are organized into diverse domains giving rise to dynamic molecular patchworks. However, the very definition of membrane domains has been the subject of continuous debate. For example, in the plant field, membrane domains are often referred to as nanodomains, nanoclusters, microdomains, lipid rafts, membrane rafts, signalling platforms, foci or liquid-ordered membranes without any clear rationale. In the context of plant-microbe interactions, microdomains have sometimes been used to refer to the large area at the plant-microbe interface. Some of these terms have partially overlapping meanings at best, but they are often used interchangeably in the literature. This situation generates much confusion and limits conceptual progress. There is thus an urgent need for us as a scientific community to resolve these semantic and conceptual controversies by defining an unambiguous nomenclature of membrane domains. In this Review, experts in the field get together to provide explicit definitions of plasma membrane domains in plant systems and experimental guidelines for their study. We propose that plasma membrane domains should not be considered on the basis of their size alone but rather according to the biological system being considered, such as the local membrane environment or the entire cell.
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Affiliation(s)
- Yvon Jaillais
- Laboratoire Reproduction et Développement des Plantes, Université de Lyon, ENS de Lyon, UCB Lyon 1, CNRS, INRAE, Lyon, France.
| | - Emmanuelle Bayer
- Laboratoire de Biogénèse Membranaire, UMR5200, Université de Bordeaux, CNRS, Villenave d'Ornon, France
| | - Dominique C Bergmann
- Department of Biology, Stanford University, Stanford, CA, USA
- Howard Hughes Medical Institute, Stanford University, Stanford, CA, USA
| | - Miguel A Botella
- Departamento de Biología Molecular y Bioquímica, Instituto de Hortifruticultura Subtropical y Mediterránea 'La Mayora', Universidad de Málaga-Consejo Superior de Investigaciones Científicas, Universidad de Málaga, Málaga, Spain
| | - Yohann Boutté
- Laboratoire de Biogénèse Membranaire, UMR5200, Université de Bordeaux, CNRS, Villenave d'Ornon, France
| | | | - Marie-Cecile Caillaud
- Laboratoire Reproduction et Développement des Plantes, Université de Lyon, ENS de Lyon, UCB Lyon 1, CNRS, INRAE, Lyon, France
| | - Véronique Germain
- Laboratoire de Biogénèse Membranaire, UMR5200, Université de Bordeaux, CNRS, Villenave d'Ornon, France
| | - Guido Grossmann
- Institute of Cell and Interaction Biology, CEPLAS Cluster of Excellence on Plant Sciences, Heinrich-Heine Universität Düsseldorf, Düsseldorf, Germany
| | - Ingo Heilmann
- Institute of Biochemistry and Biotechnology, Department of Plant Biochemistry, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Piers A Hemsley
- Division of Plant Sciences, School of Life Sciences, University of Dundee, Dundee, UK
- Cell and Molecular Sciences, James Hutton Institute, Dundee, UK
| | - Charlotte Kirchhelle
- Laboratoire Reproduction et Développement des Plantes, Université de Lyon, ENS de Lyon, UCB Lyon 1, CNRS, INRAE, Lyon, France
| | - Alexandre Martinière
- IPSiM, Université de Montpellier, CNRS, INRAE, Institut Agro, Montpellier, France
| | - Yansong Miao
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Sebastien Mongrand
- Laboratoire de Biogénèse Membranaire, UMR5200, Université de Bordeaux, CNRS, Villenave d'Ornon, France
| | - Sabine Müller
- Department of Biology, Friedrich Alexander Universität Erlangen Nuremberg, Erlangen, Germany
| | - Lise C Noack
- Copenhagen Plant Science Center, Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Yoshihisa Oda
- Department of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Japan
| | - Thomas Ott
- Cell Biology, Faculty of Biology, University of Freiburg, Freiburg, Germany
- Centre of Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany
| | - Xue Pan
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario, Canada
| | - Roman Pleskot
- Institute of Experimental Botany, Czech Academy of Sciences, Prague, Czech Republic
| | - Martin Potocky
- Institute of Experimental Botany, Czech Academy of Sciences, Prague, Czech Republic
| | - Stéphanie Robert
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, Umeå, Sweden
| | - Clara Sanchez Rodriguez
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid-Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Campus de Montegancedo UPM, Pozuelo de Alarcón, Spain
| | | | - Eugenia Russinova
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Daniel Van Damme
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Jaimie M Van Norman
- Department of Botany and Plant Sciences, Center for Plant Cell Biology, Institute of Integrative Genome Biology, University of California, Riverside, Riverside, CA, USA
| | - Dolf Weijers
- Laboratory of Biochemistry, Wageningen University, Wageningen, the Netherlands
| | - Shaul Yalovsky
- School of Plant Sciences and Food Security, Tel Aviv University, Tel Aviv, Israel
| | - Zhenbiao Yang
- Institute of Integrative Genome Biology, Department of Botany and Plant Sciences, University of California, Riverside, Riverside, CA, USA
- Faculty of Synthetic Biology, Shenzhen Institute of Advanced Technology, Shenzhen, China
- Key Laboratory of Quantitative Synthetic Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
- Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Enric Zelazny
- IPSiM, Université de Montpellier, CNRS, INRAE, Institut Agro, Montpellier, France
| | - Julien Gronnier
- NanoSignaling Lab, Zentrum für Molekularbiologie der Pflanzen, Eberhard Karls Universität Tübingen, Tübingen, Germany.
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7
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Qiao P, Odenkirk MT, Zheng W, Wang Y, Chen J, Xu W, Baker ES. Elucidating the role of lipid interactions in stabilizing the membrane protein KcsA. Biophys J 2024:S0006-3495(24)00478-8. [PMID: 39030907 DOI: 10.1016/j.bpj.2024.07.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2024] [Revised: 06/12/2024] [Accepted: 07/15/2024] [Indexed: 07/22/2024] Open
Abstract
The significant effects of lipid binding on the functionality of potassium channel KcsA have been validated by brilliant studies. However, the specific interactions between lipids and KcsA, such as binding parameters for each binding event, have not been fully elucidated. In this study, we employed native mass spectrometry to investigate the binding of lipids to KcsA and their effects on the channel. The tetrameric structure of KcsA remains intact even in the absence of lipid binding. However, the subunit architecture of the E71A mutant, which is constantly open at low pH, relies on tightly associated copurified lipids. Furthermore, we observed that lipids exhibit weak binding to KcsA at high pH when the channel is at a closed/inactivation state in the absence of permeant cation K+. This feeble interaction potentially facilitates the association of K+ ions, leading to the transition of the channel to a resting closed/open state. Interestingly, both anionic and zwitterionic lipids strongly bind to KcsA at low pH when the channel is in an open/inactivation state. We also investigated the binding patterns of KcsA with natural lipids derived from E. coli and Streptomyces lividans. Interestingly, lipids from E. coli exhibited much stronger binding affinity compared to the lipids from S. lividans. Among the natural lipids from S. lividans, free fatty acids and triacylglycerols demonstrated the tightest binding to KcsA, whereas no detectable binding events were observed with natural phosphatidic acid lipids. These findings suggest that the lipid association pattern in S. lividans, the natural host for KcsA, warrants further investigation. In conclusion, our study sheds light on the role of lipids in stabilizing KcsA and highlights the importance of specific lipid-protein interactions in modulating its conformational states.
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Affiliation(s)
- Pei Qiao
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China; Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas.
| | - Melanie T Odenkirk
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina
| | - Weiyi Zheng
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Yuchen Wang
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Jinhui Chen
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Wenhao Xu
- Collaborative Innovation Center of Yangtze River Delta Region Green Pharmaceuticals, Zhejiang University of Technology, Hangzhou, China
| | - Erin S Baker
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
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8
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Stover L, Zhu Y, Schrecke S, Laganowsky A. TREK2 Lipid Binding Preferences Revealed by Native Mass Spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2024; 35:1516-1522. [PMID: 38843438 PMCID: PMC11228984 DOI: 10.1021/jasms.4c00112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2024] [Revised: 05/24/2024] [Accepted: 05/28/2024] [Indexed: 07/04/2024]
Abstract
TREK2, a two-pore domain potassium channel, is recognized for its regulation by various stimuli, including lipids. While previous members of the TREK subfamily, TREK1 and TRAAK, have been investigated to elucidate their lipid affinity and selectivity, TREK2 has not been similarly studied in this regard. Our findings indicate that while TRAAK and TREK2 exhibit similarities in terms of electrostatics and share an overall structural resemblance, there are notable distinctions in their interaction with lipids. Specifically, SAPI(4,5)P2,1-stearoyl-2-arachidonoyl-sn-glycero-3-phospho-(1'-myo-inositol-4',5'-bisphosphate) exhibits a strong affinity for TREK2, surpassing that of dOPI(4,5)P2,1,2-dioleoyl-sn-glycero-3-phospho-(1'-myo-inositol-4',5'-bisphosphate), which differs in its acyl chains. TREK2 displays lipid binding preferences not only for the headgroup of lipids but also toward the acyl chains. Functional studies draw a correlation for lipid binding affinity and activity of the channel. These findings provide important insight into elucidating the molecular prerequisites for specific lipid binding to TREK2 important for function.
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Affiliation(s)
- Lauren Stover
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Yun Zhu
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Samantha Schrecke
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Arthur Laganowsky
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
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9
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Kumar S, Stover L, Wang L, Bahramimoghaddam H, Zhou M, Russell DH, Laganowsky A. Native mass spectrometry of membrane protein-lipid interactions in different detergent environments. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.27.601044. [PMID: 38979331 PMCID: PMC11230385 DOI: 10.1101/2024.06.27.601044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
Native mass spectrometry (MS) is revealing the role of specific lipids in modulating membrane protein structure and function. Membrane proteins solubilized in detergents are often introduced into the mass spectrometer; however, commonly used detergents for structural studies, such as dodecylmaltoside, tend to generate highly charged ions, leading to protein unfolding, thereby diminishing their utility for characterizing protein-lipid interactions. Thus, there is a critical need to develop approaches to investigate protein-lipid interactions in different detergents. Here, we demonstrate how charge-reducing molecules, such as spermine and trimethylamine-N-oxide, enable characterization of lipid binding to the bacterial water channel (AqpZ) and ammonia channel (AmtB) in complex with regulatory protein GlnK in different detergent environments. We find protein-lipid interactions are not only protein-dependent but can also be influenced by the detergent and type of charge-reducing molecule. AqpZ-lipid interactions are enhanced in LDAO (n-dodecyl-N,N-dimethylamine-N-oxide), whereas the interaction of AmtB-GlnK with lipids is comparable among different detergents. A fluorescent lipid binding assay also shows detergent dependence for AqpZ-lipid interactions, consistent with results from native MS. Taken together, native MS will play a pivotal role in establishing optimal experimental parameters that will be invaluable for various applications, such as drug discovery, as well as biochemical and structural investigations.
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Affiliation(s)
- Smriti Kumar
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Lauren Stover
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Lie Wang
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas 77030, United States
| | | | - Ming Zhou
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas 77030, United States
| | - David H. Russell
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Arthur Laganowsky
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
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10
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Jayasekera HS, Mohona FA, Ewbank M, Marty MT. Simultaneous Native Mass Spectrometry Analysis of Single and Double Mutants To Probe Lipid Binding to Membrane Proteins. Anal Chem 2024; 96:10426-10433. [PMID: 38859611 PMCID: PMC11215972 DOI: 10.1021/acs.analchem.4c01704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2024]
Abstract
Lipids are critical modulators of membrane protein structure and function. However, it is challenging to investigate the thermodynamics of protein-lipid interactions because lipids can simultaneously bind membrane proteins at different sites with different specificities. Here, we developed a native mass spectrometry (MS) approach using single and double mutants to measure the relative energetic contributions of specific residues on Aquaporin Z (AqpZ) toward cardiolipin (CL) binding. We first mutated potential lipid-binding residues on AqpZ, and mixed mutant and wild-type proteins together with CL. By using native MS to simultaneously resolve lipid binding to the mutant and wild-type proteins in a single spectrum, we directly determined the relative affinities of CL binding, thereby revealing the relative Gibbs free energy change for lipid binding caused by the mutation. Comparing different mutants revealed that W14 contributes to the tightest CL binding site, with R224 contributing to a lower affinity site. Using double mutant cycling, we investigated the synergy between W14 and R224 sites on CL binding. Overall, this novel native MS approach provides unique insights into the binding of lipids to specific sites on membrane proteins.
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Affiliation(s)
- Hiruni S. Jayasekera
- Department of Chemistry and Biochemistry and Bio5 Institute, University of Arizona, Tucson, Arizona 85721
| | - Farhana Afrin Mohona
- Department of Chemistry and Biochemistry and Bio5 Institute, University of Arizona, Tucson, Arizona 85721
| | - Megan Ewbank
- Department of Chemistry and Biochemistry and Bio5 Institute, University of Arizona, Tucson, Arizona 85721
| | - Michael T. Marty
- Department of Chemistry and Biochemistry and Bio5 Institute, University of Arizona, Tucson, Arizona 85721
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11
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Zhao C, Tu J, Wang C, Liu W, Gu J, Yin Y, Zhang S, Li D, Diao J, Zhu ZJ, Liu C. Lysophosphatidylcholine binds α-synuclein and prevents its pathological aggregation. Natl Sci Rev 2024; 11:nwae182. [PMID: 38962715 PMCID: PMC11221426 DOI: 10.1093/nsr/nwae182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Revised: 04/28/2024] [Accepted: 05/20/2024] [Indexed: 07/05/2024] Open
Abstract
Accumulation of aggregated α-synuclein (α-syn) in Lewy bodies is the pathological hallmark of Parkinson's disease (PD). Genetic mutations in lipid metabolism are causative for a subset of patients with Parkinsonism. The role of α-syn's lipid interactions in its function and aggregation is recognized, yet the specific lipids involved and how lipid metabolism issues trigger α-syn aggregation and neurodegeneration remain unclear. Here, we found that α-syn shows a preference for binding to lysophospholipids (LPLs), particularly targeting lysophosphatidylcholine (LPC) without relying on electrostatic interactions. LPC is capable of maintaining α-syn in a compact conformation, significantly reducing its propensity to aggregate both in vitro and within cellular environments. Conversely, a reduction in the production of cellular LPLs is associated with an increase in α-syn accumulation. Our work underscores the critical role of LPLs in preserving the natural conformation of α-syn to inhibit improper aggregation, and establishes a potential connection between lipid metabolic dysfunction and α-syn aggregation in PD.
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Affiliation(s)
- Chunyu Zhao
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jia Tu
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Chuchu Wang
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Wenbin Liu
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China
| | - Jinge Gu
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yandong Yin
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China
| | - Shengnan Zhang
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China
| | - Dan Li
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong University, Shanghai 200030, China
- Zhangjiang Institute for Advanced Study, Shanghai Jiao Tong University, Shanghai 200040, China
| | - Jiajie Diao
- Department of Cancer Biology, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Zheng-Jiang Zhu
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China
| | - Cong Liu
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China
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12
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van Aalst EJ, Yekefallah M, A M van Beekveld R, Breukink E, Weingarth M, Wylie BJ. Coordination of bilayer properties by an inward-rectifier K + channel is a cooperative process driven by protein-lipid interaction. J Struct Biol X 2024; 9:100101. [PMID: 38883399 PMCID: PMC11176924 DOI: 10.1016/j.yjsbx.2024.100101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2024] [Accepted: 05/27/2024] [Indexed: 06/18/2024] Open
Abstract
Physical properties of biological membranes directly or indirectly govern biological processes. Yet, the interplay between membrane and integral membrane proteins is difficult to assess due to reciprocal effects between membrane proteins, individual lipids, and membrane architecture. Using solid-state NMR (SSNMR) we previously showed that KirBac1.1, a bacterial Inward-Rectifier K+ channel, nucleates bilayer ordering and microdomain formation through tethering anionic lipids. Conversely, these lipids cooperatively bind cationic residues to activate the channel and initiate K+ flux. The mechanistic details governing the relationship between cooperative lipid loading and bilayer ordering are, however, unknown. To investigate, we generated KirBac1.1 samples with different concentrations of 13C-lableded phosphatidyl glycerol (PG) lipids and acquired a full suite of SSNMR 1D temperature series experiments using the ordered all-trans (AT) and disordered trans-gauche (TG) acyl conformations as markers of bilayer dynamics. We observed increased AT ordered signal, decreased TG disordered signal, and increased bilayer melting temperature with increased PG concentration. Further, we identified cooperativity between ordering and direct binding of PG lipids, indicating KirBac1.1-driven bilayer ordering and microdomain formation is a classically cooperative Hill-type process driven by and predicated upon direct binding of PG lipids. Our results provide unique mechanistic insight into how proteins and lipids in tandem contribute to supramolecular bilayer heterogeneity in the lipid membrane.
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Affiliation(s)
- Evan J van Aalst
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409, USA
| | - Maryam Yekefallah
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409, USA
| | - Roy A M van Beekveld
- Department of Chemistry, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH, Utrecht, the Netherlands
| | - Eefjan Breukink
- Membrane Biochemistry and Biophysics, Department of Chemistry, Utrecht University, Padualaan 8, 3584 CH, Utrecht, the Netherlands
| | - Markus Weingarth
- Department of Chemistry, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH, Utrecht, the Netherlands
| | - Benjamin J Wylie
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409, USA
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13
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Stover L, Bahramimoghaddam H, Wang L, Schrecke S, Yadav GP, Zhou M, Laganowsky A. Grafting the ALFA tag for structural studies of aquaporin Z. J Struct Biol X 2024; 9:100097. [PMID: 38361954 PMCID: PMC10867769 DOI: 10.1016/j.yjsbx.2024.100097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 01/29/2024] [Accepted: 01/30/2024] [Indexed: 02/17/2024] Open
Abstract
Aquaporin Z (AqpZ), a bacterial water channel, forms a tetrameric complex and, like many other membrane proteins, activity is regulated by lipids. Various methods have been developed to facilitate structure determination of membrane proteins, such as the use of antibodies. Here, we graft onto AqpZ the ALFA tag (AqpZ-ALFA), an alpha helical epitope, to make use of the high-affinity anti-ALFA nanobody (nB). Native mass spectrometry reveals the AqpZ-ALFA fusion forms a stable, 1:1 complex with nB. Single-particle cryogenic electron microscopy studies reveal the octameric (AqpZ-ALFA)4(nB)4 complex forms a dimeric assembly and the structure was determined to 1.9 Å resolution. Dimerization of the octamer is mediated through stacking of the symmetrically bound nBs. Tube-like density is also observed, revealing a potential cardiolipin binding site. Grafting of the ALFA tag, or other epitope, along with binding and association of nBs to promote larger complexes will have applications in structural studies and protein engineering.
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Affiliation(s)
- Lauren Stover
- Department of Chemistry, Texas A&M University, College Station, TX 77843, United States
| | | | - Lie Wang
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, United States
| | - Samantha Schrecke
- Department of Chemistry, Texas A&M University, College Station, TX 77843, United States
| | - Gaya P. Yadav
- Laboratory for Biomolecular Structure and Dynamics (LBSD), Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, United States
| | - Ming Zhou
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, United States
| | - Arthur Laganowsky
- Department of Chemistry, Texas A&M University, College Station, TX 77843, United States
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14
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Brodmerkel MN, Thiede L, De Santis E, Uetrecht C, Caleman C, Marklund EG. Collision induced unfolding and molecular dynamics simulations of norovirus capsid dimers reveal strain-specific stability profiles. Phys Chem Chem Phys 2024; 26:13094-13105. [PMID: 38628116 DOI: 10.1039/d3cp06344e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2024]
Abstract
Collision induced unfolding (CIU) is a method used with ion mobility mass spectrometry to examine protein structures and their stability. Such experiments yield information about higher order protein structures, yet are unable to provide details about the underlying processes. That information can however be provided using molecular dynamics simulations. Here, we investigate the gas-phase unfolding of norovirus capsid dimers from the Norwalk and Kawasaki strains by employing molecular dynamics simulations over a range of temperatures, representing different levels of activation, together with CIU experiments. The dimers have highly similar structures, but their CIU reveals different stability that can be explained by the different dynamics that arises in response to the activation seen in the simulations, including a part of the sequence with previously observed strain-specific dynamics in solution. Our findings show how similar protein variants can be examined using mass spectrometric techniques in conjunction with atomistic molecular dynamics simulations to reveal differences in stability as well as differences in how and where unfolding takes place upon activation.
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Affiliation(s)
- Maxim N Brodmerkel
- Department of Chemistry - BMC, Uppsala University, 75123 Uppsala, Sweden.
| | - Lars Thiede
- CSSB Centre for Structural Systems Biology, Deutsches Elektronen-Synchrotron DESY, Leibniz Institute of Virology (LIV), Notkestrasse 85, 22607 Hamburg, Germany
- Institute of Chemistry and Metabolomics, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany
| | - Emiliano De Santis
- Department of Chemistry - BMC, Uppsala University, 75123 Uppsala, Sweden.
- Department of Physics and Astronomy, Uppsala University, 75120 Uppsala, Sweden
| | - Charlotte Uetrecht
- CSSB Centre for Structural Systems Biology, Deutsches Elektronen-Synchrotron DESY, Leibniz Institute of Virology (LIV), Notkestrasse 85, 22607 Hamburg, Germany
- Institute of Chemistry and Metabolomics, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany
| | - Carl Caleman
- Department of Physics and Astronomy, Uppsala University, 75120 Uppsala, Sweden
- Center for Free-Electron Laser Science CFEL, Deutsches Elektronen-Synchrotron, DESY, Notkestrasse 85, 22607 Hamburg, Germany
| | - Erik G Marklund
- Department of Chemistry - BMC, Uppsala University, 75123 Uppsala, Sweden.
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15
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Jandu RS, Yu H, Zhao Z, Le HT, Kim S, Huan T, Duong van Hoa F. Capture of endogenous lipids in peptidiscs and effect on protein stability and activity. iScience 2024; 27:109382. [PMID: 38577106 PMCID: PMC10993126 DOI: 10.1016/j.isci.2024.109382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Revised: 12/17/2023] [Accepted: 02/27/2024] [Indexed: 04/06/2024] Open
Abstract
Compared to protein-protein and protein-nucleic acid interactions, our knowledge of protein-lipid interactions remains limited. This is primarily due to the inherent insolubility of membrane proteins (MPs) in aqueous solution. The traditional use of detergents to overcome the solubility barrier destabilizes MPs and strips away certain lipids that are increasingly recognized as crucial for protein function. Recently, membrane mimetics have been developed to circumvent the limitations. In this study, using the peptidisc, we find that MPs in different lipid states can be isolated based on protein purification and reconstitution methods, leading to observable effects on MP activity and stability. Peptidisc also enables re-incorporating specific lipids to fine-tune the protein microenvironment and assess the impact on downstream protein associations. This study offers a first look at the illusive protein-lipid interaction specificity, laying the path for a systematic evaluation of lipid identity and contributions to membrane protein function.
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Affiliation(s)
- Rupinder Singh Jandu
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, Life Sciences Institute, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Huaxu Yu
- Department of Chemistry, Faculty of Science, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Zhiyu Zhao
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, Life Sciences Institute, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Hai Tuong Le
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, Life Sciences Institute, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Sehyeon Kim
- Department of Chemistry, Faculty of Science, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Tao Huan
- Department of Chemistry, Faculty of Science, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Franck Duong van Hoa
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, Life Sciences Institute, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
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16
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Lawrence SS, Kirschbaum C, Bennett JL, Lutomski CA, El-Baba TJ, Robinson CV. Phospholipids Differentially Regulate Ca 2+ Binding to Synaptotagmin-1. ACS Chem Biol 2024; 19:953-961. [PMID: 38566504 PMCID: PMC11040605 DOI: 10.1021/acschembio.3c00772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Revised: 03/20/2024] [Accepted: 03/21/2024] [Indexed: 04/04/2024]
Abstract
Synaptotagmin-1 (Syt-1) is a calcium sensing protein that is resident in synaptic vesicles. It is well established that Syt-1 is essential for fast and synchronous neurotransmitter release. However, the role of Ca2+ and phospholipid binding in the function of Syt-1, and ultimately in neurotransmitter release, is unclear. Here, we investigate the binding of Ca2+ to Syt-1, first in the absence of lipids, using native mass spectrometry to evaluate individual binding affinities. Syt-1 binds to one Ca2+ with a KD ∼ 45 μM. Each subsequent binding affinity (n ≥ 2) is successively unfavorable. Given that Syt-1 has been reported to bind anionic phospholipids to modulate the Ca2+ binding affinity, we explored the extent that Ca2+ binding was mediated by selected anionic phospholipid binding. We found that phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) and dioleoylphosphatidylserine (DOPS) positively modulated Ca2+ binding. However, the extent of Syt-1 binding to phosphatidylinositol 3,5-bisphosphate (PI(3,5)P2) was reduced with increasing [Ca2+]. Overall, we find that specific lipids differentially modulate Ca2+ binding. Given that these lipids are enriched in different subcellular compartments and therefore may interact with Syt-1 at different stages of the synaptic vesicle cycle, we propose a regulatory mechanism involving Syt-1, Ca2+, and anionic phospholipids that may also control some aspects of vesicular exocytosis.
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Affiliation(s)
- Sophie
A. S. Lawrence
- Department
of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ, U.K.
- The
Kavli Institute for Nanoscience Discovery, University of Oxford, South Parks Road, Oxford OX1 3QU, U.K.
| | - Carla Kirschbaum
- Department
of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ, U.K.
- The
Kavli Institute for Nanoscience Discovery, University of Oxford, South Parks Road, Oxford OX1 3QU, U.K.
| | - Jack L. Bennett
- Department
of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ, U.K.
- The
Kavli Institute for Nanoscience Discovery, University of Oxford, South Parks Road, Oxford OX1 3QU, U.K.
| | - Corinne A. Lutomski
- Department
of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ, U.K.
- The
Kavli Institute for Nanoscience Discovery, University of Oxford, South Parks Road, Oxford OX1 3QU, U.K.
| | - Tarick J. El-Baba
- Department
of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ, U.K.
- The
Kavli Institute for Nanoscience Discovery, University of Oxford, South Parks Road, Oxford OX1 3QU, U.K.
| | - Carol. V. Robinson
- Department
of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ, U.K.
- The
Kavli Institute for Nanoscience Discovery, University of Oxford, South Parks Road, Oxford OX1 3QU, U.K.
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17
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Szczepaniak F, Dehez F, Roux B. Configurational Sampling of All-Atom Solvated Membranes Using Hybrid Nonequilibrium Molecular Dynamics Monte Carlo Simulations. J Phys Chem Lett 2024; 15:3796-3804. [PMID: 38557030 DOI: 10.1021/acs.jpclett.4c00305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
All-atom simulations are a powerful approach to study the structure and dynamics of biological membranes. However, sampling the atomic configurations of inhomogeneous membranes can be challenging due to the slow lateral diffusion of the various constituents. To address this issue, a hybrid nonequilibrium molecular dynamics Monte Carlo (neMD/MC) simulation method is proposed in which randomly chosen lipid molecules are swapped to generate configurations that are subsequently accepted or rejected according to a Metropolis criterion based on the alchemical work for the attempted swap calculated via a short trajectory. A dual-topology framework constraining the common atoms of the exchanging molecules yields a good acceptance probability using switching trajectories as short as 10 ps. The performance of the hybrid neMD/MC algorithm and its ability to sample the distribution of lipids near a transmembrane helix carrying a net charge are illustrated for a binary mixture of charged and zwitterionic lipids.
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Affiliation(s)
- Florence Szczepaniak
- CNRS, LPCT, Université de Lorraine, F-54000 Nancy, France
- Department of Chemistry, University of Chicago, Chicago, Illinois 60637,United States
| | - François Dehez
- CNRS, LPCT, Université de Lorraine, F-54000 Nancy, France
- Laboratoire International Associé Centre National de la Recherche Scientifique et University of Illinois at Urbana-Champaign, Université de Lorraine, LPCT, F-54000 Nancy, France
| | - Benoît Roux
- Department of Chemistry, University of Chicago, Chicago, Illinois 60637,United States
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18
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Urner LH, Fiorentino F, Shutin D, Sauer JB, Agasid MT, El-Baba TJ, Bolla JR, Stansfeld PJ, Robinson CV. Detergents with Scalable Properties Identify Noncanonical Lipopolysaccharide Binding to Bacterial Inner Membrane Proteins. J Am Chem Soc 2024; 146. [PMID: 38604609 PMCID: PMC11046432 DOI: 10.1021/jacs.3c14358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 02/27/2024] [Accepted: 02/27/2024] [Indexed: 04/13/2024]
Abstract
Lipopolysaccharide (LPS) is vital for maintaining the outer membrane barrier in Gram-negative bacteria. LPS is also frequently obtained in complex with the inner membrane proteins after detergent purification. The question of whether or not LPS binding to inner membrane proteins not involved in outer membrane biogenesis reflects native lipid environments remains unclear. Here, we leverage the control of the hydrophilic-lipophilic balance and packing parameter concepts to chemically tune detergents that can be used to qualitatively differentiate the degree to which proteins copurify with phospholipids (PLs) and/or LPS. Given the scalable properties of these detergents, we demonstrate a detergent fine-tuning that enables the facile investigation of intact proteins and their complexes with lipids by native mass spectrometry (nMS). We conclude that LPS, a lipid that is believed to be important for outer membranes, can also affect the activity of membrane proteins that are currently not assigned to be involved in outer membrane biogenesis. Our results deliver a scalable detergent chemistry for a streamlined biophysical characterization of protein-lipid interactions, provide a rationale for the high affinity of LPS-protein binding, and identify noncanonical associations between LPS and inner membrane proteins with relevance for membrane biology and antibiotic research.
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Affiliation(s)
- Leonhard H. Urner
- TU
Dortmund University, Department of Chemistry
and Chemical Biology, Otto-Hahn-Strasse 6, Dortmund 44227, Germany
- Kavli
Institute for Nanoscience Discovery,
South Parks Road, Oxford OX1 3QU, United Kingdom
| | - Francesco Fiorentino
- Department
of Drug Chemistry and Technologies, Sapienza
University Rome, Piazzale Aldo Moro 5, Rome 00185, Italy
| | - Denis Shutin
- Kavli
Institute for Nanoscience Discovery,
South Parks Road, Oxford OX1 3QU, United Kingdom
| | - Joshua B. Sauer
- Kavli
Institute for Nanoscience Discovery,
South Parks Road, Oxford OX1 3QU, United Kingdom
| | - Mark T. Agasid
- Kavli
Institute for Nanoscience Discovery,
South Parks Road, Oxford OX1 3QU, United Kingdom
| | - Tarick J. El-Baba
- Kavli
Institute for Nanoscience Discovery,
South Parks Road, Oxford OX1 3QU, United Kingdom
| | - Jani R. Bolla
- Kavli
Institute for Nanoscience Discovery,
South Parks Road, Oxford OX1 3QU, United Kingdom
- Department
of Biology, University of Oxford, South Parks Road, Oxford OX1 3RB, United Kingdom
| | - Phillip J. Stansfeld
- School
of Life Sciences, Gibbet Hill Campus, The
University of Warwick, Coventry CV4 7AL, United
Kingdom
| | - Carol V. Robinson
- Kavli
Institute for Nanoscience Discovery,
South Parks Road, Oxford OX1 3QU, United Kingdom
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19
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Cropley TC, Liu FC, Chai M, Bush MF, Bleiholder C. Metastability of Protein Solution Structures in the Absence of a Solvent: Rugged Energy Landscape and Glass-like Behavior. J Am Chem Soc 2024. [PMID: 38598661 DOI: 10.1021/jacs.3c12892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/12/2024]
Abstract
Native ion mobility/mass spectrometry is well-poised to structurally screen proteomes but characterizes protein structures in the absence of a solvent. This raises long-standing unanswered questions about the biological significance of protein structures identified through ion mobility/mass spectrometry. Using newly developed computational and experimental ion mobility/ion mobility/mass spectrometry methods, we investigate the unfolding of the protein ubiquitin in a solvent-free environment. Our data suggest that the folded, solvent-free ubiquitin observed by ion mobility/mass spectrometry exists in a largely native fold with an intact β-grasp motif and α-helix. The ensemble of folded, solvent-free ubiquitin ions can be partitioned into kinetically stable subpopulations that appear to correspond to the structural heterogeneity of ubiquitin in solution. Time-resolved ion mobility/ion mobility/mass spectrometry measurements show that folded, solvent-free ubiquitin exhibits a strongly stretched-exponential time dependence, which simulations trace to a rugged energy landscape with kinetic traps. Unfolding rate constants are estimated to be approximately 800 to 20,000 times smaller than in the presence of water, effectively quenching the unfolding process on the time scale of typical ion mobility/mass spectrometry measurements. Our proposed unfolding pathway of solvent-free ubiquitin shares substantial characteristics with that established for the presence of solvent, including a polarized transition state with significant native content in the N-terminal β-hairpin and α-helix. Our experimental and computational data suggest that (1) the energy landscape governing the motions of folded, solvent-free proteins is rugged in analogy to that of glassy systems; (2) large-scale protein motions may at least partially be determined by the amino acid sequence of a polypeptide chain; and (3) solvent facilitates, rather than controls, protein motions.
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Affiliation(s)
- Tyler C Cropley
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32304, United States
| | - Fanny C Liu
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32304, United States
| | - Mengqi Chai
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32304, United States
| | - Matthew F Bush
- Department of Chemistry, University of Washington, Box 351700, Seattle, Washington 98195-1700, United States
| | - Christian Bleiholder
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32304, United States
- Institute of Molecular Biophysics, Florida State University, Tallahassee, Florida 32304, United States
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20
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Sandberg JW, Santiago-McRae E, Ennis J, Brannigan G. The density-threshold affinity: Calculating lipid binding affinities from unbiased coarse-grained molecular dynamics simulations. Methods Enzymol 2024; 701:47-82. [PMID: 39025580 DOI: 10.1016/bs.mie.2024.03.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/20/2024]
Abstract
Many membrane proteins are sensitive to their local lipid environment. As structural methods for membrane proteins have improved, there is growing evidence of direct, specific binding of lipids to protein surfaces. Unfortunately the workhorse of understanding protein-small molecule interactions, the binding affinity for a given site, is experimentally inaccessible for these systems. Coarse-grained molecular dynamics simulations can be used to bridge this gap, and are relatively straightforward to learn. Such simulations allow users to observe spontaneous binding of lipids to membrane proteins and quantify localized densities of individual lipids or lipid fragments. In this chapter we outline a protocol for extracting binding affinities from these localized distributions, known as the "density threshold affinity." The density threshold affinity uses an adaptive and flexible definition of site occupancy that alleviates the need to distinguish between "bound'' lipids and bulk lipids that are simply diffusing through the site. Furthermore, the method allows "bead-level" resolution that is suitable for the case where lipids share binding sites, and circumvents ambiguities about a relevant reference state. This approach provides a convenient and straightforward method for comparing affinities of a single lipid species for multiple sites, multiple lipids for a single site, and/or a single lipid species modeled using multiple forcefields.
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Affiliation(s)
- Jesse W Sandberg
- Center for Computational and Integrative Biology, Rutgers University, Camden, NJ, United States
| | - Ezry Santiago-McRae
- Center for Computational and Integrative Biology, Rutgers University, Camden, NJ, United States
| | - Jahmal Ennis
- Center for Computational and Integrative Biology, Rutgers University, Camden, NJ, United States
| | - Grace Brannigan
- Center for Computational and Integrative Biology, Rutgers University, Camden, NJ, United States; Department of Physics, Rutgers University, Camden, NJ, United States.
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21
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Ayub H, Murray RJ, Kuyler GC, Napier-Khwaja F, Gunner J, Dafforn TR, Klumperman B, Poyner DR, Wheatley M. GPCRs in the round: SMA-like copolymers and SMALPs as a platform for investigating GPCRs. Arch Biochem Biophys 2024; 754:109946. [PMID: 38395122 DOI: 10.1016/j.abb.2024.109946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Revised: 01/21/2024] [Accepted: 02/20/2024] [Indexed: 02/25/2024]
Abstract
G-protein-coupled receptors (GPCRs) are the largest family of membrane proteins, regulate a plethora of physiological responses and are the therapeutic target for 30-40% of clinically-prescribed drugs. They are integral membrane proteins deeply embedded in the plasma membrane where they activate intracellular signalling via coupling to G-proteins and β-arrestin. GPCRs are in intimate association with the bilayer lipids and that lipid environment regulates the signalling functions of GPCRs. This complex lipid 'landscape' is both heterogeneous and dynamic. GPCR function is modulated by bulk membrane properties including membrane fluidity, microdomains, curvature, thickness and asymmetry but GPCRs are also regulated by specific lipid:GPCR binding, including cholesterol and anionic lipids. Understanding the molecular mechanisms whereby GPCR signalling is regulated by lipids is a very active area of research currently. A major advance in membrane protein research in recent years was the application of poly(styrene-co-maleic acid) (SMA) copolymers. These spontaneously generate SMA lipid particles (SMALPs) encapsulating membrane protein in a nano-scale disc of cell membrane, thereby removing the historical need for detergent and preserving lipid:GPCR interaction. The focus of this review is how GPCR-SMALPs are increasing our understanding of GPCR structure and function at the molecular level. Furthermore, an increasing number of 'second generation' SMA-like copolymers have been reported recently. These are reviewed from the context of increasing our understanding of GPCR molecular mechanisms. Moreover, their potential as a novel platform for downstream biophysical and structural analyses is assessed and looking ahead, the translational application of SMA-like copolymers to GPCR drug discovery programmes in the future is considered.
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Affiliation(s)
- Hoor Ayub
- Centre for Health and Life Sciences, Coventry University, Coventry, CV1 2DS, UK.
| | - Rebecca J Murray
- Centre for Health and Life Sciences, Coventry University, Coventry, CV1 2DS, UK; Department of Chemistry and Polymer Sciences, Stellenbosch University, Private Bag X1, Matieland, 7602, South Africa
| | - Gestél C Kuyler
- Centre for Health and Life Sciences, Coventry University, Coventry, CV1 2DS, UK; Department of Chemistry and Polymer Sciences, Stellenbosch University, Private Bag X1, Matieland, 7602, South Africa
| | | | - Joseph Gunner
- School of Life and Health Sciences, Aston University, Birmingham, B4 7ET, UK
| | - Tim R Dafforn
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Bert Klumperman
- Department of Chemistry and Polymer Sciences, Stellenbosch University, Private Bag X1, Matieland, 7602, South Africa
| | - David R Poyner
- School of Life and Health Sciences, Aston University, Birmingham, B4 7ET, UK
| | - Mark Wheatley
- Centre for Health and Life Sciences, Coventry University, Coventry, CV1 2DS, UK; Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK
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22
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Woods H, Leman JK, Meiler J. Modeling membrane geometries implicitly in Rosetta. Protein Sci 2024; 33:e4908. [PMID: 38358133 PMCID: PMC10868433 DOI: 10.1002/pro.4908] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 01/05/2024] [Accepted: 01/08/2024] [Indexed: 02/16/2024]
Abstract
Interactions between membrane proteins (MPs) and lipid bilayers are critical for many cellular functions. In the Rosetta molecular modeling suite, the implicit membrane energy function is based on a "slab" model, which represent the membrane as a flat bilayer. However, in nature membranes often have a curvature that is important for function and/or stability. Even more prevalent, in structural biology research MPs are reconstituted in model membrane systems such as micelles, bicelles, nanodiscs, or liposomes. Thus, we have modified the existing membrane energy potentials within the RosettaMP framework to allow users to model MPs in different membrane geometries. We show that these modifications can be utilized in core applications within Rosetta such as structure refinement, protein-protein docking, and protein design. For MP structures found in curved membranes, refining these structures in curved, implicit membranes produces higher quality models with structures closer to experimentally determined structures. For MP systems embedded in multiple membranes, representing both membranes results in more favorable scores compared to only representing one of the membranes. Modeling MPs in geometries mimicking the membrane model system used in structure determination can improve model quality and model discrimination.
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Affiliation(s)
- Hope Woods
- Center of Structural Biology, Vanderbilt UniversityNashvilleTennesseeUSA
- Chemical and Physical Biology ProgramVanderbilt UniversityNashvilleTennesseeUSA
| | | | - Jens Meiler
- Center of Structural Biology, Vanderbilt UniversityNashvilleTennesseeUSA
- Department of ChemistryVanderbilt UniversityNashvilleTennesseeUSA
- Institute for Drug Discovery, Leipzig University Medical SchoolLeipzigGermany
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23
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Young JW, Pfitzner E, van Wee R, Kirschbaum C, Kukura P, Robinson CV. Characterization of membrane protein interactions by peptidisc-mediated mass photometry. iScience 2024; 27:108785. [PMID: 38303728 PMCID: PMC10831248 DOI: 10.1016/j.isci.2024.108785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 10/25/2023] [Accepted: 01/02/2024] [Indexed: 02/03/2024] Open
Abstract
Membrane proteins perform numerous critical functions in the cell, making many of them primary drug targets. However, their preference for a lipid environment makes them challenging to study using established solution-based methods. Here, we show that peptidiscs, a recently developed membrane mimetic, provide an ideal platform to study membrane proteins and their interactions with mass photometry (MP) in detergent-free conditions. The mass resolution for membrane protein complexes is similar to that achievable with soluble proteins owing to the low carrier heterogeneity. Using the ABC transporter BtuCD, we show that MP can quantify interactions between peptidisc-reconstituted membrane protein receptors and their soluble protein binding partners. Using the BAM complex, we further show that MP reveals interactions between a membrane protein receptor and a bactericidal antibody. Our results highlight the utility of peptidiscs for membrane protein characterization in detergent-free solution and provide a rapid and powerful platform for quantifying membrane protein interactions.
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Affiliation(s)
- John William Young
- Department of Chemistry, Kavli Institute for Nanoscience Discovery, Dorothy Crowfoot Hodgkin Building, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Emanuel Pfitzner
- Department of Chemistry, Kavli Institute for Nanoscience Discovery, Dorothy Crowfoot Hodgkin Building, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Raman van Wee
- Department of Chemistry, Kavli Institute for Nanoscience Discovery, Dorothy Crowfoot Hodgkin Building, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
- Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford OX1 3QX, UK
| | - Carla Kirschbaum
- Department of Chemistry, Kavli Institute for Nanoscience Discovery, Dorothy Crowfoot Hodgkin Building, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Philipp Kukura
- Department of Chemistry, Kavli Institute for Nanoscience Discovery, Dorothy Crowfoot Hodgkin Building, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Carol V. Robinson
- Department of Chemistry, Kavli Institute for Nanoscience Discovery, Dorothy Crowfoot Hodgkin Building, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
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24
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Jojoa-Cruz S, Burendei B, Lee WH, Ward AB. Structure of mechanically activated ion channel OSCA2.3 reveals mobile elements in the transmembrane domain. Structure 2024; 32:157-167.e5. [PMID: 38103547 PMCID: PMC10872982 DOI: 10.1016/j.str.2023.11.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 09/29/2023] [Accepted: 11/21/2023] [Indexed: 12/19/2023]
Abstract
Members of the OSCA/TMEM63 family are mechanically activated ion channels and structures of some OSCA members have revealed the architecture of these channels and structural features that are potentially involved in mechanosensation. However, these structures are all in a similar state and information about the motion of different elements of the structure is limited, preventing a deeper understanding of how these channels work. Here, we used cryoelectron microscopy to determine high-resolution structures of Arabidopsis thaliana OSCA1.2 and OSCA2.3 in peptidiscs. The structure of OSCA1.2 matches previous structures of the same protein in different environments. Yet, in OSCA2.3, the TM6a-TM7 linker adopts a different conformation that constricts the pore on its cytoplasmic side. Furthermore, coevolutionary sequence analysis uncovered a conserved interaction between the TM6a-TM7 linker and the beam-like domain (BLD). Our results reveal conformational heterogeneity and differences in conserved interactions between the TMD and BLD among members of the OSCA family.
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Affiliation(s)
- Sebastian Jojoa-Cruz
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Batuujin Burendei
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Wen-Hsin Lee
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Andrew B Ward
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA.
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25
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Williamson G, Harris T, Bizior A, Hoskisson PA, Pritchard L, Javelle A. Biological ammonium transporters: evolution and diversification. FEBS J 2024. [PMID: 38265636 DOI: 10.1111/febs.17059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 12/14/2023] [Accepted: 01/09/2024] [Indexed: 01/25/2024]
Abstract
Although ammonium is the preferred nitrogen source for microbes and plants, in animal cells it is a toxic product of nitrogen metabolism that needs to be excreted. Thus, ammonium movement across biological membranes, whether for uptake or excretion, is a fundamental and ubiquitous biological process catalysed by the superfamily of the Amt/Mep/Rh transporters. A remarkable feature of the Amt/Mep/Rh family is that they are ubiquitous and, despite sharing low amino acid sequence identity, are highly structurally conserved. Despite sharing a common structure, these proteins have become involved in a diverse range of physiological process spanning all domains of life, with reports describing their involvement in diverse biological processes being published regularly. In this context, we exhaustively present their range of biological roles across the domains of life and after explore current hypotheses concerning their evolution to help to understand how and why the conserved structure fulfils diverse physiological functions.
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Affiliation(s)
- Gordon Williamson
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, UK
| | - Thomas Harris
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, UK
| | - Adriana Bizior
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, UK
| | - Paul Alan Hoskisson
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, UK
| | - Leighton Pritchard
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, UK
| | - Arnaud Javelle
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, UK
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26
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Faivre N, Verollet C, Dumas F. The chemokine receptor CCR5: multi-faceted hook for HIV-1. Retrovirology 2024; 21:2. [PMID: 38263120 PMCID: PMC10807162 DOI: 10.1186/s12977-024-00634-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Accepted: 01/13/2024] [Indexed: 01/25/2024] Open
Abstract
Chemokines are cytokines whose primary role is cellular activation and stimulation of leukocyte migration. They perform their various functions by interacting with G protein-coupled cell surface receptors (GPCRs) and are involved in the regulation of many biological processes such as apoptosis, proliferation, angiogenesis, hematopoiesis or organogenesis. They contribute to the maintenance of the homeostasis of lymphocytes and coordinate the function of the immune system. However, chemokines and their receptors are sometimes hijacked by some pathogens to infect the host organism. For a given chemokine receptor, there is a wide structural, organizational and conformational diversity. In this review, we describe the evidence for structural variety reported for the chemokine receptor CCR5, how this variability can be exploited by HIV-1 to infect its target cells and what therapeutic solutions are currently being developed to overcome this problem.
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Affiliation(s)
- Natacha Faivre
- Institut de Pharmacologie et de Biologie Structurale (IPBS), Université de Toulouse, CNRS, Université Toulouse III - Paul Sabatier (UPS), Toulouse, France
- International Research Laboratory (IRP) CNRS "IM-TB/HIV", Toulouse, France
- International Research Laboratory (IRP) CNRS "IM-TB/HIV", Buenos Aires, Argentina
| | - Christel Verollet
- Institut de Pharmacologie et de Biologie Structurale (IPBS), Université de Toulouse, CNRS, Université Toulouse III - Paul Sabatier (UPS), Toulouse, France
- International Research Laboratory (IRP) CNRS "IM-TB/HIV", Toulouse, France
- International Research Laboratory (IRP) CNRS "IM-TB/HIV", Buenos Aires, Argentina
| | - Fabrice Dumas
- Institut de Pharmacologie et de Biologie Structurale (IPBS), Université de Toulouse, CNRS, Université Toulouse III - Paul Sabatier (UPS), Toulouse, France.
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27
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Lyu J, Zhang T, Marty MT, Clemmer D, Russell DH, Laganowsky A. Double and triple thermodynamic mutant cycles reveal the basis for specific MsbA-lipid interactions. eLife 2024; 12:RP91094. [PMID: 38252560 PMCID: PMC10945598 DOI: 10.7554/elife.91094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2024] Open
Abstract
Structural and functional studies of the ATP-binding cassette transporter MsbA have revealed two distinct lipopolysaccharide (LPS) binding sites: one located in the central cavity and the other at a membrane-facing, exterior site. Although these binding sites are known to be important for MsbA function, the thermodynamic basis for these specific MsbA-LPS interactions is not well understood. Here, we use native mass spectrometry to determine the thermodynamics of MsbA interacting with the LPS-precursor 3-deoxy-D-manno-oct-2-ulosonic acid (Kdo)2-lipid A (KDL). The binding of KDL is solely driven by entropy, despite the transporter adopting an inward-facing conformation or trapped in an outward-facing conformation with adenosine 5'-diphosphate and vanadate. An extension of the mutant cycle approach is employed to probe basic residues that interact with KDL. We find the molecular recognition of KDL is driven by a positive coupling entropy (as large as -100 kJ/mol at 298 K) that outweighs unfavorable coupling enthalpy. These findings indicate that alterations in solvent reorganization and conformational entropy can contribute significantly to the free energy of protein-lipid association. The results presented herein showcase the advantage of native MS to obtain thermodynamic insight into protein-lipid interactions that would otherwise be intractable using traditional approaches, and this enabling technology will be instrumental in the life sciences and drug discovery.
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Affiliation(s)
- Jixing Lyu
- Department of Chemistry, Texas A&M UniversityCollege StationUnited States
| | - Tianqi Zhang
- Department of Chemistry, Texas A&M UniversityCollege StationUnited States
| | - Michael T Marty
- Department of Chemistry and Biochemistry and Bio5 Institute, The University of ArizonaTucsonUnited States
| | - David Clemmer
- Department of Chemistry, Indiana UniversityBloomingtonUnited States
| | - David H Russell
- Department of Chemistry, Texas A&M UniversityCollege StationUnited States
| | - Arthur Laganowsky
- Department of Chemistry, Texas A&M UniversityCollege StationUnited States
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28
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Selvasingh JA, McDonald EF, Neufer PD, McKinney JR, Meiler J, Ledwitch KV. Dark nanodiscs for evaluating membrane protein thermostability by differential scanning fluorimetry. Biophys J 2024; 123:68-79. [PMID: 37978799 PMCID: PMC10808023 DOI: 10.1016/j.bpj.2023.11.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 10/27/2023] [Accepted: 11/16/2023] [Indexed: 11/19/2023] Open
Abstract
Measuring protein thermostability provides valuable information on the biophysical rules that govern the structure-energy relationships of proteins. However, such measurements remain a challenge for membrane proteins. Here, we introduce a new experimental system to evaluate membrane protein thermostability. This system leverages a recently developed nonfluorescent membrane scaffold protein to reconstitute proteins into nanodiscs and is coupled with a nano-format of differential scanning fluorimetry (nanoDSF). This approach offers a label-free and direct measurement of the intrinsic tryptophan fluorescence of the membrane protein as it unfolds in solution without signal interference from the "dark" nanodisc. In this work, we demonstrate the application of this method using the disulfide bond formation protein B (DsbB) as a test membrane protein. NanoDSF measurements of DsbB reconstituted in dark nanodiscs loaded with 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and 1,2-dimyristoyl-sn-glycero-3-phosphorylglycerol (DMPG) lipids show a complex biphasic thermal unfolding pattern with a minor unfolding transition followed by a major transition. The inflection points of the thermal denaturation curve reveal two distinct unfolding midpoint melting temperatures (Tm) of 70.5°C and 77.5°C, consistent with a three-state unfolding model. Further, we show that the catalytically conserved disulfide bond between residues C41 and C130 drives the intermediate state of the unfolding pathway for DsbB in a DMPC and DMPG nanodisc. To extend the utility of this method, we evaluate and compare the thermostability of DsbB in different lipid environments. We introduce this method as a new tool that can be used to understand how compositionally and biophysically complex lipid environments drive membrane protein stability.
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Affiliation(s)
- Jazlyn A Selvasingh
- Center for Structural Biology, Vanderbilt University, Nashville, Tennessee; Department of Chemistry, Vanderbilt University, Nashville, Tennessee
| | - Eli F McDonald
- Center for Structural Biology, Vanderbilt University, Nashville, Tennessee; Department of Chemistry, Vanderbilt University, Nashville, Tennessee
| | - Preston D Neufer
- Center for Structural Biology, Vanderbilt University, Nashville, Tennessee; Department of Chemistry, Vanderbilt University, Nashville, Tennessee
| | - Jacob R McKinney
- Center for Structural Biology, Vanderbilt University, Nashville, Tennessee; Department of Chemistry, Vanderbilt University, Nashville, Tennessee
| | - Jens Meiler
- Center for Structural Biology, Vanderbilt University, Nashville, Tennessee; Department of Chemistry, Vanderbilt University, Nashville, Tennessee; Institute of Drug Discovery, Faculty of Medicine, University of Leipzig, Leipzig, Germany.
| | - Kaitlyn V Ledwitch
- Center for Structural Biology, Vanderbilt University, Nashville, Tennessee; Department of Chemistry, Vanderbilt University, Nashville, Tennessee.
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29
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Weikum J, van Dyck JF, Subramani S, Klebl DP, Storflor M, Muench SP, Abel S, Sobott F, Morth JP. The bacterial magnesium transporter MgtA reveals highly selective interaction with specific cardiolipin species. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2024; 1871:119614. [PMID: 37879515 DOI: 10.1016/j.bbamcr.2023.119614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 09/13/2023] [Accepted: 10/16/2023] [Indexed: 10/27/2023]
Abstract
The bacterial magnesium transporter A (MgtA) is a specialized P-type ATPase important for Mg2+ import into the cytoplasm; disrupted magnesium homeostasis is linked to intrinsic ribosome instability and antibacterial resistance in Salmonella strains. Here, we show that MgtA has functional specificity for cardiolipin 18:1. Still, it reaches maximum activity only in combination with cardiolipin 16:0, equivalent to the major components of native cardiolipin found in E. coli membranes. Native mass spectrometry indicates the presence of two binding sites for cardiolipin, agreeing with the kinetic studies revealing that a cooperative relationship likely exists between the two cardiolipin variants. This is the first experimental evidence of cooperative effects between lipids of the same class, with only minor variations in their acyl chain composition, acting on a membrane protein. In summary, our results reveal that MgtA exhibits a highly complex interaction with one cardiolipin 18:1 and one cardiolipin 16:0, affecting protein activity and stability, contributing to our understanding of the particular interactions between lipid environment and membrane proteins. Further, a better understanding of Mg2+ homeostasis in bacteria, due to its role as a virulence regulator, will provide further insights into the regulation and mechanism of bacterial infections.
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Affiliation(s)
- Julia Weikum
- Membrane Transport Group, Centre for Molecular Medicine Norway (NCMM), Nordic EMBL Partnership, University of Oslo, P.O. Box 1137, Blindern, 0318 Oslo, Norway; Enzyme and Protein Chemistry, Section for Protein Chemistry and Enzyme Technology, Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads, 2800 Kgs. Lyngby, Denmark
| | - Jeroen F van Dyck
- Department of Chemistry, University of Antwerp, Campus Groenenborger, Groenenborgerlaan 171, G.V. 418, 2020 Antwerpen, Belgium
| | - Saranya Subramani
- Membrane Transport Group, Centre for Molecular Medicine Norway (NCMM), Nordic EMBL Partnership, University of Oslo, P.O. Box 1137, Blindern, 0318 Oslo, Norway
| | - David P Klebl
- School of Biomedical Sciences & The Astbury Centre for Structural Molecular Biology, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, United Kingdom
| | - Merete Storflor
- Infections Biology Lab, Department of Pharmacy, UiT-The Arctic University of Norway, 9037 Tromsø, Norway
| | - Stephen P Muench
- School of Biomedical Sciences & The Astbury Centre for Structural Molecular Biology, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, United Kingdom
| | - Sören Abel
- Infections Biology Lab, Department of Pharmacy, UiT-The Arctic University of Norway, 9037 Tromsø, Norway
| | - Frank Sobott
- Department of Chemistry, University of Antwerp, Campus Groenenborger, Groenenborgerlaan 171, G.V. 418, 2020 Antwerpen, Belgium; School of Molecular and Cellular Biology & The Astbury Centre for Structural Molecular Biology, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, United Kingdom.
| | - J Preben Morth
- Membrane Transport Group, Centre for Molecular Medicine Norway (NCMM), Nordic EMBL Partnership, University of Oslo, P.O. Box 1137, Blindern, 0318 Oslo, Norway; Enzyme and Protein Chemistry, Section for Protein Chemistry and Enzyme Technology, Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads, 2800 Kgs. Lyngby, Denmark; Institute for Experimental Medical Research (IEMR), Oslo University Hospital, Ullevål PB 4956 Nydalen, NO-0424 Oslo, Norway.
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30
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Vallejo DD, Corstvet JL, Fernández FM. Triboelectric Nanogenerators: Low-Cost Power Supplies for Improved Electrospray Ionization. INTERNATIONAL JOURNAL OF MASS SPECTROMETRY 2024; 495:117167. [PMID: 38053979 PMCID: PMC10695355 DOI: 10.1016/j.ijms.2023.117167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/07/2023]
Abstract
Electrospray ionization (ESI) is one of the most popular methods to generate ions for mass spectrometry (MS). When compared with other ionization techniques, it can generate ions from liquid-phase samples without additives, retaining covalent and non-covalent interactions of the molecules of interest. When hyphenated to liquid chromatography, it greatly expands the versatility of MS analysis of complex mixtures. However, despite the extensive growth in the application of ESI, the technique still suffers from some drawbacks when powered by direct current (DC) power supplies. Triboelectric nanogenerators promise to be a new power source for the generation of ions by ESI, improving on the analytical capabilities of traditional DC ESI. In this review we highlight the fundamentals of ESI driven by DC power supplies, its contrasting qualities to triboelectric nanogenerator power supplies, and its applications to three distinct fields of research: forensics, metabolomics, and protein structure analysis.
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Affiliation(s)
- Daniel D. Vallejo
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA, USA
| | - Joseph L. Corstvet
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA, USA
| | - Facundo M. Fernández
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA, USA
- Petit Institute of Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA, USA
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31
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Wycisk V, Wagner MC, Urner LH. Trends in the Diversification of the Detergentome. Chempluschem 2024; 89:e202300386. [PMID: 37668309 DOI: 10.1002/cplu.202300386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 09/04/2023] [Accepted: 09/05/2023] [Indexed: 09/06/2023]
Abstract
Detergents are amphiphilic molecules that serve as enabling steps for today's world applications. The increasing diversity of the detergentome is key to applications enabled by detergent science. Regardless of the application, the optimal design of detergents is determined empirically, which leads to failed preparations, and raising costs. To facilitate project planning, here we review synthesis strategies that drive the diversification of the detergentome. Synthesis strategies relevant for industrial and academic applications include linear, modular, combinatorial, bio-based, and metric-assisted detergent synthesis. Scopes and limitations of individual synthesis strategies in context with industrial product development and academic research are discussed. Furthermore, when designing detergents, the selection of molecular building blocks, i. e., head, linker, tail, is as important as the employed synthesis strategy. To facilitate the design of safe-to-use and tailor-made detergents, we provide an overview of established head, linker, and tail groups and highlight selected scopes and limitations for applications. It becomes apparent that most recent contributions to the increasing chemical diversity of detergent building blocks originate from the development of detergents for membrane protein studies. The overview of synthesis strategies and molecular blocks will bring us closer to the ability to predictably design and synthesize optimal detergents for challenging future applications.
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Affiliation(s)
- Virginia Wycisk
- TU Dortmund University, Department of Chemistry and Chemical Biology, Otto-Hahn-Str. 6, 44227, Dortmund, Germany
| | - Marc-Christian Wagner
- TU Dortmund University, Department of Chemistry and Chemical Biology, Otto-Hahn-Str. 6, 44227, Dortmund, Germany
| | - Leonhard H Urner
- TU Dortmund University, Department of Chemistry and Chemical Biology, Otto-Hahn-Str. 6, 44227, Dortmund, Germany
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32
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Iwamoto M, Morito M, Oiki S, Nishitani Y, Yamamoto D, Matsumori N. Cardiolipin binding enhances KcsA channel gating via both its specific and dianion-monoanion interchangeable sites. iScience 2023; 26:108471. [PMID: 38077151 PMCID: PMC10709135 DOI: 10.1016/j.isci.2023.108471] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2023] [Revised: 10/29/2023] [Accepted: 11/13/2023] [Indexed: 01/17/2024] Open
Abstract
KcsA is a potassium channel with a plethora of structural and functional information, but its activity in the KcsA-producing actinomycete membranes remains elusive. To determine lipid species involved in channel-modulation, a surface plasmon resonance (SPR)-based methodology, characterized by immobilization of membrane proteins under a membrane environment, was applied. Dianionic cardiolipin (CL) showed extremely higher affinity for KcsA than monoanionic lipids. The SPR experiments further demonstrated that CL bound not only to the N-terminal M0 helix, a lipid-sensor domain, but to the M0 helix-deleted mutant. In contrast, monoanionic lipids interacted primarily with the M0 helix. This indicates the presence of an alternative CL-binding site, plausibly in the transmembrane domain. Single-channel recordings demonstrated that CL enhanced channel opening in an M0-independent manner. Taken together, the action of monoanionic lipids is exclusively mediated by the M0 helix, while CL binds both the M0 helix and its specific site, further enhancing the channel activity.
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Affiliation(s)
- Masayuki Iwamoto
- Department of Molecular Neuroscience, Faculty of Medical Sciences, University of Fukui, Fukui 910-1193, Japan
| | - Masayuki Morito
- Department of Chemistry, Graduate School of Science, Kyushu University, Fukuoka 819-0395 Japan
| | - Shigetoshi Oiki
- Biomedial Imaging Research Center, University of Fukui, Fukui 910-1193, Japan
| | - Yudai Nishitani
- Department of Applied Physics, Faculty of Science, Fukuoka University, Fukuoka 814-0180, Japan
| | - Daisuke Yamamoto
- Department of Applied Physics, Faculty of Science, Fukuoka University, Fukuoka 814-0180, Japan
| | - Nobuaki Matsumori
- Department of Chemistry, Graduate School of Science, Kyushu University, Fukuoka 819-0395 Japan
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33
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Zhu Y, Yun SD, Zhang T, Chang JY, Stover L, Laganowsky A. Native mass spectrometry of proteoliposomes containing integral and peripheral membrane proteins. Chem Sci 2023; 14:14243-14255. [PMID: 38098719 PMCID: PMC10718073 DOI: 10.1039/d3sc04938h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Accepted: 11/18/2023] [Indexed: 12/17/2023] Open
Abstract
Cellular membranes are critical to the function of membrane proteins, whether they are associated (peripheral) or embedded (integral) within the bilayer. While detergents have contributed to our understanding of membrane protein structure and function, there remains challenges in characterizing protein-lipid interactions within the context of an intact membrane. Here, we developed a method to prepare proteoliposomes for native mass spectrometry (MS) studies. We first use native MS to detect the encapsulation of soluble proteins within liposomes. We then find the peripheral Gβ1γ2 complex associated with the membrane can be ejected and analyzed using native MS. Four different integral membrane proteins (AmtB, AqpZ, TRAAK, and TREK2), all of which have previously been characterized in detergent, eject from the proteoliposomes as intact complexes bound to lipids that have been shown to tightly associate in detergent, drawing a correlation between the two approaches. We also show the utility of more complex lipid environments, such as a brain polar lipid extract, and show TRAAK ejects from liposomes of this extract bound to lipids. These findings underscore the capability to eject protein complexes from membranes bound to both lipids and metal ions, and this approach will be instrumental in the identification of key protein-lipid interactions.
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Affiliation(s)
- Yun Zhu
- Department of Chemistry, Texas A&M University College Station TX 77843 USA
| | - Sangho D Yun
- Department of Chemistry, Texas A&M University College Station TX 77843 USA
| | - Tianqi Zhang
- Department of Chemistry, Texas A&M University College Station TX 77843 USA
| | - Jing-Yuan Chang
- Department of Chemistry, Texas A&M University College Station TX 77843 USA
| | - Lauren Stover
- Department of Chemistry, Texas A&M University College Station TX 77843 USA
| | - Arthur Laganowsky
- Department of Chemistry, Texas A&M University College Station TX 77843 USA
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Jayasekera HS, Mohona FA, Ewbank M, Marty MT. SIMULTANEOUS NATIVE MASS SPECTROMETRY ANALYSIS OF SINGLE AND DOUBLE MUTANTS TO PROBE LIPID BINDING TO MEMBRANE PROTEINS. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.19.558516. [PMID: 37781586 PMCID: PMC10541089 DOI: 10.1101/2023.09.19.558516] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/03/2023]
Abstract
Lipids are critical modulators of membrane protein structure and function. However, it is challenging to investigate the thermodynamics of protein-lipid interactions because lipids can simultaneously bind membrane proteins at different sites with different specificities. Here, we developed a native mass spectrometry (MS) approach using single and double mutants to measure the relative energetic contributions of specific residues on Aquaporin Z (AqpZ) toward cardiolipin (CL) binding. We first mutated potential lipid-binding residues on AqpZ, and mixed mutant and wild-type proteins together with CL. By using native MS to simultaneously resolve lipid binding to the mutant and wild-type proteins in a single spectrum, we directly determined the relative affinities of CL binding, thereby revealing the relative Gibbs free energy change for lipid binding caused by the mutation. Comparing different mutants revealed that the W14 contributes to the tightest CL binding site, with R224 contributing to a lower affinity site. Using double mutant cycling, we investigated the synergy between W14 and R224 sites on CL binding. Overall, this novel native MS approach provides unique insights into lipid binding to specific sites on membrane proteins.
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Affiliation(s)
- Hiruni S. Jayasekera
- [a] Department of Chemistry and Biochemistry and Bio5 Institute, University of Arizona, Tucson, AZ 85721
| | - Farhana Afrin Mohona
- [a] Department of Chemistry and Biochemistry and Bio5 Institute, University of Arizona, Tucson, AZ 85721
| | - Megan Ewbank
- [a] Department of Chemistry and Biochemistry and Bio5 Institute, University of Arizona, Tucson, AZ 85721
| | - Michael T. Marty
- [a] Department of Chemistry and Biochemistry and Bio5 Institute, University of Arizona, Tucson, AZ 85721
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35
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Stankunas E, Köhler A. The interplay of nuclear pores and lipids. Curr Opin Cell Biol 2023; 85:102251. [PMID: 37804774 DOI: 10.1016/j.ceb.2023.102251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 08/24/2023] [Accepted: 09/07/2023] [Indexed: 10/09/2023]
Abstract
Nuclear pore complexes (NPCs) mediate the bidirectional transport of cargo across the nuclear envelope (NE). NPCs are also membrane remodeling machines with a capacity to curve and fuse the membranes of the NE. However, little is known about the interplay of NPCs and lipids at a mechanistic level. A full understanding of NPC structure and function needs to encompass how the NPC shapes membranes and is itself shaped by lipids. Here we attempt to connect recent findings in NPC research with the broader field of membrane biochemistry to illustrate how an interplay between NPCs and lipids may facilitate the conformational plasticity of NPCs and the generation of a unique pore membrane topology. We highlight the need to better understand the NPC's lipid environment and outline experimental avenues towards that goal.
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Affiliation(s)
- Edvinas Stankunas
- Max Perutz Labs, University of Vienna and Medical University of Vienna, Vienna Biocenter Campus (VBC), Dr. Bohr-Gasse 9/3, 1030 Vienna, Austria; Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical University of Vienna, A-1030 Vienna, Austria
| | - Alwin Köhler
- Max Perutz Labs, University of Vienna and Medical University of Vienna, Vienna Biocenter Campus (VBC), Dr. Bohr-Gasse 9/3, 1030 Vienna, Austria.
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36
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Kundlacz T, Schmidt C. Deciphering Solution and Gas-Phase Interactions between Peptides and Lipids by Native Mass Spectrometry. Anal Chem 2023; 95:17292-17299. [PMID: 37956985 PMCID: PMC10688224 DOI: 10.1021/acs.analchem.3c03428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 10/10/2023] [Accepted: 10/12/2023] [Indexed: 11/21/2023]
Abstract
Many biological processes depend on the interactions between proteins and lipids. Accordingly, the analysis of protein-lipid complexes has become increasingly important. Native mass spectrometry is often used to identify and characterize specific protein-lipid interactions. However, it requires the transfer of the analytes into the gas phase, where electrostatic interactions are enhanced and hydrophobic interactions do not exist. Accordingly, the question remains whether interactions that are observed in the gas phase accurately reflect interactions that are formed in solution. Here, we systematically explore noncovalent interactions between the antimicrobial peptide LL-37 and glycerophospholipids containing different headgroups or varying in fatty acyl chain length. We observe differences in peak intensities for different peptide-lipid complexes, as well as their relative binding strength in the gas phase. Accordingly, we found that ion intensities and gas-phase stability correlate well for complexes formed by electrostatic interactions. Probing hydrophobic interactions by varying the length of fatty acyl chains, we detected differences in ion intensities based on hydrophobic interactions formed in solution. The relative binding strength of these peptide-lipid complexes revealed only minor differences originating from van der Waals interactions and different binding modes of lipid headgroups in solution. In summary, our results demonstrate that hydrophobic interactions are reflected by ion intensities, while electrostatic interactions, including van der Waals interactions, determine the gas-phase stability of complexes.
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Affiliation(s)
- Til Kundlacz
- Interdisciplinary
Research Centre HALOmem, Institute of Biochemistry and Biotechnology,
Charles Tanford Protein Centre, Martin Luther
University Halle-Wittenberg, Kurt-Mothes-Str. 3a, 06120 Halle, Germany
- Institute
of Chemistry, Martin Luther University Halle-Wittenberg, von-Danckelmann-Platz 4, 06120 Halle, Germany
| | - Carla Schmidt
- Interdisciplinary
Research Centre HALOmem, Institute of Biochemistry and Biotechnology,
Charles Tanford Protein Centre, Martin Luther
University Halle-Wittenberg, Kurt-Mothes-Str. 3a, 06120 Halle, Germany
- Department
of Chemistry—Biochemistry, Johannes
Gutenberg University Mainz, Biocenter II, Hanns-Dieter-Hüsch-Weg 17, 55128 Mainz, Germany
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37
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Papadourakis M, Sinenka H, Matricon P, Hénin J, Brannigan G, Pérez-Benito L, Pande V, van Vlijmen H, de Graaf C, Deflorian F, Tresadern G, Cecchini M, Cournia Z. Alchemical Free Energy Calculations on Membrane-Associated Proteins. J Chem Theory Comput 2023; 19:7437-7458. [PMID: 37902715 PMCID: PMC11017255 DOI: 10.1021/acs.jctc.3c00365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Indexed: 10/31/2023]
Abstract
Membrane proteins have diverse functions within cells and are well-established drug targets. The advances in membrane protein structural biology have revealed drug and lipid binding sites on membrane proteins, while computational methods such as molecular simulations can resolve the thermodynamic basis of these interactions. Particularly, alchemical free energy calculations have shown promise in the calculation of reliable and reproducible binding free energies of protein-ligand and protein-lipid complexes in membrane-associated systems. In this review, we present an overview of representative alchemical free energy studies on G-protein-coupled receptors, ion channels, transporters as well as protein-lipid interactions, with emphasis on best practices and critical aspects of running these simulations. Additionally, we analyze challenges and successes when running alchemical free energy calculations on membrane-associated proteins. Finally, we highlight the value of alchemical free energy calculations calculations in drug discovery and their applicability in the pharmaceutical industry.
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Affiliation(s)
- Michail Papadourakis
- Biomedical
Research Foundation, Academy of Athens, 4 Soranou Ephessiou, 11527 Athens, Greece
| | - Hryhory Sinenka
- Institut
de Chimie de Strasbourg, UMR7177, CNRS, Université de Strasbourg, F-67083 Strasbourg Cedex, France
| | - Pierre Matricon
- Sosei
Heptares, Steinmetz Building,
Granta Park, Great Abington, Cambridge CB21 6DG, United
Kingdom
| | - Jérôme Hénin
- Laboratoire
de Biochimie Théorique UPR 9080, CNRS and Université Paris Cité, 75005 Paris, France
| | - Grace Brannigan
- Center
for Computational and Integrative Biology, Rutgers University−Camden, Camden, New Jersey 08103, United States of America
- Department
of Physics, Rutgers University−Camden, Camden, New Jersey 08102, United States
of America
| | - Laura Pérez-Benito
- CADD,
In Silico Discovery, Janssen Research &
Development, Turnhoutseweg 30, 2340 Beerse, Belgium
| | - Vineet Pande
- CADD,
In Silico Discovery, Janssen Research &
Development, Turnhoutseweg 30, 2340 Beerse, Belgium
| | - Herman van Vlijmen
- CADD,
In Silico Discovery, Janssen Research &
Development, Turnhoutseweg 30, 2340 Beerse, Belgium
| | - Chris de Graaf
- Sosei
Heptares, Steinmetz Building,
Granta Park, Great Abington, Cambridge CB21 6DG, United
Kingdom
| | - Francesca Deflorian
- Sosei
Heptares, Steinmetz Building,
Granta Park, Great Abington, Cambridge CB21 6DG, United
Kingdom
| | - Gary Tresadern
- CADD,
In Silico Discovery, Janssen Research &
Development, Turnhoutseweg 30, 2340 Beerse, Belgium
| | - Marco Cecchini
- Institut
de Chimie de Strasbourg, UMR7177, CNRS, Université de Strasbourg, F-67083 Strasbourg Cedex, France
| | - Zoe Cournia
- Biomedical
Research Foundation, Academy of Athens, 4 Soranou Ephessiou, 11527 Athens, Greece
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Zhang T, Lyu J, Zhu Y, Laganowsky A. Cardiolipin Regulates the Activity of the Mitochondrial ABC Transporter ABCB10. Biochemistry 2023; 62:3159-3165. [PMID: 37807693 PMCID: PMC10634319 DOI: 10.1021/acs.biochem.3c00417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Revised: 09/22/2023] [Indexed: 10/10/2023]
Abstract
The ATP-binding cassette (ABC) transporter ABCB10 resides in the inner membrane of mitochondria and is implicated in erythropoiesis. Mitochondria from different cell types share some specific characteristics, one of which is the high abundance of cardiolipin. Although previous studies have provided insight into ABCB10, the affinity and selectivity of this transporter toward lipids, particularly those found in the mitochondria, remain poorly understood. Here, native mass spectrometry is used to directly monitor the binding events of lipids to human ABCB10. The results reveal that ABCB10 binds avidly to cardiolipin with an affinity significantly higher than that of other phospholipids. The first three binding events of cardiolipin display positive cooperativity, which is suggestive of specific cardiolipin-binding sites on ABCB10. Phosphatidic acid is the second-best binder of the lipids investigated. The bulk lipids, phosphatidylcholine and phosphatidylethanolamine, display the weakest binding affinity for ABCB10. Other lipids bind ABCB10 with a similar affinity. Functional assays show that cardiolipin regulates the ATPase activity of ABCB10 in a dose-dependent fashion. ATPase activity of ABCB10 was also impacted in the presence of other lipids but to a lesser extent than cardiolipin. Taken together, ABCB10 has a high binding affinity for cardiolipin, and this lipid also regulates the ATPase activity of the transporter.
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Affiliation(s)
- Tianqi Zhang
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Jixing Lyu
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Yun Zhu
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Arthur Laganowsky
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
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39
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Poruthoor AJ, Sharma A, Grossfield A. Understanding the free-energy landscape of phase separation in lipid bilayers using molecular dynamics. Biophys J 2023; 122:4144-4159. [PMID: 37742069 PMCID: PMC10645549 DOI: 10.1016/j.bpj.2023.09.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 08/28/2023] [Accepted: 09/19/2023] [Indexed: 09/25/2023] Open
Abstract
Liquid-liquid phase separation inside the cell often results in biological condensates that can critically affect cell homeostasis. Such phase separation events occur in multiple parts of cells, including the cell membranes, where the "lipid raft" hypothesis posits the formation of ordered domains floating in a sea of disordered lipids. The resulting lipid domains often have functional roles. However, the thermodynamics of lipid phase separation and their resulting mechanistic effects on cell function and dysfunction are poorly understood. Understanding such complex phenomena in cell membranes, with their diverse lipid compositions, is exceptionally difficult. For these reasons, simple model systems that can recapitulate similar behavior are widely used to study this phenomenon. Despite these simplifications, the timescale and length scales of domain formation pose a challenge for molecular dynamics (MD) simulations. Thus, most MD studies focus on spontaneous lipid phase separation-essentially measuring the sign (but not the amplitude) of the free-energy change upon separation-rather than directly interrogating the thermodynamics. Here, we propose a proof-of-concept pipeline that can directly measure this free energy by combining coarse-grained MD with enhanced sampling protocols using a novel collective variable. This approach will be a useful tool to help connect the thermodynamics of phase separation with the mechanistic insights already available from MD simulations.
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Affiliation(s)
- Ashlin J Poruthoor
- Department of Biochemistry and Biophysics, University of Rochester Medical Center, Rochester, New York
| | - Akshara Sharma
- Department of Biochemistry and Biophysics, University of Rochester Medical Center, Rochester, New York
| | - Alan Grossfield
- Department of Biochemistry and Biophysics, University of Rochester Medical Center, Rochester, New York.
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40
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Lyu J, Zhang T, Marty MT, Clemmer D, Russell DH, Laganowsky A. Double and triple thermodynamic mutant cycles reveal the basis for specific MsbA-lipid interactions. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.03.547565. [PMID: 37461710 PMCID: PMC10350010 DOI: 10.1101/2023.07.03.547565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 07/27/2023]
Abstract
Structural and functional studies of the ATP-binding cassette transporter MsbA have revealed two distinct lipopolysaccharide (LPS) binding sites: one located in the central cavity and the other at a membrane-facing, exterior site. Although these binding sites are known to be important for MsbA function, the thermodynamic basis for these specific MsbA-LPS interactions is not well understood. Here, we use native mass spectrometry to determine the thermodynamics of MsbA interacting with the LPS-precursor 3-deoxy-D-manno-oct-2-ulosonic acid (Kdo)2-lipid A (KDL). The binding of KDL is solely driven by entropy, despite the transporter adopting an inward-facing conformation or trapped in an outward-facing conformation with adenosine 5'-diphosphate and vanadate. An extension of the mutant cycle approach is employed to probe basic residues that interact with KDL. We find the molecular recognition of KDL is driven by a positive coupling entropy (as large as -100 kJ/mol at 298K) that outweighs unfavorable coupling enthalpy. These findings indicate that alterations in solvent reorganization and conformational entropy can contribute significantly to the free energy of protein-lipid association. The results presented herein showcase the advantage of native MS to obtain thermodynamic insight into protein-lipid interactions that would otherwise be intractable using traditional approaches, and this enabling technology will be instrumental in the life sciences and drug discovery.
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Affiliation(s)
- Jixing Lyu
- Department of Chemistry, Texas A&M University, College Station, TX 77843
| | - Tianqi Zhang
- Department of Chemistry, Texas A&M University, College Station, TX 77843
| | - Michael T. Marty
- Department of Chemistry and Biochemistry and Bio5 Institute, The University of Arizona, Tucson, AZ 85721
| | - David Clemmer
- Department of Chemistry, Indiana University, Bloomington, IN 47405
| | - David H. Russell
- Department of Chemistry, Texas A&M University, College Station, TX 77843
| | - Arthur Laganowsky
- Department of Chemistry, Texas A&M University, College Station, TX 77843
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41
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Lai YH, Wang YS. Advances in high-resolution mass spectrometry techniques for analysis of high mass-to-charge ions. MASS SPECTROMETRY REVIEWS 2023; 42:2426-2445. [PMID: 35686331 DOI: 10.1002/mas.21790] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 01/27/2022] [Accepted: 04/07/2022] [Indexed: 06/15/2023]
Abstract
A major challenge in modern mass spectrometry (MS) is achieving high mass resolving power and accuracy for precision analyses in high mass-to-charge (m/z) regions. To advance the capability of MS for increasingly demanding applications, understanding limitations of state-of-the-art techniques and their status in applied sciences is essential. This review summarizes important instruments in high-resolution mass spectrometry (HRMS) and related advances to extend their working range to high m/z regions. It starts with an overview of HRMS techniques that provide adequate performance for macromolecular analysis, including Fourier-transform, time-of-flight (TOF), quadrupole-TOF, and related data-processing techniques. Methodologies and applications of HRMS for characterizing macromolecules in biochemistry and material sciences are summarized, such as top-down proteomics, native MS, drug discovery, structural virology, and polymer analyses.
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Affiliation(s)
- Yin-Hung Lai
- Genomics Research Center, Academia Sinica, Taipei, Taiwan, R.O.C
- Department of Chemical Engineering, National United University, Miaoli, Taiwan, R.O.C
- Institute of Food Safety and Health Risk Assessment, National Yang Ming Chiao Tung University, Taipei, Taiwan, R.O.C
| | - Yi-Sheng Wang
- Genomics Research Center, Academia Sinica, Taipei, Taiwan, R.O.C
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42
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Cao H, Liu Q, Liu X, Ma Z, Zhang J, Li X, Shen L, Yuan J, Zhang Q. Phosphatidic acid regulates ammonium uptake by interacting with AMMONIUM TRANSPORTER 1;1 in Arabidopsis. PLANT PHYSIOLOGY 2023; 193:1954-1969. [PMID: 37471275 DOI: 10.1093/plphys/kiad421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 06/26/2023] [Accepted: 06/27/2023] [Indexed: 07/22/2023]
Abstract
Ammonium (NH4+) is a key inorganic nitrogen source in cellular amino acid biosynthesis. The coupling of transcriptional and posttranslational regulation of AMMONIUM TRANSPORTER (AMT) ensures that NH4+ acquisition by plant roots is properly balanced, which allows for rapid adaptation to a variety of nitrogen conditions. Here, we report that phospholipase D (PLD)-derived phosphatidic acid (PA) interacts with AMT1;1 to mediate NH4+ uptake in Arabidopsis (Arabidopsis thaliana). We examined pldα1 pldδ-knockout mutants and found that a reduced PA level increased seedling growth under nitrogen deficiency and inhibited root growth upon NH4+ stress, which was consistent with the enhanced accumulation of cellular NH4+. PA directly bound to AMT1;1 and inhibited its transport activity. Mutation of AMT1;1 R487 to Gly (R487G) resulted in abolition of PA suppression and, subsequently, enhancement of ammonium transport activity in vitro and in vivo. Observations of AMT1;1-GFP showed suppressed endocytosis under PLD deficiency or by mutation of the PA-binding site in AMT1;1. Endocytosis was rescued by PA in the pldα1 pldδ mutant but not in the mutant AMT1;1R487G-GFP line. Together, these findings demonstrated PA-based shutoff control of plant NH4+ transport and point to a broader paradigm of lipid-transporter function.
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Affiliation(s)
- Hongwei Cao
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Qingyun Liu
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Xiao Liu
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Zhaokun Ma
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Jixiu Zhang
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Xuebing Li
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Like Shen
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Jingya Yuan
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Qun Zhang
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
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Campuzano IDG. A Research Journey: Over a Decade of Denaturing and Native-MS Analyses of Hydrophobic and Membrane Proteins in Amgen Therapeutic Discovery. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2023; 34:2413-2431. [PMID: 37643331 DOI: 10.1021/jasms.3c00175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
Membrane proteins and associated complexes currently comprise the majority of therapeutic targets and remain among the most challenging classes of proteins for analytical characterization. Through long-term strategic collaborations forged between industrial and academic research groups, there has been tremendous progress in advancing membrane protein mass spectrometry (MS) analytical methods and their concomitant application to Amgen therapeutic project progression. Herein, I will describe a detailed and personal account of how electrospray ionization (ESI) native mass spectrometry (nMS), ion mobility-MS (IM-MS), reversed phase liquid chromatographic mass spectrometry (RPLC-MS), high-throughput solid phase extraction mass spectrometry, and matrix-assisted laser desorption ionization mass spectrometry methods were developed, optimized, and validated within Amgen Research, and importantly, how these analytical methods were applied for membrane and hydrophobic protein analyses and ultimately therapeutic project support and progression. Additionally, I will discuss all the highly important and productive collaborative efforts, both internal Amgen and external academic, which were key in generating the samples, methods, and associated data described herein. I will also describe some early and previously unpublished nano-ESI (nESI) native-MS data from Amgen Research and the highly productive University of California Los Angeles (UCLA) collaboration. I will also present previously unpublished examples of real-life Amgen biotherapeutic membrane protein projects that were supported by all the MS (and IM) analytical techniques described herein. I will start by describing the initial nESI nMS experiments performed at Amgen in 2011 on empty nanodisc molecules, using a quadrupole time-of-flight MS, and how these experiments progressed on to the 15 Tesla Fourier transform ion cyclotron resonance MS at UCLA. Then described are monomeric and multimeric membrane protein data acquired in both nESI nMS and tandem-MS modes, using multiple methods of ion activation, resulting in dramatic spectral simplification. Also described is how we investigated the far less established and less published subject, that is denaturing RPLC-MS analysis of membrane proteins, and how we developed a highly robust and reproducible RPLC-MS method capable of effective separation of membrane proteins differing in only the presence or absence of an N-terminal post translational modification. Also described is the evolution of the aforementioned RPLC-MS method into a high-throughput solid phase extraction MS method. Finally, I will give my opinion on key developments and how the area of nMS of membrane proteins needs to evolve to a state where it can be applied within the biopharmaceutical research environment for routine therapeutic project support.
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Affiliation(s)
- Iain D G Campuzano
- Amgen Research, Center for Research Acceleration by Digital Innovation, Molecular Analytics, Thousand Oaks, California 91320, United States
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44
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Mahato DR, Andersson M. Dynamic lipid interactions in the plasma membrane Na +,K +-ATPase. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2023; 1870:119545. [PMID: 37481079 DOI: 10.1016/j.bbamcr.2023.119545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 06/12/2023] [Accepted: 07/13/2023] [Indexed: 07/24/2023]
Abstract
The function of ion-transporting Na+,K+-ATPases depends on the surrounding lipid environment in biological membranes. Two established lipid-interaction sites A and B within the transmembrane domain have been observed to induce protein activation and stabilization, respectively. In addition, lipid-mediated inhibition has been assigned to a site C, but with the exact location not experimentally confirmed. Also, possible effects on lipid interactions by disease mutants dwelling in the membrane-protein interface remain relatively uncharacterized. We simulated human Na+,K+-ATPase α1β1FXYD homology models in E1 and E2 states in an asymmetric, multicomponent plasma membrane to determine both wild-type and disease mutant lipid-protein interactions. The simulated wild-type lipid interactions at the established sites A and B were in agreement with experimental results thereby confirming the membrane-protein model system. The less well-characterized, proposed inhibitory site C was dominated by lipids lacking inhibitory properties. Instead, two sites hosting inhibitory lipids were identified at the extracellular side and also a cytoplasmic CHL-binding site that provide putative alternative locations of Na+,K+-ATPase inhibition. Three disease mutations, Leu302Arg, Glu840Arg and Met859Arg resided in the lipid-protein interface and caused drastic changes in the lipid interactions. The simulation results show that lipid interactions to the human Na+,K+-ATPase α1β1FXYD protein in the plasma membrane are highly state-dependent and can be disturbed by disease mutations located in the lipid interface, which can open up for new venues to understand genetic disorders.
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Affiliation(s)
- Dhani Ram Mahato
- Department of Chemistry, Umeå University, Umeå, Sweden; Institut de Química Computacional i Catàlisi, Universitat de Girona, Girona, 17003, Spain
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Chi G, Dietz L, Tang H, Snee M, Scacioc A, Wang D, Mckinley G, Mukhopadhyay SM, Pike AC, Chalk R, Burgess-Brown NA, Timmermans JP, van Putte W, Robinson CV, Dürr KL. Structural characterization of human urea transporters UT-A and UT-B and their inhibition. SCIENCE ADVANCES 2023; 9:eadg8229. [PMID: 37774028 PMCID: PMC10541013 DOI: 10.1126/sciadv.adg8229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Accepted: 08/30/2023] [Indexed: 10/01/2023]
Abstract
In this study, we present the structures of human urea transporters UT-A and UT-B to characterize them at molecular level and to detail the mechanism of UT-B inhibition by its selective inhibitor, UTBinh-14. High-resolution structures of both transporters establish the structural basis for the inhibitor's selectivity to UT-B, and the identification of multiple binding sites for the inhibitor will aid with the development of drug lead molecules targeting both transporters. Our study also discovers phospholipids associating with the urea transporters by combining structural observations, native MS, and lipidomics analysis. These insights improve our understanding of urea transporter function at a molecular level and provide a blueprint for a structure-guided design of therapeutics targeting these transporters.
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Affiliation(s)
- Gamma Chi
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford OX3 7DQ, UK
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Nuffield Department of Medicine Research Building, Oxford OX3 7FZ, UK
| | - Larissa Dietz
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford OX3 7DQ, UK
| | - Haiping Tang
- Department of Chemistry, University of Oxford, Oxford OX1 3TA, UK
- Kavli Institute for Nanoscience Discovery, University of Oxford, Oxford OX1 3QU, UK
| | - Matthew Snee
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford OX3 7DQ, UK
| | - Andreea Scacioc
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford OX3 7DQ, UK
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Nuffield Department of Medicine Research Building, Oxford OX3 7FZ, UK
| | - Dong Wang
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford OX3 7DQ, UK
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Nuffield Department of Medicine Research Building, Oxford OX3 7FZ, UK
| | - Gavin Mckinley
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford OX3 7DQ, UK
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Nuffield Department of Medicine Research Building, Oxford OX3 7FZ, UK
| | - Shubhashish M. M. Mukhopadhyay
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford OX3 7DQ, UK
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Nuffield Department of Medicine Research Building, Oxford OX3 7FZ, UK
| | - Ashley C. W. Pike
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford OX3 7DQ, UK
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Nuffield Department of Medicine Research Building, Oxford OX3 7FZ, UK
| | - Rod Chalk
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford OX3 7DQ, UK
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Nuffield Department of Medicine Research Building, Oxford OX3 7FZ, UK
| | - Nicola A. Burgess-Brown
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford OX3 7DQ, UK
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Nuffield Department of Medicine Research Building, Oxford OX3 7FZ, UK
| | - Jean-Pierre Timmermans
- Laboratory of Cell Biology and Histology (CBH) at Antwerp Centre for Advanced Microscopy (ACAM), Department of Veterinary Sciences, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium
| | - Wouter van Putte
- Laboratory of Cell Biology and Histology (CBH) at Antwerp Centre for Advanced Microscopy (ACAM), Department of Veterinary Sciences, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium
- PUXANO, Ottergemsesteenweg Zuid 713, 9000 Gent, Belgium
| | - Carol V. Robinson
- Department of Chemistry, University of Oxford, Oxford OX1 3TA, UK
- Kavli Institute for Nanoscience Discovery, University of Oxford, Oxford OX1 3QU, UK
| | - Katharina L. Dürr
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford OX3 7DQ, UK
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Nuffield Department of Medicine Research Building, Oxford OX3 7FZ, UK
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Zhang G, Odenkirk MT, Janczak CM, Lee R, Richardson K, Wang Z, Aspinwall CA, Marty MT. Identifying Membrane Protein-Lipid Interactions with Lipidomic Lipid Exchange-Mass Spectrometry. J Am Chem Soc 2023; 145:20859-20867. [PMID: 37700579 PMCID: PMC10540470 DOI: 10.1021/jacs.3c05883] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/14/2023]
Abstract
Lipids can play important roles in modulating membrane protein structure and function. However, it is challenging to identify natural lipids bound to membrane proteins in complex bilayers. Here, we developed lipidomic lipid exchange-mass spectrometry (LX-MS) to study the lipid affinity for membrane proteins on a lipidomic scale. We first mix membrane protein nanodiscs with empty nanodiscs that have no embedded membrane proteins. After allowing lipids to passively exchange between the two populations, we separate the two types of nanodiscs and perform lipidomic analysis on each with liquid chromatography and MS. Enrichment of lipids in the membrane protein nanodiscs reveals the affinity of individual lipids for binding the target membrane protein. We apply this approach to study three membrane proteins. With the Escherichia coli ammonium transporter AmtB and aquaporin AqpZ in nanodiscs with E. coli polar lipid extracts, we detected binding of cardiolipin and phosphatidyl-glycerol lipids to the proteins. With the acetylcholine receptor in nanodiscs with brain polar lipid extracts, we discovered a complex set of lipid interactions that depended on the head group and tail composition. Overall, lipidomic LX-MS provides a detailed understanding of the lipid-binding affinity and thermodynamics for membrane proteins in complex bilayers and provides a unique perspective on the chemical environment surrounding membrane proteins.
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Affiliation(s)
- Guozhi Zhang
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ, 85721, USA
| | - Melanie T. Odenkirk
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ, 85721, USA
- Bio5 Institute, University of Arizona, Tucson, AZ, 85721, USA
| | | | - Ray Lee
- Scintillation Nanotechnologies, Inc., Tucson, AZ, 85721, USA
| | | | - Zhihan Wang
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ, 85721, USA
| | - Craig A. Aspinwall
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ, 85721, USA
- Bio5 Institute, University of Arizona, Tucson, AZ, 85721, USA
| | - Michael T. Marty
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ, 85721, USA
- Bio5 Institute, University of Arizona, Tucson, AZ, 85721, USA
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47
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Chu M, Jiang Z, Wojcik M, Sun T, Sprung M, Wang J. Probing three-dimensional mesoscopic interfacial structures in a single view using multibeam X-ray coherent surface scattering and holography imaging. Nat Commun 2023; 14:5795. [PMID: 37723143 PMCID: PMC10507109 DOI: 10.1038/s41467-023-39984-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2023] [Accepted: 07/03/2023] [Indexed: 09/20/2023] Open
Abstract
Visualizing surface-supported and buried planar mesoscale structures, such as nanoelectronics, ultrathin-film quantum dots, photovoltaics, and heterogeneous catalysts, often requires high-resolution X-ray imaging and scattering. Here, we discovered that multibeam scattering in grazing-incident reflection geometry is sensitive to three-dimensional (3D) structures in a single view, which is difficult in conventional scattering or imaging approaches. We developed a 3D finite-element-based multibeam-scattering analysis to decode the heterogeneous electric-field distribution and to faithfully reproduce the complex scattering and surface features. This approach further leads to the demonstration of hard-X-ray Lloyd's mirror interference of scattering waves, resembling dark-field, high-contrast surface holography under the grazing-angle scattering conditions. A first-principles calculation of the single-view holographic images resolves the surface patterns' 3D morphology with nanometer resolutions, which is critical for ultrafine nanocircuit metrology. The holographic method and simulations pave the way for single-shot structural characterization for visualizing irreversible and morphology-transforming physical and chemical processes in situ or operando.
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Affiliation(s)
- Miaoqi Chu
- X-ray Science Division, Argonne National Laboratory, Lemont, IL, 60439, USA.
| | - Zhang Jiang
- X-ray Science Division, Argonne National Laboratory, Lemont, IL, 60439, USA
| | - Michael Wojcik
- X-ray Science Division, Argonne National Laboratory, Lemont, IL, 60439, USA
| | - Tao Sun
- X-ray Science Division, Argonne National Laboratory, Lemont, IL, 60439, USA
- Department of Materials Science and Engineering, University of Virginia, Charlottesville, VA, 22904, USA
| | - Michael Sprung
- Deutsches Elektronen-Synchrotron (DESY), Notkestr. 85, 22607, Hamburg, Germany
| | - Jin Wang
- X-ray Science Division, Argonne National Laboratory, Lemont, IL, 60439, USA.
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Zhu Y, Peng BJ, Kumar S, Stover L, Chang JY, Lyu J, Zhang T, Schrecke S, Azizov D, Russell DH, Fang L, Laganowsky A. Polyamine detergents tailored for native mass spectrometry studies of membrane proteins. Nat Commun 2023; 14:5676. [PMID: 37709761 PMCID: PMC10502129 DOI: 10.1038/s41467-023-41429-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Accepted: 08/28/2023] [Indexed: 09/16/2023] Open
Abstract
Native mass spectrometry (MS) is a powerful technique for interrogating membrane protein complexes and their interactions with other molecules. A key aspect of the technique is the ability to preserve native-like structures and noncovalent interactions, which can be challenging depending on the choice of detergent. Different strategies have been employed to reduce charge on protein complexes to minimize activation and preserve non-covalent interactions. Here, we report the synthesis of a class of polyamine detergents tailored for native MS studies of membrane proteins. These detergents, a series of spermine covalently attached to various alkyl tails, are exceptional charge-reducing molecules, exhibiting a ten-fold enhanced potency over spermine. Addition of polyamine detergents to proteins solubilized in maltoside detergents results in improved, charge-reduced native mass spectra and reduced dissociation of subunits. Polyamine detergents open new opportunities to investigate membrane proteins in different detergent environments that have thwarted previous native MS studies.
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Affiliation(s)
- Yun Zhu
- Department of Chemistry, Texas A&M University, College Station, TX, 77843, USA
| | - Bo-Ji Peng
- Department of Chemistry, Texas A&M University, College Station, TX, 77843, USA
| | - Smriti Kumar
- Department of Chemistry, Texas A&M University, College Station, TX, 77843, USA
| | - Lauren Stover
- Department of Chemistry, Texas A&M University, College Station, TX, 77843, USA
| | - Jing-Yuan Chang
- Department of Chemistry, Texas A&M University, College Station, TX, 77843, USA
| | - Jixing Lyu
- Department of Chemistry, Texas A&M University, College Station, TX, 77843, USA
| | - Tianqi Zhang
- Department of Chemistry, Texas A&M University, College Station, TX, 77843, USA
| | - Samantha Schrecke
- Department of Chemistry, Texas A&M University, College Station, TX, 77843, USA
| | - Djavdat Azizov
- Department of Chemistry, Texas A&M University, College Station, TX, 77843, USA
| | - David H Russell
- Department of Chemistry, Texas A&M University, College Station, TX, 77843, USA
| | - Lei Fang
- Department of Chemistry, Texas A&M University, College Station, TX, 77843, USA.
| | - Arthur Laganowsky
- Department of Chemistry, Texas A&M University, College Station, TX, 77843, USA.
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Panda A, Brown C, Gupta K. Studying Membrane Protein-Lipid Specificity through Direct Native Mass Spectrometric Analysis from Tunable Proteoliposomes. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2023; 34:1917-1927. [PMID: 37432128 PMCID: PMC10932607 DOI: 10.1021/jasms.3c00110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/12/2023]
Abstract
Native mass spectrometry (nMS) has emerged as a key analytical tool to study the organizational states of proteins and their complexes with both endogenous and exogenous ligands. Specifically, for membrane proteins, it provides a key analytical dimension to determine the identity of bound lipids and to decipher their effects on the observed structural assembly. We recently developed an approach to study membrane proteins directly from intact and tunable lipid membranes where both the biophysical properties of the membrane and its lipid compositions can be customized. Extending this, we use our liposome-nMS platform to decipher the lipid specificity of membrane proteins through their multiorganelle trafficking pathways. To demonstrate this, we used VAMP2 and reconstituted it in the endoplasmic reticulum (ER), Golgi, synaptic vesicle (SV), and plasma membrane (PM) mimicking liposomes. By directly studying VAMP2 from these customized liposomes, we show how the same transmembrane protein can bind to different sets of lipids in different organellar-mimicking membranes. Considering that the cellular trafficking pathway of most eukaryotic integral membrane proteins involves residence in multiple organellar membranes, this study highlights how the lipid-specificity of the same integral membrane protein may change depending on the membrane context. Further, leveraging the capability of the platform to study membrane proteins from liposomes with curated biophysical properties, we show how we can disentangle chemical versus biophysical properties, of individual lipids in regulating membrane protein assembly.
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Affiliation(s)
- Aniruddha Panda
- Nanobiology Institute, Yale University, West Haven, Connecticut 06516, United States
- Department of Cell Biology, Yale University School of Medicine, New Haven, Connecticut 06520, United States
| | - Caroline Brown
- Nanobiology Institute, Yale University, West Haven, Connecticut 06516, United States
- Department of Cell Biology, Yale University School of Medicine, New Haven, Connecticut 06520, United States
| | - Kallol Gupta
- Nanobiology Institute, Yale University, West Haven, Connecticut 06516, United States
- Department of Cell Biology, Yale University School of Medicine, New Haven, Connecticut 06520, United States
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50
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Odenkirk MT, Zhang G, Marty MT. Do Nanodisc Assembly Conditions Affect Natural Lipid Uptake? JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2023; 34:2006-2015. [PMID: 37524089 PMCID: PMC10528108 DOI: 10.1021/jasms.3c00170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/02/2023]
Abstract
Lipids play critical roles in modulating membrane protein structure, interactions, and activity. Nanodiscs provide a tunable membrane mimetic that can model these endogenous protein-lipid interactions in a nanoscale lipid bilayer. However, most studies of membrane proteins with nanodiscs use simple synthetic lipids that lack the headgroup and fatty acyl diversity of natural extracts. Prior research has successfully used natural lipid extracts in nanodiscs that more accurately mimic natural environments, but it is not clear how nanodisc assembly may bias the incorporated lipid profiles. Here, we applied lipidomics to investigate how nanodisc assembly conditions affect the profile of natural lipids in nanodiscs. Specifically, we tested the effects of assembly temperature, nanodisc size, and lipidome extract complexity. Globally, our analysis demonstrates that the lipids profiles are largely unaffected by nanodisc assembly conditions. However, a few notable changes emerged within individual lipids and lipid classes, such as a differential incorporation of cardiolipin and phosphatidylglycerol lipids from the E. coli polar lipid extract at different temperatures. Conversely, some classes of brain lipids were affected by nanodisc size at higher temperatures. Collectively, these data enable the application of nanodiscs to study protein-lipid interactions in complex lipid environments.
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Affiliation(s)
- Melanie T. Odenkirk
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ
- Bio5 Institute, University of Arizona, Tucson, AZ
| | - Guozhi Zhang
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ
| | - Michael T. Marty
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ
- Bio5 Institute, University of Arizona, Tucson, AZ
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