1
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Burgardt NI, Melian NA, González Flecha FL. Copper resistance in the cold: Genome analysis and characterisation of a P IB-1 ATPase in Bizionia argentinensis. ENVIRONMENTAL MICROBIOLOGY REPORTS 2024; 16:e13278. [PMID: 38943264 PMCID: PMC11213822 DOI: 10.1111/1758-2229.13278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Accepted: 04/19/2024] [Indexed: 07/01/2024]
Abstract
Copper homeostasis is a fundamental process in organisms, characterised by unique pathways that have evolved to meet specific needs while preserving core resistance mechanisms. While these systems are well-documented in model bacteria, information on copper resistance in species adapted to cold environments is scarce. This study investigates the potential genes related to copper homeostasis in the genome of Bizionia argentinensis (JUB59-T), a psychrotolerant bacterium isolated from Antarctic seawater. We identified several genes encoding proteins analogous to those crucial for copper homeostasis, including three sequences of copper-transport P1B-type ATPases. One of these, referred to as BaCopA1, was chosen for cloning and expression in Saccharomyces cerevisiae. BaCopA1 was successfully integrated into yeast membranes and subsequently extracted with detergent. The purified BaCopA1 demonstrated the ability to catalyse ATP hydrolysis at low temperatures. Structural models of various BaCopA1 conformations were generated and compared with mesophilic and thermophilic homologous structures. The significant conservation of critical residues and structural similarity among these proteins suggest a shared reaction mechanism for copper transport. This study is the first to report a psychrotolerant P1B-ATPase that has been expressed and purified in a functional form.
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Affiliation(s)
- Noelia I. Burgardt
- Laboratorio de Biofísica Molecular, Facultad de Farmacia y Bioquímica, Instituto de Química y Fisicoquímica BiológicasUniversidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y TécnicasBuenos AiresArgentina
- Present address:
Departamento de Ciencia y TecnologíaUniversidad Nacional de QuilmesBernalArgentina
| | - Noelia A. Melian
- Laboratorio de Biofísica Molecular, Facultad de Farmacia y Bioquímica, Instituto de Química y Fisicoquímica BiológicasUniversidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y TécnicasBuenos AiresArgentina
| | - F. Luis González Flecha
- Laboratorio de Biofísica Molecular, Facultad de Farmacia y Bioquímica, Instituto de Química y Fisicoquímica BiológicasUniversidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y TécnicasBuenos AiresArgentina
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2
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Cook KD, Tran T, Thomas VA, Devanaboyina SC, Rock DA, Pearson JT. Correlation of In Vitro Kinetic Stability to Preclinical In Vivo Pharmacokinetics for a Panel of Anti-PD-1 Monoclonal Antibody Interleukin 21 Mutein Immunocytokines. Drug Metab Dispos 2024; 52:228-235. [PMID: 38135505 DOI: 10.1124/dmd.123.001555] [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: 09/25/2023] [Revised: 12/15/2023] [Accepted: 12/18/2023] [Indexed: 12/24/2023] Open
Abstract
The development of therapeutic fusion protein drugs is often impeded by the unintended consequences that occur from fusing together domains from independent naturally occurring proteins, consequences such as altered biodistribution, tissue uptake, or rapid clearance and potential immunogenicity. For therapeutic fusion proteins containing globular domains, we hypothesized that aberrant in vivo behavior could be related to low kinetic stability of these domains leading to local unfolding and susceptibility to partial proteolysis and/or salvage and uptake. Herein we describe an assay to measure kinetic stability of therapeutic fusion proteins by way of their sensitivity to the protease thermolysin. The results indicate that in vivo pharmacokinetics of a panel of anti-programmed cell death protein 1 monocolonal antibody:interleukin 21 immunocytokines in both mice and nonhuman primates are highly correlated with their in vitro susceptibility to thermolysin-mediated proteolysis. This assay can be used as a tool to quickly identify in vivo liabilities of globular domains of therapeutic proteins, thus aiding in the optimization and development of new multispecific drug candidates. SIGNIFICANCE STATEMENT: This work describes a novel assay utilizing protein kinetic stability to identify preclinical in vivo pharmacokinetic liabilities of multispecific therapeutic fusion proteins. This provides an efficient, inexpensive method to ascertain inherent protein stability in vitro before conducting in vivo studies, which can rapidly increase the speed of preclinical drug development.
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Affiliation(s)
- Kevin D Cook
- Amgen Research, Pharmacokinetics & Drug Metabolism, South San Francisco, California
| | - Thuy Tran
- Amgen Research, Pharmacokinetics & Drug Metabolism, South San Francisco, California
| | - Veena A Thomas
- Amgen Research, Pharmacokinetics & Drug Metabolism, South San Francisco, California
| | | | - Dan A Rock
- Amgen Research, Pharmacokinetics & Drug Metabolism, South San Francisco, California
| | - Josh T Pearson
- Amgen Research, Pharmacokinetics & Drug Metabolism, South San Francisco, California
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3
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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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4
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Krishnarjuna B, Sharma G, Im SC, Auchus R, Anantharamaiah GM, Ramamoorthy A. Characterization of nanodisc-forming peptides for membrane protein studies. J Colloid Interface Sci 2024; 653:1402-1414. [PMID: 37801850 PMCID: PMC10864042 DOI: 10.1016/j.jcis.2023.09.162] [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: 07/27/2023] [Revised: 09/11/2023] [Accepted: 09/27/2023] [Indexed: 10/08/2023]
Abstract
Lipid-bilayer nanodiscs provide a stable, native-like membrane environment for the functional and structural studies of membrane proteins and other membrane-binding molecules. Peptide-based nanodiscs having unique properties are developed for membrane protein studies and other biological applications. While the self-assembly process rendering the formation of peptide-nanodiscs is attractive, it is important to understand the stability and suitability of these nanodisc systems for membrane protein studies. In this study, we investigated the nanodiscs formation by the anti-inflammatory and tumor-suppressing peptide AEM28. AEM28 is a chimeric peptide containing a cationic-rich heparan sulfate proteoglycan- (HSPG)-binding domain from human apolipoprotein E (hapoE) (141-150) followed by the 18A peptide's amino acid sequence. AEM28-based nanodiscs made with different types of lipids were characterized using various biophysical techniques and compared with the nanodiscs formed using 2F or 4F peptides. Variable temperature dynamic light-scattering and 31P NMR experiments indicated the fusion and size heterogeneity of nanodiscs at high temperatures. The suitability of AEM28 and Ac-18A-NH2- (2F-) based nanodiscs for studying membrane proteins is demonstrated by reconstituting and characterizing a drug-metabolizing enzyme, cytochrome-P450 (CYP450), or the redox complex CYP450-CYP450 reductase. AEM28 and 2F were also tested for their efficacies in solubilizing E. coli membranes to understand the possibility of using them for detergent-free membrane protein isolation. Our experimental results suggest that AEM28 nanodiscs are suitable for studying membrane proteins with a net positive charge, whereas 2F-based nanodiscs are compatible with any membrane proteins and their complexes irrespective of their charge. Furthermore, both peptides solubilized E. coli cell membranes, indicating their use in membrane protein isolation and other applications related to membrane solubilization.
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Affiliation(s)
- Bankala Krishnarjuna
- Biophysics Program, Department of Chemistry, Biomedical Engineering, Macromolecular Science and Engineering, University of Michigan, Arbor, MI 48109, USA
| | - Gaurav Sharma
- Biophysics Program, Department of Chemistry, Biomedical Engineering, Macromolecular Science and Engineering, University of Michigan, Arbor, MI 48109, USA
| | - Sang-Choul Im
- Department of Pharmacology and Internal Medicine, Division of Metabolism, Endocrinology, & Diabetes, University of Michigan, Ann Arbor, MI 48109, USA
| | - Richard Auchus
- Department of Pharmacology and Internal Medicine, Division of Metabolism, Endocrinology, & Diabetes, University of Michigan, Ann Arbor, MI 48109, USA
| | - G M Anantharamaiah
- Department of Medicine, University of Alabama at Birmingham Medical Center, Birmingham, AL 35294, USA
| | - Ayyalusamy Ramamoorthy
- Biophysics Program, Department of Chemistry, Biomedical Engineering, Macromolecular Science and Engineering, University of Michigan, Arbor, MI 48109, USA; National High Magnetic Field Laboratory, Department of Chemical and Biomedical Engineering, Tallahassee, FL 32310, USA.
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5
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Wu T, Hornsby M, Zhu L, Yu JC, Shokat KM, Gestwicki JE. Protocol for performing and optimizing differential scanning fluorimetry experiments. STAR Protoc 2023; 4:102688. [PMID: 37943662 PMCID: PMC10663957 DOI: 10.1016/j.xpro.2023.102688] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 06/21/2023] [Accepted: 10/12/2023] [Indexed: 11/12/2023] Open
Abstract
Differential scanning fluorimetry (DSF) is a widely used technique for determining the apparent melting temperature (Tma) of a purified protein. Here, we present a protocol for performing and optimizing DSF experiments. We describe steps for designing and performing the experiment, analyzing data, and optimization. We provide benchmarks for typical Tmas and ΔTmas, standard assay conditions, and upper and lower limits of commonly altered experimental variables. We also detail common pitfalls of DSF and ways to avoid, identify, and overcome them.
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Affiliation(s)
- Taiasean Wu
- Department of Pharmaceutical Chemistry and the Institute for Neurodegenerative Disease, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Michael Hornsby
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 941583, USA
| | - Lawrence Zhu
- Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Joshua C Yu
- Department of Pharmaceutical Chemistry and the Institute for Neurodegenerative Disease, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Kevan M Shokat
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 941583, USA; Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA; Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Jason E Gestwicki
- Department of Pharmaceutical Chemistry and the Institute for Neurodegenerative Disease, University of California, San Francisco, San Francisco, CA 94158, USA.
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6
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Jang Y, Park J, Kim P, Park EJ, Sun H, Baek Y, Jung J, Song TK, Doh J, Kim H. Development of exosome membrane materials-fused microbubbles for enhanced stability and efficient drug delivery of ultrasound contrast agent. Acta Pharm Sin B 2023; 13:4983-4998. [PMID: 38045059 PMCID: PMC10692476 DOI: 10.1016/j.apsb.2023.08.022] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 07/21/2023] [Accepted: 07/27/2023] [Indexed: 12/05/2023] Open
Abstract
Lipid-coated microbubbles are widely used as an ultrasound contrast agent, as well as drug delivery carriers. However, the two main limitations in ultrasound diagnosis and drug delivery using microbubbles are the short half-life in the blood system, and the difficulty of surface modification of microbubbles for active targeting. The exosome, a type of extracellular vesicle, has a preferentially targeting ability for its original cell. In this study, exosome-fused microbubbles (Exo-MBs) were developed by embedding the exosome membrane proteins into microbubbles. As a result, the stability of Exo-MBs is improved over the conventional microbubbles. On the same principle that under the exposure of ultrasound, microbubbles are cavitated and self-assembled into nano-sized particles, and Exo-MBs are self-assembled into exosome membrane proteins-embedded nanoparticles (Exo-NPs). The Exo-NPs showed favorable targeting properties to their original cells. A photosensitizer, chlorin e6, was loaded into Exo-MBs to evaluate therapeutic efficacy as a drug carrier. Much higher therapeutic efficacy of photodynamic therapy was confirmed, followed by cancer immunotherapy from immunogenic cell death. We have therefore developed a novel ultrasound image-guided drug delivery platform that overcomes the shortcomings of the conventional ultrasound contrast agent and is capable of simultaneous photodynamic therapy and cancer immunotherapy.
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Affiliation(s)
- Yongho Jang
- Department of Chemical and Biomolecular Engineering, Sogang University, Seoul 04107, Republic of Korea
| | - Jeehun Park
- Research Institute of Advanced Materials (RIAM), Institute of Engineering Research, Seoul National University, Seoul 08826, Republic of Korea
| | - Pilsu Kim
- Department of Electronic Engineering, Sogang University, Seoul 04107, Republic of Korea
| | - Eun-Joo Park
- Biomedical Research Institute & Department of Radiology, Seoul National University Hospital, Seoul 03080, Republic of Korea
| | - Hyungjin Sun
- Interdisciplinary Program in Bioengineering, Seoul National University, Seoul 08826, Republic of Korea
| | - Yujin Baek
- Department of Materials Science and Engineering, Seoul National University, Seoul 08826, Republic of Korea
| | - Jaehun Jung
- Department of Chemical and Biomolecular Engineering, Sogang University, Seoul 04107, Republic of Korea
| | - Tai-kyong Song
- Department of Electronic Engineering, Sogang University, Seoul 04107, Republic of Korea
| | - Junsang Doh
- Research Institute of Advanced Materials (RIAM), Institute of Engineering Research, Seoul National University, Seoul 08826, Republic of Korea
- Department of Materials Science and Engineering, Seoul National University, Seoul 08826, Republic of Korea
- Institute of Engineering Research, Bio-MAX Institute, Seoul National University, Seoul 08826, Republic of Korea
| | - Hyuncheol Kim
- Department of Chemical and Biomolecular Engineering, Sogang University, Seoul 04107, Republic of Korea
- Department of Biomedical Engineering, Sogang University, Seoul 04107, Republic of Korea
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7
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Zerbetto De Palma G, Recoulat Angelini AA, Vitali V, González Flecha FL, Alleva K. Cooperativity in regulation of membrane protein function: phenomenological analysis of the effects of pH and phospholipids. Biophys Rev 2023; 15:721-731. [PMID: 37681089 PMCID: PMC10480370 DOI: 10.1007/s12551-023-01095-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 07/01/2023] [Indexed: 09/09/2023] Open
Abstract
Interaction between membrane proteins and ligands plays a key role in governing a wide spectrum of cellular processes. These interactions can provide a cooperative-type regulation of protein function. A wide variety of proteins, including enzymes, channels, transporters, and receptors, displays cooperative behavior in their interactions with ligands. Moreover, the ligands involved encompass a vast diversity and include specific molecules or ions that bind to specific binding sites. In this review, our particular focus is on the interaction between integral membrane proteins and ligands that can present multiple "binding sites", such as protons or membrane phospholipids. The study of the interaction that protons or lipids have with membrane proteins often presents challenges for classical mechanistic modeling approaches. In this regard, we show that, like Hill's pioneering work on hemoglobin regulation, phenomenological modeling constitutes a powerful tool for capturing essential features of these systems.
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Affiliation(s)
- Gerardo Zerbetto De Palma
- Facultad de Farmacia y Bioquímica, Departamento de Fisicomatemática, Universidad de Buenos Aires, Buenos Aires, Argentina
- Instituto de Biotecnología, Universidad Nacional de Hurlingham, Villa Tesei, Buenos Aires, Argentina
- Instituto de Química y Fisicoquímica Biológica (IQUIFIB), CONICET, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Alvaro A. Recoulat Angelini
- Instituto de Química y Fisicoquímica Biológica (IQUIFIB), CONICET, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Victoria Vitali
- Facultad de Farmacia y Bioquímica, Departamento de Fisicomatemática, Universidad de Buenos Aires, Buenos Aires, Argentina
- Instituto de Química y Fisicoquímica Biológica (IQUIFIB), CONICET, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - F. Luis. González Flecha
- Instituto de Química y Fisicoquímica Biológica (IQUIFIB), CONICET, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Karina Alleva
- Facultad de Farmacia y Bioquímica, Departamento de Fisicomatemática, Universidad de Buenos Aires, Buenos Aires, Argentina
- Instituto de Química y Fisicoquímica Biológica (IQUIFIB), CONICET, Universidad de Buenos Aires, Buenos Aires, Argentina
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8
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Selvasingh JA, McDonald EF, Mckinney JR, Meiler J, Ledwitch KV. Dark nanodiscs as a model membrane for evaluating membrane protein thermostability by differential scanning fluorimetry. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.08.539917. [PMID: 37214798 PMCID: PMC10197605 DOI: 10.1101/2023.05.08.539917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Measuring protein thermostability provides valuable information on the biophysical rules that govern 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 non-fluorescent membrane scaffold protein (MSP) 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 show a complex biphasic thermal unfolding pattern in the presence of lipids 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 nanodisc. 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, TN 37240, USA
- Department of Chemistry, Vanderbilt University, Nashville, TN 37235, USA
| | - Eli Fritz McDonald
- Center for Structural Biology, Vanderbilt University, Nashville, TN 37240, USA
- Department of Chemistry, Vanderbilt University, Nashville, TN 37235, USA
| | - Jacob R. Mckinney
- Center for Structural Biology, Vanderbilt University, Nashville, TN 37240, USA
- Department of Chemistry, Vanderbilt University, Nashville, TN 37235, USA
| | - Jens Meiler
- Center for Structural Biology, Vanderbilt University, Nashville, TN 37240, USA
- Department of Chemistry, Vanderbilt University, Nashville, TN 37235, USA
- Institute of Drug Discovery, Faculty of Medicine, University of Leipzig, 04103 Leipzig, Germany
| | - Kaitlyn V. Ledwitch
- Center for Structural Biology, Vanderbilt University, Nashville, TN 37240, USA
- Department of Chemistry, Vanderbilt University, Nashville, TN 37235, USA
- Lead contact
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9
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Krishnarjuna B, Marte J, Ravula T, Ramamoorthy A. Enhancing the stability and homogeneity of non-ionic polymer nanodiscs by tuning electrostatic interactions. J Colloid Interface Sci 2023; 634:887-896. [PMID: 36566634 PMCID: PMC10838601 DOI: 10.1016/j.jcis.2022.12.112] [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: 08/26/2022] [Revised: 12/14/2022] [Accepted: 12/19/2022] [Indexed: 12/24/2022]
Abstract
The nanodisc technology is increasingly used for structural studies on membrane proteins and drug delivery. The development of synthetic polymer nanodiscs and the recent discovery of non-ionic inulin-based polymers have significantly broadened the scope of nanodiscs. While the lipid exchange and size flexibility properties of the self-assembled polymer-based nanodiscs are valuable for various applications, the non-ionic polymer nanodiscs are remarkably unique in that they enable the reconstitution of any protein, protein-protein complexes, or drugs irrespective of their charge. However, the non-ionic nature of the belt could influence the stability and size homogeneity of inulin-based polymer nanodiscs. In this study, we investigate the size stability and homogeneity of nanodiscs formed by non-ionic lipid-solubilizing polymers using different biophysical methods. Polymer nanodiscs containing zwitterionic DMPC and different ratios of DMPC:DMPG lipids were made using anionic SMA-EA or non-ionic pentyl-inulin polymers. Non-ionic polymer nanodiscs made using zwitterionic DMPC lipids produced a very broad elution profile on SEC due to their instability in the column, thus affecting sample monodispersity which was confirmed by DLS experiments that showed multiple peaks. However, the inclusion of anionic DMPG lipids improved the stability as observed from SEC and DLS profiles, which was further confirmed by TEM images. Whereas, anionic SMA-EA-based DMPC-nanodiscs showed excellent stability and size homogeneity when solubilizing zwitterionic lipids. The stability of DMPC:DMPG non-ionic polymer nanodiscs is attributed to the inter-nanodisc repulsion by the anionic-DMPG that prevents the uncontrolled collision and fusion of nanodiscs. Thus, the reported results demonstrate the use of electrostatic interactions to tune the solubility, stability, and size homogeneity of non-ionic polymer nanodiscs which are important features for enabling functional and atomic-resolution structural studies of membrane proteins, other lipid-binding molecules, and water-soluble biomolecules including cytosolic proteins, nucleic acids and metabolites.
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Affiliation(s)
- Bankala Krishnarjuna
- Biophysics Program, Department of Chemistry, Macromolecular Science and Engineering, Biomedical Engineering, Michigan Neuroscience Institute, The University of Michigan, Ann Arbor, MI 48109-1055, USA
| | - Joseph Marte
- Biophysics Program, Department of Chemistry, Macromolecular Science and Engineering, Biomedical Engineering, Michigan Neuroscience Institute, The University of Michigan, Ann Arbor, MI 48109-1055, USA
| | - Thirupathi Ravula
- Biophysics Program, Department of Chemistry, Macromolecular Science and Engineering, Biomedical Engineering, Michigan Neuroscience Institute, The University of Michigan, Ann Arbor, MI 48109-1055, USA
| | - Ayyalusamy Ramamoorthy
- Biophysics Program, Department of Chemistry, Macromolecular Science and Engineering, Biomedical Engineering, Michigan Neuroscience Institute, The University of Michigan, Ann Arbor, MI 48109-1055, USA.
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10
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Sarkar P, Bhat A, Chattopadhyay A. Lysine 101 in the CRAC Motif in Transmembrane Helix 2 Confers Cholesterol-Induced Thermal Stability to the Serotonin 1A Receptor. J Membr Biol 2022; 255:739-746. [PMID: 35986776 DOI: 10.1007/s00232-022-00262-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 08/05/2022] [Indexed: 12/24/2022]
Abstract
G protein-coupled receptors (GPCRs) constitute the largest class of membrane proteins that transduce signals across the plasma membrane and orchestrate a multitude of physiological processes within cells. The serotonin1A receptor is a crucial neurotransmitter receptor in the GPCR family involved in a multitude of neurological, behavioral and cognitive functions. We have previously shown, using a combination of experimental and simulation approaches, that membrane cholesterol acts as a key regulator of organization, dynamics, signaling and endocytosis of the serotonin1A receptor. In addition, we showed that membrane cholesterol stabilizes the serotonin1A receptor against thermal deactivation. In the present work, we explored the molecular basis of cholesterol-induced thermal stability of the serotonin1A receptor. For this, we explored the possible role of the K101 residue in a cholesterol recognition/interaction amino acid consensus (CRAC) motif in transmembrane helix 2 in conferring the thermal stability of the serotonin1A receptor. Our results show that a mutation in the K101 residue leads to loss in thermal stability of the serotonin1A receptor imparted by cholesterol, independent of membrane cholesterol content. We envision that our results could have potential implications in structural biological advancements of GPCRs and design of thermally stabilized receptors for drug development.
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Affiliation(s)
- Parijat Sarkar
- CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad, 500 007, India
| | - Akrati Bhat
- CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad, 500 007, India
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11
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Valsecchi WM, Faraj SE, Cerf NT, Fedosova NU, Montes MR. The transported cations impose differences in the thermostability of the gastric H,K-ATPase. A kinetic analysis. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2022; 1864:184006. [PMID: 35868405 DOI: 10.1016/j.bbamem.2022.184006] [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: 05/20/2022] [Revised: 07/06/2022] [Accepted: 07/12/2022] [Indexed: 06/15/2023]
Abstract
This work analyses the thermostability of a membrane protein, the gastric H,K-ATPase, by means of a detailed kinetic characterization of its inactivation process, which showed to exhibit first-order kinetics. We observed parallel time courses for the decrease of ATPase activity, the decrease of the autophosphorylation capacity and the loss of tertiary structure at 49 °C. Higher temperatures were required to induce a significant change in secondary structure. The correspondence between the kinetics of Trp fluorescence measured at 49 °C and the decrease of the residual activity after heating at that temperature, proves the irreversibility of the inactivation process. Inactivation proceeds at different rates in E1 or E2 conformations. The K+-induced E2 state exhibits a lower inactivation rate; the specific effect is exerted with a K0.5 similar to that found at 25 °C, providing a further inkling that K+ occlusion by the H,K-ATPase is not really favoured. Increasing [H+] from pH 8 to pH 7, which possibly shifts the protein to E1, produces a subtle destabilizing effect on the H,K-ATPase. We performed a prediction of potential intramolecular interactions and found that the differential stability between E1 and E2 may be mainly explained by the higher number of hydrophobic interactions in the α- and β-subunits of E2 conformation.
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Affiliation(s)
- W M Valsecchi
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Química Biológica, Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Universidad de Buenos Aires, Instituto de Química y Fisicoquímica Biológicas "Prof. Alejandro C. Paladini" (IQUIFIB), Buenos Aires, Argentina
| | - S E Faraj
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Química Biológica, Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Universidad de Buenos Aires, Instituto de Química y Fisicoquímica Biológicas "Prof. Alejandro C. Paladini" (IQUIFIB), Buenos Aires, Argentina
| | - N T Cerf
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Química Biológica, Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Universidad de Buenos Aires, Instituto de Química y Fisicoquímica Biológicas "Prof. Alejandro C. Paladini" (IQUIFIB), Buenos Aires, Argentina
| | - N U Fedosova
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - M R Montes
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Química Biológica, Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Universidad de Buenos Aires, Instituto de Química y Fisicoquímica Biológicas "Prof. Alejandro C. Paladini" (IQUIFIB), Buenos Aires, Argentina.
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12
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Peluffo RD, del V. Alonso S, Itri R, Flecha FLG, Barbosa LRS. Biophysical Reviews special issue call: LAFeBS-highlighting biophysics in Latin America. Biophys Rev 2022; 14:1083-1084. [PMID: 36345275 PMCID: PMC9636340 DOI: 10.1007/s12551-022-00996-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/01/2022] [Indexed: 10/14/2022] Open
Abstract
This Commentary describes a call for contributions to an upcoming Special Issue (SI) of Biophysical Reviews on the Latin American Federation of Biophysical Societies (LAFeBS). It details the reason for the SI, the SI Editors contact information and the relevant submission details for those wishing to contribute.
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Affiliation(s)
- R. Daniel Peluffo
- Group of Biophysical Chemistry, Department of Biological Sciences, CENUR Litoral Norte, Universidad de la República, Salto, Uruguay
| | - Silvia del V. Alonso
- Departamento de Ciencia y Tecnología, Laboratorio de Bio-Nanotecnología, Universidad Nacional de Quilmes, Bernal, Buenos Aires Argentina
- Grupo de Biología Estructural y Biotecnología (GBEyB), IMBICE (CONICET CCT-La Plata), Buenos Aires, Argentina
| | - Rosangela Itri
- Instituto de Fisica, Universidade de Sao Paulo, Sao Paulo, SP 05508-090 Brazil
| | - F. Luis González Flecha
- Laboratorio de Biofísica Molecular, Instituto de Química y Fisicoquímica Biológicas, Universidad de Buenos Aires - CONICET, Buenos Aires, Argentina
| | - Leandro R. S. Barbosa
- Instituto de Fisica, Universidade de Sao Paulo, Sao Paulo, SP 05508-090 Brazil
- Brazilian Synchrotron Light Laboratory (LNLS), Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, SP Brazil
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13
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Yuan W, Casier R, Duhamel J. Unfolding of Helical Poly( L-Glutamic Acid) in N, N-Dimethylformamide Probed by Pyrene Excimer Fluorescence (PEF). Polymers (Basel) 2021; 13:polym13111690. [PMID: 34067276 PMCID: PMC8196828 DOI: 10.3390/polym13111690] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 05/14/2021] [Accepted: 05/18/2021] [Indexed: 11/16/2022] Open
Abstract
The denaturation undergone by α–helical poly(L-glutamic acid) (PLGA) in N,N-dimethylformamide upon addition of guanidine hydrochloride (GdHCl) was characterized by comparing the fluorescence of a series of PLGA constructs randomly labeled with the dye pyrene (Py-PLGA) to that of a series of Py-PDLGA samples prepared from a racemic mixture of D,L-glutamic acid. The process of pyrene excimer formation (PEF) was taken advantage of to probe changes in the conformation of α–helical Py-PLGA. Fluorescence Blob Model (FBM) analysis of the fluorescence decays of the Py-PLGA and Py-PDLGA constructs yielded the average number (<Nblob>) of glutamic acids located inside a blob, which represented the volume probed by an excited pyrenyl label. <Nblob> remained constant for randomly coiled Py-PDLGA but decreased from ~20 to ~10 glutamic acids for the Py-PLGA samples as GdHCl was added to the solution. The decrease in <Nblob> reflected the decrease in the local density of PLGA as the α–helix unraveled in solution. The changes in <Nblob> with GdHCl concentration was used to determine the change in Gibbs energy required to denature the PLGA α–helix in DMF. The relationship between <Nblob> and the local density of macromolecules can now be applied to characterize the conformation of macromolecules in solution.
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Affiliation(s)
| | | | - Jean Duhamel
- Correspondence: ; Tel.: +1-519-888-4567 (ext. 35916)
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14
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Kulandaisamy A, Zaucha J, Frishman D, Gromiha MM. MPTherm-pred: Analysis and Prediction of Thermal Stability Changes upon Mutations in Transmembrane Proteins. J Mol Biol 2020; 433:166646. [PMID: 32920050 DOI: 10.1016/j.jmb.2020.09.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Revised: 09/04/2020] [Accepted: 09/04/2020] [Indexed: 01/06/2023]
Abstract
The stability of membrane proteins differs from globular proteins due to the presence of nonpolar membrane-spanning regions. Using a dataset of 929 membrane protein mutations whose effects on thermal stability (ΔTm) were experimentally determined, we found that the average ΔTm due to 190 stabilizing and 232 destabilizing mutations occurring in membrane-spanning regions are 2.43(3.1) °C and -5.48(5.5) °C, respectively. The ΔTm values for mutations occurring in solvent-exposed regions are 2.56(2.82) and - 6.8(7.2) °C. We have systematically analyzed the factors influencing the stability of mutants and observed that changes in hydrophobicity, number of contacts between Cα atoms and frequency of aliphatic residues are important determinants of the stability change induced by mutations occurring in membrane-spanning regions. We have developed structure- and sequence-based machine learning predictors of ΔTm due to mutations specifically for membrane proteins. They showed a correlation and mean absolute error (MAE) of 0.72 and 2.85 °C, respectively, between experimental and predicted ΔTm for mutations in membrane-spanning regions on 10-fold group-wise cross-validation. The average correlation and MAE for mutations in aqueous regions are 0.73 and 3.7 °C, respectively. These MAE values are about 50% lower than standard deviations from the mean ΔTm values. The reliability of the method was affirmed on a test set of mutations occurring in evolutionary independent protein sequences. The developed MPTherm-pred server for predicting thermal stability changes upon mutations in membrane proteins is available at https://web.iitm.ac.in/bioinfo2/mpthermpred/. Our results provide insights into factors influencing the stability of membrane proteins and can aid in designing mutants that are more resistant to thermal stress.
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Affiliation(s)
- A Kulandaisamy
- Department of Biotechnology, Bhupat and Jyoti Mehta School of BioSciences, Indian Institute of Technology Madras, Chennai 600 036, Tamilnadu, India
| | - Jan Zaucha
- Department of Bioinformatics, Technische Universität München, Wissenschaftszentrum Weihenstephan, Freising, Germany
| | - Dmitrij Frishman
- Department of Bioinformatics, Technische Universität München, Wissenschaftszentrum Weihenstephan, Freising, Germany; Department of Bioinformatics, Peter the Great St. Petersburg Polytechnic University, St. Petersburg, Russian Federation
| | - M Michael Gromiha
- Department of Biotechnology, Bhupat and Jyoti Mehta School of BioSciences, Indian Institute of Technology Madras, Chennai 600 036, Tamilnadu, India.
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15
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Álvarez-Rodríguez I, Ugarte-Uribe B, de la Arada I, Arrondo JLR, Garbisu C, Alkorta I. Conjugative Coupling Proteins and the Role of Their Domains in Conjugation, Secondary Structure and in vivo Subcellular Location. Front Mol Biosci 2020; 7:185. [PMID: 32850972 PMCID: PMC7431656 DOI: 10.3389/fmolb.2020.00185] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 07/14/2020] [Indexed: 01/11/2023] Open
Abstract
Type IV Coupling Proteins (T4CPs) are essential elements in many type IV secretion systems (T4SSs). The members of this family display sequence, length, and domain architecture heterogeneity, being the conserved Nucleotide-Binding Domain the motif that defines them. In addition, most T4CPs contain a Transmembrane Domain (TMD) in the amino end and an All-Alpha Domain facing the cytoplasm. Additionally, a few T4CPs present a variable domain at the carboxyl end. The structural paradigm of this family is TrwBR388, the T4CP of conjugative plasmid R388. This protein has been widely studied, in particular the role of the TMD on the different characteristics of TrwBR388. To gain knowledge about T4CPs and their TMD, in this work a chimeric protein containing the TMD of TraJpKM101 and the cytosolic domain of TrwBR388 has been constructed. Additionally, one of the few T4CPs of mobilizable plasmids, MobBCloDF13 of mobilizable plasmid CloDF13, together with its TMD-less mutant MobBΔTMD have been studied. Mating studies showed that the chimeric protein is functional in vivo and that it exerted negative dominance against the native proteins TrwBR388 and TraJpKM101. Also, it was observed that the TMD of MobBCloDF13 is essential for the mobilization of CloDF13 plasmid. Analysis of the secondary structure components showed that the presence of a heterologous TMD alters the structure of the cytosolic domain in the chimeric protein. On the contrary, the absence of the TMD in MobBCloDF13 does not affect the secondary structure of its cytosolic domain. Subcellular localization studies showed that T4CPs have a unipolar or bipolar location, which is enhanced by the presence of the remaining proteins of the conjugative system. Unlike what has been described for TrwBR388, the TMD is not an essential element for the polar location of MobBCloDF13. The main conclusion is that the characteristics described for the paradigmatic TrwBR388 T4CP should not be ascribed to the whole T4CP family. Specifically, it has been proven that the mobilizable plasmid-related MobBCloDF13 presents different characteristics regarding the role of its TMD. This work will contribute to better understand the T4CP family, a key element in bacterial conjugation, the main mechanism responsible for antibiotic resistance spread.
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Affiliation(s)
- Itxaso Álvarez-Rodríguez
- Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), Leioa, Spain.,Instituto Biofisika (UPV/EHU, CSIC), University of the Basque Country (UPV/EHU), Spanish Research Council (CSIC), Leioa, Spain
| | - Begoña Ugarte-Uribe
- Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), Leioa, Spain
| | - Igor de la Arada
- Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), Leioa, Spain.,Instituto Biofisika (UPV/EHU, CSIC), University of the Basque Country (UPV/EHU), Spanish Research Council (CSIC), Leioa, Spain
| | - José Luis R Arrondo
- Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), Leioa, Spain.,Instituto Biofisika (UPV/EHU, CSIC), University of the Basque Country (UPV/EHU), Spanish Research Council (CSIC), Leioa, Spain
| | - Carlos Garbisu
- NEIKER, Soil Microbial Ecology Group, Department of Conservation of Natural Resources, Derio, Spain
| | - Itziar Alkorta
- Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), Leioa, Spain.,Instituto Biofisika (UPV/EHU, CSIC), University of the Basque Country (UPV/EHU), Spanish Research Council (CSIC), Leioa, Spain
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16
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Iyer BR, Gupta S, Noordeen H, Ravi R, Pawar MD, George A, Mahalakshmi R. Molecular Switch between Structural Compaction and Thermodynamic Stability by the Xxx-Pro Interface in Transmembrane β-Barrels. Biochemistry 2020; 59:303-314. [PMID: 31777252 DOI: 10.1021/acs.biochem.9b00731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Transmembrane β-barrel scaffolds found in outer membrane proteins are formed and stabilized by a defined pattern of interstrand intraprotein H-bonds, in hydrophobic lipid bilayers. Introducing the conformationally constrained proline in β-barrels can cause significant destabilization of these structural regions that require H-bonding, with proline additionally acting as a secondary structure breaker. Membrane protein β-barrels are therefore expected to show poor tolerance to the presence of a transmembrane proline. Here, we assign a thermodynamic measure for the extent to which a single proline can be tolerated at the C-terminal interface of the model transmembrane β-barrel PagP. We find that proline drastically destabilizes PagP by 7.0 kcal mol-1 with respect to wild-type PagP (F161 → P161). Interestingly, strategic modulation of the preceding residue can modify the measured energetics. Placing a hydrophobic or bulky side chain as the preceding residue increases the thermodynamic stability by ≤8.0 kcal mol-1. While polar substituents at the preceding residue decrease the PagP stability, these residues demonstrate stronger tertiary packing interactions in the barrel and retain the catalytic activity of native PagP. This biophysical interplay between enhanced thermodynamic stability and attaining a structurally compact functional β-barrel scaffold highlights the detrimental effect caused by proline incorporation. Our findings also reveal alternative mechanisms that protein sequences can employ to salvage the structural integrity of transmembrane protein structures.
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Affiliation(s)
- Bharat Ramasubramanian Iyer
- Molecular Biophysics Laboratory, Department of Biological Sciences , Indian Institute of Science Education and Research , Bhopal 462066 , India
| | - Swadha Gupta
- Molecular Biophysics Laboratory, Department of Biological Sciences , Indian Institute of Science Education and Research , Bhopal 462066 , India
| | - Henna Noordeen
- Molecular Biophysics Laboratory, Department of Biological Sciences , Indian Institute of Science Education and Research , Bhopal 462066 , India
| | - Roshika Ravi
- Molecular Biophysics Laboratory, Department of Biological Sciences , Indian Institute of Science Education and Research , Bhopal 462066 , India
| | - Meera Daulatrao Pawar
- Molecular Biophysics Laboratory, Department of Biological Sciences , Indian Institute of Science Education and Research , Bhopal 462066 , India
| | - Anjana George
- Molecular Biophysics Laboratory, Department of Biological Sciences , Indian Institute of Science Education and Research , Bhopal 462066 , India
| | - Radhakrishnan Mahalakshmi
- Molecular Biophysics Laboratory, Department of Biological Sciences , Indian Institute of Science Education and Research , Bhopal 462066 , India
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17
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Sedlák E, Sedláková D, Marek J, Hančár J, Garajová K, Žoldák G. Ion-Specific Protein/Water Interface Determines the Hofmeister Effect on the Kinetic Stability of Glucose Oxidase. J Phys Chem B 2019; 123:7965-7973. [DOI: 10.1021/acs.jpcb.9b05195] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Erik Sedlák
- Center for Interdisciplinary Biosciences, Technology and Innovation Park P.J. Šafárik University, Jesenna 5, 041 54 Košice, Slovakia
- Department of Biochemistry, Faculty of Science, P. J. Šafárik University in Košice, Moyzesova 11, 04001 Košice, Slovakia
| | - Dagmar Sedláková
- Department of Biophysics, Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, 04001 Košice, Slovakia
| | - Jozef Marek
- Department of Biophysics, Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, 04001 Košice, Slovakia
| | - Jozef Hančár
- Department of Biochemistry, Faculty of Science, P. J. Šafárik University in Košice, Moyzesova 11, 04001 Košice, Slovakia
| | - Katarína Garajová
- Department of Biochemistry, Faculty of Science, P. J. Šafárik University in Košice, Moyzesova 11, 04001 Košice, Slovakia
| | - Gabriel Žoldák
- Center for Interdisciplinary Biosciences, Technology and Innovation Park P.J. Šafárik University, Jesenna 5, 041 54 Košice, Slovakia
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18
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Solid-state NMR spectroscopy based atomistic view of a membrane protein unfolding pathway. Nat Commun 2019; 10:3867. [PMID: 31455771 PMCID: PMC6711998 DOI: 10.1038/s41467-019-11849-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 08/06/2019] [Indexed: 01/17/2023] Open
Abstract
Membrane protein folding, structure, and function strongly depend on a cell membrane environment, yet detailed characterization of folding within a lipid bilayer is challenging. Studies of reversible unfolding yield valuable information on the energetics of folding and on the hierarchy of interactions contributing to protein stability. Here, we devise a methodology that combines hydrogen-deuterium (H/D) exchange and solid-state NMR (SSNMR) to follow membrane protein unfolding in lipid membranes at atomic resolution through detecting changes in the protein water-accessible surface, and concurrently monitoring the reversibility of unfolding. We obtain atomistic description of the reversible part of a thermally induced unfolding pathway of a seven-helical photoreceptor. The pathway is visualized through SSNMR-detected snapshots of H/D exchange patterns as a function of temperature, revealing the unfolding intermediate and its stabilizing factors. Our approach is transferable to other membrane proteins, and opens additional ways to characterize their unfolding and stabilizing interactions with atomic resolution.
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19
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Arutyunova E, Jiang Z, Yang J, Kulepa AN, Young HS, Verhelst S, O’Donoghue AJ, Lemieux MJ. An internally quenched peptide as a new model substrate for rhomboid intramembrane proteases. Biol Chem 2018; 399:1389-1397. [DOI: 10.1515/hsz-2018-0255] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Accepted: 07/09/2018] [Indexed: 12/31/2022]
Abstract
AbstractRhomboids are ubiquitous intramembrane serine proteases that cleave transmembrane substrates. Their functions include growth factor signaling, mitochondrial homeostasis, and parasite invasion. A recent study revealed that theEscherichia colirhomboid protease EcGlpG is essential for its extraintestinal pathogenic colonization within the gut. Crystal structures of EcGlpG and theHaemophilus influenzaerhomboid protease HiGlpG have deciphered an active site that is buried within the lipid bilayer but exposed to the aqueous environment via a cavity at the periplasmic face. A lack of physiological transmembrane substrates has hampered progression for understanding their catalytic mechanism and screening inhibitor libraries. To identify a soluble substrate for use in the study of rhomboid proteases, an array of internally quenched peptides were assayed with HiGlpG, EcGlpG and PsAarA fromProvidencia stuartti. One substrate was identified that was cleaved by all three rhomboid proteases, with HiGlpG having the highest cleavage efficiency. Mass spectrometry analysis determined that all enzymes hydrolyze this substrate between norvaline and tryptophan. Kinetic analysis in both detergent and bicellular systems demonstrated that this substrate can be cleaved in solution and in the lipid environment. The substrate was subsequently used to screen a panel of benzoxazin-4-one inhibitors to validate its use in inhibitor discovery.
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20
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Colón W, Church J, Sen J, Thibeault J, Trasatti H, Xia K. Biological Roles of Protein Kinetic Stability. Biochemistry 2017; 56:6179-6186. [PMID: 29087706 DOI: 10.1021/acs.biochem.7b00942] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
A protein's stability may range from nonexistent, as in the case of intrinsically disordered proteins, to very high, as indicated by a protein's resistance to degradation, even under relatively harsh conditions. The stability of this latter group is usually under kinetic control because of a high activation energy for unfolding that virtually traps the protein in a specific conformation, thereby conferring resistance to proteolytic degradation and misfolding aggregation. The usual outcome of kinetic stability is a longer protein half-life. Thus, the protective role of protein kinetic stability is often appreciated, but relatively little is known about the extent of biological roles related to this property. In this Perspective, we will discuss several known or putative biological roles of protein kinetic stability, including protection from stressors to avoid aggregation or premature degradation, achieving long-term phenotypic change, and regulating cellular processes by controlling the trigger and timing of molecular motion. The picture that emerges from this analysis is that protein kinetic stability is involved in a myriad of known and yet to be discovered biological functions via its ability to confer degradation resistance and control the timing, extent, and permanency of molecular motion.
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Affiliation(s)
- Wilfredo Colón
- Department of Chemistry and Chemical Biology, ‡Center for Biotechnology and Interdisciplinary Studies, and §Biochemistry and Biophysics Graduate Program, Rensselaer Polytechnic Institute , Troy, New York 12180, United States
| | - Jennifer Church
- Department of Chemistry and Chemical Biology, ‡Center for Biotechnology and Interdisciplinary Studies, and §Biochemistry and Biophysics Graduate Program, Rensselaer Polytechnic Institute , Troy, New York 12180, United States
| | - Jayeeta Sen
- Department of Chemistry and Chemical Biology, ‡Center for Biotechnology and Interdisciplinary Studies, and §Biochemistry and Biophysics Graduate Program, Rensselaer Polytechnic Institute , Troy, New York 12180, United States
| | - Jane Thibeault
- Department of Chemistry and Chemical Biology, ‡Center for Biotechnology and Interdisciplinary Studies, and §Biochemistry and Biophysics Graduate Program, Rensselaer Polytechnic Institute , Troy, New York 12180, United States
| | - Hannah Trasatti
- Department of Chemistry and Chemical Biology, ‡Center for Biotechnology and Interdisciplinary Studies, and §Biochemistry and Biophysics Graduate Program, Rensselaer Polytechnic Institute , Troy, New York 12180, United States
| | - Ke Xia
- Department of Chemistry and Chemical Biology, ‡Center for Biotechnology and Interdisciplinary Studies, and §Biochemistry and Biophysics Graduate Program, Rensselaer Polytechnic Institute , Troy, New York 12180, United States
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