1
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Domanska M, Setny P. Exploring the Properties of Curved Lipid Membranes: Comparative Analysis of Atomistic and Coarse-Grained Force Fields. J Phys Chem B 2024; 128:7160-7171. [PMID: 38990314 DOI: 10.1021/acs.jpcb.4c02310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/12/2024]
Abstract
Curvature emerges as a fundamental membrane characteristic crucial for diverse biological processes, including vesicle formation, cell signaling, and membrane trafficking. Increasingly valuable insights into atomistic details governing curvature-dependent membrane properties are provided by computer simulations. Nevertheless, the underlying force field models are conventionally calibrated and tested in relation to experimentally derived parameters of planar bilayers, thereby leaving uncertainties concerning their consistency in reproducing curved lipid systems. In this study we compare the depiction of buckled phosphatidylcholine (POPC) and POPC-cholesterol membranes by four popular force field models. Aside from agreement with respect to general trends in curvature dependence of a number of parameters, we observe a few qualitative differences. Among the most prominent ones is the difference between atomistic and coarse grained force fields in their representation of relative compressibility of the polar headgroup region and hydrophobic lipid core. Through a number of downstream effects, this discrepancy can influence the way in which curvature modulates the behavior of membrane bound proteins depending on the adopted simulation model.
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Affiliation(s)
- Maria Domanska
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097 Warsaw, Poland
| | - Piotr Setny
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097 Warsaw, Poland
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2
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Chng CP, Dowd A, Mechler A, Hsia KJ. Molecular dynamics simulations reliably identify vibrational modes in far-IR spectra of phospholipids. Phys Chem Chem Phys 2024; 26:18715-18726. [PMID: 38932689 DOI: 10.1039/d4cp00521j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/28/2024]
Abstract
The properties of self-assembled phospholipid membranes are of essential importance in biochemistry and physical chemistry, providing a platform for many cellular life functions. Far-infrared (far-IR) vibrational spectroscopy, on the other hand, is a highly information-rich method to characterize intermolecular interactions and collective behaviour of lipids that can help explain, e.g., chain packing, thermodynamic phase behaviour, and sequestration. However, reliable interpretation of the far-IR spectra is still lacking. Here we present a molecular dynamics (MD) based approach to simulate vibrational modes of individual lipids and in an ensemble. The results are a good match to synchrotron far-IR measurements and enable identification of the molecular motions corresponding to each vibrational mode, thus allowing the correct interpretation of membrane spectra with high accuracy and resolving the longstanding ambiguities in the literature in this regard. Our results demonstrate the feasibility of using MD simulations for interpreting far-IR spectra broadly, opening new avenues for practical use of this powerful method.
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Affiliation(s)
- Choon-Peng Chng
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore 639798, Republic of Singapore.
| | - Annette Dowd
- School of Mathematical and Physical Sciences, University of Technology Sydney, Ultimo, NSW 2007, Australia
| | - Adam Mechler
- Department of Biochemistry and Chemistry, La Trobe Institute for Molecular Science, La Trobe University, Bundoora, Victoria 3086, Australia.
| | - K Jimmy Hsia
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore 639798, Republic of Singapore.
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore 637459, Republic of Singapore
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3
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Ocket E, Matthaeus C. Insights in caveolae protein structure arrangements and their local lipid environment. Biol Chem 2024; 0:hsz-2024-0046. [PMID: 38970809 DOI: 10.1515/hsz-2024-0046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2024] [Accepted: 06/19/2024] [Indexed: 07/08/2024]
Abstract
Caveolae are 50-80 nm sized plasma membrane invaginations found in adipocytes, endothelial cells or fibroblasts. They are involved in endocytosis, lipid uptake and the regulation of the cellular lipid metabolism as well as sensing and adapting to changes in plasma membrane tension. Caveolae are characterized by their unique lipid composition and their specific protein coat consisting of caveolin and cavin proteins. Recently, detailed structural information was obtained for the major caveolae protein caveolin1 showing the formation of a disc-like 11-mer protein complex. Furthermore, the importance of the cavin disordered regions in the generation of cavin trimers and caveolae at the plasma membrane were revealed. Thus, finally, structural insights about the assembly of the caveolar coat can be elucidated. Here, we review recent developments in caveolae structural biology with regard to caveolae coat formation and caveolae curvature generation. Secondly, we discuss the importance of specific lipid species necessary for caveolae curvature and formation. In the last years, it was shown that specifically sphingolipids, cholesterol and fatty acids can accumulate in caveolae invaginations and may drive caveolae endocytosis. Throughout, we summarize recent studies in the field and highlight future research directions.
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Affiliation(s)
- Esther Ocket
- Institute of Nutritional Science, Cellular Physiology of Nutrition, University of Potsdam, Karl-Liebknecht-Str. 24/25, Building 29, Room 0.08, D-14476 Potsdam, Germany
| | - Claudia Matthaeus
- Institute of Nutritional Science, Cellular Physiology of Nutrition, University of Potsdam, Karl-Liebknecht-Str. 24/25, Building 29, Room 0.08, D-14476 Potsdam, Germany
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4
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Mayorga LS, Masone D. The Secret Ballet Inside Multivesicular Bodies. ACS NANO 2024; 18:15651-15660. [PMID: 38830824 DOI: 10.1021/acsnano.4c01590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2024]
Abstract
Lipid bilayers possess the capacity for self-assembly due to the amphipathic nature of lipid molecules, which have both hydrophobic and hydrophilic regions. When confined, lipid bilayers exhibit astonishing versatility in their forms, adopting diverse shapes that are challenging to observe through experimental means. Exploiting this adaptability, lipid structures motivate the development of bio-inspired mechanomaterials and integrated nanobio-interfaces that could seamlessly merge with biological entities, ultimately bridging the gap between synthetic and biological systems. In this work, we demonstrate how, in numerical simulations of multivesicular bodies, a fascinating evolution unfolds from an initial semblance of order toward states of higher entropy over time. We observe dynamic rearrangements in confined vesicles that reveal unexpected limit shapes of distinct geometric patterns. We identify five structures as the basic building blocks that systematically repeat under various conditions of size and composition. Moreover, we observe more complex and less frequent shapes that emerge in confined spaces. Our results provide insights into the dynamics of multivesicular systems, offering a richer understanding of how confined lipid bodies spontaneously self-organize.
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Affiliation(s)
- Luis S Mayorga
- Instituto de Histología y Embriología de Mendoza (IHEM), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional de Cuyo (UNCuyo), 5500 Mendoza, Argentina
- Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Cuyo (UNCuyo), 5500, Mendoza, Argentina
| | - Diego Masone
- Instituto de Histología y Embriología de Mendoza (IHEM), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional de Cuyo (UNCuyo), 5500 Mendoza, Argentina
- Facultad de Ingeniería, Universidad Nacional de Cuyo (UNCuyo), 5500 Mendoza, Argentina
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5
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Fábián B, Javanainen M. Diffusion Analyses along Mean and Gaussian-Curved Membranes with CurD. J Phys Chem Lett 2024; 15:3214-3220. [PMID: 38483514 PMCID: PMC11444424 DOI: 10.1021/acs.jpclett.4c00338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Revised: 03/05/2024] [Accepted: 03/07/2024] [Indexed: 03/22/2024]
Abstract
Curved cellular membranes are both abundant and functionally relevant. While novel tomography approaches reveal the structural details of curved membranes, their dynamics pose an experimental challenge. Curvature especially affects the diffusion of lipids and macromolecules, yet neither experiments nor continuum models distinguish geometric effects from those caused by curvature-induced changes in membrane properties. Molecular simulations could excel here, yet despite community interest toward curved membranes, tools for their analysis are still lacking. Here, we satisfy this demand by introducing CurD, our novel and openly available implementation of the Vertex-oriented Triangle Propagation algorithm to the study of lipid diffusion along membranes with mean and/or Gaussian curvature. This approach, aided by our highly optimized implementation, computes geodetic distances significantly faster than conventional implementations of path-finding algorithms. Our tool, applied to coarse-grained simulations, allows for the first time the analysis of curvature effects on diffusion at size scales relevant to physiological processes such as endocytosis. Our analyses with different membrane geometries reveal that Gaussian curvature plays a surprisingly small role on lipid motion, whereas mean curvature; i.e., the packing of lipid headgroups largely dictates their mobility.
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Affiliation(s)
- Balázs Fábián
- Institute
of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo nám. 542/2, CZ-16000 Prague 6, Czech Republic
| | - Matti Javanainen
- Institute
of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo nám. 542/2, CZ-16000 Prague 6, Czech Republic
- Institute
of Biotechnology, University of Helsinki, FI-00790 Helsinki, Finland
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6
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Kang C, Fujioka K, Sun R. Atomistic Insight into the Lipid Nanodomains of Synaptic Vesicles. J Phys Chem B 2024; 128:2707-2716. [PMID: 38325816 DOI: 10.1021/acs.jpcb.3c07982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
Membrane curvature, once regarded as a passive consequence of membrane composition and cellular architecture, has been shown to actively modulate various properties of the cellular membrane. These changes could also lead to segregation of the constituents of the membrane, generating nanodomains with precise biological properties. Proteins often linked with neurodegeneration (e.g., tau, alpha-synuclein) exhibit an unintuitive affinity for synaptic vesicles in neurons, which are reported to lack distinct, ordered nanodomains based on their composition. In this study, all-atom molecular dynamics simulations are used to study a full-scale synaptic vesicle of realistic Gaussian curvature and its effect on the membrane dynamics and lipid nanodomain organization. Compelling indicators of nanodomain formation, from the perspective of composition, surface areas per lipid, order parameter, and domain lifetime, are identified in the vesicle membrane, which are absent in a flat bilayer of the same lipid composition. Therefore, our study supports the idea that curvature may induce phase separation in an otherwise fluid, disordered membrane.
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Affiliation(s)
- Christopher Kang
- Department of Chemistry, The University of Hawai'i, Ma̅noa, 2545 McCarthy Mall, Honolulu, Hawaii 96822, United States
| | - Kazuumi Fujioka
- Department of Chemistry, The University of Hawai'i, Ma̅noa, 2545 McCarthy Mall, Honolulu, Hawaii 96822, United States
| | - Rui Sun
- Department of Chemistry, The University of Hawai'i, Ma̅noa, 2545 McCarthy Mall, Honolulu, Hawaii 96822, United States
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7
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Schleutker R, Luschnig S. Palmitoylation of proteolipid protein M6 promotes tricellular junction assembly in epithelia of Drosophila. J Cell Sci 2024; 137:jcs261916. [PMID: 38345097 DOI: 10.1242/jcs.261916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Accepted: 02/02/2024] [Indexed: 03/21/2024] Open
Abstract
Tricellular junctions (TCJs) seal epithelial cell vertices and are essential for tissue integrity and physiology, but how TCJs are assembled and maintained is poorly understood. In Drosophila, the transmembrane proteins Anakonda (Aka, also known as Bark), Gliotactin (Gli) and M6 organize occluding TCJs. Aka and M6 localize in an interdependent manner to vertices and act jointly to localize Gli, but how these proteins interact to assemble TCJs was not previously known. Here, we show that the proteolipid protein M6 physically interacts with Aka and with itself, and that M6 is palmitoylated on conserved juxta-membrane cysteine residues. This modification promotes vertex localization of M6 and binding to Aka, but not to itself, and becomes essential when TCJ protein levels are reduced. Abolishing M6 palmitoylation leads to delayed localization of M6 and Aka but does not affect the rate of TCJ growth or mobility of M6 or Aka. Our findings suggest that palmitoylation-dependent recruitment of Aka by M6 promotes initiation of TCJ assembly, whereas subsequent TCJ growth relies on different mechanisms that are independent of M6 palmitoylation.
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Affiliation(s)
- Raphael Schleutker
- Institute of Integrative Cell Biology and Physiology, Cells in Motion (CiM) Interfaculty Centre, University of Münster, D-48149 Münster, Germany
| | - Stefan Luschnig
- Institute of Integrative Cell Biology and Physiology, Cells in Motion (CiM) Interfaculty Centre, University of Münster, D-48149 Münster, Germany
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8
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Pajtinka P, Vácha R. Amphipathic Helices Can Sense Both Positive and Negative Curvatures of Lipid Membranes. J Phys Chem Lett 2024; 15:175-179. [PMID: 38153203 PMCID: PMC10788957 DOI: 10.1021/acs.jpclett.3c02785] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Revised: 12/09/2023] [Accepted: 12/19/2023] [Indexed: 12/29/2023]
Abstract
Curvature sensing is an essential ability of biomolecules to preferentially localize to membrane regions of a specific curvature. It has been shown that amphipathic helices (AHs), helical peptides with both hydrophilic and hydrophobic regions, could sense a positive membrane curvature. The origin of this AH sensing has been attributed to their ability to exploit lipid-packing defects that are enhanced in regions of positive curvature. In this study, we revisit an alternative framework where AHs act as sensors of local internal stress within the membrane, suggesting the possibility of an AH sensing a negative membrane curvature. Using molecular dynamics simulations, we gradually tuned the hydrophobicity of AHs, thereby adjusting their insertion depth so that the curvature preference of AHs is switched from positive to negative. This study suggests that highly hydrophobic AHs could preferentially localize proteins to regions of a negative membrane curvature.
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Affiliation(s)
- Peter Pajtinka
- CEITEC
− Central European Institute of Technology, Masaryk University, Kamenice 753/5, 625 00 Brno, Czech Republic
- National
Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
| | - Robert Vácha
- CEITEC
− Central European Institute of Technology, Masaryk University, Kamenice 753/5, 625 00 Brno, Czech Republic
- National
Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
- Department
of Condensed Matter Physics, Faculty of Science, Masaryk University, Kotlářská 267/2, 611 37 Brno, Czech
Republic
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9
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Golla VK, Boyd KJ, May ER. Curvature sensing lipid dynamics in a mitochondrial inner membrane model. Commun Biol 2024; 7:29. [PMID: 38182788 PMCID: PMC10770132 DOI: 10.1038/s42003-023-05657-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Accepted: 11/30/2023] [Indexed: 01/07/2024] Open
Abstract
Membrane curvature is essential for many cellular structures and processes, and factors such as leaflet asymmetry, lipid composition, and proteins all play important roles. Cardiolipin is the signature lipid of mitochondrial membranes and is essential for maintaining the highly curved shapes of the inner mitochondrial membrane (IMM) and the spatial arrangement of membrane proteins. In this study, we investigate the partitioning behavior of various lipids present in the IMM using coarse-grained molecular dynamics simulations. This study explores curved bilayer systems containing phosphatidylcholine (PC), phosphatidylethanolamine (PE), and cardiolipin (CDL) in binary and ternary component mixtures. Curvature properties such as mean and Gaussian curvatures, as well as the distribution of lipids into the various curved regions of the cristae models, are quantified. Overall, this work represents an advance beyond previous studies on lipid curvature sensing by simulating these systems in a geometry that has the morphological features and scales of curvature consistent with regions of the IMM. We find that CDL has a stronger preference for accumulating in regions of negative curvature than PE lipids, in agreement with previous results. Furthermore, we find lipid partitioning propensity is dominated by sensitivity to mean curvature, while there is a weaker correlation with Gaussian curvature.
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Affiliation(s)
- Vinaya Kumar Golla
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, 06269, USA
- Department of Cell Biology, University of Virginia School of Medicine, Charlottesville, VA, 22903, USA
| | - Kevin J Boyd
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, 06269, USA
- NVIDIA, 2860 County Hwy G4, Santa Clara, CA, 95051, USA
| | - Eric R May
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, 06269, USA.
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10
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Davoudi S, Raemdonck K, Braeckmans K, Ghysels A. Capric Acid and Myristic Acid Permeability Enhancers in Curved Liposome Membranes. J Chem Inf Model 2023; 63:6789-6806. [PMID: 37917127 DOI: 10.1021/acs.jcim.3c00936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2023]
Abstract
Liposomes are considered as advanced drug delivery systems for cancer treatment. A generation of pH-sensitive liposomes is being developed that use fatty acids (FAs) as a trigger for drug release in tumor tissues. However, FAs are also known to enhance permeability, and it is unclear whether FAs in liposomes may cause drug leakage or premature drug release. The passive permeability of the drug through the membrane of the liposome is thus a crucial factor for timely drug delivery. To investigate how the curvature and lipid composition of liposomes affect their passive permeability, coarse-grained molecular dynamics were performed. The permeability was determined with a counting method. Flat bilayers and three liposomes with varying diameters were studied, which had varying lipid compositions of dipalmitoylphosphatidylcholine, cholesterol, and deprotonated or neutral saturated FAs. The investigated permeants were water and two other small permeants, which have different free energy profiles (solubility) across the membrane. First, for the curvature effect, our results showed that curvature increases the water permeability by reducing the membrane thickness. The permeability increase for water is about a factor of 1.7 for the most curved membranes. However, a high curvature decreases permeability for permeants with free energy profiles that are a mix of wells and barriers in the headgroup region of the membrane. Importantly, the type of experimental setup is expected to play a dominant role in the permeability value, i.e., whether permeants are escaping or entering the liposomes. Second, for the composition effect, FAs decrease both the area per lipid (APL) and the membrane thickness, resulting in permeability increases of up to 55%. Cholesterol has a similar effect on the APL but has the opposite impact on membrane thickness and permeability. Therefore, FAs and cholesterol have opposing effects on permeability, with cholesterol's effect being slightly stronger in our simulated bilayers. As all permeability values were well within a factor of 2, and with liposomes usually being larger and less curved in experimental applications, it can be concluded that the passive drug release from a pH-sensitive liposome does not seem to be significantly affected by the presence of FAs.
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Affiliation(s)
- Samaneh Davoudi
- IBiTech─BioMMedA Group, Ghent University, Corneel Heymanslaan 10, Block B-Entrance 36, 9000 Gent, Belgium
| | - Koen Raemdonck
- Ghent Research Group on Nanomedicines, Laboratory for General Biochemistry and Physical Pharmacy, Ghent University, Ottergemsesteenweg 460, 9000 Gent, Belgium
| | - Kevin Braeckmans
- Bio-Photonic Imaging Group, Laboratory for General Biochemistry and Physical Pharmacy, Ghent University, Ottergemsesteenweg 460, 9000 Gent, Belgium
| | - An Ghysels
- IBiTech─BioMMedA Group, Ghent University, Corneel Heymanslaan 10, Block B-Entrance 36, 9000 Gent, Belgium
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11
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Woodward X, Javanainen M, Fábián B, Kelly CV. Nanoscale membrane curvature sorts lipid phases and alters lipid diffusion. Biophys J 2023; 122:2203-2215. [PMID: 36604961 PMCID: PMC10257122 DOI: 10.1016/j.bpj.2023.01.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 11/23/2022] [Accepted: 01/03/2023] [Indexed: 01/06/2023] Open
Abstract
The precise spatiotemporal control of nanoscale membrane shape and composition is the result of a complex interplay of individual and collective molecular behaviors. Here, we employed single-molecule localization microscopy and computational simulations to observe single-lipid diffusion and sorting in model membranes with varying compositions, phases, temperatures, and curvatures. Supported lipid bilayers were created over 50-nm-radius nanoparticles to mimic the size of naturally occurring membrane buds, such as endocytic pits and the formation of viral envelopes. The curved membranes recruited liquid-disordered lipid phases while altering the diffusion and sorting of tracer lipids. Disorder-preferring fluorescent lipids sorted to and experienced faster diffusion on the nanoscale curvature only when embedded in a membrane capable of sustaining lipid phase separation at low temperatures. The curvature-induced sorting and faster diffusion even occurred when the sample temperature was above the miscibility temperature of the planar membrane, implying that the nanoscale curvature could induce phase separation in otherwise homogeneous membranes. Further confirmation and understanding of these results are provided by continuum and coarse-grained molecular dynamics simulations with explicit and spontaneous curvature-phase coupling, respectively. The curvature-induced membrane compositional heterogeneity and altered dynamics were achieved only with a coupling of the curvature with a lipid phase separation. These cross-validating results demonstrate the complex interplay of lipid phases, molecular diffusion, and nanoscale membrane curvature that are critical for membrane functionality.
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Affiliation(s)
- Xinxin Woodward
- Department of Physics and Astronomy, Wayne State University, Detroit, Michigan
| | - Matti Javanainen
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czech Republic; Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Balázs Fábián
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czech Republic
| | - Christopher V Kelly
- Department of Physics and Astronomy, Wayne State University, Detroit, Michigan.
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12
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Davoudi S, Ghysels A. Defining permeability of curved membranes in molecular dynamics simulations. Biophys J 2023; 122:2082-2091. [PMID: 36419351 PMCID: PMC10257088 DOI: 10.1016/j.bpj.2022.11.028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 11/11/2022] [Accepted: 11/17/2022] [Indexed: 11/25/2022] Open
Abstract
Many phospholipid membranes in the cell have a high curvature; for instance, in caveolae, mitochondrial crystae, nanotubes, membrane pearls, small liposomes, or exosomes. Molecular dynamics (MD) simulations are a computational tool to gain insight in the transport behavior at the atomic scale. Membrane permeability is a key kinetic property that might be affected in these highly curved membranes. Unfortunately, the geometry of highly curved membranes creates ambiguity in the permeability value, even with an arbitrarily large factor purely based on geometry, caused by the radial flux not being a constant value in steady state. In this contribution, the ambiguity in permeability for liposomes is countered by providing a new permeability definition. First, the inhomogeneous solubility diffusion model based on the Smoluchowski equation is solved analytically under radial symmetry, from which the entrance and escape permeabilities are defined. Next, the liposome permeability is defined guided by the criterion that a flat and curved membrane should have equal permeability, in case these were to be carved out from an imaginary homogeneous medium. With this criterion, our new definition allows for a fair comparison of flat and curved membranes. The definition is then transferred to the counting method, which is a practical computational approach to derive permeability by counting complete membrane crossings. Finally, the usability of the approach is illustrated with MD simulations of diphosphatidylcholine (DPPC) bilayers, without or with some cholesterol content. Our new liposome permeability definition allows us to compare a spherically shaped membrane with its flat counterpart, thus showcasing how the curvature effect on membrane transport may be assessed.
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Affiliation(s)
- Samaneh Davoudi
- IBiTech - Biommeda Group, Faculty of Engineering and Architecture, Ghent University, Gent, Belgium
| | - An Ghysels
- IBiTech - Biommeda Group, Faculty of Engineering and Architecture, Ghent University, Gent, Belgium.
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13
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Daniel M, Eleršič Filipič K, Filová E, Judl T, Fojt J. Modelling the role of membrane mechanics in cell adhesion on titanium oxide nanotubes. Comput Methods Biomech Biomed Engin 2023; 26:281-290. [PMID: 35380071 DOI: 10.1080/10255842.2022.2058875] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Titanium surface treated with titanium oxide nanotubes was used in many studies to quantify the effect of surface topography on cell fate. However, the predicted optimal diameter of nanotubes considerably differs among studies. We propose a model that explains cell adhesion to a nanostructured surface by considering the deformation energy of cell protrusions into titanium nanotubes and the adhesion to the surface. The optimal surface topology is defined as a geometry that gives the membrane a minimum energy shape. A dimensionless parameter, the cell interaction index, was proposed to describe the interplay between the cell membrane bending, the intrinsic curvature, and the strength of cell adhesion. Model simulation shows that an optimal nanotube diameter ranging from 20 nm to 100 nm (cell interaction index between 0.2 and 1, respectively) is feasible within a certain range of parameters describing cell membrane adhesion and bending. The results indicate a possibility to tune the topology of a nanostructural surface in order to enhance the proliferation and differentiation of cells mechanically compatible with the given surface geometry while suppressing the growth of other mechanically incompatible cells.
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Affiliation(s)
- Matej Daniel
- Faculty of Mechanical Engineering, Czech Technical University in Prague, Prague, Czechia
| | | | - Eva Filová
- Institute of Experimental Medicine of the Czech Academy of Sciences, Prague, Czechia
| | | | - Jaroslav Fojt
- Faculty of Chemical Technology, University of Chemistry and Technology Prague, Prague, Czechia
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14
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Lirussi F, Pyrshev K, Yesylevskyy S, Rivel T, Lopez T, Coppens E, Mura S, Couvreur P, Ramseyer C. Plasma membrane lipid bilayer is druggable: Selective delivery of gemcitabine-squalene nano-medicine to cancer cells. Biochim Biophys Acta Mol Basis Dis 2023; 1869:166614. [PMID: 36494037 DOI: 10.1016/j.bbadis.2022.166614] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 11/27/2022] [Accepted: 11/28/2022] [Indexed: 12/12/2022]
Abstract
Up to now the lipid bilayers were rarely considered as targets in cancer therapy despite pronounced differences in lipid composition between plasma membranes of benign and malignant cells. In this study we demonstrate that the lipid bilayer of the plasma membrane is druggable and suitable for facilitating selective delivery of amphiphilic gemcitabine-squalene nanomedicines to cancer cells. Data from radioactive assays, fluorescent membrane probes and molecular dynamics simulations provide evidence of selective accumulation of gemcitabine-squalene in the plasma membranes with disrupted lipid asymmetry and its subsequent preferential uptake by malignant cells. This causes pronounced cytotoxicity on cancer cells in comparison to their benign counterparts originating from the same tissue.
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Affiliation(s)
- Frédéric Lirussi
- UMR 1231, Lipides Nutrition Cancer, INSERM, F-21000 Dijon, France; UFR des Sciences de Santé, Université Bourgogne Franche-Comté, F-25000 Besançon, France; Plateforme PACE, Laboratoire de Pharmacologie-Toxicologie, Centre Hospitalo-Universitaire Besançon, F-25000 Besançon, France.
| | - Kyrylo Pyrshev
- UFR des Sciences de Santé, Université Bourgogne Franche-Comté, F-25000 Besançon, France; Department of Physics of Biological Systems, Institute of Physics of the National Academy of Sciences of Ukraine, 46 Nauky ave, 03028 Kyiv, Ukraine; Department of Integrative Biology and Pharmacology, The University of Texas Health Science Center at Houston, 6431 Fannin St., Houston, TX 77030, USA; Department of Neurochemistry, Palladin Institute of Biochemistry of the NAS of Ukraine, 9 Leontovycha str., 01601 Kyiv, Ukraine
| | - Semen Yesylevskyy
- Department of Physics of Biological Systems, Institute of Physics of the National Academy of Sciences of Ukraine, 46 Nauky ave, 03028 Kyiv, Ukraine; Laboratoire Chrono Environnement UMR CNRS 6249, Université de Bourgogne Franche-Comté, 16 route de Gray, 25030 Besançon Cedex, France; Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, CZ-166 10, Prague 6, Czech Republic; Receptor.AI Inc, 20-22 Wenlock Road, London N1 7GU, United Kingdom
| | - Timothée Rivel
- Laboratoire Chrono Environnement UMR CNRS 6249, Université de Bourgogne Franche-Comté, 16 route de Gray, 25030 Besançon Cedex, France; CEITEC - Central European Institute of Technology, Masaryk University, Kamenice, CZ-62500, Brno, Czech Republic
| | - Tatiana Lopez
- UMR 1231, Lipides Nutrition Cancer, INSERM, F-21000 Dijon, France; UFR des Sciences de Santé, Université Bourgogne Franche-Comté, F-25000 Besançon, France
| | - Eleonore Coppens
- Université Paris-Saclay, CNRS, Institut Galien Paris-Saclay, 92296, Châtenay-Malabry, France
| | - Simona Mura
- Université Paris-Saclay, CNRS, Institut Galien Paris-Saclay, 92296, Châtenay-Malabry, France
| | - Patrick Couvreur
- Université Paris-Saclay, CNRS, Institut Galien Paris-Saclay, 92296, Châtenay-Malabry, France
| | - Christophe Ramseyer
- Laboratoire Chrono Environnement UMR CNRS 6249, Université de Bourgogne Franche-Comté, 16 route de Gray, 25030 Besançon Cedex, France
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15
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Moss FR, Lincoff J, Tucker M, Mohammed A, Grabe M, Frost A. Brominated lipid probes expose structural asymmetries in constricted membranes. Nat Struct Mol Biol 2023; 30:167-175. [PMID: 36624348 PMCID: PMC9935397 DOI: 10.1038/s41594-022-00898-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Accepted: 11/11/2022] [Indexed: 01/11/2023]
Abstract
Lipids in biological membranes are thought to be functionally organized, but few experimental tools can probe nanoscale membrane structure. Using brominated lipids as contrast probes for cryo-EM and a model ESCRT-III membrane-remodeling system composed of human CHMP1B and IST1, we observed leaflet-level and protein-localized structural lipid patterns within highly constricted and thinned membrane nanotubes. These nanotubes differed markedly from protein-free, flat bilayers in leaflet thickness, lipid diffusion rates and lipid compositional and conformational asymmetries. Simulations and cryo-EM imaging of brominated stearoyl-docosahexanenoyl-phosphocholine showed how a pair of phenylalanine residues scored the outer leaflet with a helical hydrophobic defect where polyunsaturated docosahexaenoyl tails accumulated at the bilayer surface. Combining cryo-EM of halogenated lipids with molecular dynamics thus enables new characterizations of the composition and structure of membranes on molecular length scales.
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Affiliation(s)
- Frank R Moss
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA, USA
- SLAC National Accelerator Laboratory, Menlo Park, CA, USA
- Altos Labs, Redwood City, CA, USA
| | - James Lincoff
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA, USA
- Cardiovascular Research Institute, University of California San Francisco (UCSF), San Francisco, CA, USA
| | - Maxwell Tucker
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA, USA
- Cardiovascular Research Institute, University of California San Francisco (UCSF), San Francisco, CA, USA
| | - Arshad Mohammed
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA, USA
- University of California Berkeley, Berkeley, CA, USA
- Altos Labs, Redwood City, CA, USA
| | - Michael Grabe
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA, USA.
- Cardiovascular Research Institute, University of California San Francisco (UCSF), San Francisco, CA, USA.
| | - Adam Frost
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA, USA.
- Chan Zuckerberg Biohub, San Francisco, CA, USA.
- Department of Biochemistry, University of Utah, Salt Lake City, UT, USA.
- Altos Labs, Redwood City, CA, USA.
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16
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Molugu TR, Thurmond RL, Alam TM, Trouard TP, Brown MF. Phospholipid headgroups govern area per lipid and emergent elastic properties of bilayers. Biophys J 2022; 121:4205-4220. [PMID: 36088534 PMCID: PMC9674990 DOI: 10.1016/j.bpj.2022.09.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 08/10/2022] [Accepted: 09/06/2022] [Indexed: 11/24/2022] Open
Abstract
Phospholipid bilayers are liquid-crystalline materials whose intermolecular interactions at mesoscopic length scales have key roles in the emergence of membrane physical properties. Here we investigated the combined effects of phospholipid polar headgroups and acyl chains on biophysical functions of membranes with solid-state 2H NMR spectroscopy. We compared the structural and dynamic properties of phosphatidylethanolamine and phosphatidylcholine with perdeuterated acyl chains in the solid-ordered (so) and liquid-disordered (ld) phases. Our analysis of spectral lineshapes of 1,2-diperdeuteriopalmitoyl-sn-glycero-3-phosphoethanolamine (DPPE-d62) and 1,2-diperdeuteriopalmitoyl-sn-glycero-3-phosphocholine (DPPC-d62) in the so (gel) phase indicated an all-trans rotating chain structure for both lipids. Greater segmental order parameters (SCD) were observed in the ld (liquid-crystalline) phase for DPPE-d62 than for DPPC-d62 membranes, while their mixtures had intermediate values irrespective of the deuterated lipid type. Our results suggest the SCD profiles of the acyl chains are governed by methylation of the headgroups and are averaged over the entire system. Variations in the acyl chain molecular dynamics were further investigated by spin-lattice (R1Z) and quadrupolar-order relaxation (R1Q) measurements. The two acyl-perdeuterated lipids showed distinct differences in relaxation behavior as a function of the order parameter. The R1Z rates had a square-law dependence on SCD, implying collective mesoscopic dynamics, with a higher bending rigidity for DPPE-d62 than for DPPC-d62 lipids. Remodeling of lipid average and dynamic properties by methylation of the headgroups thus provides a mechanism to control the actions of peptides and proteins in biomembranes.
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Affiliation(s)
- Trivikram R Molugu
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona
| | | | - Todd M Alam
- Department of Organic Materials Science, Sandia National Laboratories, Albuquerque, New Mexico
| | - Theodore P Trouard
- Department of Biomedical Engineering, University of Arizona, Tucson, Arizona
| | - Michael F Brown
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona; Department of Physics, University of Arizona, Tucson, Arizona.
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17
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Dronadula MT, Aluru NR. Phospholipid Monolayer/Graphene Interfaces: Curvature Effect on Lipid Morphology and Dynamics. J Phys Chem B 2022; 126:6261-6270. [PMID: 35951540 DOI: 10.1021/acs.jpcb.2c00896] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Phospholipids are an important class of lipids that are widely used as model platforms for the study of biological processes and interactions. These lipids can form stable interfaces with solid substrates, such as graphene, and these interfaces have potential applications in biosensing and targeted drug delivery. In this paper, we perform molecular dynamics simulations of graphene-supported lipid monolayers to characterize the lipid properties of such interfaces. We observed substantial differences between the supported monolayer and free-standing bilayer in terms of the lipid properties, such as the tail order parameters, density profiles, diffusion rates, and so on. Furthermore, we studied these interfaces on sinusoidally deformed graphene substrates to understand the effect of curvature on the supported lipids. Here, we observed that the nature of the substrate curvature, that is, concave or convex, can locally affect the lipid/substrate adhesion strength and induce structural and dynamic changes in the adsorbed lipid monolayer. Together, these results help characterize the properties of lipid/graphene interfaces and provide insights into the substrate curvature effect on these interfaces, which can enable the tuning of lipid properties for various sensor devices and drug delivery applications.
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Affiliation(s)
- Mohan Teja Dronadula
- Oden Institute for Computational Engineering and Sciences, Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| | - N R Aluru
- Oden Institute for Computational Engineering and Sciences, Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
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18
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Krisanova N, Pozdnyakova N, Pastukhov A, Dudarenko M, Shatursky O, Gnatyuk O, Afonina U, Pyrshev K, Dovbeshko G, Yesylevskyy S, Borisova T. Amphiphilic anti-SARS-CoV-2 drug remdesivir incorporates into the lipid bilayer and nerve terminal membranes influencing excitatory and inhibitory neurotransmission. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2022; 1864:183945. [PMID: 35461828 PMCID: PMC9023372 DOI: 10.1016/j.bbamem.2022.183945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 04/03/2022] [Accepted: 04/17/2022] [Indexed: 12/05/2022]
Abstract
Remdesivir is a novel antiviral drug, which is active against the SARS-CoV-2 virus. Remdesivir is known to accumulate in the brain but it is not clear whether it influences the neurotransmission. Here we report diverse and pronounced effects of remdesivir on transportation and release of excitatory and inhibitory neurotransmitters in rat cortex nerve terminals (synaptosomes) in vitro. Direct incorporation of remdesivir molecules into the cellular membranes was shown by FTIR spectroscopy, planar phospholipid bilayer membranes and computational techniques. Remdesivir decreases depolarization-induced exocytotic release of L-[14C] glutamate and [3H] GABA, and also [3H] GABA uptake and extracellular level in synaptosomes in a dose-dependent manner. Fluorimetric studies confirmed remdesivir-induced impairment of exocytosis in nerve terminals and revealed a decrease in synaptic vesicle acidification. Our data suggest that remdesivir dosing during antiviral therapy should be precisely controlled to prevent possible neuromodulatory action at the presynaptic level. Further studies of neurotropic and membranotropic effects of remdesivir are necessary.
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Affiliation(s)
- Natalia Krisanova
- The Department of Neurochemistry, Palladin Institute of Biochemistry, NAS of Ukraine, 9 Leontovicha Str., Kyiv 01054, Ukraine
| | - Natalia Pozdnyakova
- The Department of Neurochemistry, Palladin Institute of Biochemistry, NAS of Ukraine, 9 Leontovicha Str., Kyiv 01054, Ukraine
| | - Artem Pastukhov
- The Department of Neurochemistry, Palladin Institute of Biochemistry, NAS of Ukraine, 9 Leontovicha Str., Kyiv 01054, Ukraine
| | - Marina Dudarenko
- The Department of Neurochemistry, Palladin Institute of Biochemistry, NAS of Ukraine, 9 Leontovicha Str., Kyiv 01054, Ukraine
| | - Oleg Shatursky
- The Department of Neurochemistry, Palladin Institute of Biochemistry, NAS of Ukraine, 9 Leontovicha Str., Kyiv 01054, Ukraine
| | - Olena Gnatyuk
- The Department of Physics of biological systems, Institute of Physics, NAS of Ukraine, 46 Nauky Ave., Kyiv 03680, Ukraine
| | - Uliana Afonina
- The Department of Physics of biological systems, Institute of Physics, NAS of Ukraine, 46 Nauky Ave., Kyiv 03680, Ukraine
| | - Kyrylo Pyrshev
- The Department of Neurochemistry, Palladin Institute of Biochemistry, NAS of Ukraine, 9 Leontovicha Str., Kyiv 01054, Ukraine
| | - Galina Dovbeshko
- The Department of Physics of biological systems, Institute of Physics, NAS of Ukraine, 46 Nauky Ave., Kyiv 03680, Ukraine
| | - Semen Yesylevskyy
- The Department of Physics of biological systems, Institute of Physics, NAS of Ukraine, 46 Nauky Ave., Kyiv 03680, Ukraine; Laboratoire Chrono Environnement UMR CNRS 6249, Université de Bourgogne Franche-Comté, 16 route de Gray, 25030 Besançon Cedex, France
| | - Tatiana Borisova
- The Department of Neurochemistry, Palladin Institute of Biochemistry, NAS of Ukraine, 9 Leontovicha Str., Kyiv 01054, Ukraine.
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19
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Larsen AH. Molecular Dynamics Simulations of Curved Lipid Membranes. Int J Mol Sci 2022; 23:8098. [PMID: 35897670 PMCID: PMC9331392 DOI: 10.3390/ijms23158098] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 07/19/2022] [Accepted: 07/20/2022] [Indexed: 02/04/2023] Open
Abstract
Eukaryotic cells contain membranes with various curvatures, from the near-plane plasma membrane to the highly curved membranes of organelles, vesicles, and membrane protrusions. These curvatures are generated and sustained by curvature-inducing proteins, peptides, and lipids, and describing these mechanisms is an important scientific challenge. In addition to that, some molecules can sense membrane curvature and thereby be trafficked to specific locations. The description of curvature sensing is another fundamental challenge. Curved lipid membranes and their interplay with membrane-associated proteins can be investigated with molecular dynamics (MD) simulations. Various methods for simulating curved membranes with MD are discussed here, including tools for setting up simulation of vesicles and methods for sustaining membrane curvature. The latter are divided into methods that exploit scaffolding virtual beads, methods that use curvature-inducing molecules, and methods applying virtual forces. The variety of simulation tools allow researcher to closely match the conditions of experimental studies of membrane curvatures.
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20
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Williams A, Zhan CG. Fast Prediction of Binding Affinities of SARS-CoV-2 Spike Protein and Its Mutants with Antibodies through Intermolecular Interaction Modeling-Based Machine Learning. J Phys Chem B 2022; 126:5194-5206. [PMID: 35817617 PMCID: PMC9301770 DOI: 10.1021/acs.jpcb.2c02123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 06/28/2022] [Indexed: 11/30/2022]
Abstract
Since the introduction of the novel SARS-CoV-2 virus (COVID-19) in late 2019, various new variants have appeared with mutations that confer resistance to the vaccines and monoclonal antibodies that were developed in response to the wild-type virus. As we continue through the pandemic, an accurate and efficient methodology is needed to help predict the effects certain mutations will have on both our currently produced therapeutics and those that are in development. Using published cryo-electron microscopy and X-ray crystallography structures of the spike receptor binding domain region with currently known antibodies, in the present study, we created and cross-validated an intermolecular interaction modeling-based multi-layer perceptron machine learning approach that can accurately predict the mutation-caused shifts in the binding affinity between the spike protein (wild-type or mutant) and various antibodies. This validated artificial intelligence (AI) model was used to predict the binding affinity (Kd) of reported SARS-CoV-2 antibodies with various variants of concern, including the most recently identified "Deltamicron" (or "Deltacron") variant. This AI model may be employed in the future to predict the Kd of developed novel antibody therapeutics to overcome the challenging antibody resistance issue and develop structural bases for the effects of both current and new mutants of the spike protein. In addition, the similar AI strategy and approach based on modeling of the intermolecular interactions may be useful in development of machine learning models predicting binding affinities for other protein-protein binding systems, including other antibodies binding with their antigens.
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Affiliation(s)
- Alexander
H. Williams
- Molecular
Modeling and Biopharmaceutical Center, University
of Kentucky, 789 South Limestone Street, Lexington, Kentucky 40536, United States
- Department
of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, Kentucky 40536, United States
| | - Chang-Guo Zhan
- Molecular
Modeling and Biopharmaceutical Center, University
of Kentucky, 789 South Limestone Street, Lexington, Kentucky 40536, United States
- Department
of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, Kentucky 40536, United States
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21
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Experimental Investigations on the Conductance of Lipid Membranes under Differential Hydrostatic Pressure. MEMBRANES 2022; 12:membranes12050479. [PMID: 35629805 PMCID: PMC9144669 DOI: 10.3390/membranes12050479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 04/22/2022] [Accepted: 04/27/2022] [Indexed: 02/05/2023]
Abstract
The unassisted transport of inorganic ions through lipid membranes has become increasingly relevant to an expansive range of biological phenomena. Recent simulations indicate a strong influence of a lipid membrane's curvature on its permeability, which may be part of the overall cell sensitivity to mechanical stimulation. However, most ionic permeability experiments employ a flat, uncurved lipid membrane, which disregards the physiological relevance of curvature on such investigations. To fill this gap in our knowledge, we adapted a traditional experimental system consisting of a planar lipid membrane, which we exposed to a controlled, differential hydrostatic pressure. Our electrophysiology experiments indicate a strong correlation between the changes in membrane geometry elicited by the application of pressure, as inferred from capacitance measurements, and the resulting conductance. Our experiments also confirmed the well-established influence of cholesterol addition to lipid membranes in adjusting their mechanical properties and overall permeability. Therefore, the proposed experimental system may prove useful for a better understanding of the intricate connections between membrane mechanics and adjustments of cellular functionalities upon mechanical stimulation, as well as for confirmation of predictions made by simulations and theoretical modeling.
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22
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Williams AH, Zhan CG. Generalized Methodology for the Quick Prediction of Variant SARS-CoV-2 Spike Protein Binding Affinities with Human Angiotensin-Converting Enzyme II. J Phys Chem B 2022; 126:2353-2360. [PMID: 35315274 PMCID: PMC8982491 DOI: 10.1021/acs.jpcb.1c10718] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 02/24/2022] [Indexed: 12/25/2022]
Abstract
Variants of the SARS-CoV-2 virus continue to remain a threat 2 years from the beginning of the pandemic. As more variants arise, and the B.1.1.529 (Omicron) variant threatens to create another wave of infections, a method is needed to predict the binding affinity of the spike protein quickly and accurately with human angiotensin-converting enzyme II (ACE2). We present an accurate and convenient energy minimization/molecular mechanics Poisson-Boltzmann surface area methodology previously used with engineered ACE2 therapeutics to predict the binding affinity of the Omicron variant. Without any additional data from the variants discovered after the publication of our first model, the methodology can accurately predict the binding of the spike/ACE2 variant complexes. From this methodology, we predicted that the Omicron variant spike has a Kd of ∼22.69 nM (which is very close to the experimental Kd of 20.63 nM published during the review process of the current report) and that spike protein of the new "Stealth" Omicron variant (BA.2) will display a Kd of ∼12.9 nM with the wild-type ACE2 protein. This methodology can be used with as-yet discovered variants, allowing for quick determinations regarding the variant's infectivity versus either the wild-type virus or its variants.
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Affiliation(s)
- Alexander H. Williams
- Molecular Modeling and Biopharmaceutical Center, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536
| | - Chang-Guo Zhan
- Molecular Modeling and Biopharmaceutical Center, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536
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23
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Nguyen HL, Man VH, Li MS, Derreumaux P, Wang J, Nguyen PH. Elastic moduli of normal and cancer cell membranes revealed by molecular dynamics simulations. Phys Chem Chem Phys 2022; 24:6225-6237. [PMID: 35229839 DOI: 10.1039/d1cp04836h] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Recent studies indicate that there are mechanical differences between normal cells and cancer cells. Because the cell membrane takes part in a variety of vital processes, we test the hypothesis of whether or not two fundamental alterations in the cell membrane, i.e., the overexpression of phosphatidylserine lipids in the outer leaflet and a reduction in cholesterol concentration, could cause the softening in cancer cells. Adopting ten models of normal and cancer cell membranes, we carry out 1 μs all-atom molecular dynamics simulations to compare the structural properties and elasticity properties of two membrane types. We find that the overexpression of the phosphatidylserine lipids in the outer leaflet does not significantly alter the area per lipid, the membrane thickness, the lipid order parameters and the elasticity moduli of the cancer membranes. However, a reduction in the cholesterol concentration leads to clear changes in those quantities, especially decreases in the bending, tilt and twist moduli. This implies that the reduction of cholesterol concentration in the cancer membranes could contribute to the softening of cancer cells.
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Affiliation(s)
- Hoang Linh Nguyen
- Institute for Computational Science and Technology, SBI Building, Quang Trung Software City, Tan Chanh Hiep Ward, District 12, Ho Chi Minh City, Vietnam
| | - Viet Hoang Man
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Mai Suan Li
- Institute for Computational Science and Technology, SBI Building, Quang Trung Software City, Tan Chanh Hiep Ward, District 12, Ho Chi Minh City, Vietnam.,Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw, Poland
| | - Philippe Derreumaux
- CNRS, Université de Paris, UPR9080, Laboratoire de Biochimie Théorique, Paris, France
| | - Junmei Wang
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Phuong H Nguyen
- CNRS, Université de Paris, UPR9080, Laboratoire de Biochimie Théorique, Paris, France.,Institut de Biologie Physico-Chimique, Fondation Edmond de Rothschild, PSL Research University, Paris, France.
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24
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Kayal C, Tamayo-Elizalde M, Adam C, Ye H, Jerusalem A. Voltage-Driven Alterations to Neuron Viscoelasticity. Bioelectricity 2022; 4:31-38. [PMID: 39372227 PMCID: PMC11450331 DOI: 10.1089/bioe.2021.0028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Background The consideration of neurons as coupled mechanical-electrophysiological systems is supported by a growing body of experimental evidence, including observations that cell membranes mechanically deform during the propagation of an action potential. However, the short-term (seconds to minutes) influence of membrane voltage on the mechanical properties of a neuron at the single-cell level remains unknown. Materials and Methods Here, we use microscale dynamic mechanical analysis to demonstrate that changes in membrane potential induce changes in the mechanical properties of individual neurons. We simultaneously measured the membrane potential and mechanical properties of individual neurons through a multiphysics single-cell setup. Membrane voltage of a single neuron was measured through whole-cell patch clamp. The mechanical properties of the same neuron were measured through a nanoindenter, which applied a dynamic indentation to the neuron at different frequencies. Results Neuronal storage and loss moduli were lower for positive voltages than negative voltages. Conclusion The observed effects of membrane voltage on neuron mechanics could be due to piezoelectric or flexoelectric effects and altered ion distributions under the applied voltage. Such effects could change cell mechanics by changing the intermolecular interactions between ions and the various biomolecules within the membrane and cytoskeleton.
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Affiliation(s)
- Celine Kayal
- Department of Engineering Science, University of Oxford, Oxford, United Kingdom
- Department of Engineering Science, Institute of Biomedical Engineering, University of Oxford, Oxford, United Kingdom
| | - Miren Tamayo-Elizalde
- Department of Engineering Science, University of Oxford, Oxford, United Kingdom
- Department of Engineering Science, Institute of Biomedical Engineering, University of Oxford, Oxford, United Kingdom
| | - Casey Adam
- Department of Engineering Science, University of Oxford, Oxford, United Kingdom
- Department of Engineering Science, Institute of Biomedical Engineering, University of Oxford, Oxford, United Kingdom
| | - Hua Ye
- Department of Engineering Science, University of Oxford, Oxford, United Kingdom
- Department of Engineering Science, Institute of Biomedical Engineering, University of Oxford, Oxford, United Kingdom
| | - Antoine Jerusalem
- Department of Engineering Science, University of Oxford, Oxford, United Kingdom
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25
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Coleman PS, Parlo RA. Cancer’s Camouflage — Microvesicle Shedding from Cholesterol-Rich Tumor Plasma Membranes Might Blindfold First-Responder Immunosurveillance Strategies. Eur J Cell Biol 2022; 101:151219. [DOI: 10.1016/j.ejcb.2022.151219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 03/14/2022] [Accepted: 03/20/2022] [Indexed: 11/03/2022] Open
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26
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Rituper B, Guček A, Lisjak M, Gorska U, Šakanović A, Bobnar ST, Lasič E, Božić M, Abbineni PS, Jorgačevski J, Kreft M, Verkhratsky A, Platt FM, Anderluh G, Stenovec M, Božič B, Coorssen JR, Zorec R. Vesicle cholesterol controls exocytotic fusion pore. Cell Calcium 2021; 101:102503. [PMID: 34844123 DOI: 10.1016/j.ceca.2021.102503] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 11/15/2021] [Accepted: 11/16/2021] [Indexed: 12/24/2022]
Abstract
In some lysosomal storage diseases (LSD) cholesterol accumulates in vesicles. Whether increased vesicle cholesterol affects vesicle fusion with the plasmalemma, where the fusion pore, a channel between the vesicle lumen and the extracellular space, is formed, is unknown. Super-resolution microscopy revealed that after stimulation of exocytosis, pituitary lactotroph vesicles discharge cholesterol which transfers to the plasmalemma. Cholesterol depletion in lactotrophs and astrocytes, both exhibiting Ca2+-dependent exocytosis regulated by distinct Ca2+sources, evokes vesicle secretion. Although this treatment enhanced cytosolic levels of Ca2+ in lactotrophs but decreased it in astrocytes, this indicates that cholesterol may well directly define the fusion pore. In an attempt to explain this mechanism, a new model of cholesterol-dependent fusion pore regulation is proposed. High-resolution membrane capacitance measurements, used to monitor fusion pore conductance, a parameter related to fusion pore diameter, confirm that at resting conditions reducing cholesterol increases, while enrichment with cholesterol decreases the conductance of the fusion pore. In resting fibroblasts, lacking the Npc1 protein, a cellular model of LSD in which cholesterol accumulates in vesicles, the fusion pore conductance is smaller than in controls, showing that vesicle cholesterol controls fusion pore and is relevant for pathophysiology of LSD.
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Affiliation(s)
- Boštjan Rituper
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, University of Ljubljana, Faculty of Medicine, Ljubljana, Slovenia
| | - Alenka Guček
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, University of Ljubljana, Faculty of Medicine, Ljubljana, Slovenia
| | - Marjeta Lisjak
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, University of Ljubljana, Faculty of Medicine, Ljubljana, Slovenia
| | - Urszula Gorska
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, University of Ljubljana, Faculty of Medicine, Ljubljana, Slovenia
| | - Aleksandra Šakanović
- Laboratory for Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Ljubljana, Slovenia
| | - Saša Trkov Bobnar
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, University of Ljubljana, Faculty of Medicine, Ljubljana, Slovenia; Celica Biomedical, 1000, Ljubljana, Slovenia
| | - Eva Lasič
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, University of Ljubljana, Faculty of Medicine, Ljubljana, Slovenia
| | - Mićo Božić
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, University of Ljubljana, Faculty of Medicine, Ljubljana, Slovenia
| | - Prabhodh S Abbineni
- Department of Pharmacology, University of Michigan, Ann Arbor, MI 48109-5632, United States of America
| | - Jernej Jorgačevski
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, University of Ljubljana, Faculty of Medicine, Ljubljana, Slovenia; Celica Biomedical, 1000, Ljubljana, Slovenia
| | - Marko Kreft
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, University of Ljubljana, Faculty of Medicine, Ljubljana, Slovenia; Celica Biomedical, 1000, Ljubljana, Slovenia
| | - Alexei Verkhratsky
- Celica Biomedical, 1000, Ljubljana, Slovenia; Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, M13 9PT, United Kingdom; Achucarro Center for Neuroscience, IKERBASQUE, 48011 Bilbao, Spain
| | - Frances M Platt
- Department of Pharmacology, University of Oxford, Oxford, OX1 3QT, United Kingdom
| | - Gregor Anderluh
- Laboratory for Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Ljubljana, Slovenia
| | - Matjaž Stenovec
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, University of Ljubljana, Faculty of Medicine, Ljubljana, Slovenia; Celica Biomedical, 1000, Ljubljana, Slovenia
| | - Bojan Božič
- Institute of Biophysics, Faculty of Medicine, University of Ljubljana, Slovenia
| | - Jens R Coorssen
- Department of Health Sciences, Faculty of Applied Health Sciences and Department of Biological Sciences, Faculty of Mathematics & Science, Brock University, St Catherine's, Ontario, Canada
| | - Robert Zorec
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, University of Ljubljana, Faculty of Medicine, Ljubljana, Slovenia; Celica Biomedical, 1000, Ljubljana, Slovenia.
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27
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Herrera-León C, Ramos-Martín F, Antonietti V, Sonnet P, D'Amelio N. The impact of phosphatidylserine exposure on cancer cell membranes on the activity of the anticancer peptide HB43. FEBS J 2021; 289:1984-2003. [PMID: 34767285 DOI: 10.1111/febs.16276] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 10/19/2021] [Accepted: 11/10/2021] [Indexed: 02/04/2023]
Abstract
HB43 (FAKLLAKLAKKLL) is a synthetic peptide active against cell lines derived from breast, colon, melanoma, lung, prostate, and cervical cancers. Despite its remarkable spectrum of activity, the mechanism of action at the molecular level has never been investigated, preventing further optimization of its selectivity. The alternation of charged and hydrophobic residues suggests amphipathicity, but the formation of alpha-helical structure seems discouraged by its short length and the large number of positively charged residues. Using different biophysical and in silico approaches we show that HB43 is completely unstructured in solution but assumes alpha-helical conformation in the presence of DPC micelles and liposomes exposing phosphatidylserine (PS) used as mimics of cancer cell membranes. Membrane permeabilization assays demonstrate that the interaction leads to the preferential destabilization of PS-containing vesicles with respect to PC-containing ones, here used as noncancerous cell mimics. ssNMR reveals that HB43 is able to fluidify the internal structure of cancer-cell mimicking liposomes while MD simulations show its internalization in such bilayers. This is achieved by the formation of specific interactions between the lysine side chains and the carboxylate group of phosphatidylserine and/or the phosphate oxygen atoms of targeted phospholipids, which could catalyze the formation of the alpha helix required for internalization. With the aim of better understanding the peptide biocompatibility and the additional antibacterial activity, the interaction with noncancerous cell mimicking liposomes exposing phosphatidylcholine (PC) and bacterial mimicking bilayers exposing phosphatidylglycerol (PG) is also described.
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Affiliation(s)
- Claudia Herrera-León
- Unité de Génie Enzymatique et Cellulaire, UMR 7025, CNRS, Université de Picardie Jules Verne, Amiens, France
| | - Francisco Ramos-Martín
- Unité de Génie Enzymatique et Cellulaire, UMR 7025, CNRS, Université de Picardie Jules Verne, Amiens, France
| | - Viviane Antonietti
- Agents Infectieux, Résistance et Chimiothérapie, UFR de Pharmacie, AGIR UR 4294, Université de Picardie Jules Verne, Amiens, France
| | - Pascal Sonnet
- Agents Infectieux, Résistance et Chimiothérapie, UFR de Pharmacie, AGIR UR 4294, Université de Picardie Jules Verne, Amiens, France
| | - Nicola D'Amelio
- Unité de Génie Enzymatique et Cellulaire, UMR 7025, CNRS, Université de Picardie Jules Verne, Amiens, France
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28
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Wilson KA, Wang L, O’Mara ML. Site of Cholesterol Oxidation Impacts Its Localization and Domain Formation in the Neuronal Plasma Membrane. ACS Chem Neurosci 2021; 12:3873-3884. [PMID: 34633798 DOI: 10.1021/acschemneuro.1c00395] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Cholesterol is integral to the structure of mammalian cell membranes. Oxidation of cholesterol alters how it behaves in the membrane and influences the membrane biophysical properties. Elevated levels of oxidized cholesterol are associated with neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, multiple sclerosis, and Huntington's disease. Previous work has investigated the impact of oxidized cholesterol in the context of simple model membrane systems. However, there is a growing body of literature that shows that complex membranes possessing physiological phospholipid distributions have different properties from those of binary or trinary model membranes. In the current work, the impact of oxidized cholesterol on the biophysical properties of a complex neuronal plasma membrane is investigated using coarse-grained Martini molecular dynamics simulations. Comparison of the native neuronal membrane to neuronal membranes containing 10% tail-oxidized or 10% head-oxidized cholesterol shows that the site of oxidization changes the behavior of the oxidized cholesterol in the membrane. Furthermore, species-specific domain formation is observed between each oxidized cholesterol and minor lipid classes. Although both tail-oxidized and head-oxidized cholesterols modulate the biophysical properties of the membrane, smaller changes are observed in the complex neuronal membrane than seen in the previous work on simple binary or trinary model membranes. This work highlights the presence of compensatory effects of lipid diversity in the complex neuronal membrane. Overall, this study improves our molecular-level understanding of the effects of oxidized cholesterol on the properties of neuronal tissue and emphasizes the importance of studying membranes with realistic lipid compositions.
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Affiliation(s)
- Katie A. Wilson
- Research School of Chemistry, College of Science, The Australian National University, Canberra, Australian Capital Territory 2601, Australia
| | - Lily Wang
- Research School of Chemistry, College of Science, The Australian National University, Canberra, Australian Capital Territory 2601, Australia
| | - Megan L. O’Mara
- Research School of Chemistry, College of Science, The Australian National University, Canberra, Australian Capital Territory 2601, Australia
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29
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Sahoo A, Matysiak S. Effects of applied surface-tension on membrane-assisted Aβ aggregation. Phys Chem Chem Phys 2021; 23:20627-20633. [PMID: 34514475 DOI: 10.1039/d1cp02642a] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Accumulation of protein-based (Aβ) aggregates on cellular membranes with varying structural properties is commonly recognized as the key step in Alzheimer's pathogenesis. But experimental and computational challenges have made this biophysical characterization difficult. In particular, studies connecting biological membrane organization and Aβ aggregation are limited. While experiments have suggested that an increased membrane curvature results in faster Aβ peptide aggregation in the context of Alzheimer's disease, a mechanistic explanation for this relation is missing. In this work, we are leveraging molecular simulations with a physics-based coarse grained model to address and understand the relationships between curved cellular membranes and aggregation of a model template peptide Aβ 16-22. In agreement with experimental results, our simulations also suggest a positive correlation between increased peptide aggregation and membrane curvature. More curved membranes have higher lipid packing defects that engage peptide hydrophobic groups and promote faster diffusion leading to peptide fibrillar structures. In addition, we curated the effects of peptide aggregation on the membrane's structure and organization. Interfacial peptide aggregation results in heterogeneous headgroup-peptide interactions and an induced crowding effect at the lipid headgroup region, leading to a more ordered headgroup region and disordered lipid-tails at the membrane core. This work presents a mechanistic and morphological overview of the relationships between the biomembrane local structure and organization, and Aβ peptide aggregation.
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Affiliation(s)
- Abhilash Sahoo
- Biophysics Program, Institute of Physical Science and Technology, University of Maryland, College Park, MD, USA
| | - Silvina Matysiak
- Biophysics Program, Institute of Physical Science and Technology, University of Maryland, College Park, MD, USA.,Fischell Department of Bioengineering, University of Maryland, College Park, MD, USA.
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30
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Loh D, Reiter RJ. Melatonin: Regulation of Biomolecular Condensates in Neurodegenerative Disorders. Antioxidants (Basel) 2021; 10:1483. [PMID: 34573116 PMCID: PMC8465482 DOI: 10.3390/antiox10091483] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 09/10/2021] [Accepted: 09/13/2021] [Indexed: 12/12/2022] Open
Abstract
Biomolecular condensates are membraneless organelles (MLOs) that form dynamic, chemically distinct subcellular compartments organizing macromolecules such as proteins, RNA, and DNA in unicellular prokaryotic bacteria and complex eukaryotic cells. Separated from surrounding environments, MLOs in the nucleoplasm, cytoplasm, and mitochondria assemble by liquid-liquid phase separation (LLPS) into transient, non-static, liquid-like droplets that regulate essential molecular functions. LLPS is primarily controlled by post-translational modifications (PTMs) that fine-tune the balance between attractive and repulsive charge states and/or binding motifs of proteins. Aberrant phase separation due to dysregulated membrane lipid rafts and/or PTMs, as well as the absence of adequate hydrotropic small molecules such as ATP, or the presence of specific RNA proteins can cause pathological protein aggregation in neurodegenerative disorders. Melatonin may exert a dominant influence over phase separation in biomolecular condensates by optimizing membrane and MLO interdependent reactions through stabilizing lipid raft domains, reducing line tension, and maintaining negative membrane curvature and fluidity. As a potent antioxidant, melatonin protects cardiolipin and other membrane lipids from peroxidation cascades, supporting protein trafficking, signaling, ion channel activities, and ATPase functionality during condensate coacervation or dissolution. Melatonin may even control condensate LLPS through PTM and balance mRNA- and RNA-binding protein composition by regulating N6-methyladenosine (m6A) modifications. There is currently a lack of pharmaceuticals targeting neurodegenerative disorders via the regulation of phase separation. The potential of melatonin in the modulation of biomolecular condensate in the attenuation of aberrant condensate aggregation in neurodegenerative disorders is discussed in this review.
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Affiliation(s)
- Doris Loh
- Independent Researcher, Marble Falls, TX 78654, USA
| | - Russel J. Reiter
- Department of Cellular and Structural Biology, UT Health Science Center, San Antonio, TX 78229, USA
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31
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Rogers JR, Espinoza Garcia G, Geissler PL. Membrane hydrophobicity determines the activation free energy of passive lipid transport. Biophys J 2021; 120:3718-3731. [PMID: 34302793 PMCID: PMC8456290 DOI: 10.1016/j.bpj.2021.07.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 07/07/2021] [Accepted: 07/19/2021] [Indexed: 12/16/2022] Open
Abstract
The collective behavior of lipids with diverse chemical and physical features determines a membrane's thermodynamic properties. Yet, the influence of lipid physicochemical properties on lipid dynamics, in particular interbilayer transport, remains underexplored. Here, we systematically investigate how the activation free energy of passive lipid transport depends on lipid chemistry and membrane phase. Through all-atom molecular dynamics simulations of 11 chemically distinct glycerophospholipids, we determine how lipid acyl chain length, unsaturation, and headgroup influence the free energy barriers for two elementary steps of lipid transport: lipid desorption, which is rate limiting, and lipid insertion into a membrane. Consistent with previous experimental measurements, we find that lipids with longer, saturated acyl chains have increased activation free energies compared to lipids with shorter, unsaturated chains. Lipids with different headgroups exhibit a range of activation free energies; however, no clear trend based solely on chemical structure can be identified, mirroring difficulties in the interpretation of previous experimental results. Compared to liquid-crystalline phase membranes, gel phase membranes exhibit substantially increased free energy barriers. Overall, we find that the activation free energy depends on a lipid's local hydrophobic environment in a membrane and that the free energy barrier for lipid insertion depends on a membrane's interfacial hydrophobicity. Both of these properties can be altered through changes in lipid acyl chain length, lipid headgroup, and membrane phase. Thus, the rate of lipid transport can be tuned through subtle changes in local membrane composition and order, suggesting an unappreciated role for nanoscale membrane domains in regulating cellular lipid dynamics.
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Affiliation(s)
- Julia R Rogers
- Department of Chemistry, University of California Berkeley, Berkeley, California.
| | | | - Phillip L Geissler
- Department of Chemistry, University of California Berkeley, Berkeley, California; Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California.
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32
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Almeida ER, Dos Santos HF, Capriles PVSZ. Carbon nanohorns as nanocontainers for cisplatin: insight into their interaction with the plasma membranes of normal and breast cancer cells. Phys Chem Chem Phys 2021; 23:16376-16389. [PMID: 34318822 DOI: 10.1039/d1cp02015c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Cisplatin (cddp)-based chemotherapy is one of the most effective therapeutic alternatives for breast cancer treatment, the most common form of cancer, despite the severe side effects related to the high toxicity and low selectivity of cddp. To circumvent these drawbacks, the encapsulation of cddp into oxidized carbon nanohorns (CNHoxs) has been shown as a promising formulation with biocompatibility and low toxicity. However, there is still a lack of studies regarding the behavior of this cddp@CNHox nanovector on the cell membranes. This study presents an in silico description of the interactions between cddp@CNHox and membrane models of cancer (C_memb) and normal (N_memb) cells referring to a typical human breast. The results revealed the interaction mechanism of the inclusion complex 3cddp@CNHox (three cddp molecules are included in the CNHox cavity) with these biomembranes, which is a multistep process including approach, landing, insertion, and penetration. The 3cddp@CNHox stability was monitored over time, and demonstrated the trapping of cddp molecules inside the CNHox cavity over all simulations. The van der Waals contribution played a primary role (∼74%) for the complex stability. Moreover, the binding free energy calculations indicated that the interaction of the 3cddp@CNHox complex with the C_memb model was slightly more favorable, on average, than with the N_memb model. Analysis of the hydrogen bonds (HBs) formed over simulations of 800 ns explains the selectivity for the C_memb model, since the total number of HBs established between the inclusion complex and the C_memb model was about three times greater than that with the N_memb model. By reinforcing the potentiality of oxidized CNHox as a nanovector of cddp, the results presented in this study may assist and drive new experimental studies with this nanomaterial, focusing on the development of less aggressive formulations for breast cancer treatment.
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Affiliation(s)
- Eduardo R Almeida
- Núcleo de Estudos em Química Computacional (NEQC), Departamento de Química, Instituto de Ciências Exatas, Universidade Federal de Juiz de Fora (UFJF), Campus Universitário, Martelos, Juiz de Fora, MG 36036-330, Brazil.
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33
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Stroh KS, Risselada HJ. Quantifying Membrane Curvature Sensing of Peripheral Proteins by Simulated Buckling and Umbrella Sampling. J Chem Theory Comput 2021; 17:5276-5286. [PMID: 34261315 DOI: 10.1021/acs.jctc.1c00021] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Membrane curvature plays an essential role in the organization and trafficking of membrane associated proteins. Comparison or prediction of the experimentally resolved protein concentrations adopted at different membrane curvatures requires direct quantification of the relative partitioning free energy. Here, we present a highly efficient and simple to implement a free-energy calculation method which is able to directly resolve the relative partitioning free energy of proteins as a direct function of membrane curvature, i.e., a curvature sensing profile, within (coarse-grained) molecular dynamics simulations. We demonstrate its utility by resolving these profiles for two known curvature sensing peptides, namely ALPS and α-synuclein, for a membrane curvature ranging from -1/6.5 to +1/6.5 nm-1. We illustrate that the difference in relative partitioning (binding) free energy between these two extrema is only about 13 kBT for both peptides, illustrating that the driving force of curvature sensing is subtle. Furthermore, we illustrate that ALPS and α-synuclein sense curvature via a contrasting mechanism, which is differentially affected by membrane composition. In addition, we demonstrate that the intrinsic spontaneous curvature of both of these peptides lies beyond the range of membrane curvature accessible in micropipette aspiration experiments, being about 1/7 nm -1. Our approach offers an efficient and simple to implement in silico tool for exploring and screening the membrane curvature sensing mechanisms of proteins.
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Affiliation(s)
- Kai Steffen Stroh
- Institute for Theoretical Physics, Georg-August University Göttingen, Göttingen, Germany
| | - Herre Jelger Risselada
- Institute for Theoretical Physics, Georg-August University Göttingen, Göttingen, Germany.,Leiden Institute of Chemistry, Leiden University, Leiden, The Netherlands.,Leibniz Institute for Surface Engineering, Leipzig, Germany
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34
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Navikas V, Leitao SM, Grussmayer KS, Descloux A, Drake B, Yserentant K, Werther P, Herten DP, Wombacher R, Radenovic A, Fantner GE. Correlative 3D microscopy of single cells using super-resolution and scanning ion-conductance microscopy. Nat Commun 2021; 12:4565. [PMID: 34315910 PMCID: PMC8316521 DOI: 10.1038/s41467-021-24901-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Accepted: 07/14/2021] [Indexed: 02/07/2023] Open
Abstract
High-resolution live-cell imaging is necessary to study complex biological phenomena. Modern fluorescence microscopy methods are increasingly combined with complementary, label-free techniques to put the fluorescence information into the cellular context. The most common high-resolution imaging approaches used in combination with fluorescence imaging are electron microscopy and atomic-force microscopy (AFM), originally developed for solid-state material characterization. AFM routinely resolves atomic steps, however on soft biological samples, the forces between the tip and the sample deform the fragile membrane, thereby distorting the otherwise high axial resolution of the technique. Here we present scanning ion-conductance microscopy (SICM) as an alternative approach for topographical imaging of soft biological samples, preserving high axial resolution on cells. SICM is complemented with live-cell compatible super-resolution optical fluctuation imaging (SOFI). To demonstrate the capabilities of our method we show correlative 3D cellular maps with SOFI implementation in both 2D and 3D with self-blinking dyes for two-color high-order SOFI imaging. Finally, we employ correlative SICM/SOFI microscopy for visualizing actin dynamics in live COS-7 cells with subdiffraction-resolution.
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Affiliation(s)
- Vytautas Navikas
- Laboratory of Nanoscale Biology, Institute of Bioengineering, School of Engineering, Swiss Federal InstSIitute of Technology Lausanne (EPFL), Lausanne, Switzerland
| | - Samuel M Leitao
- Laboratory for Bio- and Nano-Instrumentation, Institute of Bioengineering, School of Engineering, Swiss Federal Institute of Technology Lausanne (EPFL), Lausanne, Switzerland
| | - Kristin S Grussmayer
- Laboratory of Nanoscale Biology, Institute of Bioengineering, School of Engineering, Swiss Federal InstSIitute of Technology Lausanne (EPFL), Lausanne, Switzerland
- Grussmayer Lab, Department of Bionanoscience, Faculty of Applied Science and Kavli Institute for Nanoscience Delft, Delft University of Technology, Delft, Netherlands
| | - Adrien Descloux
- Laboratory of Nanoscale Biology, Institute of Bioengineering, School of Engineering, Swiss Federal InstSIitute of Technology Lausanne (EPFL), Lausanne, Switzerland
| | - Barney Drake
- Laboratory for Bio- and Nano-Instrumentation, Institute of Bioengineering, School of Engineering, Swiss Federal Institute of Technology Lausanne (EPFL), Lausanne, Switzerland
| | - Klaus Yserentant
- College of Medical and Dental Sciences, Medical School & School of Chemistry, University of Birmingham, Birmingham, United Kingdom
| | - Philipp Werther
- Institute of Pharmacy and Molecular Biotechnology, Heidelberg University, Heidelberg, Germany
| | - Dirk-Peter Herten
- College of Medical and Dental Sciences, Medical School & School of Chemistry, University of Birmingham, Birmingham, United Kingdom
| | - Richard Wombacher
- Institute of Pharmacy and Molecular Biotechnology, Heidelberg University, Heidelberg, Germany
- Department of Chemical Biology, Max Planck Institute for Medical Research, Heidelberg, Germany
| | - Aleksandra Radenovic
- Laboratory of Nanoscale Biology, Institute of Bioengineering, School of Engineering, Swiss Federal InstSIitute of Technology Lausanne (EPFL), Lausanne, Switzerland.
| | - Georg E Fantner
- Laboratory for Bio- and Nano-Instrumentation, Institute of Bioengineering, School of Engineering, Swiss Federal Institute of Technology Lausanne (EPFL), Lausanne, Switzerland.
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35
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Wilson KA, Fairweather SJ, MacDermott-Opeskin HI, Wang L, Morris RA, O'Mara ML. The role of plasmalogens, Forssman lipids, and sphingolipid hydroxylation in modulating the biophysical properties of the epithelial plasma membrane. J Chem Phys 2021; 154:095101. [PMID: 33685172 DOI: 10.1063/5.0040887] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
A coarse-grain model of the epithelial plasma membrane was developed from high-resolution lipidomic data and simulated using the MARTINI force field to characterize its biophysical properties. Plasmalogen lipids, Forssman glycosphingolipids, and hydroxylated Forssman glycosphingolipids and sphingomyelin were systematically added to determine their structural effects. Plasmalogen lipids have a minimal effect on the overall biophysical properties of the epithelial plasma membrane. In line with the hypothesized role of Forssman lipids in the epithelial apical membrane, the introduction of Forssman lipids initiates the formation of glycosphingolipid-rich nanoscale lipid domains, which also include phosphatidylethanolamine (PE), sphingomyelin (SM), and cholesterol (CHOL). This decreases the lateral diffusion in the extracellular leaflet, as well as the area per lipid of domain forming lipids, most notably PE. Finally, hydroxylation of the Forssman glycosphingolipids and sphingomyelin further modulates the lateral organization of the membrane. Through comparison to the previously studied average and neuronal plasma membranes, the impact of membrane lipid composition on membrane properties was characterized. Overall, this study furthers our understanding of the biophysical properties of complex membranes and the impact of lipid diversity in modulating membrane properties.
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Affiliation(s)
- Katie A Wilson
- Research School of Chemistry, College of Science, The Australian National University, Canberra, ACT 2601, Australia
| | - Stephen J Fairweather
- Research School of Chemistry, College of Science, The Australian National University, Canberra, ACT 2601, Australia
| | - Hugo I MacDermott-Opeskin
- Research School of Chemistry, College of Science, The Australian National University, Canberra, ACT 2601, Australia
| | - Lily Wang
- Research School of Chemistry, College of Science, The Australian National University, Canberra, ACT 2601, Australia
| | - Richard A Morris
- Research School of Chemistry, College of Science, The Australian National University, Canberra, ACT 2601, Australia
| | - Megan L O'Mara
- Research School of Chemistry, College of Science, The Australian National University, Canberra, ACT 2601, Australia
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36
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Williams AH, Zhan CG. Fast Prediction of Binding Affinities of the SARS-CoV-2 Spike Protein Mutant N501Y (UK Variant) with ACE2 and Miniprotein Drug Candidates. J Phys Chem B 2021; 125:4330-4336. [PMID: 33881861 PMCID: PMC8084269 DOI: 10.1021/acs.jpcb.1c00869] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Revised: 03/30/2021] [Indexed: 12/28/2022]
Abstract
A recently identified variant of SARS-CoV-2 virus, known as the United Kingdom (UK) variant (lineage B.1.1.7), has an N501Y mutation on its spike protein. SARS-CoV-2 spike protein binds with angiotensin-converting enzyme 2 (ACE2), a key protein for the viral entry into the host cells. Here, we report an efficient computational approach, including the simple energy minimizations and binding free energy calculations, starting from an experimental structure of the binding complex along with experimental calibration of the calculated binding free energies, to rapidly and reliably predict the binding affinities of the N501Y mutant with human ACE2 (hACE2) and recently reported miniprotein and hACE2 decoy (CTC-445.2) drug candidates. It has been demonstrated that the N501Y mutation markedly increases the ACE2-spike protein binding affinity (Kd) from 22 to 0.44 nM, which could partially explain why the UK variant is more infectious. The miniproteins are predicted to have ∼10,000- to 100,000-fold diminished binding affinities with the N501Y mutant, creating a need for design of novel therapeutic candidates to overcome the N501Y mutation-induced drug resistance. The N501Y mutation is also predicted to decrease the binding affinity of a hACE2 decoy (CTC-445.2) binding with the spike protein by ∼200-fold. This convenient computational approach along with experimental calibration may be similarly used in the future to predict the binding affinities of potential new variants of the spike protein.
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Affiliation(s)
- Alexander H. Williams
- Molecular Modeling and Biopharmaceutical Center, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536
| | - Chang-Guo Zhan
- Molecular Modeling and Biopharmaceutical Center, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536
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37
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Annaval T, Ramos-Martín F, Herrera-León C, Adélaïde M, Antonietti V, Buchoux S, Sonnet P, Sarazin C, D'Amelio N. Antimicrobial Bombinin-like Peptide 3 Selectively Recognizes and Inserts into Bacterial Biomimetic Bilayers in Multiple Steps. J Med Chem 2021; 64:5185-5197. [PMID: 33851832 DOI: 10.1021/acs.jmedchem.1c00310] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Bombinins are a wide family of antimicrobial peptides from Xenopus skin. By sequence clustering, we highlighted at least three families named A, B, and H, which might exert antibacterial activity by different modes of action. In this work, we study bombinin-like peptide 3 (BLP-3) as a nonhemolytic representative of the quite unexplored class A due to its appealing activity toward WHO-priority-list bacteria such as Neisseria, Pseudomonas aeruginosa, and Staphylococcus aureus. A marked preference for cardiolipin and phosphatidylglycerol head groups, typically found in bacteria, is proven with biomimetic membranes studied by liquid and solid NMR and MD simulations. BLP-3 gets structured upon interaction and penetrates deeply into the bilayer in two steps involving a superficial insertion of key side chains and subsequent internalization. All along the pathway, a fundamental role is played by lysine residues in the conserved region 11-19, which act in synergy with other key residues.
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Affiliation(s)
- Thibault Annaval
- Unité de Génie Enzymatique et Cellulaire UMR 7025 CNRS, Université de Picardie Jules Verne, Amiens 80039, France.,Institut de Biologie Structurale, UMR 5075, Université Grenoble Alpes, CNRS, CEA, Grenoble 38000, France
| | - Francisco Ramos-Martín
- Unité de Génie Enzymatique et Cellulaire UMR 7025 CNRS, Université de Picardie Jules Verne, Amiens 80039, France
| | - Claudia Herrera-León
- Unité de Génie Enzymatique et Cellulaire UMR 7025 CNRS, Université de Picardie Jules Verne, Amiens 80039, France
| | - Morgane Adélaïde
- Unité de Génie Enzymatique et Cellulaire UMR 7025 CNRS, Université de Picardie Jules Verne, Amiens 80039, France
| | - Viviane Antonietti
- Agents Infectieux, Résistance et Chimiothérapie, AGIR UR 4294, Université de Picardie Jules Verne, UFR de Pharmacie, Amiens 80037, France
| | - Sébastien Buchoux
- Unité de Génie Enzymatique et Cellulaire UMR 7025 CNRS, Université de Picardie Jules Verne, Amiens 80039, France
| | - Pascal Sonnet
- Agents Infectieux, Résistance et Chimiothérapie, AGIR UR 4294, Université de Picardie Jules Verne, UFR de Pharmacie, Amiens 80037, France
| | - Catherine Sarazin
- Unité de Génie Enzymatique et Cellulaire UMR 7025 CNRS, Université de Picardie Jules Verne, Amiens 80039, France
| | - Nicola D'Amelio
- Unité de Génie Enzymatique et Cellulaire UMR 7025 CNRS, Université de Picardie Jules Verne, Amiens 80039, France
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38
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Yesylevskyy S, Khandelia H. EnCurv: Simple Technique of Maintaining Global Membrane Curvature in Molecular Dynamics Simulations. J Chem Theory Comput 2021; 17:1181-1193. [DOI: 10.1021/acs.jctc.0c00800] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Semen Yesylevskyy
- Department of Physics of Biological Systems, Institute of Physics of the National Academy of Sciences of Ukraine, Prospect Nauky 46, 03028 Kyiv, Ukraine
- Laboratoire Chrono Environnement UMR CNRS 6249, Université de Bourgogne Franche-Comté, 16 route de Gray, 25030 Besançon Cedex, France
| | - Himanshu Khandelia
- PHYLIFE: Physical Life Science, Department of Physics Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, Odense 5230 M, Denmark
- MEMPHYS: Center for Biomembrane Physics,
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39
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Ramos-Martín F, D’Amelio N. Molecular Basis of the Anticancer and Antibacterial Properties of CecropinXJ Peptide: An In Silico Study. Int J Mol Sci 2021; 22:E691. [PMID: 33445613 PMCID: PMC7826669 DOI: 10.3390/ijms22020691] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 01/06/2021] [Accepted: 01/07/2021] [Indexed: 02/04/2023] Open
Abstract
Esophageal cancer is an aggressive lethal malignancy causing thousands of deaths every year. While current treatments have poor outcomes, cecropinXJ (CXJ) is one of the very few peptides with demonstrated in vivo activity. The great interest in CXJ stems from its low toxicity and additional activity against most ESKAPE bacteria and fungi. Here, we present the first study of its mechanism of action based on molecular dynamics (MD) simulations and sequence-property alignment. Although unstructured in solution, predictions highlight the presence of two helices separated by a flexible hinge containing P24 and stabilized by the interaction of W2 with target biomembranes: an amphipathic helix-I and a poorly structured helix-II. Both MD and sequence-property alignment point to the important role of helix I in both the activity and the interaction with biomembranes. MD reveals that CXJ interacts mainly with phosphatidylserine (PS) but also with phosphatidylethanolamine (PE) headgroups, both found in the outer leaflet of cancer cells, while salt bridges with phosphate moieties are prevalent in bacterial biomimetic membranes composed of PE, phosphatidylglycerol (PG) and cardiolipin (CL). The antibacterial activity of CXJ might also explain its interaction with mitochondria, whose phospholipid composition recalls that of bacteria and its capability to induce apoptosis in cancer cells.
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Affiliation(s)
- Francisco Ramos-Martín
- Unité de Génie Enzymatique et Cellulaire UMR 7025 CNRS, Université de Picardie Jules Verne, 80039 Amiens, France
| | - Nicola D’Amelio
- Unité de Génie Enzymatique et Cellulaire UMR 7025 CNRS, Université de Picardie Jules Verne, 80039 Amiens, France
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40
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Ramos-Martín F, Herrera-León C, Antonietti V, Sonnet P, Sarazin C, D’Amelio N. Antimicrobial Peptide K11 Selectively Recognizes Bacterial Biomimetic Membranes and Acts by Twisting Their Bilayers. Pharmaceuticals (Basel) 2020; 14:1. [PMID: 33374932 PMCID: PMC7821925 DOI: 10.3390/ph14010001] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 12/14/2020] [Accepted: 12/19/2020] [Indexed: 12/14/2022] Open
Abstract
K11 is a synthetic peptide originating from the introduction of a lysine residue in position 11 within the sequence of a rationally designed antibacterial scaffold. Despite its remarkable antibacterial properties towards many ESKAPE bacteria and its optimal therapeutic index (320), a detailed description of its mechanism of action is missing. As most antimicrobial peptides act by destabilizing the membranes of the target organisms, we investigated the interaction of K11 with biomimetic membranes of various phospholipid compositions by liquid and solid-state NMR. Our data show that K11 can selectively destabilize bacterial biomimetic membranes and torque the surface of their bilayers. The same is observed for membranes containing other negatively charged phospholipids which might suggest additional biological activities. Molecular dynamic simulations reveal that K11 can penetrate the membrane in four steps: after binding to phosphate groups by means of the lysine residue at the N-terminus (anchoring), three couples of lysine residues act subsequently to exert a torque in the membrane (twisting) which allows the insertion of aromatic side chains at both termini (insertion) eventually leading to the flip of the amphipathic helix inside the bilayer core (helix flip and internalization).
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Affiliation(s)
- Francisco Ramos-Martín
- Unité de Génie Enzymatique et Cellulaire UMR 7025 CNRS, Université de Picardie Jules Verne, 80039 Amiens, France; (C.H.-L.); (C.S.)
| | - Claudia Herrera-León
- Unité de Génie Enzymatique et Cellulaire UMR 7025 CNRS, Université de Picardie Jules Verne, 80039 Amiens, France; (C.H.-L.); (C.S.)
| | - Viviane Antonietti
- Agents Infectieux, Résistance et Chimiothérapie, AGIR UR 4294, Université de Picardie Jules Verne, UFR de Pharmacie, 80037 Amiens, France; (V.A.); (P.S.)
| | - Pascal Sonnet
- Agents Infectieux, Résistance et Chimiothérapie, AGIR UR 4294, Université de Picardie Jules Verne, UFR de Pharmacie, 80037 Amiens, France; (V.A.); (P.S.)
| | - Catherine Sarazin
- Unité de Génie Enzymatique et Cellulaire UMR 7025 CNRS, Université de Picardie Jules Verne, 80039 Amiens, France; (C.H.-L.); (C.S.)
| | - Nicola D’Amelio
- Unité de Génie Enzymatique et Cellulaire UMR 7025 CNRS, Université de Picardie Jules Verne, 80039 Amiens, France; (C.H.-L.); (C.S.)
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41
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Ingólfsson HI, Bhatia H, Zeppelin T, Bennett WFD, Carpenter KA, Hsu PC, Dharuman G, Bremer PT, Schiøtt B, Lightstone FC, Carpenter TS. Capturing Biologically Complex Tissue-Specific Membranes at Different Levels of Compositional Complexity. J Phys Chem B 2020; 124:7819-7829. [PMID: 32790367 PMCID: PMC7553384 DOI: 10.1021/acs.jpcb.0c03368] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
Plasma membranes
(PMs) contain hundreds of different lipid species
that contribute differently to overall bilayer properties. By modulation
of these properties, membrane protein function can be affected. Furthermore,
inhomogeneous lipid mixing and domains of lipid enrichment/depletion
can sort proteins and provide optimal local environments. Recent coarse-grained
(CG) Martini molecular dynamics efforts have provided glimpses into
lipid organization of different PMs: an “Average” and
a “Brain” PM. Their high complexity and large size require
long simulations (∼80 μs) for proper sampling. Thus,
these simulations are computationally taxing. This level of complexity
is beyond the possibilities of all-atom simulations, raising the question—what
complexity is needed for “realistic” bilayer properties?
We constructed CG Martini PM models of varying complexity (63 down
to 8 different lipids). Lipid tail saturations and headgroup combinations
were kept as consistent as possible for the “tissues’”
(Average/Brain) at three levels of compositional complexity. For each
system, we analyzed membrane properties to evaluate which features
can be retained at lower complexity and validate eight-component bilayers
that can act as reliable mimetics for Average or Brain PMs. Systems
of reduced complexity deliver a more robust and malleable tool for
computational membrane studies and allow for equivalent all-atom simulations
and experiments.
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Affiliation(s)
- Helgi I Ingólfsson
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, United States
| | - Harsh Bhatia
- Center for Applied Scientific Computing, Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, United States
| | - Talia Zeppelin
- Department of Chemistry and the Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Langelandsgade 140, 8000 Aarhus, Denmark
| | - W F Drew Bennett
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, United States
| | - Kristy A Carpenter
- Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Pin-Chia Hsu
- Department of Chemistry and the Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Langelandsgade 140, 8000 Aarhus, Denmark
| | - Gautham Dharuman
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, United States
| | - Peer-Timo Bremer
- Center for Applied Scientific Computing, Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, United States.,Center for Extreme Data Management Analysis and Visualization (CEDMAV) Institute, University of Utah, 72 South Central Campus Drive, Salt Lake City, Utah 84112, United States
| | - Birgit Schiøtt
- Department of Chemistry and the Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Langelandsgade 140, 8000 Aarhus, Denmark
| | - Felice C Lightstone
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, United States
| | - Timothy S Carpenter
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, United States
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42
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Yvan-Charvet L, Bonacina F, Guinamard RR, Norata GD. Immunometabolic function of cholesterol in cardiovascular disease and beyond. Cardiovasc Res 2020; 115:1393-1407. [PMID: 31095280 DOI: 10.1093/cvr/cvz127] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Revised: 03/20/2019] [Accepted: 05/07/2019] [Indexed: 12/16/2022] Open
Abstract
Inflammation represents the driving feature of many diseases, including atherosclerosis, cancer, autoimmunity and infections. It is now established that metabolic processes shape a proper immune response and within this context the alteration in cellular cholesterol homeostasis has emerged as a culprit of many metabolic abnormalities observed in chronic inflammatory diseases. Cholesterol accumulation supports the inflammatory response of myeloid cells (i.e. augmentation of toll-like receptor signalling, inflammasome activation, and production of monocytes and neutrophils) which is beneficial in the response to infections, but worsens diseases associated with chronic metabolic inflammation including atherosclerosis. In addition to the innate immune system, cells of adaptive immunity, upon activation, have also been shown to undergo a reprogramming of cellular cholesterol metabolism, which results in the amplification of inflammatory responses. Aim of this review is to discuss (i) the molecular mechanisms linking cellular cholesterol metabolism to specific immune functions; (ii) how cellular cholesterol accumulation sustains chronic inflammatory diseases such as atherosclerosis; (iii) the immunometabolic profile of patients with defects of genes affecting cholesterol metabolism including familial hypercholesterolaemia, cholesteryl ester storage disease, Niemann-Pick type C, and immunoglobulin D syndrome/mevalonate kinase deficiency. Available data indicate that cholesterol immunometabolism plays a key role in directing immune cells function and set the stage for investigating the repurposing of existing 'metabolic' drugs to modulate the immune response.
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Affiliation(s)
- Laurent Yvan-Charvet
- Institut National de la Santé et de la Recherche Médicale (Inserm) U1065, Université Côte d'Azur, Centre Méditerranéen de Médecine Moléculaire (C3M), Fédération Hospitalo-Universitaire (FHU) Oncoage, Nice, France
| | - Fabrizia Bonacina
- Department of Excellence of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milan, Italy
| | - Rodolphe Renè Guinamard
- Institut National de la Santé et de la Recherche Médicale (Inserm) U1065, Université Côte d'Azur, Centre Méditerranéen de Médecine Moléculaire (C3M), Fédération Hospitalo-Universitaire (FHU) Oncoage, Nice, France
| | - Giuseppe Danilo Norata
- Institut National de la Santé et de la Recherche Médicale (Inserm) U1065, Université Côte d'Azur, Centre Méditerranéen de Médecine Moléculaire (C3M), Fédération Hospitalo-Universitaire (FHU) Oncoage, Nice, France.,Center for the Study of Atherosclerosis, E. Bassini Hospital, Cinisello Balsamo, Milan, Italy
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43
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Pezeshkian W, König M, Wassenaar TA, Marrink SJ. Backmapping triangulated surfaces to coarse-grained membrane models. Nat Commun 2020; 11:2296. [PMID: 32385270 PMCID: PMC7210967 DOI: 10.1038/s41467-020-16094-y] [Citation(s) in RCA: 75] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 04/07/2020] [Indexed: 12/14/2022] Open
Abstract
Many biological processes involve large-scale changes in membrane shape. Computer simulations of these processes are challenging since they occur across a wide range of spatiotemporal scales that cannot be investigated in full by any single current simulation technique. A potential solution is to combine different levels of resolution through a multiscale scheme. Here, we present a multiscale algorithm that backmaps a continuum membrane model represented as a dynamically triangulated surface (DTS) to its corresponding molecular model based on the coarse-grained (CG) Martini force field. Thus, we can use DTS simulations to equilibrate slow large-scale membrane conformational changes and then explore the local properties at CG resolution. We demonstrate the power of our method by backmapping a vesicular bud induced by binding of Shiga toxin and by transforming the membranes of an entire mitochondrion to near-atomic resolution. Our approach opens the way to whole cell simulations at molecular detail. Computer simulations of large-scale changes in membrane shape are challenging since they occur across a wide range of spatiotemporal scales. Here, authors present a multiscale algorithm that backmaps a continuum membrane model represented as a dynamically triangulated surface to its corresponding molecular model based on the coarse-grained Martini force field.
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Affiliation(s)
- Weria Pezeshkian
- Groningen Biomolecular Sciences and Biotechnology Institute and Zernike Institute for Advanced Materials, University of Groningen, Groningen, Netherlands.
| | - Melanie König
- Groningen Biomolecular Sciences and Biotechnology Institute and Zernike Institute for Advanced Materials, University of Groningen, Groningen, Netherlands
| | - Tsjerk A Wassenaar
- Groningen Biomolecular Sciences and Biotechnology Institute and Zernike Institute for Advanced Materials, University of Groningen, Groningen, Netherlands
| | - Siewert J Marrink
- Groningen Biomolecular Sciences and Biotechnology Institute and Zernike Institute for Advanced Materials, University of Groningen, Groningen, Netherlands.
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44
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Vandera KKA, Picconi P, Valero M, González-Gaitano G, Woods A, Zain NMM, Bruce KD, Clifton LA, Skoda MWA, Rahman KM, Harvey RD, Dreiss CA. Antibiotic-in-Cyclodextrin-in-Liposomes: Formulation Development and Interactions with Model Bacterial Membranes. Mol Pharm 2020; 17:2354-2369. [DOI: 10.1021/acs.molpharmaceut.0c00096] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Kalliopi-Kelli A. Vandera
- School of Cancer & Pharmaceutical Science, Institute of Pharmaceutical Science, King’s College London, Franklin-Wilkins Building, 150 Stamford Street, London SE1 9NH, U.K
| | - Pietro Picconi
- School of Cancer & Pharmaceutical Science, Institute of Pharmaceutical Science, King’s College London, Franklin-Wilkins Building, 150 Stamford Street, London SE1 9NH, U.K
| | - Margarita Valero
- Department of Physical Chemistry, University of Salamanca, ES E-37007 Salamanca, Spain
| | | | - Arcadia Woods
- School of Cancer & Pharmaceutical Science, Institute of Pharmaceutical Science, King’s College London, Franklin-Wilkins Building, 150 Stamford Street, London SE1 9NH, U.K
| | - Nur Masirah M. Zain
- School of Cancer & Pharmaceutical Science, Institute of Pharmaceutical Science, King’s College London, Franklin-Wilkins Building, 150 Stamford Street, London SE1 9NH, U.K
| | - Kenneth D. Bruce
- School of Cancer & Pharmaceutical Science, Institute of Pharmaceutical Science, King’s College London, Franklin-Wilkins Building, 150 Stamford Street, London SE1 9NH, U.K
| | - Luke A. Clifton
- Rutherford Appleton Laboratory, ISIS, 1-27, R3, Harwell Campus, Didcot OX11 0QX, U.K
| | | | - Khondaker Miraz Rahman
- School of Cancer & Pharmaceutical Science, Institute of Pharmaceutical Science, King’s College London, Franklin-Wilkins Building, 150 Stamford Street, London SE1 9NH, U.K
| | - Richard D. Harvey
- Department of Pharmaceutical Chemistry, University of Vienna, Althanstraße 14, Vienna, Austria
| | - Cécile A. Dreiss
- School of Cancer & Pharmaceutical Science, Institute of Pharmaceutical Science, King’s College London, Franklin-Wilkins Building, 150 Stamford Street, London SE1 9NH, U.K
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45
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Kim J, Lee J, Jang J, Ye F, Hong SJ, Petrich BG, Ulmer TS, Kim C. Topological Adaptation of Transmembrane Domains to the Force-Modulated Lipid Bilayer Is a Basis of Sensing Mechanical Force. Curr Biol 2020; 30:1614-1625.e5. [PMID: 32169208 DOI: 10.1016/j.cub.2020.02.028] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 01/23/2020] [Accepted: 02/12/2020] [Indexed: 12/27/2022]
Abstract
Cells can sense and respond to various mechanical stimuli from their surrounding environment. One of the explanations for mechanosensitivity, a lipid-bilayer model, suggests that a stretch of the membrane induced by mechanical force alters the physical state of the lipid bilayer, driving mechanosensors to assume conformations better matched to the altered membrane. However, mechanosensors of this class are restricted to ion channels. Here, we reveal that integrin αIIbβ3, a prototypic adhesion receptor, can be activated by various mechanical stimuli including stretch, shear stress, and osmotic pressure. The force-induced integrin activation was not dependent on its known intracellular activation signaling events and was even observed in reconstituted cell-free liposomes. Instead, these mechanical stimuli were found to alter the lipid embedding of the integrin β3 transmembrane domain (TMD) and subsequently weaken the αIIb-β3 TMD interaction, which results in activation of the receptor. Moreover, artificial modulation of the membrane curvature near integrin αIIbβ3 can induce its activation in cells as well as in lipid nanodiscs, suggesting that physical deformation of the lipid bilayer, either by mechanical force or curvature, can induce integrin activation. Thus, our results establish the adhesion receptor as a bona fide mechanosensor that directly senses and responds to the force-modulated lipid environment. Furthermore, this study expands the lipid-bilayer model by suggesting that the force-induced topological change of TMDs and subsequent alteration in the TMD interactome is a molecular basis of sensing mechanical force transmitted via the lipid bilayer.
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Affiliation(s)
- Jiyoon Kim
- Department of Life Sciences, Korea University, Seoul 02841, Republic of Korea
| | - Joonha Lee
- Department of Life Sciences, Korea University, Seoul 02841, Republic of Korea
| | - Jiyoung Jang
- Department of Life Sciences, Korea University, Seoul 02841, Republic of Korea
| | - Feng Ye
- Department of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Soon Jun Hong
- Department of Cardiology, Cardiovascular Center, Korea University Anam Hospital, Seoul 02841, Republic of Korea
| | - Brian G Petrich
- Department of Pediatrics, Aflac Cancer and Blood Disorders Center, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Tobias S Ulmer
- Department of Physiology and Neuroscience, Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, CA 90033, USA
| | - Chungho Kim
- Department of Life Sciences, Korea University, Seoul 02841, Republic of Korea.
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46
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Aranha MP, Mukherjee D, Petridis L, Khomami B. An Atomistic Molecular Dynamics Study of Titanium Dioxide Adhesion to Lipid Bilayers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:1043-1052. [PMID: 31944772 DOI: 10.1021/acs.langmuir.9b03075] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Titanium dioxide (TiO2) nanoparticles are found in an array of consumer and industrial products, and human exposure to these nanoparticles involves interaction with biological membranes. To understand the effect of the membrane lipid composition on bilayer perturbation by TiO2, we performed all-atom molecular dynamics simulations of nanosized TiO2 interacting with three single component bilayers differing only in their headgroup composition: the zwitterionic DOPC, which is overall neutral containing negatively charged phosphate and positively charged choline in its head, DOPG, which is overall anionic containing negatively charged phosphate and neutral glycerol, and the anionic DOPS, containing negatively charged phosphate attached to the hydroxyl side-chain of the amino acid, serine containing negatively charged carboxyl and positively charged ammonium. The nanoparticle adheres to all three bilayers causing a negative curvature on their top leaflet. However, the local deformation of DOPG was more pronounced than DOPC and DOPS. The anionic DOPG, which is the thinnest of the three bilayers, interacted most strongly with the TiO2. DOPS has the next strongest interaction; however, its high bending modulus enables it to resist deformation by the nanoparticle. DOPC has the weakest interaction with the nanoparticle of the three as it has the highest bending modulus and its zwitterionic head groups have strong cohesive interactions. We also observed a nonuniform response of the bilayers: the orientational order of the lipids near the nanoparticle decreases, while that of the lipids away from the nanoparticle increases. The overall thickness and bending modulus of DOPG increased upon contact with the nanoparticle owing to overall stiffening of the bilayer despite local softening, while the average structural and mechanical properties of DOPC and DOPS remain unchanged, which can be explained in part by the greater bilayer bending elasticicty of DOPC and DOPS. The above findings suggest that regions of biological membranes populated by anionic lipids with weaker bending elasticity will be more susceptible to perturbation by TiO2 nanoparticles than zwitterionic-rich regions.
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Affiliation(s)
- Michelle P Aranha
- Department of Biochemistry and Cellular and Molecular Biology , University of Tennessee 1311 Cumberland Ave , Knoxville , Tennessee 37916 , United States
- UT/ORNL Center for Molecular Biophysics , Oak Ridge National Laboratory , 1 Bethel Valley Road , Oak Ridge , Tennessee 37830 , United States
| | - Dibyendu Mukherjee
- Department of Chemical and Biomolecular Engineering , University of Tennessee , 1512 Middle Dr , Knoxville , Tennessee 37996 , United States
| | - Loukas Petridis
- Department of Biochemistry and Cellular and Molecular Biology , University of Tennessee 1311 Cumberland Ave , Knoxville , Tennessee 37916 , United States
- UT/ORNL Center for Molecular Biophysics , Oak Ridge National Laboratory , 1 Bethel Valley Road , Oak Ridge , Tennessee 37830 , United States
| | - Bamin Khomami
- Department of Chemical and Biomolecular Engineering , University of Tennessee , 1512 Middle Dr , Knoxville , Tennessee 37996 , United States
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47
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Wilson KA, Wang L, MacDermott-Opeskin H, O'Mara ML. The Fats of Life: Using Computational Chemistry to Characterise the Eukaryotic Cell Membrane. Aust J Chem 2020. [DOI: 10.1071/ch19353] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Our current knowledge of the structural dynamics and complexity of lipid bilayers is still developing. Computational techniques, especially molecular dynamics simulations, have increased our understanding significantly as they allow us to model functions that cannot currently be experimentally resolved. Here we review available computational tools and techniques, the role of the major lipid species, insights gained into lipid bilayer structure and function from molecular dynamics simulations, and recent progress towards the computational modelling of the physiological complexity of eukaryotic lipid bilayers.
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48
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Yesylevskyy S, Rivel T, Ramseyer C. Curvature increases permeability of the plasma membrane for ions, water and the anti-cancer drugs cisplatin and gemcitabine. Sci Rep 2019; 9:17214. [PMID: 31748538 PMCID: PMC6868207 DOI: 10.1038/s41598-019-53952-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2019] [Accepted: 09/26/2019] [Indexed: 01/15/2023] Open
Abstract
In this work the permeability of a model asymmetric plasma membrane, for ions, water and the anti-cancer drugs cisplatin and gemcitabine is studied by means of all-atom molecular dynamics simulations. It is shown for the first time that permeability of the highly curved membrane increases from one to three orders of magnitude upon membrane bending depending on the compound and the sign of curvature. Our results suggest that the membrane curvature could be an important factor of drug translocation through the membrane.
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Affiliation(s)
- Semen Yesylevskyy
- Laboratoire Chrono Environnement UMR CNRS 6249, Université de Bourgogne Franche-Comté, 16 route de Gray, 25030, Besançon, Cedex, France.
- Department of Physics of Biological Systems, Institute of Physics of the National Academy of Sciences of Ukraine, Prospect Nauky 46, 03028, Kyiv, Ukraine.
| | - Timothée Rivel
- Laboratoire Chrono Environnement UMR CNRS 6249, Université de Bourgogne Franche-Comté, 16 route de Gray, 25030, Besançon, Cedex, France
| | - Christophe Ramseyer
- Laboratoire Chrono Environnement UMR CNRS 6249, Université de Bourgogne Franche-Comté, 16 route de Gray, 25030, Besançon, Cedex, France
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49
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Singharoy A, Maffeo C, Delgado-Magnero KH, Swainsbury DJK, Sener M, Kleinekathöfer U, Vant JW, Nguyen J, Hitchcock A, Isralewitz B, Teo I, Chandler DE, Stone JE, Phillips JC, Pogorelov TV, Mallus MI, Chipot C, Luthey-Schulten Z, Tieleman DP, Hunter CN, Tajkhorshid E, Aksimentiev A, Schulten K. Atoms to Phenotypes: Molecular Design Principles of Cellular Energy Metabolism. Cell 2019; 179:1098-1111.e23. [PMID: 31730852 PMCID: PMC7075482 DOI: 10.1016/j.cell.2019.10.021] [Citation(s) in RCA: 105] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 09/04/2019] [Accepted: 10/21/2019] [Indexed: 01/01/2023]
Abstract
We report a 100-million atom-scale model of an entire cell organelle, a photosynthetic chromatophore vesicle from a purple bacterium, that reveals the cascade of energy conversion steps culminating in the generation of ATP from sunlight. Molecular dynamics simulations of this vesicle elucidate how the integral membrane complexes influence local curvature to tune photoexcitation of pigments. Brownian dynamics of small molecules within the chromatophore probe the mechanisms of directional charge transport under various pH and salinity conditions. Reproducing phenotypic properties from atomistic details, a kinetic model evinces that low-light adaptations of the bacterium emerge as a spontaneous outcome of optimizing the balance between the chromatophore's structural integrity and robust energy conversion. Parallels are drawn with the more universal mitochondrial bioenergetic machinery, from whence molecular-scale insights into the mechanism of cellular aging are inferred. Together, our integrative method and spectroscopic experiments pave the way to first-principles modeling of whole living cells.
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Affiliation(s)
- Abhishek Singharoy
- School of Molecular Sciences, Center for Applied Structural Discovery, Arizona State University at Tempe, Tempe, AZ 85282, USA.
| | - Christopher Maffeo
- Department of Physics, NSF Center for the Physics of Living Cells, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Karelia H Delgado-Magnero
- Centre for Molecular Simulation and Department of Biological Sciences, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - David J K Swainsbury
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, UK
| | - Melih Sener
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Ulrich Kleinekathöfer
- Department of Physics and Earth Sciences, Jacobs University Bremen, 28759 Bremen, Germany
| | - John W Vant
- School of Molecular Sciences, Center for Applied Structural Discovery, Arizona State University at Tempe, Tempe, AZ 85282, USA
| | - Jonathan Nguyen
- School of Molecular Sciences, Center for Applied Structural Discovery, Arizona State University at Tempe, Tempe, AZ 85282, USA
| | - Andrew Hitchcock
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, UK
| | - Barry Isralewitz
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Ivan Teo
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Danielle E Chandler
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - John E Stone
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - James C Phillips
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Taras V Pogorelov
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Department of Chemistry, School of Chemical Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; National Center for Supercomputing Applications, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - M Ilaria Mallus
- Department of Physics and Earth Sciences, Jacobs University Bremen, 28759 Bremen, Germany
| | - Christophe Chipot
- Department of Physics, NSF Center for the Physics of Living Cells, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Laboratoire International Associé CNRS-UIUC, UMR 7019, Université de Lorraine, 54506 Vandœuvre-lès-Nancy, France
| | - Zaida Luthey-Schulten
- Department of Physics, NSF Center for the Physics of Living Cells, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Department of Chemistry, School of Chemical Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - D Peter Tieleman
- Centre for Molecular Simulation and Department of Biological Sciences, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - C Neil Hunter
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, UK.
| | - Emad Tajkhorshid
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Departments of Biochemistry, Chemistry, Bioengineering, and Pharmacology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
| | - Aleksei Aksimentiev
- Department of Physics, NSF Center for the Physics of Living Cells, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
| | - Klaus Schulten
- Department of Physics, NSF Center for the Physics of Living Cells, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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Siggel M, Bhaskara RM, Hummer G. Phospholipid Scramblases Remodel the Shape of Asymmetric Membranes. J Phys Chem Lett 2019; 10:6351-6354. [PMID: 31566982 DOI: 10.1021/acs.jpclett.9b02531] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The cell membrane and many organellar membranes are asymmetric and highly curved. In experiments, it is challenging to reconstitute and characterize membranes that differ in the lipid composition of their leaflets. Here we use molecular dynamics simulations to study the large-scale membrane shape changes associated with lipid shuttling between asymmetric leaflets. We exploit leaflet asymmetry to create a stable, near-spherical vesicle bud connected to a flat bilayer under periodic boundary conditions. Then we demonstrate how the lipid scramblase nhTMEM16 relaxes the lipid-number asymmetry. By mediating the flipping of lipids, this transmembrane protein dissipates the mechanochemical gradient between the leaflets and drives a large-scale membrane reorganization, converting the vesicle bud into a flat membrane. Our procedure to exploit bilayer asymmetry for simulations of highly curved membranes can be used to study the function of other lipid transporters and membrane-shaping proteins.
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Affiliation(s)
- Marc Siggel
- Department of Theoretical Biophysics , Max Planck Institute of Biophysics , Max-von-Laue Str. 3 , 60438 Frankfurt am Main , Germany
| | - Ramachandra M Bhaskara
- Department of Theoretical Biophysics , Max Planck Institute of Biophysics , Max-von-Laue Str. 3 , 60438 Frankfurt am Main , Germany
| | - Gerhard Hummer
- Department of Theoretical Biophysics , Max Planck Institute of Biophysics , Max-von-Laue Str. 3 , 60438 Frankfurt am Main , Germany
- Institute of Biophysics , Goethe University Frankfurt , 60438 Frankfurt am Main , Germany
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