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Pamungkas KKP, Fureraj I, Assies L, Sakai N, Mercier V, Chen XX, Vauthey E, Matile S. Core-Alkynylated Fluorescent Flippers: Altered Ultrafast Photophysics to Track Thick Membranes. Angew Chem Int Ed Engl 2024:e202406204. [PMID: 38758302 DOI: 10.1002/anie.202406204] [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: 04/01/2024] [Revised: 05/06/2024] [Accepted: 05/16/2024] [Indexed: 05/18/2024]
Abstract
Fluorescent flippers have been introduced as small-molecule probes to image membrane tension in living systems. This study describes the design, synthesis, spectroscopic and imaging properties of flippers that are elongated by one and two alkynes inserted between the push and the pull dithienothiophene domains. The resulting mechanophores combine characteristics of flippers, reporting on physical compression in the ground state, and molecular rotors, reporting on torsional motion in the excited state, to take their photophysics to new level of sophistication. Intensity ratios in broadened excitation bands from differently twisted conformers of core-alkynylated flippers thus report on mechanical compression. Lifetime boosts from ultrafast excited-state planarization and lifetime drops from competitive intersystem crossing into triplet states report on viscosity. In standard lipid bilayer membranes, core-alkynylated flippers are too long for one leaflet and tilt or extend into disordered interleaflet space, which preserves rotor-like torsional disorder and thus weak, blue-shifted fluorescence. Flipper-like planarization occurs only in highly ordered membranes of matching leaflet thickness, where they light up and selectively report on these thick membranes with red-shifted, sharpened excitation maxima, high intensity and long lifetime.
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Affiliation(s)
| | - Ina Fureraj
- Department of Physical Chemistry, University of Geneva, Geneva, Switzerland
| | - Lea Assies
- Department of Organic Chemistry, University of Geneva, Geneva, Switzerland
| | - Naomi Sakai
- Department of Organic Chemistry, University of Geneva, Geneva, Switzerland
| | | | - Xiao-Xiao Chen
- Department of Organic Chemistry, University of Geneva, Geneva, Switzerland
| | - Eric Vauthey
- Department of Physical Chemistry, University of Geneva, Geneva, Switzerland
| | - Stefan Matile
- Department of Organic Chemistry, University of Geneva, Geneva, Switzerland
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2
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Umegawa Y, Kato S, Seo S, Shinoda W, Kawatake S, Matsuoka S, Murata M. Protein-lipid acyl chain interactions: Depth-dependent changes of segmental mobility of phospholipid in contact with bacteriorhodopsin. Biophys Chem 2024; 308:107204. [PMID: 38412762 DOI: 10.1016/j.bpc.2024.107204] [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: 12/02/2023] [Revised: 01/31/2024] [Accepted: 02/20/2024] [Indexed: 02/29/2024]
Abstract
Boundary lipids surrounding membrane proteins play an essential role in protein function and structure. These protein-lipid interactions are mainly divided into electrostatic interactions between the polar amino acids of proteins and polar heads of phospholipids, and hydrophobic interactions between protein transmembrane sites and phospholipid acyl chains. Our previous report (Kawatake et al., Biochim. Biophys. Acta 1858 [2016] 2106-2115) covered a method for selectively analyzing boundary lipid interactions and showed differences in membrane protein-peripheral lipid interactions due to differences in their head group. Interactions in the hydrophobic acyl chains of phospholipids are relatively consistent among proteins, but the details of these interactions have not been elucidated. In this study, we reconstituted bacteriorhodopsin as a model protein into phospholipid membranes labeled with 2H and 13C for solid-state NMR measurement to investigate the depth-dependent effect of the head group structure on the lipid bilayer. The results showed that the position of the phospholipid near the carbonyl carbon was affected by the head group in terms of selectivity for protein surfaces, whereas in the deep interior of the bilayer near the leaflet interface, there was little difference between the head groups, indicating that the dependence of their interactions on the head group was much reduced.
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Affiliation(s)
- Yuichi Umegawa
- JST-ERATO, Lipid Active Structure Project, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan; Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan; Forefront Research Center, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan.
| | - Sho Kato
- JST-ERATO, Lipid Active Structure Project, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan; Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
| | - Sangjae Seo
- Department of Materials Chemistry, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan; Division of Supercomputing, Korea Institute of Science and Technology Information, 245 Daehak-ro, Yuseong-gu, Daejeon 34141, South Korea
| | - Wataru Shinoda
- Department of Materials Chemistry, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan; Research Institute for Interdisciplinary Science, Okayama University, 3-1-1, Tsushima-naka, Okayama 700-8530, Japan
| | - Satoshi Kawatake
- JST-ERATO, Lipid Active Structure Project, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan; Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan; Forefront Research Center, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
| | - Shigeru Matsuoka
- JST-ERATO, Lipid Active Structure Project, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan; Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan; Forefront Research Center, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
| | - Michio Murata
- JST-ERATO, Lipid Active Structure Project, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan; Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
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3
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Thakur GCN, Uday A, Cebecauer M, Roos WH, Cwiklik L, Hof M, Jurkiewicz P, Melcrová A. Charge of a transmembrane peptide alters its interaction with lipid membranes. Colloids Surf B Biointerfaces 2024; 235:113765. [PMID: 38309153 DOI: 10.1016/j.colsurfb.2024.113765] [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: 09/18/2023] [Revised: 01/19/2024] [Accepted: 01/21/2024] [Indexed: 02/05/2024]
Abstract
Transmembrane (TM) proteins interact closely with the surrounding membrane lipids. Lipids in the vicinity of TM proteins were reported to have hindered mobility, which has been associated with lipids being caught up in the rough surface of the TM domains. These reports, however, neglect one important factor that largely influences the membrane behavior - electrostatics of the TM peptides that are usually positively charged at their cytosolic end. Here, we study on the example of a neutral and a positively charged WALP peptide, how the charge of a TM peptide influences the membrane. We investigate both its dynamics and mechanics by: (i) time dependent fluorescent shift in combination with classical and FRET generalized polarization to evaluate the mobility of lipids at short and long-range distance from the peptide, (ii) atomic force microscopy to observe the mechanical stability of the peptide-containing membranes, and (iii) molecular dynamics simulations to analyze the peptide-lipid interactions. We show that both TM peptides lower lipid mobility in their closest surroundings. The peptides cause lateral heterogeneity in lipid mobility, which in turn prevents free lipid rearrangement and lowers the membrane ability to seal ruptures after mechanical indentations. Introduction of a positive charge to the peptide largely enhances these effects, affecting the whole membrane. We thus highlight that unspecific peptide-lipid interactions, especially the electrostatics, should not be overlooked as they have a great impact on the mechanics and dynamics of the whole membrane.
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Affiliation(s)
- Garima C N Thakur
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, 182 23 Prague 8, Czech Republic; University of Chemical and Technology, Technická 5, Dejvice, 160 00 Prague 6, Czech Republic
| | - Arunima Uday
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, 182 23 Prague 8, Czech Republic; University of Chemical and Technology, Technická 5, Dejvice, 160 00 Prague 6, Czech Republic
| | - Marek Cebecauer
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, 182 23 Prague 8, Czech Republic
| | - Wouter H Roos
- Zernike Institute for Advanced Materials, Rijksuniversiteit Groningen, Nijenborgh 4, 9747 AG Groningen, the Netherlands
| | - Lukasz Cwiklik
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, 182 23 Prague 8, Czech Republic; Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, 166 10 Prague 6, Czech Republic
| | - Martin Hof
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, 182 23 Prague 8, Czech Republic
| | - Piotr Jurkiewicz
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, 182 23 Prague 8, Czech Republic.
| | - Adéla Melcrová
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, 182 23 Prague 8, Czech Republic; Zernike Institute for Advanced Materials, Rijksuniversiteit Groningen, Nijenborgh 4, 9747 AG Groningen, the Netherlands.
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4
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Moral R, Paul S. Exploring Cyclic Peptide Nanotube Stability Across Diverse Lipid Bilayers and Unveiling Water Transport Dynamics. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024; 40:882-895. [PMID: 38134046 DOI: 10.1021/acs.langmuir.3c03030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2023]
Abstract
Cyclic Peptide Nanotubes (CPNTs) have emerged as compelling candidates for various applications, particularly as nanochannels within lipid bilayers. In this study, the stability of two CPNTs, namely 8 × [(Cys-Gly-Met-Gly)2] and 8 × [(Gly-Leu)4], are comprehensively investigated across different lipid bilayers, including 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), a mixed model membrane (POPE/POPG), and a realistic yeast model membrane. The results demonstrate that both CPNTs maintain their tubular structures in all lipid bilayers, with [(Cys-Gly-Met-Gly)2] showing increased stability over an extended period in these lipid membranes. The insertion of CPNTs shows negligible impact on lipid bilayer properties, including area per lipid, volume per lipid, and bilayer thickness. The study demonstrates that the CPNT preserves its two-line water movement pattern within all the lipid membranes, reaffirming their potential as water channels. The MSD curves further reveal that the dynamics of water molecules inside the nanotube are similar for all the bilayer systems with minor differences that arise due to different lipid environments.
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Affiliation(s)
- Rimjhim Moral
- Department of Chemistry, Indian Institute of Technology, Guwahati, Assam 781039, India
| | - Sandip Paul
- Department of Chemistry, Indian Institute of Technology, Guwahati, Assam 781039, India
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5
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Zhao Z, Li Y, Wang H, Shan Y, Liu X, Wu M, Zhang X, Song X. Ultra-Tough Self-Healing Hydrogel via Hierarchical Energy Associative Dissipation. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2303315. [PMID: 37505367 PMCID: PMC10520617 DOI: 10.1002/advs.202303315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 06/28/2023] [Indexed: 07/29/2023]
Abstract
Owing to high water content and homogeneous texture, conventional hydrogels hardly reach satisfactory mechanical performance. Tensile-resistant groups and structural heterogeneity are employed to fabricate tough hydrogels. However, those techniques significantly increase the complexity and cost of material synthesis, and have only limited applicability. Here, it is shown that ultra-tough hydrogels can be obtained via a unique hierarchical architecture composed of chemically coupled self-assembly units. The associative energy dissipation among them may be rationally engineered to yield libraries of tough gels with self-healing capability. Tunable tensile strength, fracture strain, and toughness of up to 19.6 MPa, 20 000%, and 135.7 MJ cm⁻3 are achieved, all of which exceed the best known records. The results demonstrate a universal strategy to prepare desired ultra-tough hydrogels in predictable and controllable manners.
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Affiliation(s)
- Zhi Zhao
- Key Laboratory of Advanced Functional MaterialsEducation Ministry of ChinaFaculty of Materials and ManufacturingBeijing University of TechnologyBeijing100124China
| | - Yurong Li
- Key Laboratory of Advanced Functional MaterialsEducation Ministry of ChinaFaculty of Materials and ManufacturingBeijing University of TechnologyBeijing100124China
- Institute of Information Photonics TechnologyFaculty of ScienceBeijing University of TechnologyBeijing100124China
| | - Haibin Wang
- Key Laboratory of Advanced Functional MaterialsEducation Ministry of ChinaFaculty of Materials and ManufacturingBeijing University of TechnologyBeijing100124China
| | - Yupeng Shan
- Key Laboratory of Advanced Functional MaterialsEducation Ministry of ChinaFaculty of Materials and ManufacturingBeijing University of TechnologyBeijing100124China
| | - Xuemei Liu
- Key Laboratory of Advanced Functional MaterialsEducation Ministry of ChinaFaculty of Materials and ManufacturingBeijing University of TechnologyBeijing100124China
| | - Mengfei Wu
- Department of Engineering MechanicsBeijing University of TechnologyBeijing100124China
| | - Xinping Zhang
- Institute of Information Photonics TechnologyFaculty of ScienceBeijing University of TechnologyBeijing100124China
| | - Xiaoyan Song
- Key Laboratory of Advanced Functional MaterialsEducation Ministry of ChinaFaculty of Materials and ManufacturingBeijing University of TechnologyBeijing100124China
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6
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Almeida PF. In Search of a Molecular View of Peptide-Lipid Interactions in Membranes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023. [PMID: 37478368 DOI: 10.1021/acs.langmuir.3c00538] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/23/2023]
Abstract
Lipid bilayer membranes are often represented as a continuous nonpolar slab with a certain thickness bounded by two more polar interfaces. Phenomena such as peptide binding to the membrane surface, folding, insertion, translocation, and diffusion are typically interpreted on the basis of this view. In this Perspective, I argue that this membrane representation as a hydrophobic continuum solvent is not adequate to understand peptide-lipid interactions. Lipids are not small compared to membrane-active peptides: their sizes are similar. Therefore, peptide diffusion needs to be understood in terms of free volume, not classical continuum mechanics; peptide solubility or partitioning in membranes cannot be interpreted in terms of hydrophobic mismatch between membrane thickness and peptide length; peptide folding and translocation, often involving cationic peptides, can only be understood if realizing that lipids adapt to the presence of peptides and the membrane may undergo considerable lipid redistribution in the process. In all of those instances, the detailed molecular interactions between the peptide residues and the lipid components are essential to understand the mechanisms involved.
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Affiliation(s)
- Paulo F Almeida
- Department of Chemistry and Biochemistry, University of North Carolina Wilmington, Wilmington, North Carolina 28403, United States
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7
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Cané L, Guzmán F, Balatti G, Daza Millone MA, Pucci Molineris M, Maté S, Martini MF, Herlax V. Biophysical Analysis to Assess the Interaction of CRAC and CARC Motif Peptides of Alpha Hemolysin of Escherichia coli with Membranes. Biochemistry 2023. [PMID: 37224476 DOI: 10.1021/acs.biochem.3c00164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Alpha hemolysin of Escherichia coli (HlyA) is a pore-forming protein, which is a prototype of the "Repeat in Toxins" (RTX) family. It was demonstrated that HlyA-cholesterol interaction facilitates the insertion of the toxin into membranes. Putative cholesterol-binding sites, called cholesterol recognition/amino acid consensus (CRAC), and CARC (analogous to CRAC but with the opposite orientation) were identified in the HlyA sequence. In this context, two peptides were synthesized, one derived from a CARC site from the insertion domain of the toxin (residues 341-353) (PEP 1) and the other one from a CRAC site from the domain between the acylated lysines (residues 639-644) (PEP 2), to study their role in the interaction of HlyA with membranes. The interaction of peptides with membranes of different lipid compositions (pure POPC and POPC/Cho of 4:1 and 2:1 molar ratios) was analyzed by surface plasmon resonance and molecular dynamics simulations. Results demonstrate that both peptides interact preferentially with Cho-containing membranes, although PEP 2 presents a lower KD than PEP 1. Molecular dynamics simulation results indicate that the insertion and interaction of PEP 2 with Cho-containing membranes are more prominent than those caused by PEP 1. The hemolytic activity of HlyA in the presence of peptides indicates that PEP 2 was the only one that inhibits HlyA activity, interfering in the binding between the toxin and cholesterol.
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Affiliation(s)
- Lucía Cané
- CCT-La Plata, CONICET, Facultad de Ciencias Médicas, Universidad Nacional de La Plata, Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), 60 y 120, La Plata 1900, Argentina
| | - Fanny Guzmán
- Núcleo de Biotecnología Curauma (NBC), Pontificia Universidad Católica de Valparaíso, Valparaíso 2373223, Chile
| | - Galo Balatti
- Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes. Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET). Roque Sáenz Peña 352, Bernal, Buenos Aires 1876, Argentina
- Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Química y Metabolismo del Fármaco (IQUIMEFA). Junín 956, Buenos Aires 1113, Argentina
| | - María Antonieta Daza Millone
- CCT-La Plata, CONICET. Universidad Nacional de La Plata, Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), Sucursal 4 Casilla de Correo 16, La Plata 1900, Argentina
| | - Melisa Pucci Molineris
- CCT-La Plata, CONICET, Facultad de Ciencias Médicas, Universidad Nacional de La Plata, Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), 60 y 120, La Plata 1900, Argentina
| | - Sabina Maté
- CCT-La Plata, CONICET, Facultad de Ciencias Médicas, Universidad Nacional de La Plata, Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), 60 y 120, La Plata 1900, Argentina
| | - M Florencia Martini
- Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Química y Metabolismo del Fármaco (IQUIMEFA). Junín 956, Buenos Aires 1113, Argentina
- Cátedra de Química Medicinal, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Junín 956, Buenos Aires 1113, Argentina
| | - Vanesa Herlax
- CCT-La Plata, CONICET, Facultad de Ciencias Médicas, Universidad Nacional de La Plata, Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), 60 y 120, La Plata 1900, Argentina
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8
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Spinti JK, Neiva Nunes F, Melo MN. Room for improvement in the initial martini 3 parameterization of peptide interactions. Chem Phys Lett 2023. [DOI: 10.1016/j.cplett.2023.140436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/01/2023]
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9
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Braverman D, Gershberg J, Sal-Man N. The transmembrane domains of the type III secretion system effector Tir are involved in its secretion and cellular activities. Front Cell Infect Microbiol 2023; 13:1103552. [PMID: 36864885 PMCID: PMC9971567 DOI: 10.3389/fcimb.2023.1103552] [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: 11/20/2022] [Accepted: 02/01/2023] [Indexed: 02/16/2023] Open
Abstract
Introduction Enteropathogenic Escherichia coli (EPEC) is a diarrheagenic pathogen and one of the major causes of gastrointestinal illness in developing countries. EPEC, similar to many other Gram-negative bacterial pathogens, possesses essential virulence machinery called the type III secretion system (T3SS) that enables the injection of effector proteins from the bacteria into the host cytoplasm. Of these, the translocated intimin receptor (Tir) is the first effector to be injected, and its activity is essential for the formation of attaching and effacing lesions, the hallmark of EPEC colonization. Tir belongs to a unique group of transmembrane domain (TMD)-containing secreted proteins, which have two conflicting destination indications, one for bacterial membrane integration and another for protein secretion. In this study, we examined whether TMDs participate in the secretion, translocation, and function of Tir in host cells. Methods We created Tir TMD variants with the original or alternative TMD sequence. Results We found that the C-terminal TMD of Tir (TMD2) is critical for the ability of Tir to escape integration into the bacterial membrane. However, the TMD sequence was not by itself sufficient and its effect was context-dependent. Moreover, the N-terminal TMD of Tir (TMD1) was important for the postsecretion function of Tir at the host cell. Discussion Taken together, our study further supports the hypothesis that the TMD sequences of translocated proteins encode information crucial for protein secretion and their postsecretion function.
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Affiliation(s)
- Dor Braverman
- The Shraga Segal Department of Microbiology, Immunology, and Genetics, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Jenia Gershberg
- The Shraga Segal Department of Microbiology, Immunology, and Genetics, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
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10
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Barrantes FJ. Fluorescence microscopy imaging of a neurotransmitter receptor and its cell membrane lipid milieu. Front Mol Biosci 2022; 9:1014659. [PMID: 36518846 PMCID: PMC9743973 DOI: 10.3389/fmolb.2022.1014659] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 11/01/2022] [Indexed: 05/02/2024] Open
Abstract
Hampered by the diffraction phenomenon, as expressed in 1873 by Abbe, applications of optical microscopy to image biological structures were for a long time limited to resolutions above the ∼200 nm barrier and restricted to the observation of stained specimens. The introduction of fluorescence was a game changer, and since its inception it became the gold standard technique in biological microscopy. The plasma membrane is a tenuous envelope of 4 nm-10 nm in thickness surrounding the cell. Because of its highly versatile spectroscopic properties and availability of suitable instrumentation, fluorescence techniques epitomize the current approach to study this delicate structure and its molecular constituents. The wide spectral range covered by fluorescence, intimately linked to the availability of appropriate intrinsic and extrinsic probes, provides the ability to dissect membrane constituents at the molecular scale in the spatial domain. In addition, the time resolution capabilities of fluorescence methods provide complementary high precision for studying the behavior of membrane molecules in the time domain. This review illustrates the value of various fluorescence techniques to extract information on the topography and motion of plasma membrane receptors. To this end I resort to a paradigmatic membrane-bound neurotransmitter receptor, the nicotinic acetylcholine receptor (nAChR). The structural and dynamic picture emerging from studies of this prototypic pentameric ligand-gated ion channel can be extrapolated not only to other members of this superfamily of ion channels but to other membrane-bound proteins. I also briefly discuss the various emerging techniques in the field of biomembrane labeling with new organic chemistry strategies oriented to applications in fluorescence nanoscopy, the form of fluorescence microscopy that is expanding the depth and scope of interrogation of membrane-associated phenomena.
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Affiliation(s)
- Francisco J. Barrantes
- Biomedical Research Institute (BIOMED), Catholic University of Argentina (UCA)–National Scientific and Technical Research Council (CONICET), Buenos Aires, Argentina
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11
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Engberg O, Ulbricht D, Döbel V, Siebert V, Frie C, Penk A, Lemberg MK, Huster D. Rhomboid-catalyzed intramembrane proteolysis requires hydrophobic matching with the surrounding lipid bilayer. SCIENCE ADVANCES 2022; 8:eabq8303. [PMID: 36149963 PMCID: PMC9506719 DOI: 10.1126/sciadv.abq8303] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 08/09/2022] [Indexed: 06/16/2023]
Abstract
Membrane thinning by rhomboid proteins has been proposed to reduce hydrophobic mismatch, providing a unique environment for important functions ranging from intramembrane proteolysis to retrotranslocation in protein degradation. We show by in vitro reconstitution and solid-state nuclear magnetic resonance that the lipid environment of the Escherichia coli rhomboid protease GlpG influences its activity with an optimal hydrophobic membrane thickness between 24 and 26 Å. While phosphatidylcholine membranes are only negligibly altered by GlpG, in an E. coli-relevant lipid mix of phosphatidylethanolamine and phosphatidylglycerol, a thinning by 1.1 Å per leaflet is observed. Protease activity is strongly correlated with membrane thickness and shows no lipid headgroup specificity. We infer from these results that, by adjusting the thickness of specific membrane domains, membrane proteins shape the bilayer for their specific needs.
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Affiliation(s)
- Oskar Engberg
- Institute for Medical Physics and Biophysics, University of Leipzig, Härtelstr. 16/18, D-04107 Leipzig, Germany
| | - David Ulbricht
- Institute for Medical Physics and Biophysics, University of Leipzig, Härtelstr. 16/18, D-04107 Leipzig, Germany
| | - Viola Döbel
- Institute for Medical Physics and Biophysics, University of Leipzig, Härtelstr. 16/18, D-04107 Leipzig, Germany
| | - Verena Siebert
- Center for Molecular Biology of Heidelberg University (ZMBH), Im Neuenheimer Feld 282, D-69120 Heidelberg, Germany
- Center for Biochemistry and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Medical Faculty, University of Cologne, Joseph-Stelzmann-Str. 52, D-50931 Cologne, Germany
| | - Christian Frie
- Center for Biochemistry and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Medical Faculty, University of Cologne, Joseph-Stelzmann-Str. 52, D-50931 Cologne, Germany
| | - Anja Penk
- Institute for Medical Physics and Biophysics, University of Leipzig, Härtelstr. 16/18, D-04107 Leipzig, Germany
| | - Marius K. Lemberg
- Center for Molecular Biology of Heidelberg University (ZMBH), Im Neuenheimer Feld 282, D-69120 Heidelberg, Germany
- Center for Biochemistry and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Medical Faculty, University of Cologne, Joseph-Stelzmann-Str. 52, D-50931 Cologne, Germany
| | - Daniel Huster
- Institute for Medical Physics and Biophysics, University of Leipzig, Härtelstr. 16/18, D-04107 Leipzig, Germany
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12
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Sharma GP, Meyer AC, Habeeb S, Karbach M, Müller G. Free-energy landscapes and insertion pathways for peptides in membrane environment. Phys Rev E 2022; 106:014404. [PMID: 35974613 DOI: 10.1103/physreve.106.014404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Accepted: 07/04/2022] [Indexed: 06/15/2023]
Abstract
Free-energy landscapes for short peptides-specifically for variants of the pH low insertion peptide (pHLIP)-in the heterogeneous environment of a lipid bilayer or cell membrane are constructed, taking into account a set of dominant interactions and the conformational preferences of the peptide backbone. Our methodology interprets broken internal H-bonds along the backbone of a polypeptide as statistically interacting quasiparticles, activated from the helix reference state. The favored conformation depends on the local environment (ranging from polar to nonpolar), specifically on the availability of external H-bonds (with H_{2}O molecules or lipid headgroups) to replace internal H-bonds. The dominant side-chain contribution is accounted for by residue-specific transfer free energies between polar and nonpolar environments. The free-energy landscape is sensitive to the level of pH in the aqueous environment surrounding the membrane. For high pH, we identify pathways of descending free energy that suggest a coexistence of membrane-adsorbed peptides with peptides in solution. A drop in pH raises the degree of protonation of negatively charged residues and thus increases the hydrophobicity of peptide segments near the C terminus. For low pH, we identify insertion pathways between the membrane-adsorbed state and a stable trans-membrane state with the C terminus having crossed the membrane.
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Affiliation(s)
- Ganga P Sharma
- Department of Physics, University of Rhode Island, Kingston, Rhode Island 02881, USA
| | - Aaron C Meyer
- Department of Physics, University of Rhode Island, Kingston, Rhode Island 02881, USA
| | - Suhail Habeeb
- Department of Physics, University of Rhode Island, Kingston, Rhode Island 02881, USA
| | - Michael Karbach
- Fachgruppe Physik, Bergische Universität Wuppertal, D-42097 Wuppertal, Germany
| | - Gerhard Müller
- Department of Physics, University of Rhode Island, Kingston, Rhode Island 02881, USA
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13
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Alavizargar A, Elting A, Wedlich-Söldner R, Heuer A. Lipid-Mediated Association of the Slg1 Transmembrane Domains in Yeast Plasma Membranes. J Phys Chem B 2022; 126:3240-3256. [PMID: 35446028 DOI: 10.1021/acs.jpcb.2c00192] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Clustering of transmembrane proteins underlies a multitude of fundamental biological processes at the plasma membrane (PM) such as receptor activation, lateral domain formation, and mechanotransduction. The self-association of the respective transmembrane domains (TMDs) has also been suggested to be responsible for the micron-scaled patterns seen for integral membrane proteins in the budding yeast PM. However, the underlying interplay between the local lipid composition and the TMD identity is still not mechanistically understood. In this work, we combined coarse-grained molecular dynamics simulations of simplified bilayer systems with high-resolution live-cell microscopy to analyze the distribution of a representative helical yeast TMD from the PM sensor Slg1 within different lipid environments. In our simulations, we specifically evaluated the effects of acyl chain saturation and anionic lipid head groups on the association of two TMDs. We found that weak lipid-protein interactions significantly affect the configuration of TMD dimers and the free energy of association. Increased amounts of unsaturated phospholipids (PLs) strongly reduced the helix-helix interaction, while the presence of anionic phosphatidylserine (PS) hardly affected the dimer formation. We could experimentally confirm this surprising lack of effect of PS using the network factor, a mesoscopic measure of PM pattern formation in yeast cells. Simulations also showed that the formation of TMD dimers in turn increased the order parameter of the surrounding lipids and induced long-range perturbations in lipid organization. In summary, our results shed new light on the mechanisms of lipid-mediated dimerization of TMDs in complex lipid mixtures.
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Affiliation(s)
- Azadeh Alavizargar
- Institute of Physical Chemistry, University of Muenster, Corrensstr. 28/30, 48149 Muenster, Germany
| | - Annegret Elting
- Institute of Cell Dynamics and Imaging, University of Muenster, Von-Esmarch-Str. 56, 48149 Muenster, Germany
| | - Roland Wedlich-Söldner
- Institute of Cell Dynamics and Imaging, University of Muenster, Von-Esmarch-Str. 56, 48149 Muenster, Germany
| | - Andreas Heuer
- Institute of Physical Chemistry, University of Muenster, Corrensstr. 28/30, 48149 Muenster, Germany
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14
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Zizzi EA, Cavaglià M, Tuszynski JA, Deriu MA. Alteration of lipid bilayer mechanics by volatile anesthetics: Insights from μs-long molecular dynamics simulations. iScience 2022; 25:103946. [PMID: 35265816 PMCID: PMC8898909 DOI: 10.1016/j.isci.2022.103946] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 01/25/2022] [Accepted: 02/15/2022] [Indexed: 11/24/2022] Open
Abstract
Very few drugs in clinical practice feature the chemical diversity, narrow therapeutic window, unique route of administration, and reversible cognitive effects of volatile anesthetics. The correlation between their hydrophobicity and their potency and the increasing amount of evidence suggesting that anesthetics exert their action on transmembrane proteins, justifies the investigation of their effects on phospholipid bilayers at the molecular level, given the strong functional and structural link between transmembrane proteins and the surrounding lipid matrix. Molecular dynamics simulations of a model lipid bilayer in the presence of ethylene, desflurane, methoxyflurane, and the nonimmobilizer 1,2-dichlorohexafluorocyclobutane (also called F6 or 2N) at different concentrations highlight the structural consequences of VA partitioning in the lipid phase, with a decrease of lipid order and bilayer thickness, an increase in overall lipid lateral mobility and area-per-lipid, and a marked reduction in the mechanical stiffness of the membrane, that strongly correlates with the compounds' hydrophobicity. Molecular simulations of lipid bilayer interaction with volatile anesthetics Comparison of volatile anesthetics' and nonimmobilizers' effects on lipid bilayers Ligand-dependent partitioning of the compounds in the lipid phase Effects on bilayer thickness, stiffness, and lipid order upon ligand partitioning
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15
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Brady R, Harris NJ, Pellowe GA, Gulaidi Breen S, Booth PJ. How lipids affect the energetics of co-translational alpha helical membrane protein folding. Biochem Soc Trans 2022; 50:555-567. [PMID: 35212365 PMCID: PMC9022994 DOI: 10.1042/bst20201063] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 02/08/2022] [Accepted: 02/14/2022] [Indexed: 11/23/2022]
Abstract
Membrane proteins need to fold with precision in order to function correctly, with misfolding potentially leading to disease. The proteins reside within a hydrophobic lipid membrane and must insert into the membrane and fold correctly, generally whilst they are being translated by the ribosome. Favourable and unfavourable free energy contributions are present throughout each stage of insertion and folding. The unfavourable energy cost of transferring peptide bonds into the hydrophobic membrane interior is compensated for by the favourable hydrophobic effect of partitioning a hydrophobic transmembrane alpha-helix into the membrane. Native membranes are composed of many different types of lipids, but how these different lipids influence folding and the associated free energies is not well understood. Altering the lipids in the bilayer is known to affect the probability of transmembrane helix insertion into the membrane, and lipids also affect protein stability and can promote successful folding. This review will summarise the free energy contributions associated with insertion and folding of alpha helical membrane proteins, as well as how lipids can make these processes more or less favourable. We will also discuss the implications of this work for the free energy landscape during the co-translational folding of alpha helical membrane proteins.
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Affiliation(s)
- Ryan Brady
- King's College London, Department of Chemistry, Britannia House, 7 Trinity Street, London SE1 1DB, U.K
| | - Nicola J. Harris
- King's College London, Department of Chemistry, Britannia House, 7 Trinity Street, London SE1 1DB, U.K
| | - Grant A. Pellowe
- King's College London, Department of Chemistry, Britannia House, 7 Trinity Street, London SE1 1DB, U.K
| | - Samuel Gulaidi Breen
- King's College London, Department of Chemistry, Britannia House, 7 Trinity Street, London SE1 1DB, U.K
- The Francis Crick Institute, 1 Midland Road, London NW1 1AT, U.K
| | - Paula J. Booth
- King's College London, Department of Chemistry, Britannia House, 7 Trinity Street, London SE1 1DB, U.K
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16
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Oliveira AA, Róg T, da Silva ABF, Amaro RE, Johnson MS, Postila PA. Examining the Effect of Charged Lipids on Mitochondrial Outer Membrane Dynamics Using Atomistic Simulations. Biomolecules 2022; 12:biom12020183. [PMID: 35204684 PMCID: PMC8961577 DOI: 10.3390/biom12020183] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 01/18/2022] [Accepted: 01/19/2022] [Indexed: 11/11/2022] Open
Abstract
The outer mitochondrial membrane (OMM) is involved in multiple cellular functions such as apoptosis, inflammation and signaling via its membrane-associated and -embedded proteins. Despite the central role of the OMM in these vital phenomena, the structure and dynamics of the membrane have regularly been investigated in silico using simple two-component models. Accordingly, the aim was to generate the realistic multi-component model of the OMM and inspect its properties using atomistic molecular dynamics (MD) simulations. All major lipid components, phosphatidylinositol (PI), phosphatidylcholine (PC), phosphatidylethanolamine (PE), and phosphatidylserine (PS), were included in the probed OMM models. Because increased levels of anionic PS lipids have potential effects on schizophrenia and, more specifically, on monoamine oxidase B enzyme activity, the effect of varying the PS concentration was explored. The MD simulations indicate that the complex membrane lipid composition (MLC) behavior is notably different from the two-component PC-PE model. The MLC changes caused relatively minor effects on the membrane structural properties such as membrane thickness or area per lipid; however, notable effects could be seen with the dynamical parameters at the water-membrane interface. Increase of PS levels appears to slow down lateral diffusion of all lipids and, in general, the presence of anionic lipids reduced hydration and slowed down the PE headgroup rotation. In addition, sodium ions could neutralize the membrane surface, when PI was the main anionic component; however, a similar effect was not seen for high PS levels. Based on these results, it is advisable for future studies on the OMM and its protein or ligand partners, especially when wanting to replicate the correct properties on the water-membrane interface, to use models that are sufficiently complex, containing anionic lipid types, PI in particular.
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Affiliation(s)
- Aline A. Oliveira
- Department of Chemistry and Biochemistry, University of California San Diego, San Diego, CA 92093-0340, USA; (A.A.O.); (R.E.A.)
- Instituto de Química de São Carlos, Universidade de São Paulo, CP 780, São Carlos 13560-970, Brazil;
| | - Tomasz Róg
- Department of Physics, University of Helsinki, P.O. Box 64, FI-00014 Helsinki, Finland;
| | - Albérico B. F. da Silva
- Instituto de Química de São Carlos, Universidade de São Paulo, CP 780, São Carlos 13560-970, Brazil;
| | - Rommie E. Amaro
- Department of Chemistry and Biochemistry, University of California San Diego, San Diego, CA 92093-0340, USA; (A.A.O.); (R.E.A.)
| | - Mark S. Johnson
- Structural Bioinformatics Laboratory, Biochemistry, Faculty of Science and Engineering, Åbo Akademi University, 20520 Turku, Finland;
- InFLAMES Research Flagship Center, Åbo Akademi University, 20520 Turku, Finland
| | - Pekka A. Postila
- Department of Chemistry and Biochemistry, University of California San Diego, San Diego, CA 92093-0340, USA; (A.A.O.); (R.E.A.)
- Structural Bioinformatics Laboratory, Biochemistry, Faculty of Science and Engineering, Åbo Akademi University, 20520 Turku, Finland;
- InFLAMES Research Flagship Center, Åbo Akademi University, 20520 Turku, Finland
- Institute of Biomedicine, Kiinamyllynkatu 10, Integrative Physiology and Pharmacy, University of Turku, FI-20520 Turku, Finland
- Aurlide Ltd., FI-21420 Lieto, Finland
- InFLAMES Research Flagship Center, University of Turku, FI-20520 Turku, Finland
- Correspondence:
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17
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The Electrostatic Basis of Diacylglycerol Pyrophosphate—Protein Interaction. Cells 2022; 11:cells11020290. [PMID: 35053406 PMCID: PMC8774204 DOI: 10.3390/cells11020290] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2021] [Revised: 01/04/2022] [Accepted: 01/07/2022] [Indexed: 01/08/2023] Open
Abstract
Diacylglycerol pyrophosphate (DGPP) is an anionic phospholipid formed in plants, yeast, and parasites under multiple stress stimuli. It is synthesized by the phosphorylation action of phosphatidic acid (PA) kinase on phosphatidic acid, a signaling lipid with multifunctional properties. PA functions in the membrane through the interaction of its negatively charged phosphomonoester headgroup with positively charged proteins and ions. DGPP, like PA, can interact electrostatically via the electrostatic-hydrogen bond switch mechanism but differs from PA in its overall charge and shape. The formation of DGPP from PA alters the physicochemical properties as well as the structural dynamics of the membrane. This potentially impacts the molecular and ionic binding of cationic proteins and ions with the DGPP enriched membrane. However, the results of these important interactions in the stress response and in DGPP’s overall intracellular function is unknown. Here, using 31P MAS NMR, we analyze the effect of the interaction of low DGPP concentrations in model membranes with the peptides KALP23 and WALP23, which are flanked by positively charged Lysine and neutral Tryptophan residues, respectively. Our results show a significant effect of KALP23 on the charge of DGPP as compared to WALP23. There was, however, no significant effect on the charge of the phosphomonoester of DGPP due to the interaction with positively charged lipids, dioleoyl trimethylammonium propane (DOTAP) and dioleoyl ethyl-phosphatidylcholine (EtPC). Divalent calcium and magnesium cations induce deprotonation of the DGPP headgroup but showed no noticeable differences on DGPP’s charge. Our results lead to a novel model for DGPP—protein interaction.
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18
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Kondrashov OV, Kuzmin PI, Akimov SA. Hydrophobic Mismatch Controls the Mode of Membrane-Mediated Interactions of Transmembrane Peptides. MEMBRANES 2022; 12:89. [PMID: 35054615 PMCID: PMC8781805 DOI: 10.3390/membranes12010089] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 12/29/2021] [Accepted: 01/10/2022] [Indexed: 01/01/2023]
Abstract
Various cellular processes require the concerted cooperative action of proteins. The possibility for such synchronization implies the occurrence of specific long-range interactions between the involved protein participants. Bilayer lipid membranes can mediate protein-protein interactions via relatively long-range elastic deformations induced by the incorporated proteins. We considered the interactions between transmembrane peptides mediated by elastic deformations using the framework of the theory of elasticity of lipid membranes. An effective peptide shape was assumed to be cylindrical, hourglass-like, or barrel-like. The interaction potentials were obtained for membranes of different thicknesses and elastic rigidities. Cylindrically shaped peptides manifest almost neutral average interactions-they attract each other at short distances and repel at large ones, independently of membrane thickness or rigidity. The hourglass-like peptides repel each other in thin bilayers and strongly attract each other in thicker bilayers. On the contrary, the barrel-like peptides repel each other in thick bilayers and attract each other in thinner membranes. These results potentially provide possible mechanisms of control for the mode of protein-protein interactions in membrane domains with different bilayer thicknesses.
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Affiliation(s)
- Oleg V. Kondrashov
- Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, 31/4 Leninskiy Prospekt, 119071 Moscow, Russia;
| | | | - Sergey A. Akimov
- Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, 31/4 Leninskiy Prospekt, 119071 Moscow, Russia;
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19
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Abstract
Membrane proteins (MPs) play essential roles in numerous cellular processes. Because around 70% of the currently marketed drugs target MPs, a detailed understanding of their structure, binding properties, and functional dynamics in a physiologically relevant environment is crucial for a more detailed understanding of this important protein class. We here summarize the benefits of using lipid nanodiscs for NMR structural investigations and provide a detailed overview of the currently used lipid nanodisc systems as well as their applications in solution-state NMR. Despite the increasing use of other structural methods for the structure determination of MPs in lipid nanodiscs, solution NMR turns out to be a versatile tool to probe a wide range of MP features, ranging from the structure determination of small to medium-sized MPs to probing ligand and partner protein binding as well as functionally relevant dynamical signatures in a lipid nanodisc setting. We will expand on these topics by discussing recent NMR studies with lipid nanodiscs and work out a key workflow for optimizing the nanodisc incorporation of an MP for subsequent NMR investigations. With this, we hope to provide a comprehensive background to enable an informed assessment of the applicability of lipid nanodiscs for NMR studies of a particular MP of interest.
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Affiliation(s)
- Umut Günsel
- Bavarian NMR Center (BNMRZ) at the Department of Chemistry, Technical University of Munich, Ernst-Otto-Fischer-Strasse 2, 85748 Garching, Germany
| | - Franz Hagn
- Bavarian NMR Center (BNMRZ) at the Department of Chemistry, Technical University of Munich, Ernst-Otto-Fischer-Strasse 2, 85748 Garching, Germany.,Institute of Structural Biology, Helmholtz Zentrum München, Ingolstädter Landstraße 1, 85764 Neuherberg, Germany
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20
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Das S, Meinel MK, Wu Z, Müller-Plathe F. The role of the envelope protein in the stability of a coronavirus model membrane against an ethanolic disinfectant. J Chem Phys 2021; 154:245101. [PMID: 34241335 DOI: 10.1063/5.0055331] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Ethanol is highly effective against various enveloped viruses and can disable the virus by disintegrating the protective envelope surrounding it. The interactions between the coronavirus envelope (E) protein and its membrane environment play key roles in the stability and function of the viral envelope. By using molecular dynamics simulation, we explore the underlying mechanism of ethanol-induced disruption of a model coronavirus membrane and, in detail, interactions of the E-protein and lipids. We model the membrane bilayer as N-palmitoyl-sphingomyelin and 1-palmitoyl-2-oleoylphosphatidylcholine lipids and the coronavirus E-protein. The study reveals that ethanol causes an increase in the lateral area of the bilayer along with thinning of the bilayer membrane and orientational disordering of lipid tails. Ethanol resides at the head-tail region of the membrane and enhances bilayer permeability. We found an envelope-protein-mediated increase in the ordering of lipid tails. Our simulations also provide important insights into the orientation of the envelope protein in a model membrane environment. At ∼25 mol. % of ethanol in the surrounding ethanol-water phase, we observe disintegration of the lipid bilayer and dislocation of the E-protein from the membrane environment.
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Affiliation(s)
- Shubhadip Das
- Technische Universität Darmstadt, Eduard-Zintl-Institute für Anorganische und Physikalische Chemie, Alarich-Weiss-Strasse 8, 64287 Darmstadt, Germany
| | - Melissa K Meinel
- Technische Universität Darmstadt, Eduard-Zintl-Institute für Anorganische und Physikalische Chemie, Alarich-Weiss-Strasse 8, 64287 Darmstadt, Germany
| | - Zhenghao Wu
- Technische Universität Darmstadt, Eduard-Zintl-Institute für Anorganische und Physikalische Chemie, Alarich-Weiss-Strasse 8, 64287 Darmstadt, Germany
| | - Florian Müller-Plathe
- Technische Universität Darmstadt, Eduard-Zintl-Institute für Anorganische und Physikalische Chemie, Alarich-Weiss-Strasse 8, 64287 Darmstadt, Germany
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21
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Muñoz-López J, Oliveira JCL, Michel DAGR, Ferreira CS, Neto FG, Salnikov ES, Verly RM, Bechinger B, Resende JM. Membrane interactions of Ocellatins. Where do antimicrobial gaps stem from? Amino Acids 2021; 53:1241-1256. [PMID: 34251525 DOI: 10.1007/s00726-021-03029-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 06/25/2021] [Indexed: 10/20/2022]
Abstract
The antimicrobial peptides Ocellatin-LB1, -LB2 and -F1, isolated from frogs, are identical from residue 1 to 22, which correspond to the -LB1 sequence, whereas -LB2 carries an extra N and -F1 additional NKL residues at their C-termini. Despite the similar sequences, previous investigations showed different spectra of activities and biophysical investigations indicated a direct correlation between both membrane-disruptive properties and activities, i.e., ocellatin-F1 > ocellatin-LB1 > ocellatin-LB2. This study presents experimental evidence as well as results from theoretical studies that contribute to a deeper understanding on how these peptides exert their antimicrobial activities and how small differences in the amino acid composition and their secondary structure can be correlated to these activity gaps. Solid-state NMR experiments allied to the simulation of anisotropic NMR parameters allowed the determination of the membrane topologies of these ocellatins. Interestingly, the extra Asn residue at the Ocellatin-LB2 C-terminus results in increased topological flexibility, which is mainly related to wobbling of the helix main axis as noticed by molecular dynamics simulations. Binding kinetics and thermodynamics of the interactions have also been assessed by Surface Plasmon Resonance and Isothermal Titration Calorimetry. Therefore, these investigations allowed to understand in atomic detail the relationships between peptide structure and membrane topology, which are in tune within the series -F1 > > -LB1 ≥ -LB2, as well as how peptide dynamics can affect membrane topology, insertion and binding.
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Affiliation(s)
- José Muñoz-López
- Departamento de Química, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, P.O. Box 486, Belo Horizonte, MG, 31270-901, Brazil.,UMR7177, Institut de Chimie, Université de Strasbourg/CNRS, 4, rue Blaise Pascal , 67000, Strasbourg, France
| | - Jade C L Oliveira
- Departamento de Química, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, P.O. Box 486, Belo Horizonte, MG, 31270-901, Brazil
| | - Daniel A G R Michel
- Departamento de Química, Universidade Federal Dos Vales do Jequitinhonha e Mucuri, Diamantina, MG, 39100-000, Brazil
| | - Carolina S Ferreira
- Departamento de Química, Universidade Federal Dos Vales do Jequitinhonha e Mucuri, Diamantina, MG, 39100-000, Brazil
| | - Francisco Gomes Neto
- Laboratório de Toxinologia, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, 21040-900, Brazil
| | - Evgeniy S Salnikov
- UMR7177, Institut de Chimie, Université de Strasbourg/CNRS, 4, rue Blaise Pascal , 67000, Strasbourg, France
| | - Rodrigo M Verly
- Departamento de Química, Universidade Federal Dos Vales do Jequitinhonha e Mucuri, Diamantina, MG, 39100-000, Brazil
| | - Burkhard Bechinger
- UMR7177, Institut de Chimie, Université de Strasbourg/CNRS, 4, rue Blaise Pascal , 67000, Strasbourg, France.,Institut Universitaire de France, 75005, Paris, France
| | - Jarbas M Resende
- Departamento de Química, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, P.O. Box 486, Belo Horizonte, MG, 31270-901, Brazil.
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22
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Lujan P, Campelo F. Should I stay or should I go? Golgi membrane spatial organization for protein sorting and retention. Arch Biochem Biophys 2021; 707:108921. [PMID: 34038703 DOI: 10.1016/j.abb.2021.108921] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 04/12/2021] [Accepted: 05/03/2021] [Indexed: 12/23/2022]
Abstract
The Golgi complex is the membrane-bound organelle that lies at the center of the secretory pathway. Its main functions are to maintain cellular lipid homeostasis, to orchestrate protein processing and maturation, and to mediate protein sorting and export. These functions are not independent of one another, and they all require that the membranes of the Golgi complex have a well-defined biochemical composition. Importantly, a finely-regulated spatiotemporal organization of the Golgi membrane components is essential for the correct performance of the organelle. In here, we review our current mechanistic and molecular understanding of how Golgi membranes are spatially organized in the lateral and axial directions to fulfill their functions. In particular, we highlight the current evidence and proposed models of intra-Golgi transport, as well as the known mechanisms for the retention of Golgi residents and for the sorting and export of transmembrane cargo proteins. Despite the controversies, conflicting evidence, clashes between models, and technical limitations, the field has moved forward and we have gained extensive knowledge in this fascinating topic. However, there are still many important questions that remain to be completely answered. We hope that this review will help boost future investigations on these issues.
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Affiliation(s)
- Pablo Lujan
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860, Barcelona, Spain.
| | - Felix Campelo
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860, Barcelona, Spain.
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23
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Identification of a pocket factor that is critical to Zika virus assembly. Nat Commun 2020; 11:4953. [PMID: 33009400 PMCID: PMC7532219 DOI: 10.1038/s41467-020-18747-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 09/09/2020] [Indexed: 02/06/2023] Open
Abstract
Zika virus (ZIKV) is an emerging mosquito borne flavivirus and a major public health concern causing severe disease. Due to the presence of a lipid membrane and structural heterogeneity, attaining an atomic resolution structure is challenging, but important to understand virus assembly and life cycle mechanisms that offer distinct targets for therapeutic intervention. We here use subvolume refinement to achieve a 3.4 Å resolution structure and identify two distinct lipid moieties. The first arises from the inner leaflet and is coordinated by hydrophobic residues of the M and E transmembrane helices that form a binding pocket not previously characterized. The second lipid arises from the outer leaflet coordinate between two E protein helices. Structure-based mutagenesis identifies critical hydrophobic interactions and their effect on the virus life cycle. Results show that lipids play an essential role in the ZIKV assembly pathway revealing a potential target of lipid based antiviral drug development. Here, the authors provide a 3.4 Å resolution structure of mature Zika virus (ZIKV) and identify two lipid moieties, coordinated by hydrophobic residues of the M and E transmembrane helices and between two helices of E protein, that play an essential role in the ZIKV assembly pathway.
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24
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Schachter I, Allolio C, Khelashvili G, Harries D. Confinement in Nanodiscs Anisotropically Modifies Lipid Bilayer Elastic Properties. J Phys Chem B 2020; 124:7166-7175. [PMID: 32697588 PMCID: PMC7526989 DOI: 10.1021/acs.jpcb.0c03374] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
![]()
Lipid
nanodiscs are small synthetic lipid bilayer structures that
are stabilized in solution by special circumscribing (or scaffolding)
proteins or polymers. Because they create native-like environments
for transmembrane proteins, lipid nanodiscs have become a powerful
tool for structural determination of this class of systems when combined
with cryo-electron microscopy or nuclear magnetic resonance. The elastic
properties of lipid bilayers determine how the lipid environment responds
to membrane protein perturbations, and how the lipid in turn modifies
the conformational state of the embedded protein. However, despite
the abundant use of nanodiscs in determining membrane protein structure,
the elastic material properties of even pure lipid nanodiscs (i.e.,
without embedded proteins) have not yet been quantitatively investigated.
A major hurdle is due to the inherently nonlocal treatment of the
elastic properties of lipid systems implemented by most existing methods,
both experimental and computational. In addition, these methods are
best suited for very large “infinite” size lipidic assemblies,
or ones that contain periodicity, in the case of simulations. We have
previously described a computational analysis of molecular dynamics
simulations designed to overcome these limitations, so it allows quantification
of the bending rigidity (KC) and tilt
modulus (κt) on a local scale even for finite, nonperiodic
systems, such as lipid nanodiscs. Here we use this computational approach
to extract values of KC and κt for a set of lipid nanodisc systems that vary in size and
lipid composition. We find that the material properties of lipid nanodiscs
are different from those of infinite bilayers of corresponding lipid
composition, highlighting the effect of nanodisc confinement. Nanodiscs
tend to show higher stiffness than their corresponding macroscopic
bilayers, and moreover, their material properties vary spatially within
them. For small-size MSP1 nanodiscs, the stiffness decreases radially,
from a value that is larger in their center than the moduli of the
corresponding bilayers by a factor of ∼2–3. The larger
nanodiscs (MSP1E3D1 and MSP2N2) show milder spatial changes of moduli
that are composition dependent and can be maximal in the center or
at some distance from it. These trends in moduli correlate with spatially
varying structural properties, including the area per lipid and the
nanodisc thickness. Finally, as has previously been reported, nanodiscs
tend to show deformations from perfectly flat circular geometries
to varying degrees, depending on size and lipid composition. The modulations
of lipid elastic properties that we find should be carefully considered
when making structural and functional inferences concerning embedded
proteins.
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Affiliation(s)
- Itay Schachter
- Institute of Chemistry, the Fritz Haber Research Center, and the Harvey M. Kruger center for Nanoscience & Nanotechnology, The Hebrew University, Jerusalem 9190401, Israel
| | - Christoph Allolio
- Institute of Mathematics, Faculty of Mathematics and Physics, Charles University, Prague 18674, Czech Republic
| | - George Khelashvili
- Department of Physiology and Biophysics, Weill Cornell Medical College of Cornell University, New York, New York 10065, United States.,Institute for Computational Biomedicine, Weill Cornell Medical College of Cornell University, New York, New York 10065, United States
| | - Daniel Harries
- Institute of Chemistry, the Fritz Haber Research Center, and the Harvey M. Kruger center for Nanoscience & Nanotechnology, The Hebrew University, Jerusalem 9190401, Israel
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25
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Dhara M, Mantero Martinez M, Makke M, Schwarz Y, Mohrmann R, Bruns D. Synergistic actions of v-SNARE transmembrane domains and membrane-curvature modifying lipids in neurotransmitter release. eLife 2020; 9:e55152. [PMID: 32391794 PMCID: PMC7239655 DOI: 10.7554/elife.55152] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Accepted: 05/07/2020] [Indexed: 01/01/2023] Open
Abstract
Vesicle fusion is mediated by assembly of SNARE proteins between opposing membranes. While previous work suggested an active role of SNARE transmembrane domains (TMDs) in promoting membrane merger (Dhara et al., 2016), the underlying mechanism remained elusive. Here, we show that naturally-occurring v-SNARE TMD variants differentially regulate fusion pore dynamics in mouse chromaffin cells, indicating TMD flexibility as a mechanistic determinant that facilitates transmitter release from differentially-sized vesicles. Membrane curvature-promoting phospholipids like lysophosphatidylcholine or oleic acid profoundly alter pore expansion and fully rescue the decelerated fusion kinetics of TMD-rigidifying VAMP2 mutants. Thus, v-SNARE TMDs and phospholipids cooperate in supporting membrane curvature at the fusion pore neck. Oppositely, slowing of pore kinetics by the SNARE-regulator complexin-2 withstands the curvature-driven speeding of fusion, indicating that pore evolution is tightly coupled to progressive SNARE complex formation. Collectively, TMD-mediated support of membrane curvature and SNARE force-generated membrane bending promote fusion pore formation and expansion.
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Affiliation(s)
- Madhurima Dhara
- Institute for Physiology, Center of Integrative Physiology and Molecular Medicine, Saarland UniversityHomburgGermany
| | - Maria Mantero Martinez
- Institute for Physiology, Center of Integrative Physiology and Molecular Medicine, Saarland UniversityHomburgGermany
| | - Mazen Makke
- Institute for Physiology, Center of Integrative Physiology and Molecular Medicine, Saarland UniversityHomburgGermany
| | - Yvonne Schwarz
- Institute for Physiology, Center of Integrative Physiology and Molecular Medicine, Saarland UniversityHomburgGermany
| | - Ralf Mohrmann
- Institute for Physiology, Otto-von-Guericke UniversityMagdeburgGermany
| | - Dieter Bruns
- Institute for Physiology, Center of Integrative Physiology and Molecular Medicine, Saarland UniversityHomburgGermany
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26
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Radyukhin VA, Baratova LA. Molecular Mechanisms of Raft Organization in Biological Membranes. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2020. [DOI: 10.1134/s1068162020030164] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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27
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Bai J, Wang J, Ravula T, Im SC, Anantharamaiah GM, Waskell L, Ramamoorthy A. Expression, purification, and functional reconstitution of 19F-labeled cytochrome b5 in peptide nanodiscs for NMR studies. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2020; 1862:183194. [PMID: 31953231 PMCID: PMC7050362 DOI: 10.1016/j.bbamem.2020.183194] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 01/06/2020] [Accepted: 01/10/2020] [Indexed: 02/07/2023]
Abstract
Microsomal cytochrome b5 (cytb5) is a membrane-bound protein capable of donating the second electron to cytochrome P450s (cytP450s) in the cytP450s monooxygenase reactions. Recent studies have demonstrated the importance of the transmembrane domain of cytb5 in the interaction with cytP450 by stabilizing its monomeric structure. While recent NMR studies have provided high-resolution insights into the structural interactions between the soluble domains of ~16-kDa cytb5 and ~57-kDa cytP450 in a membrane environment, there is need for studies to probe the residues in the transmembrane region as well as to obtain intermolecular distance constraints to better understand the very large size cytb5-cytP450 complex structure in a near native membrane environment. In this study, we report the expression, purification, functional reconstitution of 19F-labeled full-length rabbit cytb5 in peptide based nanodiscs for structural studies using NMR spectroscopy. Size exclusion chromatography, dynamic light scattering, transmission electron microscopy, and NMR experiments show a stable reconstitution of cytb5 in 4F peptide-based lipid-nanodiscs. The reported results demonstrate the use of 19F NMR experiments to study 19F-labeled (with 5-fluorotryptophan (5FW)) cytb5 reconstituted in peptide-nanodiscs and the detection of residues from the transmembrane domain by solution 19F NMR experiments. 19F NMR results revealing the interaction of the transmembrane domain of cytb5 with the full-length rabbit cytochrome P450 2B4 (CYP2B4) are also presented. We expect the results presented in this study to be useful to devise approaches to probe the structure, dynamics and functional roles of transmembrane domains of a membrane protein, and also to measure intermolecular 19F-19F distance constraints to determine the structural interactions between the transmembrane domains.
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Affiliation(s)
- Jia Bai
- Biophysics Program, Department of Chemistry, Biomedical Engineering, Macromolecular Science and Engineering, The University of Michigan, Ann Arbor, MI 48109-1055, USA
| | - Jian Wang
- Biophysics Program, Department of Chemistry, Biomedical Engineering, Macromolecular Science and Engineering, The University of Michigan, Ann Arbor, MI 48109-1055, USA
| | - Thirupathi Ravula
- Biophysics Program, Department of Chemistry, Biomedical Engineering, Macromolecular Science and Engineering, The University of Michigan, Ann Arbor, MI 48109-1055, USA
| | - Sang-Choul Im
- Department of Internal Medicine, The University of Michigan, and VA Medical Center, Ann Arbor, MI 48105, USA
| | | | - Lucy Waskell
- Department of Anesthesiology, The University of Michigan, and VA Medical Center, Ann Arbor, MI 48105, USA
| | - Ayyalusamy Ramamoorthy
- Biophysics Program, Department of Chemistry, Biomedical Engineering, Macromolecular Science and Engineering, The University of Michigan, Ann Arbor, MI 48109-1055, USA.
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28
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Dandurand J, Ostuni A, Francesca Armentano M, Antonietta Crudele M, Dolce V, Marra F, Samouillan V, Bisaccia F. Calorimetry and FTIR reveal the ability of URG7 protein to modify the aggregation state of both cell lysate and amylogenic α-synuclein. AIMS BIOPHYSICS 2020. [DOI: 10.3934/biophy.2020015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
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29
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Wilson BA, Ramanathan A, Lopez CF. Cardiolipin-Dependent Properties of Model Mitochondrial Membranes from Molecular Simulations. Biophys J 2019; 117:429-444. [PMID: 31349988 PMCID: PMC6697365 DOI: 10.1016/j.bpj.2019.06.023] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Revised: 06/17/2019] [Accepted: 06/24/2019] [Indexed: 01/30/2023] Open
Abstract
Cardiolipin is an anionic lipid found in the mitochondrial membranes of eukaryotes ranging from unicellular microorganisms to metazoans. This unique lipid contributes to various mitochondrial functions, including metabolism, mitochondrial membrane fusion and/or fission dynamics, and apoptosis. However, differences in cardiolipin content between the two mitochondrial membranes, as well as dynamic fluctuations in cardiolipin content in response to stimuli and cellular signaling events, raise questions about how cardiolipin concentration affects mitochondrial membrane structure and dynamics. Although cardiolipin’s structural and dynamic roles have been extensively studied in binary mixtures with other phospholipids, the biophysical properties of cardiolipin in higher number lipid mixtures are still not well resolved. Here, we used molecular dynamics simulations to investigate the cardiolipin-dependent properties of ternary lipid bilayer systems that mimic the major components of mitochondrial membranes. We found that changes to cardiolipin concentration only resulted in minor changes to bilayer structural features but that the lipid diffusion was significantly affected by those alterations. We also found that cardiolipin position along the bilayer surfaces correlated to negative curvature deflections, consistent with the induction of negative curvature stress in the membrane monolayers. This work contributes to a foundational understanding of the role of cardiolipin in altering the properties in ternary lipid mixtures composed of the major mitochondrial phospholipids, providing much-needed insights to help understand how cardiolipin concentration modulates the biophysical properties of mitochondrial membranes.
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Affiliation(s)
- Blake A Wilson
- Department of Biochemistry, Vanderbilt University, Nashville, Tennessee
| | - Arvind Ramanathan
- Computational Science and Engineering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee; Health Data Sciences Institute, Oak Ridge National Laboratory, Oak Ridge, Tennessee
| | - Carlos F Lopez
- Department of Biochemistry, Vanderbilt University, Nashville, Tennessee; Department of Biomedical Informatics, Vanderbilt University Medical Center, Nashville, Tennessee; Department of Pharmacology, Vanderbilt University, Nashville, Tennessee.
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Park S, Nam T, You J, Kim ES, Choi I, Park J, Cho KH. Evaluating membrane fouling potentials of dissolved organic matter in brackish water. WATER RESEARCH 2019; 149:65-73. [PMID: 30419468 DOI: 10.1016/j.watres.2018.10.079] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2018] [Revised: 10/24/2018] [Accepted: 10/27/2018] [Indexed: 06/09/2023]
Abstract
Isolating dissolved organic matter (DOM) is a preliminary step that improves the accuracy of its characterization. In this study, DOM in brackish water was clearly separated and evaluated by multiple characterization analyses. The sample was divided into three fractions by preparative high-performance liquid chromatography (preparative HPLC) according to molecular size. The homogeneity of each fraction was estimated by analytical size exclusion chromatography (SEC) and fluorescence excitation-emission matrix (FEEM). Pyrolysis gas chromatography-mass spectrometry (Py-GC/MS) and liquid chromatography-organic carbon detection (LC-OCD) were used to characterize the physicochemical properties of each fraction. Py-GC/MS revealed that Fraction 1 consisted of evenly distributed organic matter in order polysaccharides, proteins, polyhydroxy aromatics, lignins, and lipids. However, Fraction 2 was primarily composed of dominant lipids and low portion of proteins, and Fraction 3 was composed predominantly of lignins and lipids. The LC-OCD results showed that Fractions 1 and 2 had similar organic carbon (OC) compositions: a humic substance (ca. 37%), building blocks (ca. 10%), and neutrals (ca. 37%), whereas Fraction 3 contained a high proportion of neutrals (62%). In the fouling experiments, the distinct DOM characteristics in each fraction resulted in different declining flux behaviors, ranked as: Fraction 2 > Fraction 1 > Fraction 3.
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Affiliation(s)
- Sanghun Park
- School of Urban and Environmental Engineering, Ulsan National Institute of Science and Technology, UNIST-gil 50, Ulsan, 44919, Republic of Korea
| | - Taewoo Nam
- School of Urban and Environmental Engineering, Ulsan National Institute of Science and Technology, UNIST-gil 50, Ulsan, 44919, Republic of Korea
| | - Jeongyeop You
- School of Urban and Environmental Engineering, Ulsan National Institute of Science and Technology, UNIST-gil 50, Ulsan, 44919, Republic of Korea
| | - Eun-Sik Kim
- Department of Environmental System Engineering, Chonnam National University, Yeosu, Jeonnam, 59626, Republic of Korea
| | - Ilhwan Choi
- Water Analysis and Research Center, K-water, 34350 Sintanjin-ro, Daedeok-gu, Daejeon, Republic of Korea
| | - Jongkwan Park
- School of Urban and Environmental Engineering, Ulsan National Institute of Science and Technology, UNIST-gil 50, Ulsan, 44919, Republic of Korea.
| | - Kyung Hwa Cho
- School of Urban and Environmental Engineering, Ulsan National Institute of Science and Technology, UNIST-gil 50, Ulsan, 44919, Republic of Korea.
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31
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Thermodynamically reversible paths of the first fusion intermediate reveal an important role for membrane anchors of fusion proteins. Proc Natl Acad Sci U S A 2019; 116:2571-2576. [PMID: 30700547 DOI: 10.1073/pnas.1818200116] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Biological membrane fusion proceeds via an essential topological transition of the two membranes involved. Known players such as certain lipid species and fusion proteins are generally believed to alter the free energy and thus the rate of the fusion reaction. Quantifying these effects by theory poses a major challenge since the essential reaction intermediates are collective, diffusive and of a molecular length scale. We conducted molecular dynamics simulations in conjunction with a state-of-the-art string method to resolve the minimum free-energy path of the first fusion intermediate state, the so-called stalk. We demonstrate that the isolated transmembrane domains (TMDs) of fusion proteins such as SNARE molecules drastically lower the free energy of both the stalk barrier and metastable stalk, which is not trivially explained by molecular shape arguments. We relate this effect to the local thinning of the membrane (negative hydrophobic mismatch) imposed by the TMDs which favors the nearby presence of the highly bent stalk structure or prestalk dimple. The distance between the membranes is the most crucial determinant of the free energy of the stalk, whereas the free-energy barrier changes only slightly. Surprisingly, fusion enhancing lipids, i.e., lipids with a negative spontaneous curvature, such as PE lipids have little effect on the free energy of the stalk barrier, likely because of its single molecular nature. In contrast, the lipid shape plays a crucial role in overcoming the hydration repulsion between two membranes and thus rather lowers the total work required to form a stalk.
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32
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Olšinová M, Jurkiewicz P, Kishko I, Sýkora J, Sabó J, Hof M, Cwiklik L, Cebecauer M. Roughness of Transmembrane Helices Reduces Lipid Membrane Dynamics. iScience 2018; 10:87-97. [PMID: 30508721 PMCID: PMC6277224 DOI: 10.1016/j.isci.2018.11.026] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Revised: 10/23/2018] [Accepted: 11/14/2018] [Indexed: 01/23/2023] Open
Abstract
The dynamics of cellular membranes is primarily determined by lipid species forming a bilayer. Proteins are considered mainly as effector molecules of diverse cellular processes. In addition to large assemblies of proteins, which were found to influence properties of fluid membranes, biological membranes are densely populated by small, highly mobile proteins. However, little is known about the effect of such proteins on the dynamics of membranes. Using synthetic peptides, we demonstrate that transmembrane helices interfere with the mobility of membrane components by trapping lipid acyl chains on their rough surfaces. The effect is more pronounced in the presence of cholesterol, which segregates from the rough surface of helical peptides. This may contribute to the formation or stabilization of membrane heterogeneities. Since roughness is a general property of helical transmembrane segments, our results suggest that, independent of their size or cytoskeleton linkage, integral membrane proteins affect local membrane dynamics and organization.
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Affiliation(s)
- Marie Olšinová
- Department of Biophysical Chemistry, J. Heyrovsky Institute of Physical Chemistry of the Czech Academy of Sciences, Dolejškova 3, 182 23 Prague, Czech Republic
| | - Piotr Jurkiewicz
- Department of Biophysical Chemistry, J. Heyrovsky Institute of Physical Chemistry of the Czech Academy of Sciences, Dolejškova 3, 182 23 Prague, Czech Republic
| | - Iryna Kishko
- Department of Biophysical Chemistry, J. Heyrovsky Institute of Physical Chemistry of the Czech Academy of Sciences, Dolejškova 3, 182 23 Prague, Czech Republic
| | - Jan Sýkora
- Department of Biophysical Chemistry, J. Heyrovsky Institute of Physical Chemistry of the Czech Academy of Sciences, Dolejškova 3, 182 23 Prague, Czech Republic
| | - Ján Sabó
- Department of Biophysical Chemistry, J. Heyrovsky Institute of Physical Chemistry of the Czech Academy of Sciences, Dolejškova 3, 182 23 Prague, Czech Republic
| | - Martin Hof
- Department of Biophysical Chemistry, J. Heyrovsky Institute of Physical Chemistry of the Czech Academy of Sciences, Dolejškova 3, 182 23 Prague, Czech Republic
| | - Lukasz Cwiklik
- Department of Theoretical Chemistry, J. Heyrovsky Institute of Physical Chemistry of the Czech Academy of Sciences, Dolejškova 3, 182 23 Prague, Czech Republic
| | - Marek Cebecauer
- Department of Biophysical Chemistry, J. Heyrovsky Institute of Physical Chemistry of the Czech Academy of Sciences, Dolejškova 3, 182 23 Prague, Czech Republic.
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33
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A minimal helical-hairpin motif provides molecular-level insights into misfolding and pharmacological rescue of CFTR. Commun Biol 2018; 1:154. [PMID: 30302398 PMCID: PMC6162264 DOI: 10.1038/s42003-018-0153-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Accepted: 08/24/2018] [Indexed: 12/11/2022] Open
Abstract
Our meagre understanding of CFTR misfolding and its reversal by small-molecule correctors hampers the development of mechanism-based therapies of cystic fibrosis. Here we exploit a helical-hairpin construct—the simplest proxy of membrane-protein tertiary contacts—containing CFTR’s transmembrane helices 3 and 4 and its corresponding disease phenotypic mutant V232D to gain molecular-level insights into CFTR misfolding and drug rescue by the corrector Lumacaftor. Using a single-molecule FRET approach to study hairpin conformations in lipid bilayers, we find that the wild-type hairpin is well folded, whereas the V232D mutant assumes an open conformation in bilayer thicknesses mimicking the endoplasmic reticulum. Addition of Lumacaftor reverses the aberrant opening of the mutant hairpin to restore a compact state as in the wild type. The observed membrane escape of the V232D hairpin and its reversal by Lumacaftor complement cell-based analyses of the full-length protein, thereby providing in vivo and in vitro correlates of CFTR misfolding and drug-action mechanisms. Georg Krainer and Antoine Treff et al. use a helical-hairpin construct derived from the cystic fibrosis transmembrane conductance regulator (CFTR) to investigate misfolding caused by the disease-linked V232D mutation. Using single-molecule FRET, they show that the V232D hairpin assumes an open conformation in lipid bilayers, which is reversed by the pharmacological corrector Lumacaftor.
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34
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Dunina-Barkovskaya AY, Vishnyakova KS, Golovko AO, Arutyunyan AM, Baratova LA, Bathishchev OV, Radyukhin VA. Amphipathic CRAC-Containing Peptides Derived from the Influenza Virus A M1 Protein Modulate Cholesterol-Dependent Activity of Cultured IC-21 Macrophages. BIOCHEMISTRY (MOSCOW) 2018; 83:982-991. [PMID: 30208834 DOI: 10.1134/s0006297918080096] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Entry of many viral and bacterial pathogens into host cells depends on cholesterol and/or cholesterol-enriched domains (lipid rafts) in the cell membrane. Earlier, we showed that influenza virus A matrix protein M1 contains amphipathic α-helices with exposed cholesterol-recognizing amino acid consensus (CRAC) motifs. In order to test possible functional activity of these motifs, we studied the effects of three synthetic peptides corresponding to the CRAC-containing α-helices of the viral M1 protein on the phagocytic activity of cultured mouse IC-21 macrophages. The following peptides were used: LEVLMEWLKTR (M1 α-helix 3, a.a. 39-49; further referred to as peptide 1), NNMDKAVKLYRKLK (M1 α-helix 6, a.a. 91-105; peptide 2), and GLKNDLLENLQAYQKR (M1 α-helix 13, a.a. 228-243; peptide 3). We found that all three peptides modulated interactions of IC-21 macrophages with non-opsonized 2-µm target particles. The greatest effect was demonstrated by peptide 2: in the presence of 35 μM peptide 2, the phagocytic index of IC-21 macrophages exceeded the control value by 60%; 10-11 mM methyl-β-cyclodextrin abolished this effect. Peptides 1 and 3 exerted weak inhibitory effect in a narrow concentration range of 5-10 μM. The dose-response curves could be approximated by a sum of two (stimulatory and inhibitory) components with different Hill coefficients, suggesting existence of at least two peptide-binding sites with different affinities on the cell surface. CD spectroscopy confirmed that the peptides exhibit structural flexibility in solutions. Altogether, our data indicate that amphipathic CRAC-containing peptides derived from the viral M1 protein modulate lipid raft-dependent processes in IC-21 macrophages.
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Affiliation(s)
- A Ya Dunina-Barkovskaya
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia.
| | - Kh S Vishnyakova
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, 119991, Russia
| | - A O Golovko
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow, 119991, Russia
| | - A M Arutyunyan
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
| | - L A Baratova
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
| | - O V Bathishchev
- Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, Moscow, 119071, Russia
| | - V A Radyukhin
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia.
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35
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Roberts MF, Khan HM, Goldstein R, Reuter N, Gershenson A. Search and Subvert: Minimalist Bacterial Phosphatidylinositol-Specific Phospholipase C Enzymes. Chem Rev 2018; 118:8435-8473. [DOI: 10.1021/acs.chemrev.8b00208] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Mary F. Roberts
- Department of Chemistry, Boston College, Chestnut Hill, Massachusetts 02467, United States
| | | | - Rebecca Goldstein
- Department of Chemistry, Boston College, Chestnut Hill, Massachusetts 02467, United States
| | | | - Anne Gershenson
- Department of Biochemistry and Molecular Biology, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States
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36
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Kamp F, Scheidt HA, Winkler E, Basset G, Heinel H, Hutchison JM, LaPointe LM, Sanders CR, Steiner H, Huster D. Bexarotene Binds to the Amyloid Precursor Protein Transmembrane Domain, Alters Its α-Helical Conformation, and Inhibits γ-Secretase Nonselectively in Liposomes. ACS Chem Neurosci 2018; 9:1702-1713. [PMID: 29717863 DOI: 10.1021/acschemneuro.8b00068] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Bexarotene is a pleiotropic molecule that has been proposed as an amyloid-β (Aβ)-lowering drug for the treatment of Alzheimer's disease (AD). It acts by upregulation of an apolipoprotein E (apoE)-mediated Aβ clearance mechanism. However, whether bexarotene induces removal of Aβ plaques in mouse models of AD has been controversial. Here, we show by NMR and CD spectroscopy that bexarotene directly interacts with and stabilizes the transmembrane domain α-helix of the amyloid precursor protein (APP) in a region where cholesterol binds. This effect is not mediated by changes in membrane lipid packing, as bexarotene does not share with cholesterol the property of inducing phospholipid condensation. Bexarotene inhibited the intramembrane cleavage by γ-secretase of the APP C-terminal fragment C99 to release Aβ in cell-free assays of the reconstituted enzyme in liposomes, but not in cells, and only at very high micromolar concentrations. Surprisingly, in vitro, bexarotene also inhibited the cleavage of Notch1, another major γ-secretase substrate, demonstrating that its inhibition of γ-secretase is not substrate specific and not mediated by acting via the cholesterol binding site of C99. Our data suggest that bexarotene is a pleiotropic molecule that interfere with Aβ metabolism through multiple mechanisms.
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Affiliation(s)
- Frits Kamp
- Biomedical Center - BMC, Metabolic Biochemistry, Ludwig-Maximilians University, Munich 80539, Germany
| | - Holger A. Scheidt
- Institute for Medical Physics and Biophysics, Leipzig University, Härtelstr. 16-18, D-04107 Leipzig, Germany
| | - Edith Winkler
- Biomedical Center - BMC, Metabolic Biochemistry, Ludwig-Maximilians University, Munich 80539, Germany
| | - Gabriele Basset
- Biomedical Center - BMC, Metabolic Biochemistry, Ludwig-Maximilians University, Munich 80539, Germany
| | - Hannes Heinel
- Institute for Medical Physics and Biophysics, Leipzig University, Härtelstr. 16-18, D-04107 Leipzig, Germany
| | - James M. Hutchison
- Department of Biochemistry and Center for Structural Biology, Vanderbilt University, Nashville, Tennessee 37240, United States
| | - Loren M. LaPointe
- Department of Biochemistry and Center for Structural Biology, Vanderbilt University, Nashville, Tennessee 37240, United States
| | - Charles R. Sanders
- Department of Biochemistry and Center for Structural Biology, Vanderbilt University, Nashville, Tennessee 37240, United States
| | - Harald Steiner
- Biomedical Center - BMC, Metabolic Biochemistry, Ludwig-Maximilians University, Munich 80539, Germany
- German Center for Neurodegenerative Diseases (DZNE)−Munich, Feodor-Lynen-Str. 17, D-81377 Munich, Germany
| | - Daniel Huster
- Institute for Medical Physics and Biophysics, Leipzig University, Härtelstr. 16-18, D-04107 Leipzig, Germany
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37
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Corradi V, Mendez-Villuendas E, Ingólfsson HI, Gu RX, Siuda I, Melo MN, Moussatova A, DeGagné LJ, Sejdiu BI, Singh G, Wassenaar TA, Delgado Magnero K, Marrink SJ, Tieleman DP. Lipid-Protein Interactions Are Unique Fingerprints for Membrane Proteins. ACS CENTRAL SCIENCE 2018; 4:709-717. [PMID: 29974066 PMCID: PMC6028153 DOI: 10.1021/acscentsci.8b00143] [Citation(s) in RCA: 205] [Impact Index Per Article: 34.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Indexed: 05/08/2023]
Abstract
Cell membranes contain hundreds of different proteins and lipids in an asymmetric arrangement. Our current understanding of the detailed organization of cell membranes remains rather elusive, because of the challenge to study fluctuating nanoscale assemblies of lipids and proteins with the required spatiotemporal resolution. Here, we use molecular dynamics simulations to characterize the lipid environment of 10 different membrane proteins. To provide a realistic lipid environment, the proteins are embedded in a model plasma membrane, where more than 60 lipid species are represented, asymmetrically distributed between the leaflets. The simulations detail how each protein modulates its local lipid environment in a unique way, through enrichment or depletion of specific lipid components, resulting in thickness and curvature gradients. Our results provide a molecular glimpse of the complexity of lipid-protein interactions, with potentially far-reaching implications for our understanding of the overall organization of real cell membranes.
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Affiliation(s)
- Valentina Corradi
- Centre
for Molecular Simulation and Department of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4, Canada
| | - Eduardo Mendez-Villuendas
- Centre
for Molecular Simulation and Department of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4, Canada
| | - Helgi I. Ingólfsson
- Groningen
Biomolecular Sciences and Biotechnology Institute and Zernike Institute
for Advanced Materials, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Ruo-Xu Gu
- Centre
for Molecular Simulation and Department of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4, Canada
| | - Iwona Siuda
- Centre
for Molecular Simulation and Department of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4, Canada
| | - Manuel N. Melo
- Groningen
Biomolecular Sciences and Biotechnology Institute and Zernike Institute
for Advanced Materials, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Anastassiia Moussatova
- Centre
for Molecular Simulation and Department of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4, Canada
| | - Lucien J. DeGagné
- Centre
for Molecular Simulation and Department of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4, Canada
| | - Besian I. Sejdiu
- Centre
for Molecular Simulation and Department of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4, Canada
| | - Gurpreet Singh
- Centre
for Molecular Simulation and Department of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4, Canada
| | - Tsjerk A. Wassenaar
- Groningen
Biomolecular Sciences and Biotechnology Institute and Zernike Institute
for Advanced Materials, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Karelia Delgado Magnero
- Centre
for Molecular Simulation and Department of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4, Canada
| | - Siewert J. Marrink
- Groningen
Biomolecular Sciences and Biotechnology Institute and Zernike Institute
for Advanced Materials, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - D. Peter Tieleman
- Centre
for Molecular Simulation and Department of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4, Canada
- E-mail:
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38
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Jaipuria G, Ukmar-Godec T, Zweckstetter M. Challenges and approaches to understand cholesterol-binding impact on membrane protein function: an NMR view. Cell Mol Life Sci 2018; 75:2137-2151. [PMID: 29520423 PMCID: PMC11105689 DOI: 10.1007/s00018-018-2789-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 02/16/2018] [Accepted: 02/27/2018] [Indexed: 01/27/2023]
Abstract
Experimental evidence for a direct role of lipids in determining the structure, dynamics, and function of membrane proteins leads to the term 'functional lipids'. In particular, the sterol molecule cholesterol modulates the activity of many membrane proteins. The precise nature of cholesterol-binding sites and the consequences of modulation of local membrane micro-viscosity by cholesterol, however, is often unknown. Here, we review the current knowledge of the interaction of cholesterol with transmembrane proteins, with a special focus on structural aspects of the interaction derived from nuclear magnetic resonance approaches. We highlight examples of the importance of cholesterol modulation of membrane protein function, discuss the specificity of cholesterol binding, and review the proposed binding motifs from a molecular perspective. We conclude with a short perspective on what could be future trends in research efforts targeted towards a better understanding of cholesterol/membrane protein interactions.
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Affiliation(s)
- Garima Jaipuria
- German Center for Neurodegenerative Diseases (DZNE), Von-Siebold-Str. 3a, 37075, Göttingen, Germany
| | - Tina Ukmar-Godec
- German Center for Neurodegenerative Diseases (DZNE), Von-Siebold-Str. 3a, 37075, Göttingen, Germany
- Department of Neurology, University Medical Center Göttingen, University of Göttingen, Waldweg 33, 37073, Göttingen, Germany
| | - Markus Zweckstetter
- German Center for Neurodegenerative Diseases (DZNE), Von-Siebold-Str. 3a, 37075, Göttingen, Germany.
- Department of Neurology, University Medical Center Göttingen, University of Göttingen, Waldweg 33, 37073, Göttingen, Germany.
- Department for NMR-Based Structural Biology, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077, Göttingen, Germany.
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Mizuguchi T, Matubayasi N. Free-Energy Analysis of Peptide Binding in Lipid Membrane Using All-Atom Molecular Dynamics Simulation Combined with Theory of Solutions. J Phys Chem B 2018; 122:3219-3229. [DOI: 10.1021/acs.jpcb.7b08241] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Tomoko Mizuguchi
- Institute for Molecular Science, Okazaki, Aichi 444-8585, Japan
- Institute for the Promotion of University Strategy, Kyoto Institute of Technology, Kyoto 606-8585, Japan
| | - Nobuyuki Matubayasi
- Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan
- Elements Strategy Initiative for Catalysts and Batteries, Kyoto University, Katsura, Kyoto 615-8520, Japan
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40
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Hien Nguyen T, C. Moore C, B. Moore P, Liu Z. Molecular dynamics study of homo-oligomeric ion channels: Structures of the surrounding lipids and dynamics of water movement. AIMS BIOPHYSICS 2018. [DOI: 10.3934/biophy.2018.1.50] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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41
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Falcone N, Basak S, Dong B, Syed J, Ferranco A, Lough A, She Z, Kraatz HB. A Ferrocene-Tryptophan Conjugate: The Role of the Indolic Nitrogen in Supramolecular Assembly. Chempluschem 2017; 82:1282-1289. [DOI: 10.1002/cplu.201700407] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Indexed: 12/11/2022]
Affiliation(s)
- Natashya Falcone
- Department of Chemical Engineering and Applied Chemistry; University of Toronto; 200 College St Toronto ON M5S 3E5 Canada
- Department of Physical and Environmental Sciences; University of Toronto Scarborough; 1065 Military Trail Toronto ON M1C 1A4 Canada
| | - Shibaji Basak
- Department of Physical and Environmental Sciences; University of Toronto Scarborough; 1065 Military Trail Toronto ON M1C 1A4 Canada
| | - Bin Dong
- Department of Chemistry and Chemical Engineering, School of Chemistry and Biological Engineering; University of Science and Technology Beijing; Beijing 100083 P. R. China
| | - Jebriel Syed
- Department of Physical and Environmental Sciences; University of Toronto Scarborough; 1065 Military Trail Toronto ON M1C 1A4 Canada
| | - Annaleizle Ferranco
- Department of Physical and Environmental Sciences; University of Toronto Scarborough; 1065 Military Trail Toronto ON M1C 1A4 Canada
- Department of Chemistry; University of Toronto; 80 St. George Street Toronto ON M5S 3H6 Canada
| | - Alan Lough
- Department of Chemistry; University of Toronto; 80 St. George Street Toronto ON M5S 3H6 Canada
| | - Zhe She
- Department of Physical and Environmental Sciences; University of Toronto Scarborough; 1065 Military Trail Toronto ON M1C 1A4 Canada
| | - Heinz-Bernhard Kraatz
- Department of Chemical Engineering and Applied Chemistry; University of Toronto; 200 College St Toronto ON M5S 3E5 Canada
- Department of Physical and Environmental Sciences; University of Toronto Scarborough; 1065 Military Trail Toronto ON M1C 1A4 Canada
- Department of Chemistry; University of Toronto; 80 St. George Street Toronto ON M5S 3H6 Canada
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42
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Molugu TR, Lee S, Brown MF. Concepts and Methods of Solid-State NMR Spectroscopy Applied to Biomembranes. Chem Rev 2017; 117:12087-12132. [PMID: 28906107 DOI: 10.1021/acs.chemrev.6b00619] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Concepts of solid-state NMR spectroscopy and applications to fluid membranes are reviewed in this paper. Membrane lipids with 2H-labeled acyl chains or polar head groups are studied using 2H NMR to yield knowledge of their atomistic structures in relation to equilibrium properties. This review demonstrates the principles and applications of solid-state NMR by unifying dipolar and quadrupolar interactions and highlights the unique features offered by solid-state 2H NMR with experimental illustrations. For randomly oriented multilamellar lipids or aligned membranes, solid-state 2H NMR enables direct measurement of residual quadrupolar couplings (RQCs) due to individual C-2H-labeled segments. The distribution of RQC values gives nearly complete profiles of the segmental order parameters SCD(i) as a function of acyl segment position (i). Alternatively, one can measure residual dipolar couplings (RDCs) for natural abundance lipid samples to obtain segmental SCH order parameters. A theoretical mean-torque model provides acyl-packing profiles representing the cumulative chain extension along the normal to the aqueous interface. Equilibrium structural properties of fluid bilayers and various thermodynamic quantities can then be calculated, which describe the interactions with cholesterol, detergents, peptides, and integral membrane proteins and formation of lipid rafts. One can also obtain direct information for membrane-bound peptides or proteins by measuring RDCs using magic-angle spinning (MAS) in combination with dipolar recoupling methods. Solid-state NMR methods have been extensively applied to characterize model membranes and membrane-bound peptides and proteins, giving unique information on their conformations, orientations, and interactions in the natural liquid-crystalline state.
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Affiliation(s)
- Trivikram R Molugu
- Department of Chemistry & Biochemistry and ‡Department of Physics, University of Arizona , Tucson, Arizona 85721, United States
| | - Soohyun Lee
- Department of Chemistry & Biochemistry and ‡Department of Physics, University of Arizona , Tucson, Arizona 85721, United States
| | - Michael F Brown
- Department of Chemistry & Biochemistry and ‡Department of Physics, University of Arizona , Tucson, Arizona 85721, United States
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43
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Argudo D, Bethel NP, Marcoline FV, Wolgemuth CW, Grabe M. New Continuum Approaches for Determining Protein-Induced Membrane Deformations. Biophys J 2017; 112:2159-2172. [PMID: 28538153 DOI: 10.1016/j.bpj.2017.03.040] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Revised: 03/16/2017] [Accepted: 03/27/2017] [Indexed: 01/21/2023] Open
Abstract
The influence of the membrane on transmembrane proteins is central to a number of biological phenomena, notably the gating of stretch activated ion channels. Conversely, membrane proteins can influence the bilayer, leading to the stabilization of particular membrane shapes, topological changes that occur during vesicle fission and fusion, and shape-dependent protein aggregation. Continuum elastic models of the membrane have been widely used to study protein-membrane interactions. These mathematical approaches produce physically interpretable membrane shapes, energy estimates for the cost of deformation, and a snapshot of the equilibrium configuration. Moreover, elastic models are much less computationally demanding than fully atomistic and coarse-grained simulation methodologies; however, it has been argued that continuum models cannot reproduce the distortions observed in fully atomistic molecular dynamics simulations. We suggest that this failure can be overcome by using chemically and geometrically accurate representations of the protein. Here, we present a fast and reliable hybrid continuum-atomistic model that couples the protein to the membrane. We show that the model is in excellent agreement with fully atomistic simulations of the ion channel gramicidin embedded in a POPC membrane. Our continuum calculations not only reproduce the membrane distortions produced by the channel but also accurately determine the channel's orientation. Finally, we use our method to investigate the role of membrane bending around the charged voltage sensors of the transient receptor potential cation channel TRPV1. We find that membrane deformation significantly stabilizes the energy of insertion of TRPV1 by exposing charged residues on the S4 segment to solution.
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Affiliation(s)
- David Argudo
- Cardiovascular Research Institute, Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, California
| | - Neville P Bethel
- Cardiovascular Research Institute, Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, California
| | - Frank V Marcoline
- Cardiovascular Research Institute, Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, California
| | - Charles W Wolgemuth
- Departments of Molecular and Cellular Biology and Physics, University of Arizona, Tucson, Arizona
| | - Michael Grabe
- Cardiovascular Research Institute, Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, California.
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44
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Iyer BR, Zadafiya P, Vetal PV, Mahalakshmi R. Energetics of side-chain partitioning of β-signal residues in unassisted folding of a transmembrane β-barrel protein. J Biol Chem 2017; 292:12351-12365. [PMID: 28592485 PMCID: PMC5519381 DOI: 10.1074/jbc.m117.789446] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Revised: 06/02/2017] [Indexed: 01/07/2023] Open
Abstract
The free energy of water-to-interface amino acid partitioning is a major contributing factor in membrane protein folding and stability. The interface residues at the C terminus of transmembrane β-barrels form the β-signal motif required for assisted β-barrel assembly in vivo but are believed to be less important for β-barrel assembly in vitro. Here, we experimentally measured the thermodynamic contribution of all 20 amino acids at the β-signal motif to the unassisted folding of the model β-barrel protein PagP. We obtained the partitioning free energy for all 20 amino acids at the lipid-facing interface (ΔΔG0w,i(φ)) and the protein-facing interface (ΔΔG0w,i(π)) residues and found that hydrophobic amino acids are most favorably transferred to the lipid-facing interface, whereas charged and polar groups display the highest partitioning energy. Furthermore, the change in non-polar surface area correlated directly with the partitioning free energy for the lipid-facing residue and inversely with the protein-facing residue. We also demonstrate that the interface residues of the β-signal motif are vital for in vitro barrel assembly, because they exhibit a side chain–specific energetic contribution determined by the change in nonpolar accessible surface. We further establish that folding cooperativity and hydrophobic collapse are balanced at the membrane interface for optimal stability of the PagP β-barrel scaffold. We conclude that the PagP C-terminal β-signal motif influences the folding cooperativity and stability of the folded β-barrel and that the thermodynamic contributions of the lipid- and protein-facing residues in the transmembrane protein β-signal motif depend on the nature of the amino acid side chain.
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Affiliation(s)
- Bharat Ramasubramanian Iyer
- Molecular Biophysics Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research, Bhauri, Bhopal 462066, India
| | - Punit Zadafiya
- Molecular Biophysics Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research, Bhauri, Bhopal 462066, India
| | - Pallavi Vijay Vetal
- Molecular Biophysics Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research, Bhauri, Bhopal 462066, India
| | - Radhakrishnan Mahalakshmi
- Molecular Biophysics Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research, Bhauri, Bhopal 462066, India.
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45
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Radyukhin VA, Dadinova LA, Orlov IA, Baratova LA. Amphipathic secondary structure elements and putative cholesterol recognizing amino acid consensus (CRAC) motifs as governing factors of highly specific matrix protein interactions with raft-type membranes in enveloped viruses. J Biomol Struct Dyn 2017; 36:1351-1359. [PMID: 28492103 DOI: 10.1080/07391102.2017.1323012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Victor A Radyukhin
- a Belozersky Institute of Physico-Chemical Biology , Moscow State University , Moscow , Russia
| | - Liubov A Dadinova
- b A.V. Shubnikov Institute of Crystallography of Federal Scientific Research Centre 'Crystallography and Photonics' of Russian Academy of Sciences , Moscow , Russia
| | - Ivan A Orlov
- c Joint Institute for Nuclear Research , Dubna , Russia
| | - Ludmila A Baratova
- a Belozersky Institute of Physico-Chemical Biology , Moscow State University , Moscow , Russia
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46
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Antimicrobial peptide cWFW kills by combining lipid phase separation with autolysis. Sci Rep 2017; 7:44332. [PMID: 28276520 PMCID: PMC5343580 DOI: 10.1038/srep44332] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Accepted: 02/07/2017] [Indexed: 12/17/2022] Open
Abstract
The synthetic cyclic hexapeptide cWFW (cyclo(RRRWFW)) has a rapid bactericidal activity against both Gram-positive and Gram-negative bacteria. Its detailed mode of action has, however, remained elusive. In contrast to most antimicrobial peptides, cWFW neither permeabilizes the membrane nor translocates to the cytoplasm. Using a combination of proteome analysis, fluorescence microscopy, and membrane analysis we show that cWFW instead triggers a rapid reduction of membrane fluidity both in live Bacillus subtilis cells and in model membranes. This immediate activity is accompanied by formation of distinct membrane domains which differ in local membrane fluidity, and which severely disrupts membrane protein organisation by segregating peripheral and integral proteins into domains of different rigidity. These major membrane disturbances cause specific inhibition of cell wall synthesis, and trigger autolysis. This novel antibacterial mode of action holds a low risk to induce bacterial resistance, and provides valuable information for the design of new synthetic antimicrobial peptides.
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47
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Briones R, Aponte-Santamaría C, de Groot BL. Localization and Ordering of Lipids Around Aquaporin-0: Protein and Lipid Mobility Effects. Front Physiol 2017; 8:124. [PMID: 28303107 PMCID: PMC5332469 DOI: 10.3389/fphys.2017.00124] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Accepted: 02/15/2017] [Indexed: 11/13/2022] Open
Abstract
Hydrophobic matching, lipid sorting, and protein oligomerization are key principles by which lipids and proteins organize in biological membranes. The Aquaporin-0 channel (AQP0), solved by electron crystallography (EC) at cryogenic temperatures, is one of the few protein-lipid complexes of which the structure is available in atomic detail. EC and room-temperature molecular dynamics (MD) of dimyristoylglycerophosphocholine (DMPC) annular lipids around AQP0 show similarities, however, crystal-packing and temperature might affect the protein surface or the lipids distribution. To understand the role of temperature, lipid phase, and protein mobility in the localization and ordering of AQP0-lipids, we used MD simulations of an AQP0-DMPC bilayer system. Simulations were performed at physiological and at DMPC gel-phase temperatures. To decouple the protein and lipid mobility effects, we induced gel-phase in the lipids or restrained the protein. We monitored the lipid ordering effects around the protein. Reducing the system temperature or inducing lipid gel-phase had a marginal effect on the annular lipid localization. However, restraining the protein mobility increased the annular lipid localization around the whole AQP0 surface, resembling EC. The distribution of the inter-phosphate and hydrophobic thicknesses showed that stretching of the DMPC annular layer around AQP0 surface is the mechanism that compensates the hydrophobic mismatch in this system. The distribution of the local area-per-lipid and the acyl-chain order parameters showed particular fluid- and gel-like areas that involved several lipid layers. These areas were in contact with the surfaces of higher and lower protein mobility, respectively. We conclude that the AQP0 surfaces induce specific fluid- and gel-phase prone areas. The presence of these areas might guide the AQP0 lipid sorting interactions with other membrane components, and is compatible with the squared array oligomerization of AQP0 tetramers separated by a layer of annular lipids.
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Affiliation(s)
- Rodolfo Briones
- Computational Biomolecular Dynamics Group, Max Planck Institute for Biophysical Chemistry Göttingen, Germany
| | - Camilo Aponte-Santamaría
- Molecular Biomechanics Group, Heidelberg Institute for Theoretical Studies and Interdisciplinary Center for Scientific Computing Heidelberg, Germany
| | - Bert L de Groot
- Computational Biomolecular Dynamics Group, Max Planck Institute for Biophysical Chemistry Göttingen, Germany
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48
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Hädicke A, Blume A. Binding of cationic model peptides (KX) 4 K to anionic lipid bilayers: Lipid headgroup size influences secondary structure of bound peptides. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1859:415-424. [DOI: 10.1016/j.bbamem.2016.12.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Revised: 12/07/2016] [Accepted: 12/23/2016] [Indexed: 01/04/2023]
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49
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Sannigrahi A, Maity P, Karmakar S, Chattopadhyay K. Interaction of KMP-11 with Phospholipid Membranes and Its Implications in Leishmaniasis: Effects of Single Tryptophan Mutations and Cholesterol. J Phys Chem B 2017; 121:1824-1834. [DOI: 10.1021/acs.jpcb.6b11948] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Achinta Sannigrahi
- Structural Biology & Bio-Informatics Division, CSIR-Indian Institute of Chemical Biology, 4, Raja S. C. Mallick Road, Kolkata 700032, India
| | - Pabitra Maity
- Department
of Physics, Jadavpur University, 188, Raja S. C. Mallick Road, Kolkata 700032, India
| | - Sanat Karmakar
- Department
of Physics, Jadavpur University, 188, Raja S. C. Mallick Road, Kolkata 700032, India
| | - Krishnananda Chattopadhyay
- Structural Biology & Bio-Informatics Division, CSIR-Indian Institute of Chemical Biology, 4, Raja S. C. Mallick Road, Kolkata 700032, India
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50
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Sato T. Chemical synthesis of transmembrane peptide and its application for research on the transmembrane-juxtamembrane region of membrane protein. Biopolymers 2017; 106:613-21. [PMID: 26573237 DOI: 10.1002/bip.22775] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Revised: 10/28/2015] [Accepted: 11/02/2015] [Indexed: 12/11/2022]
Abstract
Membrane proteins possess one or more hydrophobic regions that span the membrane and interact with the lipids that constitute the membrane. The interactions between the transmembrane (TM) region and lipids affect the structure and function of these membrane proteins. Molecular characterization of synthetic TM peptides in lipid bilayers helps to understand how the TM region participates in the formation of the structure and in the function of membrane proteins. The use of synthetic peptides enables site-specific labeling and modification and allows for designing of an artificial TM sequence. Research involving such samples has resulted in significant increase in the knowledge of the mechanisms that govern membrane biology. In this review, the chemical synthesis of TM peptides has been discussed. The preparation of synthetic TM peptides is still not trivial; however, the accumulated knowledge summarized here should provide a basis for preparing samples for spectroscopic analyses. The application of synthetic TM peptides for gaining insights into the mechanism of signal transduction by receptor tyrosine kinase (RTK) has also been discussed. RTK is a single TM protein and is one of the difficult targets in structural biology as crystallization of the full-length receptor has not been successful. This review describes the structural characterization of the synthetic TM-juxtamembrane sequence and proposes a possible scheme for the structural changes in this region for the activation of ErbBs, the epidermal growth factor receptor family. © 2015 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 106: 613-621, 2016.
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Affiliation(s)
- Takeshi Sato
- Laboratory of Protein Organic Chemistry, Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka 565-0871, Japan
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