1
|
Oliveira AC, Filipe HAL, Geraldes CF, Voth GA, Moreno MJ, Loura LMS. Interaction of MRI Contrast Agent [Gd(DOTA)] - with Lipid Membranes: A Molecular Dynamics Study. Inorg Chem 2024; 63:10897-10914. [PMID: 38795015 PMCID: PMC11186012 DOI: 10.1021/acs.inorgchem.4c00972] [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: 03/08/2024] [Revised: 04/16/2024] [Accepted: 04/30/2024] [Indexed: 05/27/2024]
Abstract
Contrast agents are important imaging probes in clinical MRI, allowing the identification of anatomic changes that otherwise would not be possible. Intensive research on the development of new contrast agents is being made to image specific pathological markers or sense local biochemical changes. The most widely used MRI contrast agents are based on gadolinium(III) complexes. Due to their very high charge density, they have low permeability through tight biological barriers such as the blood-brain barrier, hampering their application in the diagnosis of neurological disorders. In this study, we explore the interaction between the widely used contrast agent [Gd(DOTA)]- (Dotarem) and POPC lipid bilayers by means of molecular dynamics simulations. This metal complex is a standard reference where several chemical modifications have been introduced to improve key properties such as bioavailability and targeting. The simulations unveil detailed insights into the agent's interaction with the lipid bilayer, offering perspectives beyond experimental methods. Various properties, including the impact on global and local bilayer properties, were analyzed. As expected, the results indicate a low partition coefficient (KP) and high permeation barrier for this reference compound. Nevertheless, favorable interactions are established with the membrane leading to moderately long residence times. While coordination of one inner-sphere water molecule is maintained for the membrane-associated chelate, the physical-chemical attributes of [Gd(DOTA)]- as a MRI contrast agent are affected. Namely, increases in the rotational correlation times and in the residence time of the inner-sphere water are observed, with the former expected to significantly increase the water proton relaxivity. This work establishes a reference framework for the use of simulations to guide the rational design of new contrast agents with improved relaxivity and bioavailability and for the development of liposome-based formulations for use as imaging probes or theranostic agents.
Collapse
Affiliation(s)
- Alexandre C. Oliveira
- Coimbra
Chemistry Centre, Institute of Molecular
Sciences (CQC-IMS), 3004-535 Coimbra, Portugal
- Department
of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal
| | - Hugo A. L. Filipe
- Coimbra
Chemistry Centre, Institute of Molecular
Sciences (CQC-IMS), 3004-535 Coimbra, Portugal
- CPIRN-IPG—Center
of Potential and Innovation of Natural Resources, Polytechnic Institute of Guarda, 6300-559 Guarda, Portugal
| | - Carlos F.G.C. Geraldes
- Coimbra
Chemistry Centre, Institute of Molecular
Sciences (CQC-IMS), 3004-535 Coimbra, Portugal
- Department
of Life Sciences, University of Coimbra, Calçada Martim de Freitas, 3000-393 Coimbra, Portugal
- CIBIT/ICNAS
- Instituto de Ciências Nucleares Aplicadas à Saúde, Pólo das Ciências
da Saúde, Azinhaga de Santa Comba, 3000-548 Coimbra, Portugal
| | - Gregory A. Voth
- Department
of Chemistry, Chicago Center for Theoretical Chemistry, James Franck
Institute, and Institute for Biophysical Dynamics, University of Chicago, Chicago, Illinois 60637, United States
| | - Maria João Moreno
- Coimbra
Chemistry Centre, Institute of Molecular
Sciences (CQC-IMS), 3004-535 Coimbra, Portugal
- Department
of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal
- CNC−Center
for Neuroscience and Cell Biology, University
of Coimbra, 3004-517 Coimbra, Portugal
| | - Luís M. S. Loura
- Coimbra
Chemistry Centre, Institute of Molecular
Sciences (CQC-IMS), 3004-535 Coimbra, Portugal
- Faculty
of Pharmacy, University of Coimbra, 3000-548 Coimbra, Portugal
- CNC−Center
for Neuroscience and Cell Biology, University
of Coimbra, 3004-517 Coimbra, Portugal
| |
Collapse
|
2
|
Yamamoto E, Joo K, Lee J, Sansom MSP, Yasui M. Molecular mechanism of anion permeation through aquaporin 6. Biophys J 2024:S0006-3495(24)00410-7. [PMID: 38894539 DOI: 10.1016/j.bpj.2024.06.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 04/07/2024] [Accepted: 06/12/2024] [Indexed: 06/21/2024] Open
Abstract
Aquaporins (AQPs) are recognized as transmembrane water channels that facilitate selective water permeation through their monomeric pores. Among the AQP family, AQP6 has an intriguing characteristic as an anion channel, which is allosterically controlled by pH conditions and is eliminated by a single amino acid mutation. However, the molecular mechanism of anion permeation through AQP6 remains unclear. Using molecular dynamics simulations in the presence of a transmembrane voltage utilizing an ion concentration gradient, we show that chloride ions permeate through the pore corresponding to the central axis of the AQP6 homotetramer. Under low pH conditions, a subtle opening of the hydrophobic selectivity filter (SF), located near the extracellular part of the central pore, becomes wetted and enables anion permeation. Our simulations also indicate that a single mutation (N63G) in human AQP6, located at the central pore, significantly reduces anion conduction, consistent with experimental data. Moreover, we demonstrate that the pH-sensing mechanism in which the protonation of H184 and H189 under low pH conditions allosterically triggers the gating of the SF region. These results suggest a unique pH-dependent allosteric anion permeation mechanism in AQP6 and could clarify the role of the central pore in some of the AQP tetramers.
Collapse
Affiliation(s)
- Eiji Yamamoto
- Department of System Design Engineering, Keio University, Yokohama, Kanagawa, Japan.
| | - Keehyoung Joo
- Center for Advanced Computation, Korea Institute for Advanced Study, Seoul, Korea
| | - Jooyoung Lee
- School of Computational Sciences, Korea Institute for Advanced Study, Seoul, Korea
| | - Mark S P Sansom
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| | - Masato Yasui
- Department of Pharmacology, Keio University School of Medicine, Tokyo, Japan
| |
Collapse
|
3
|
Rysiewicz B, Błasiak E, Dziedzicka-Wasylewska M, Polit A. The polybasic region in Gαi proteins: Relevant or not? Insights from Gαi 3 research. Cell Signal 2024; 118:111138. [PMID: 38467243 DOI: 10.1016/j.cellsig.2024.111138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Revised: 02/18/2024] [Accepted: 03/08/2024] [Indexed: 03/13/2024]
Abstract
Heterotrimeric G proteins are responsible for signal transduction from G-protein-coupled receptors (GPCRs) to intracellular effectors. This process is only possible when G proteins are located on the inner side of the cell membrane due to the specific localization of GPCR receptors. The Gα subunit is directed to the cell membrane through several signals, including modification by fatty acid moieties, interaction with the Gβγ complex, and, as observed in some Gα proteins, the presence of basic amino acid residues in the N-terminal region. In this work, we focused on investigating the influence of the polybasic region on the localization and function of a representative member of the Gαi family, Gαi3. Through the use of confocal microscopy and fluorescence lifetime microscopy, we showed that, in the case of this protein, neutralizing the positive charge does not significantly affect its abundance in the cell membrane. However, it does affect its spatial arrangement concerning the dopamine D2 receptor and influences inhibitory effect of Gαi3 on intracellular cAMP production triggered by D2 receptor stimulation. Moreover, in this work, we have shown, for the first time, that nonlipidated Gαi3 binds to negatively charged lipids through electrostatic interactions, and membrane fluidity plays a significant role in this interaction.
Collapse
Affiliation(s)
- Beata Rysiewicz
- Department of Physical Biochemistry, Faculty of Biochemistry Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland.
| | - Ewa Błasiak
- Department of Physical Biochemistry, Faculty of Biochemistry Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland.
| | - Marta Dziedzicka-Wasylewska
- Department of Physical Biochemistry, Faculty of Biochemistry Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland.
| | - Agnieszka Polit
- Department of Physical Biochemistry, Faculty of Biochemistry Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland.
| |
Collapse
|
4
|
Newstead S, Parker J, Deme J, Lichtinger S, Kuteyi G, Biggin P, Lea S. Structural basis for antibiotic transport and inhibition in PepT2, the mammalian proton-coupled peptide transporter. RESEARCH SQUARE 2024:rs.3.rs-4435259. [PMID: 38903084 PMCID: PMC11188089 DOI: 10.21203/rs.3.rs-4435259/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/22/2024]
Abstract
The uptake and elimination of beta-lactam antibiotics in the human body are facilitated by the proton-coupled peptide transporters PepT1 (SLC15A1) and PepT2 (SLC15A2). The mechanism by which SLC15 family transporters recognize and discriminate between different drug classes and dietary peptides remains unclear, hampering efforts to improve antibiotic pharmacokinetics through targeted drug design and delivery. Here, we present cryo-EM structures of the mammalian proton-coupled peptide transporter, PepT2, in complex with the widely used beta-lactam antibiotics cefadroxil, amoxicillin and cloxacillin. Our structures, combined with pharmacophore mapping, molecular dynamics simulations and biochemical assays, establish the mechanism of antibiotic recognition and the important role of protonation in drug binding and transport.
Collapse
Affiliation(s)
| | | | - Justin Deme
- National Cancer Institute, National Institutes of Health
| | | | | | | | - Susan Lea
- Center for Structural Biology, Center for Cancer Research, National Cancer Institute
| |
Collapse
|
5
|
Antila HS, Dixit S, Kav B, Madsen JJ, Miettinen MS, Ollila OHS. Evaluating Polarizable Biomembrane Simulations against Experiments. J Chem Theory Comput 2024; 20:4325-4337. [PMID: 38718349 PMCID: PMC11137822 DOI: 10.1021/acs.jctc.3c01333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Revised: 04/10/2024] [Accepted: 04/10/2024] [Indexed: 05/29/2024]
Abstract
Owing to the increase of available computational capabilities and the potential for providing a more accurate description, polarizable molecular dynamics force fields are gaining popularity in modeling biomolecular systems. It is, however, crucial to evaluate how much precision is truly gained with increasing cost and complexity of the simulation. Here, we leverage the NMRlipids open collaboration and Databank to assess the performance of available polarizable lipid models─the CHARMM-Drude and the AMOEBA-based parameters─against high-fidelity experimental data and compare them to the top-performing nonpolarizable models. While some improvement in the description of ion binding to membranes is observed in the most recent CHARMM-Drude parameters, and the conformational dynamics of AMOEBA-based parameters are excellent, the best nonpolarizable models tend to outperform their polarizable counterparts for each property we explored. The identified shortcomings range from inaccuracies in describing the conformational space of lipids to excessively slow conformational dynamics. Our results provide valuable insights for the further refinement of polarizable lipid force fields and for selecting the best simulation parameters for specific applications.
Collapse
Affiliation(s)
- Hanne S. Antila
- Department
of Theory and Bio-Systems, Max Planck Institute
of Colloids and Interfaces, Potsdam 14476, Germany
- Department
of Biomedicine, University of Bergen, Bergen 5020, Norway
- Computational
Biology Unit, Department of Informatics, University of Bergen, Bergen 5008, Norway
| | - Sneha Dixit
- Department
of Theory and Bio-Systems, Max Planck Institute
of Colloids and Interfaces, Potsdam 14476, Germany
| | - Batuhan Kav
- Institute
of Biological Information Processing: Structural Biochemistry (IBI-7), Forschungszentrum Jülich, Jïulich 52428, Germany
| | - Jesper J. Madsen
- Department
of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida 33612, United States
- Center
for Global Health and Infectious Diseases Research, Global and Planetary
Health, College of Public Health, University
of South Florida, Tampa, Florida 33612, United States of America
| | - Markus S. Miettinen
- Department
of Theory and Bio-Systems, Max Planck Institute
of Colloids and Interfaces, Potsdam 14476, Germany
- Computational
Biology Unit, Department of Informatics, University of Bergen, Bergen 5008, Norway
- Department
of Chemistry, University of Bergen, Bergen 5007, Norway
| | - O. H. Samuli Ollila
- VTT Technical
Research Centre of Finland, Espoo 02044, Finland
- Institute
of Biotechnology, University of Helsinki, Helsinki 00014, Finland
| |
Collapse
|
6
|
Bartoš L, Drabinová M, Vácha R. Optimizing properties of translocation-enhancing transmembrane proteins. Biophys J 2024; 123:1240-1252. [PMID: 38615194 PMCID: PMC11140465 DOI: 10.1016/j.bpj.2024.04.009] [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: 01/07/2024] [Revised: 03/31/2024] [Accepted: 04/09/2024] [Indexed: 04/15/2024] Open
Abstract
Cell membranes act as semi-permeable barriers, often restricting the entry of large or hydrophilic molecules. Nonetheless, certain amphiphilic molecules, such as antimicrobial and cell-penetrating peptides, can cross these barriers. In this study, we demonstrate that specific properties of transmembrane proteins/peptides can enhance membrane permeation of amphiphilic peptides. Using coarse-grained molecular dynamics with free-energy calculations, we identify key translocation-enhancing attributes of transmembrane proteins/peptides: a continuous hydrophilic patch, charged residues preferably in the membrane center, and aromatic hydrophobic residues. By employing both coarse-grained and atomistic simulations, complemented by experimental validation, we show that these properties not only enhance peptide translocation but also speed up lipid flip-flop. The enhanced flip-flop reinforces the idea that proteins such as scramblases and insertases not only share structural features but also operate through identical biophysical mechanisms enhancing the insertion and translocation of amphiphilic molecules. Our insights offer guidelines for the designing of translocation-enhancing proteins/peptides that could be used in medical and biotechnological applications.
Collapse
Affiliation(s)
- Ladislav Bartoš
- CEITEC - Central European Institute of Technology, Masaryk University, Brno, Czech Republic; National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Martina Drabinová
- CEITEC - Central European Institute of Technology, Masaryk University, Brno, Czech Republic
| | - Robert Vácha
- CEITEC - Central European Institute of Technology, Masaryk University, Brno, Czech Republic; National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Brno, Czech Republic; Department of Condensed Matter Physics, Faculty of Science, Masaryk University, Brno, Czech Republic.
| |
Collapse
|
7
|
Park P, Matsubara DK, Barzotto DR, Lima FS, Chaimovich H, Marrink SJ, Cuccovia IM. Vesicle protrusion induced by antimicrobial peptides suggests common carpet mechanism for short antimicrobial peptides. Sci Rep 2024; 14:9701. [PMID: 38678109 PMCID: PMC11055889 DOI: 10.1038/s41598-024-60601-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Accepted: 04/25/2024] [Indexed: 04/29/2024] Open
Abstract
Short-cationic alpha-helical antimicrobial peptides (SCHAMPs) are promising candidates to combat the growing global threat of antimicrobial resistance. They are short-sequenced, selective against bacteria, and have rapid action by destroying membranes. A full understanding of their mechanism of action will provide key information to design more potent and selective SCHAMPs. Molecular Dynamics (MD) simulations are invaluable tools that provide detailed insights into the peptide-membrane interaction at the atomic- and meso-scale level. We use atomistic and coarse-grained MD to look into the exact steps that four promising SCHAMPs-BP100, Decoralin, Neurokinin-1, and Temporin L-take when they interact with membranes. Following experimental set-ups, we explored the effects of SCHAMPs on anionic membranes and vesicles at multiple peptide concentrations. Our results showed all four peptides shared similar binding steps, initially binding to the membrane through electrostatic interactions and then flipping on their axes, dehydrating, and inserting their hydrophobic moieties into the membrane core. At higher concentrations, fully alpha-helical peptides induced membrane budding and protrusions. Our results suggest the carpet mode of action is fit for the description of SCHAMPs lysis activity and discuss the importance of large hydrophobic residues in SCHAMPs design and activity.
Collapse
Affiliation(s)
- Peter Park
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
- Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, 9747 AG, Groningen, the Netherlands
| | - Danilo K Matsubara
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | - Domenico R Barzotto
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | - Filipe S Lima
- Departamento de Química Fundamental, Centro de Ciências Exatas e da Natureza, Universidade Federal de Pernambuco, Recife, Brazil
| | - Hernan Chaimovich
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | - Siewert J Marrink
- Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, 9747 AG, Groningen, the Netherlands.
| | - Iolanda M Cuccovia
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil.
| |
Collapse
|
8
|
Sharma P, Vaiwala R, Gopinath AK, Chockalingam R, Ayappa KG. Structure of the Bacterial Cell Envelope and Interactions with Antimicrobials: Insights from Molecular Dynamics Simulations. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024; 40:7791-7811. [PMID: 38451026 DOI: 10.1021/acs.langmuir.3c03474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/08/2024]
Abstract
Bacteria have evolved over 3 billion years, shaping our intrinsic and symbiotic coexistence with these single-celled organisms. With rising populations of drug-resistant strains, the search for novel antimicrobials is an ongoing area of research. Advances in high-performance computing platforms have led to a variety of molecular dynamics simulation strategies to study the interactions of antimicrobial molecules with different compartments of the bacterial cell envelope of both Gram-positive and Gram-negative species. In this review, we begin with a detailed description of the structural aspects of the bacterial cell envelope. Simulations concerned with the transport and associated free energy of small molecules and ions through the outer membrane, peptidoglycan, inner membrane and outer membrane porins are discussed. Since surfactants are widely used as antimicrobials, a section is devoted to the interactions of surfactants with the cell wall and inner membranes. The review ends with a discussion on antimicrobial peptides and the insights gained from the molecular simulations on the free energy of translocation. Challenges involved in developing accurate molecular models and coarse-grained strategies that provide a trade-off between atomic details with a gain in sampling time are highlighted. The need for efficient sampling strategies to obtain accurate free energies of translocation is also discussed. Molecular dynamics simulations have evolved as a powerful tool that can potentially be used to design and develop novel antimicrobials and strategies to effectively treat bacterial infections.
Collapse
Affiliation(s)
- Pradyumn Sharma
- Department of Chemical Engineering, Indian Institute of Science, Bangalore, Karnataka, India, 560012
| | - Rakesh Vaiwala
- Department of Chemical Engineering, Indian Institute of Science, Bangalore, Karnataka, India, 560012
| | - Amar Krishna Gopinath
- Department of Chemical Engineering, Indian Institute of Science, Bangalore, Karnataka, India, 560012
| | - Rajalakshmi Chockalingam
- Department of Chemical Engineering, Indian Institute of Science, Bangalore, Karnataka, India, 560012
| | - K Ganapathy Ayappa
- Department of Chemical Engineering, Indian Institute of Science, Bangalore, Karnataka, India, 560012
| |
Collapse
|
9
|
Qutbuddin Y, Guinart A, Gavrilović S, Al Nahas K, Feringa BL, Schwille P. Light-Activated Synthetic Rotary Motors in Lipid Membranes Induce Shape Changes Through Membrane Expansion. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2311176. [PMID: 38215457 DOI: 10.1002/adma.202311176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 12/16/2023] [Indexed: 01/14/2024]
Abstract
Membranes are the key structures to separate and spatially organize cellular systems. Their rich dynamics and transformations during the cell cycle are orchestrated by specific membrane-targeted molecular machineries, many of which operate through energy dissipation. Likewise, man-made light-activated molecular rotary motors have previously shown drastic effects on cellular systems, but their physical roles on and within lipid membranes remain largely unexplored. Here, the impact of rotary motors on well-defined biological membranes is systematically investigated. Notably, dramatic mechanical transformations are observed in these systems upon motor irradiation, indicative of motor-induced membrane expansion. The influence of several factors on this phenomenon is systematically explored, such as motor concentration and membrane composition., Membrane fluidity is found to play a crucial role in motor-induced deformations, while only minor contributions from local heating and singlet oxygen generation are observed. Most remarkably, the membrane area expansion under the influence of the motors continues as long as irradiation is maintained, and the system stays out-of-equilibrium. Overall, this research contributes to a comprehensive understanding of molecular motors interacting with biological membranes, elucidating the multifaceted factors that govern membrane responses and shape transitions in the presence of these remarkable molecular machines, thereby supporting their future applications in chemical biology.
Collapse
Affiliation(s)
- Yusuf Qutbuddin
- Cellular and Molecular Biophysics, Max Planck Institute of Biochemistry, 82152, Martinsried, Germany
| | - Ainoa Guinart
- Stratingh Institute for Chemistry, University of Groningen, Groningen, 9747 AG, The Netherlands
| | - Svetozar Gavrilović
- Cellular and Molecular Biophysics, Max Planck Institute of Biochemistry, 82152, Martinsried, Germany
| | - Kareem Al Nahas
- Cellular and Molecular Biophysics, Max Planck Institute of Biochemistry, 82152, Martinsried, Germany
| | - Ben L Feringa
- Stratingh Institute for Chemistry, University of Groningen, Groningen, 9747 AG, The Netherlands
| | - Petra Schwille
- Cellular and Molecular Biophysics, Max Planck Institute of Biochemistry, 82152, Martinsried, Germany
| |
Collapse
|
10
|
Rao RM, El Dhaybi I, Cadet F, Etchebest C, Diharce J. The mutual and dynamic role of TSPO and ligands in their binding process: An example with PK-11195. Biochimie 2024:S0300-9084(24)00067-1. [PMID: 38494108 DOI: 10.1016/j.biochi.2024.03.009] [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: 10/30/2023] [Revised: 02/12/2024] [Accepted: 03/15/2024] [Indexed: 03/19/2024]
Abstract
Translocator protein (TSPO) is an 18 kDa transmembrane protein, localized primarily on the outer mitochondrial membrane. It has been found to be involved in various physiological processes and pathophysiological conditions. Though studies on its structure have been performed only recently, there is little information on the nature of dynamics and doubts about some structures referenced in the literature, especially the NMR structure of mouse TSPO. In the present work, we thoroughly study the dynamics of mouse TSPO protein by means of atomistic molecular dynamics simulations, in presence as well as in absence of the diagnostic ligand PKA. We considered two starting structures: the NMR structure and a homology model (HM) generated on the basis of X-ray structures from bacterial TSPO. We examine the conformational landscape in both the modes for both starting points, in presence and absence of the ligand, in order to measure its impact for both structures. The analysis highlights high flexibility of the protein globally, but NMR simulations show a surprisingly flexibility even in the presence of the ligand. Interestingly, this is not the case for HM calculations, to the point that the ligand seems not so stable as in the NMR system and an unbinding event process is partially sampled. All those results tend to show that the NMR structure of mTSPO seems not deficient but is just in another portion of the global conformation space of TSPO.
Collapse
Affiliation(s)
- Rajas M Rao
- Data Analytics, Bioinformatics and Structural Biology Division, Yenepoya Research Centre, Yenepoya (Deemed to be University), Mangalore, India; Université Paris Cité and Université de la Réunion and Université des Antilles, INSERM, BIGR, DSIMB UMR_S1134, F-74014, Paris, France
| | - Ibaa El Dhaybi
- Université Paris Cité and Université de la Réunion and Université des Antilles, INSERM, BIGR, DSIMB UMR_S1134, F-74014, Paris, France
| | - Frédéric Cadet
- Université Paris Cité and Université de la Réunion and Université des Antilles, INSERM, BIGR, DSIMB UMR_S1134, F-74014, Paris, France; Laboratory of Excellence GR-Ex, Paris, France; Université Paris Cité and Université de la Réunion and Université des Antilles, INSERM, BIGR, DSIMB, F-97715, Saint Denis Messag, France; PEACCEL, Artificial Intelligence Department, Paris, 75013 France
| | - Catherine Etchebest
- Université Paris Cité and Université de la Réunion and Université des Antilles, INSERM, BIGR, DSIMB UMR_S1134, F-74014, Paris, France; Laboratory of Excellence GR-Ex, Paris, France
| | - Julien Diharce
- Université Paris Cité and Université de la Réunion and Université des Antilles, INSERM, BIGR, DSIMB UMR_S1134, F-74014, Paris, France; Laboratory of Excellence GR-Ex, Paris, France.
| |
Collapse
|
11
|
Thakur GCN, Uday A, Cebecauer M, Roos WH, Cwiklik L, Hof M, Jurkiewicz P, Melcrová A. Charge of a transmembrane peptide alters its interaction with lipid membranes. Colloids Surf B Biointerfaces 2024; 235:113765. [PMID: 38309153 DOI: 10.1016/j.colsurfb.2024.113765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 01/19/2024] [Accepted: 01/21/2024] [Indexed: 02/05/2024]
Abstract
Transmembrane (TM) proteins interact closely with the surrounding membrane lipids. Lipids in the vicinity of TM proteins were reported to have hindered mobility, which has been associated with lipids being caught up in the rough surface of the TM domains. These reports, however, neglect one important factor that largely influences the membrane behavior - electrostatics of the TM peptides that are usually positively charged at their cytosolic end. Here, we study on the example of a neutral and a positively charged WALP peptide, how the charge of a TM peptide influences the membrane. We investigate both its dynamics and mechanics by: (i) time dependent fluorescent shift in combination with classical and FRET generalized polarization to evaluate the mobility of lipids at short and long-range distance from the peptide, (ii) atomic force microscopy to observe the mechanical stability of the peptide-containing membranes, and (iii) molecular dynamics simulations to analyze the peptide-lipid interactions. We show that both TM peptides lower lipid mobility in their closest surroundings. The peptides cause lateral heterogeneity in lipid mobility, which in turn prevents free lipid rearrangement and lowers the membrane ability to seal ruptures after mechanical indentations. Introduction of a positive charge to the peptide largely enhances these effects, affecting the whole membrane. We thus highlight that unspecific peptide-lipid interactions, especially the electrostatics, should not be overlooked as they have a great impact on the mechanics and dynamics of the whole membrane.
Collapse
Affiliation(s)
- Garima C N Thakur
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, 182 23 Prague 8, Czech Republic; University of Chemical and Technology, Technická 5, Dejvice, 160 00 Prague 6, Czech Republic
| | - Arunima Uday
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, 182 23 Prague 8, Czech Republic; University of Chemical and Technology, Technická 5, Dejvice, 160 00 Prague 6, Czech Republic
| | - Marek Cebecauer
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, 182 23 Prague 8, Czech Republic
| | - Wouter H Roos
- Zernike Institute for Advanced Materials, Rijksuniversiteit Groningen, Nijenborgh 4, 9747 AG Groningen, the Netherlands
| | - Lukasz Cwiklik
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, 182 23 Prague 8, Czech Republic; Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, 166 10 Prague 6, Czech Republic
| | - Martin Hof
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, 182 23 Prague 8, Czech Republic
| | - Piotr Jurkiewicz
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, 182 23 Prague 8, Czech Republic.
| | - Adéla Melcrová
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, 182 23 Prague 8, Czech Republic; Zernike Institute for Advanced Materials, Rijksuniversiteit Groningen, Nijenborgh 4, 9747 AG Groningen, the Netherlands.
| |
Collapse
|
12
|
Vaiwala R, Ayappa KG. Martini-3 Coarse-Grained Models for the Bacterial Lipopolysaccharide Outer Membrane of Escherichia coli. J Chem Theory Comput 2024; 20:1704-1716. [PMID: 37676287 DOI: 10.1021/acs.jctc.3c00471] [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: 09/08/2023]
Abstract
The outer lipopolysaccharide (LPS) membrane of Gram-negative bacteria forms the main barrier for transport of antimicrobial molecules into the bacterial cell. In this study we develop coarse-grained models for the outer membrane of Escherichia coli in the Martini-3 framework. The coarse-grained model force field was parametrized and validated using all-atom simulations of symmetric membranes of lipid A and rough LPS as well as a complete asymmetric membrane of LPS with the O-antigen. The bonded parameters were obtained using an iterative refinement procedure with target bonded distributions obtained from all-atom simulations. The membrane thickness, area of the LPS, and density distributions for the different regions as well as the water and ion densities in Martini-3 simulations show excellent agreement with the all-atom data. Additionally the solvent accessible surface area for individual molecules in water was found to be in good agreement. The binding of calcium ions with phosphate and carboxylate moieties of LPS is accurately captured in the Martini-3 model, indicative of the integrity of the highly negatively charged LPS molecules in the outer membranes of Gram-negative bacteria. The melting transition of the coarse-grained lipid A membrane model was found to occur between 300 and 310 K, and the model captured variations in area per LPS, order parameter, and membrane thickness across the melting transition. Our study reveals that the proposed Martini-3 models for LPS are able to capture the physicochemical balance of the complex sugar architecture of the outer membrane of Escherichia coli. The coarse-grained models developed in this study would be useful for determining membrane protein interactions and permeation of potential antimicrobials through bacterial membranes at mesoscopic spatial and temporal scales.
Collapse
Affiliation(s)
- Rakesh Vaiwala
- Department of Chemical Engineering, Indian Institute of Science, Bangalore 560012, India
| | - K Ganapathy Ayappa
- Department of Chemical Engineering, Indian Institute of Science, Bangalore 560012, India
| |
Collapse
|
13
|
Lombardo Pontillo A, Ferrari M, Rospiccio M, Buffo A. Molecular Modeling of the Adsorption of an Egg Yolk Protein on a Water-Oil Interface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024. [PMID: 38315870 DOI: 10.1021/acs.langmuir.3c03272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2024]
Abstract
Egg yolk contains several molecular species with emulsifying properties, such as proteins and phospholipids. In particular, these molecules have both polar and nonpolar parts and thus can act as surfactants. One of the most surface-active proteins from egg yolk low-density lipoproteins is the so-called Apovitellenin-1. Experimental studies have been hindered by difficulties in isolating individual species from egg yolk lipoproteins. The purpose of this work was to assess the emulsifying properties of Apovitellenin-1 and any potential cooperative or competitive behavior in the presence of phospholipids. To do so, molecular simulations were carried out in a liquid-liquid interfacial system consisting of water and soybean oil, with varying concentrations of phospholipids and for different spatial configurations. To evaluate the conformational stability of the protein at the water-oil interface, the Gibbs free energy was computed from Metadynamics simulations as a function of the distance from the interface and of the radius of gyration. Moreover, a detailed analysis was also performed to determine which peptide residues were responsible for the protein adsorption at the oil-water interface as well as the lowering of the interfacial tension. Lastly, we combined the simulation results with a thermodynamic model to predict the interfacial tension behavior at increasing protein bulk concentration, which cannot be measured experimentally.
Collapse
Affiliation(s)
- Alessio Lombardo Pontillo
- Department of Applied Science and Technology, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino, Italy
| | - Marco Ferrari
- Department of Applied Science and Technology, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino, Italy
| | - Marcello Rospiccio
- Department of Applied Science and Technology, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino, Italy
| | - Antonio Buffo
- Department of Applied Science and Technology, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino, Italy
| |
Collapse
|
14
|
Wang M, Ni SD, Yin YW, Ma YQ, Ding HM. Molecular Modeling of the Fluorination Effect on the Penetration of Nanoparticles across Lipid Bilayers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024; 40:1295-1304. [PMID: 38173387 DOI: 10.1021/acs.langmuir.3c02817] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
The fluorinated decorations have recently been widely used in many biomedical applications. However, the potential mechanism of the fluorination effect on the cellular delivery of nanoparticles (NPs) still remains elusive. In this work, we systemically explore the penetration of a perfluoro-octanethiol-coated gold NP (PF-Au NP) and, for comparison, an octanethiol-coated gold NP (OT-Au NP) across lipid bilayers. We also investigated the effect of these two types of NPs on the properties of lipid bilayers. Our findings indicate that the lipid type and the surface tension of the lipid bilayer significantly impact the penetration capabilities of the fluorinated gold NP. By examining the distribution of ligands on the surface of the two types of NPs in water and during the penetration process, we unveil their distinct penetration characteristics. Specifically, the PF-Au NP exhibits amphiphobic behavior (both hydrophobic and lipophobic), while the OT-Au NP exhibits solely hydrophobic characteristics. Finally, we observe that the penetration capabilities can be increased by adjusting the degree of fluorination of the ligands on the NP surface. Overall, this study provides useful physical insights into the unique properties of the fluorinated decorations in NP permeation.
Collapse
Affiliation(s)
- Min Wang
- Center for Soft Condensed Matter Physics and Interdisciplinary Research, School of Physical Science and Technology, Soochow University, Suzhou 215006, China
| | - Song-Di Ni
- Shanghai Marine Electronic Equipment Research Institute, Shanghai 201100, China
| | - Yue-Wen Yin
- Center for Soft Condensed Matter Physics and Interdisciplinary Research, School of Physical Science and Technology, Soochow University, Suzhou 215006, China
| | - Yu-Qiang Ma
- National Laboratory of Solid State Microstructures and Department of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Hong-Ming Ding
- Center for Soft Condensed Matter Physics and Interdisciplinary Research, School of Physical Science and Technology, Soochow University, Suzhou 215006, China
| |
Collapse
|
15
|
Gradisch R, Schlögl K, Lazzarin E, Niello M, Maier J, Mayer FP, Alves da Silva L, Skopec SMC, Blakely RD, Sitte HH, Mihovilovic MD, Stockner T. Ligand coupling mechanism of the human serotonin transporter differentiates substrates from inhibitors. Nat Commun 2024; 15:417. [PMID: 38195746 PMCID: PMC10776687 DOI: 10.1038/s41467-023-44637-6] [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: 07/17/2023] [Accepted: 12/22/2023] [Indexed: 01/11/2024] Open
Abstract
The presynaptic serotonin transporter (SERT) clears extracellular serotonin following vesicular release to ensure temporal and spatial regulation of serotonergic signalling and neurotransmitter homeostasis. Prescription drugs used to treat neurobehavioral disorders, including depression, anxiety, and obsessive-compulsive disorder, trap SERT by blocking the transport cycle. In contrast, illicit drugs of abuse like amphetamines reverse SERT directionality, causing serotonin efflux. Both processes result in increased extracellular serotonin levels. By combining molecular dynamics simulations with biochemical experiments and using a homologous series of serotonin analogues, we uncovered the coupling mechanism between the substrate and the transporter, which triggers the uptake of serotonin. Free energy analysis showed that only scaffold-bound substrates could initiate SERT occlusion through attractive long-range electrostatic interactions acting on the bundle domain. The associated spatial requirements define substrate and inhibitor properties, enabling additional possibilities for rational drug design approaches.
Collapse
Affiliation(s)
- Ralph Gradisch
- Medical University of Vienna, Institute of Physiology and Pharmacology, Waehringer Straße 13A, 1090, Vienna, Austria
| | - Katharina Schlögl
- TU Wien, Institute of Applied Synthetic Chemistry, Getreidemarkt 9, 1060, Vienna, Austria
| | - Erika Lazzarin
- Medical University of Vienna, Institute of Physiology and Pharmacology, Waehringer Straße 13A, 1090, Vienna, Austria
| | - Marco Niello
- Medical University of Vienna, Institute of Physiology and Pharmacology, Waehringer Straße 13A, 1090, Vienna, Austria
- Genetics of Cognition Laboratory, Neuroscience area, Istituto Italiano di Tecnologia, via Morego, 30, 16163, Genova, Italy
| | - Julian Maier
- Medical University of Vienna, Institute of Physiology and Pharmacology, Waehringer Straße 13A, 1090, Vienna, Austria
| | - Felix P Mayer
- Florida Atlantic University, Department of Biomedical Science, Jupiter, FL, 33458, USA
- Stiles-Nicholson Brain Institute, Jupiter, FL, 33458, USA
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200, Copenhagen, Denmark
| | - Leticia Alves da Silva
- Medical University of Vienna, Institute of Physiology and Pharmacology, Waehringer Straße 13A, 1090, Vienna, Austria
| | - Sophie M C Skopec
- Medical University of Vienna, Institute of Physiology and Pharmacology, Waehringer Straße 13A, 1090, Vienna, Austria
| | - Randy D Blakely
- Florida Atlantic University, Department of Biomedical Science, Jupiter, FL, 33458, USA
- Stiles-Nicholson Brain Institute, Jupiter, FL, 33458, USA
| | - Harald H Sitte
- Medical University of Vienna, Institute of Physiology and Pharmacology, Waehringer Straße 13A, 1090, Vienna, Austria
- Al-Ahliyya Amman University, Hourani Center for Applied Scientific Research, Amman, Jordan
- Medical University of Vienna, Center for Addiction Research and Science, Waehringer Straße 13A, 1090, Vienna, Austria
| | - Marko D Mihovilovic
- TU Wien, Institute of Applied Synthetic Chemistry, Getreidemarkt 9, 1060, Vienna, Austria
| | - Thomas Stockner
- Medical University of Vienna, Institute of Physiology and Pharmacology, Waehringer Straße 13A, 1090, Vienna, Austria.
| |
Collapse
|
16
|
Castelli M, Marchetti F, Osuna S, F. Oliveira AS, Mulholland AJ, Serapian SA, Colombo G. Decrypting Allostery in Membrane-Bound K-Ras4B Using Complementary In Silico Approaches Based on Unbiased Molecular Dynamics Simulations. J Am Chem Soc 2024; 146:901-919. [PMID: 38116743 PMCID: PMC10785808 DOI: 10.1021/jacs.3c11396] [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: 10/13/2023] [Revised: 12/06/2023] [Accepted: 12/07/2023] [Indexed: 12/21/2023]
Abstract
Protein functions are dynamically regulated by allostery, which enables conformational communication even between faraway residues, and expresses itself in many forms, akin to different "languages": allosteric control pathways predominating in an unperturbed protein are often unintuitively reshaped whenever biochemical perturbations arise (e.g., mutations). To accurately model allostery, unbiased molecular dynamics (MD) simulations require integration with a reliable method able to, e.g., detect incipient allosteric changes or likely perturbation pathways; this is because allostery can operate at longer time scales than those accessible by plain MD. Such methods are typically applied singularly, but we here argue their joint application─as a "multilingual" approach─could work significantly better. We successfully prove this through unbiased MD simulations (∼100 μs) of the widely studied, allosterically active oncotarget K-Ras4B, solvated and embedded in a phospholipid membrane, from which we decrypt allostery using four showcase "languages": Distance Fluctuation analysis and the Shortest Path Map capture allosteric hotspots at equilibrium; Anisotropic Thermal Diffusion and Dynamical Non-Equilibrium MD simulations assess perturbations upon, respectively, either superheating or hydrolyzing the GTP that oncogenically activates K-Ras4B. Chosen "languages" work synergistically, providing an articulate, mutually coherent, experimentally consistent picture of K-Ras4B allostery, whereby distinct traits emerge at equilibrium and upon GTP cleavage. At equilibrium, combined evidence confirms prominent allosteric communication from the membrane-embedded hypervariable region, through a hub comprising helix α5 and sheet β5, and up to the active site, encompassing allosteric "switches" I and II (marginally), and two proposed pockets. Upon GTP cleavage, allosteric perturbations mostly accumulate on the switches and documented interfaces.
Collapse
Affiliation(s)
- Matteo Castelli
- Department
of Chemistry, University of Pavia, viale T. Taramelli 12, 27100 Pavia, Italy
| | - Filippo Marchetti
- Department
of Chemistry, University of Pavia, viale T. Taramelli 12, 27100 Pavia, Italy
- INSTM, via G. Giusti 9, 50121 Florence, Italy
- E4
Computer Engineering, via Martiri delle libertà 66, 42019 Scandiano (RE), Italy
| | - Sílvia Osuna
- Institut
de Química Computacional i Catàlisi (IQCC) and Departament
de Química, Universitat de Girona, Girona, Catalonia E-17071, Spain
- ICREA, Barcelona, Catalonia E-08010, Spain
| | - A. Sofia F. Oliveira
- Centre for
Computational Chemistry, School of Chemistry, University of Bristol, Bristol BS8 1TS, U.K.
| | - Adrian J. Mulholland
- Centre for
Computational Chemistry, School of Chemistry, University of Bristol, Bristol BS8 1TS, U.K.
| | - Stefano A. Serapian
- Department
of Chemistry, University of Pavia, viale T. Taramelli 12, 27100 Pavia, Italy
| | - Giorgio Colombo
- Department
of Chemistry, University of Pavia, viale T. Taramelli 12, 27100 Pavia, Italy
| |
Collapse
|
17
|
Kabedev A, Bergström CAS, Larsson P. Molecular dynamics study on micelle-small molecule interactions: developing a strategy for an extensive comparison. J Comput Aided Mol Des 2023; 38:5. [PMID: 38103089 PMCID: PMC10725378 DOI: 10.1007/s10822-023-00541-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 10/31/2023] [Indexed: 12/17/2023]
Abstract
Theoretical predictions of the solubilizing capacity of micelles and vesicles present in intestinal fluid are important for the development of new delivery techniques and bioavailability improvement. A balance between accuracy and computational cost is a key factor for an extensive study of numerous compounds in diverse environments. In this study, we aimed to determine an optimal molecular dynamics (MD) protocol to evaluate small-molecule interactions with micelles composed of bile salts and phospholipids. MD simulations were used to produce free energy profiles for three drug molecules (danazol, probucol, and prednisolone) and one surfactant molecule (sodium caprate) as a function of the distance from the colloid center of mass. To address the challenges associated with such tasks, we compared different simulation setups, including freely assembled colloids versus pre-organized spherical micelles, full free energy profiles versus only a few points of interest, and a coarse-grained model versus an all-atom model. Our findings demonstrate that combining these techniques is advantageous for achieving optimal performance and accuracy when evaluating the solubilization capacity of micelles. All-atom (AA) and coarse-grained (CG) umbrella sampling (US) simulations and point-wise free energy (FE) calculations were compared to their efficiency to computationally analyze the solubilization of active pharmaceutical ingredients in intestinal fluid colloids.
Collapse
Affiliation(s)
| | - Christel A S Bergström
- Department of Pharmacy, Uppsala University, Uppsala, Sweden
- Swedish Drug Delivery Center, Uppsala University, Uppsala, Sweden
| | - Per Larsson
- Department of Pharmacy, Uppsala University, Uppsala, Sweden.
- Swedish Drug Delivery Center, Uppsala University, Uppsala, Sweden.
| |
Collapse
|
18
|
Kulshrestha A, Punnathanam SN, Roy R, Ayappa KG. Cholesterol catalyzes unfolding in membrane-inserted motifs of the pore forming protein cytolysin A. Biophys J 2023; 122:4068-4081. [PMID: 37740492 PMCID: PMC10598289 DOI: 10.1016/j.bpj.2023.09.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2023] [Revised: 08/20/2023] [Accepted: 09/13/2023] [Indexed: 09/24/2023] Open
Abstract
Plasma membrane-induced protein folding and conformational transitions play a central role in cellular homeostasis. Several transmembrane proteins are folded in the complex lipid milieu to acquire a specific structure and function. Bacterial pore forming toxins (PFTs) are proteins expressed by a large class of pathogenic bacteria that exploit the plasma membrane environment to efficiently undergo secondary structure changes, oligomerize, and form transmembrane pores. Unregulated pore formation causes ion imbalance, leading to cell death and infection. Determining the free energy landscape of these membrane-driven-driven transitions remains a challenging problem. Although cholesterol recognition is required for lytic activity of several proteins in the PFT family of toxins, the regulatory role of cholesterol for the α-PFT, cytolysin A expressed by Escherichia coli remains unexplained. In a recent free energy computation, we showed that the β tongue, a critical membrane-inserted motif of the ClyA toxin, has an on-pathway partially unfolded intermediate that refolds into the helix-turn-helix motif of the pore state. To understand the molecular role played by cholesterol, we carry out string-method-based computations in membranes devoid of cholesterol, which reveals an increase of ∼30 times in the free energy barrier for the loss of β sheet secondary structure when compared with membranes containing cholesterol. Specifically, the tyrosine-cholesterol interaction was found to be critical to creating the unfolded intermediate. Cholesterol also increases the packing and hydrophobicity of the bilayer, resulting in enhanced interactions of the bound protein before complete membrane insertion. Our study illustrates that cholesterol is critical to catalyzing and stabilizing the membrane-inserted unfolded state of the β tongue motif of ClyA, opening up fresh insights into cholesterol-assisted unfolding of membrane proteins.
Collapse
Affiliation(s)
- Avijeet Kulshrestha
- Department of Chemical Engineering, Indian Institute of Science, Bangalore, Karnataka, India
| | - Sudeep N Punnathanam
- Department of Chemical Engineering, Indian Institute of Science, Bangalore, Karnataka, India
| | - Rahul Roy
- Department of Chemical Engineering, Indian Institute of Science, Bangalore, Karnataka, India; Center for BioSystems Science and Engineering, Indian Institute of Science, Bangalore, Karnataka, India
| | - K Ganapathy Ayappa
- Department of Chemical Engineering, Indian Institute of Science, Bangalore, Karnataka, India.
| |
Collapse
|
19
|
Sadžak A, Brkljača Z, Eraković M, Kriechbaum M, Maltar-Strmečki N, Přibyl J, Šegota S. Puncturing lipid membranes: onset of pore formation and the role of hydrogen bonding in the presence of flavonoids. J Lipid Res 2023; 64:100430. [PMID: 37611869 PMCID: PMC10518586 DOI: 10.1016/j.jlr.2023.100430] [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: 04/13/2023] [Revised: 08/02/2023] [Accepted: 08/07/2023] [Indexed: 08/25/2023] Open
Abstract
Products of lipid peroxidation induce detrimental structural changes in cell membranes, such as the formation of water pores, which occur in the presence of lipids with partially oxidized chains. However, the influence of another class of products, dicarboxylic acids, is still unclear. These products have greater mobility in the lipid bilayer, which enables their aggregation and the formation of favorable sites for the appearance of pores. Therefore, dodecanedioic acid (DDA) was selected as a model product. Additionally, the influence of several structurally different flavonoids on DDA aggregation via formation of hydrogen bonds with carboxyl groups was investigated. The molecular dynamics of DDA in DOPC lipid bilayer revealed the formation of aggregates extending over the hydrophobic region of the bilayer and increasing its polarity. Consequently, water penetration and the appearance of water wires was observed, representing a new step in the mechanism of pore formation. Furthermore, DDA molecules were found to interact with lipid polar groups, causing them to be buried in the bilayer. The addition of flavonoids to the system disrupted aggregate formation, resulting in the displacement of DDA molecules from the center of the bilayer. The placement of DDA and flavonoids in the lipid bilayer was confirmed by small-angle X-ray scattering. Atomic force microscopy and electron paramagnetic resonance were used to characterize the structural properties. The presence of DDA increased bilayer roughness and decreased the ordering of lipid chains, confirming its detrimental effects on the membrane surface, while flavonoids were found to reduce or reverse these changes.
Collapse
Affiliation(s)
- Anja Sadžak
- Division of Physical Chemistry, Ruđer Bošković Institute, Zagreb, Croatia.
| | - Zlatko Brkljača
- Division of Organic Chemistry and Biochemistry, Ruđer Bošković Institute, Zagreb, Croatia
| | - Mihael Eraković
- Division of Physical Chemistry, Ruđer Bošković Institute, Zagreb, Croatia
| | - Manfred Kriechbaum
- Institute of Inorganic Chemistry, Graz University of Technology, Graz, Austria
| | | | - Jan Přibyl
- CEITEC MU, Masaryk University, Brno, Czech Republic
| | - Suzana Šegota
- Division of Physical Chemistry, Ruđer Bošković Institute, Zagreb, Croatia.
| |
Collapse
|
20
|
Javanainen M, Heftberger P, Madsen JJ, Miettinen MS, Pabst G, Ollila OHS. Quantitative Comparison against Experiments Reveals Imperfections in Force Fields' Descriptions of POPC-Cholesterol Interactions. J Chem Theory Comput 2023; 19:6342-6352. [PMID: 37616238 PMCID: PMC10536986 DOI: 10.1021/acs.jctc.3c00648] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Indexed: 08/26/2023]
Abstract
Cholesterol is a central building block in biomembranes, where it induces orientational order, slows diffusion, renders the membrane stiffer, and drives domain formation. Molecular dynamics (MD) simulations have played a crucial role in resolving these effects at the molecular level; yet, it has recently become evident that different MD force fields predict quantitatively different behavior. Although easily neglected, identifying such limitations is increasingly important as the field rapidly progresses toward simulations of complex membranes mimicking the in vivo conditions: pertinent multicomponent simulations must capture accurately the interactions between their fundamental building blocks, such as phospholipids and cholesterol. Here, we define quantitative quality measures for simulations of binary lipid mixtures in membranes against the C-H bond order parameters and lateral diffusion coefficients from NMR spectroscopy as well as the form factors from X-ray scattering. Based on these measures, we perform a systematic evaluation of the ability of commonly used force fields to describe the structure and dynamics of binary mixtures of palmitoyloleoylphosphatidylcholine (POPC) and cholesterol. None of the tested force fields clearly outperforms the others across the tested properties and conditions. Still, the Slipids parameters provide the best overall performance in our tests, especially when dynamic properties are included in the evaluation. The quality evaluation metrics introduced in this work will, particularly, foster future force field development and refinement for multicomponent membranes using automated approaches.
Collapse
Affiliation(s)
- Matti Javanainen
- Institute
of Organic Chemistry and Biochemistry, Academy
of Sciences of the Czech Republic, 16000 Prague 6, Czech Republic
- Institute
of Biotechnology, University of Helsinki, 00790 Helsinki, Finland
| | - Peter Heftberger
- Biophysics,
Institute of Molecular Biosciences, NAWI Graz, University of Graz, 8010 Graz, Austria
| | - Jesper J. Madsen
- Global
and Planetary Health, College of Public Health, University of South Florida, Tampa, Florida 33612, United States
- Center
for Global Health and Infectious Diseases Research, College of Public
Health, University of South Florida, Tampa, Florida 33612, United States
- Department
of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida 33612, United States
| | - Markus S. Miettinen
- Fachbereich
Physik, Freie Universität Berlin, 14195 Berlin, Germany
- Department
of Chemistry, University of Bergen, 5007 Bergen, Norway
- Computational
Biology Unit, Department of Informatics, University of Bergen, 5008 Bergen, Norway
| | - Georg Pabst
- Biophysics,
Institute of Molecular Biosciences, NAWI Graz, University of Graz, 8010 Graz, Austria
- BioTechMed-Graz, 8010 Graz, Austria
- Field of Excellence
BioHealth—University of Graz, 8010 Graz, Austria
| | - O. H. Samuli Ollila
- Institute
of Biotechnology, University of Helsinki, 00790 Helsinki, Finland
- VTT Technical Research Centre of Finland, 02150 Espoo, Finland
| |
Collapse
|
21
|
Drajkowska A, Molski A. Aggregation and partitioning of amyloid peptide fragments in the presence of a lipid bilayer: A coarse grained molecular dynamics study. Biophys Chem 2023; 300:107051. [PMID: 37329644 DOI: 10.1016/j.bpc.2023.107051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Revised: 05/30/2023] [Accepted: 05/31/2023] [Indexed: 06/19/2023]
Abstract
Amyloidogenicity and toxicity of amyloid peptides have been linked to the peptide aggregation and interactions with lipid bilayers. In this work we used the coarse grained MARTINI model to study the aggregation and partitioning of amyloid peptide fragments Aβ(1-28) and Aβ(25-35) in the presence of a dipalmitoylphosphatidylcholine bilayer. We explored the peptide aggregation starting from three initial spatial arrangements where free monomers were placed in solution outside the membrane, at the membrane-solution interface, or in the membrane. We found that Aβ(1-28) and Aβ(25-35) interact with the bilayer quite differently. The Aβ(1-28) fragments show strong peptide-peptide and peptide-lipid interactions leading to irreversible aggregation where the aggregates stay confined to their initial spatial location. The Aβ(25-35) fragments show weaker peptide-peptide and peptide-lipid interaction leading to reversible aggregation and accumulation at the membrane-solution interface irrespective of their initial spatial arrangement. Those findings can be explained in terms of the shape of the potential of mean force for the single-peptide translocation across the membrane.
Collapse
Affiliation(s)
- Aleksandra Drajkowska
- Adam Mickiewicz University in Poznań, Faculty of Chemistry, ul. Uniwersytetu Poznańskiego 8, 61-614 Poznań, Poland.
| | - Andrzej Molski
- Adam Mickiewicz University in Poznań, Faculty of Chemistry, ul. Uniwersytetu Poznańskiego 8, 61-614 Poznań, Poland.
| |
Collapse
|
22
|
Nguyen JDM, da Hora GCA, Swanson JMJ. Mycolactone A vs. B: Multiscale Simulations Reveal the Roles of Localization and Association in Isomer-Specific Toxicity. Toxins (Basel) 2023; 15:486. [PMID: 37624243 PMCID: PMC10467071 DOI: 10.3390/toxins15080486] [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: 05/12/2023] [Revised: 07/22/2023] [Accepted: 07/24/2023] [Indexed: 08/26/2023] Open
Abstract
Mycolactone is an exotoxin produced by Mycobacterium ulcerans that causes the neglected tropical skin disease Buruli ulcer. This toxin inhibits the Sec61 translocon in the endoplasmic reticulum (ER), preventing the host cell from producing several secretory and transmembrane proteins, resulting in cytotoxic and immunomodulatory effects. Interestingly, only one of the two dominant isoforms of mycolactone is cytotoxic. Here, we investigate the origin of this specificity by performing extensive molecular dynamics (MD) simulations with enhanced free energy sampling to query the association trends of the two isoforms with both the Sec61 translocon, using two distinct cryo-electron microscopy (cryo-EM) models as references, and the ER membrane, which serves as a toxin reservoir prior to association. Our results suggest that mycolactone B (the cytotoxic isoform) has a stronger association with the ER membrane than mycolactone A due to more favorable interactions with membrane lipids and water molecules. This could increase the reservoir of toxin proximal to the Sec61 translocon. In one model of Sec61 inhibited by mycolactone, we find that isomer B interacts more closely with residues thought to play a key role in signal peptide recognition and, thus, are essential for subsequent protein translocation. In the other model, we find that isomer B interacts more closely with the lumenal and lateral gates of the translocon, the dynamics of which are essential for protein translocation. These interactions induce a more closed conformation, which has been suggested to block signal peptide insertion and subsequent protein translocation. Collectively, these findings suggest that isomer B's unique cytotoxicity is a consequence of both increased localization to the ER membrane and channel-locking association with the Sec61 translocon, facets that could be targeted in the development of Buruli Ulcer diagnostics and Sec61-targeted therapeutics.
Collapse
Affiliation(s)
| | | | - Jessica M. J. Swanson
- Department of Chemistry, University of Utah, Salt Lake City, UT 84112, USA; (J.D.M.N.); (G.C.A.d.H.)
| |
Collapse
|
23
|
Shen Y, Duan H, Yuan L, Asikaer A, Liu Y, Zhang R, Liu Y, Wang Y, Lin Z. Computational biology-based study of the molecular mechanism of spermidine amelioration of acute pancreatitis. Mol Divers 2023:10.1007/s11030-023-10698-4. [PMID: 37523101 DOI: 10.1007/s11030-023-10698-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Accepted: 07/10/2023] [Indexed: 08/01/2023]
Abstract
Acute pancreatitis (AP) is an acute inflammatory gastrointestinal disease, the mortality and morbility of which has been on the increase in the past years. Spermidine, a natural polyamine, has a wide range of pharmacological effects including anti-inflammation, antioxidation, anti-aging, and anti-tumorigenic. This study aimed to investigate the reliable targets and molecular mechanisms of spermidine in treating AP. By employing computational biology methods including network pharmacology, molecular docking, and molecular dynamics (MD) simulations, we explored the potential targets of spermidine in improving AP with dietary supplementation. The computational biology results revealed that spermidine had high degrees (degree: 18, betweenness: 38.91; degree: 18, betweenness: 206.41) and stable binding free energy (ΔGbind: - 12.81 ± 0.55 kcal/mol, - 15.00 ± 1.00 kcal/mol) with acetylcholinesterase (AchE) and serotonin transporter (5-HTT). Experimental validation demonstrates that spermidine treatment could reduce the necrosis and AchE activity in pancreatic acinar cells. Cellular thermal shift assay (CETSA) results revealed that spermidine could bind to and stabilize the 5-HTT protein in acinar cells. Moreover, spermidine treatment impeded the rise of the expression of 5-HTT in pancreatic tissues of caerulein induced acute pancreatitis mice. In conclusion, serotonin transporter might be a reliable target of spermidine in treating AP. This study provides new idea for the exploration of potential targets of natural compounds.
Collapse
Affiliation(s)
- Yan Shen
- Department of Pharmacy and Bioengineering, Chongqing University of Technology, Chongqing, 405400, China
- Chongqing Key Laboratory of Medicinal Chemistry and Molecular Pharmacology, Department of Pharmacy and Bioengineering, Chongqing University of Technology, Chongqing, 405400, People's Republic of China
| | - Hongtao Duan
- Department of Pharmacy and Bioengineering, Chongqing University of Technology, Chongqing, 405400, China
| | - Lu Yuan
- Department of Pharmacy and Bioengineering, Chongqing University of Technology, Chongqing, 405400, China
| | - Aiminuer Asikaer
- Department of Pharmacy and Bioengineering, Chongqing University of Technology, Chongqing, 405400, China
| | - Yiyuan Liu
- Department of Pharmacy and Bioengineering, Chongqing University of Technology, Chongqing, 405400, China
| | - Rui Zhang
- Department of Pharmacy, Guizhou Provincial People's Hospital, Guiyang, 550002, China
| | - Yang Liu
- Department of Hepatobiliary Surgery II, Guizhou Provincial People's Hospital, Guiyang, 550002, China
| | - Yuanqiang Wang
- Department of Pharmacy and Bioengineering, Chongqing University of Technology, Chongqing, 405400, China
- Chongqing Key Laboratory of Medicinal Chemistry and Molecular Pharmacology, Department of Pharmacy and Bioengineering, Chongqing University of Technology, Chongqing, 405400, People's Republic of China
| | - Zhihua Lin
- Department of Pharmacy and Bioengineering, Chongqing University of Technology, Chongqing, 405400, China.
- Chongqing Key Laboratory of Medicinal Chemistry and Molecular Pharmacology, Department of Pharmacy and Bioengineering, Chongqing University of Technology, Chongqing, 405400, People's Republic of China.
| |
Collapse
|
24
|
Syrjänen JL, Epstein M, Gómez R, Furukawa H. Structure of human CALHM1 reveals key locations for channel regulation and blockade by ruthenium red. Nat Commun 2023; 14:3821. [PMID: 37380652 PMCID: PMC10307800 DOI: 10.1038/s41467-023-39388-3] [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: 10/10/2022] [Accepted: 06/08/2023] [Indexed: 06/30/2023] Open
Abstract
Calcium homeostasis modulator 1 (CALHM1) is a voltage-dependent channel involved in neuromodulation and gustatory signaling. Despite recent progress in the structural biology of CALHM1, insights into functional regulation, pore architecture, and channel blockade remain limited. Here we present the cryo-EM structure of human CALHM1, revealing an octameric assembly pattern similar to the non-mammalian CALHM1s and the lipid-binding pocket conserved across species. We demonstrate by MD simulations that this pocket preferentially binds a phospholipid over cholesterol to stabilize its structure and regulate the channel activities. Finally, we show that residues in the amino-terminal helix form the channel pore that ruthenium red binds and blocks.
Collapse
Affiliation(s)
- Johanna L Syrjänen
- W.M. Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, NY, 11724, USA
| | - Max Epstein
- W.M. Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, NY, 11724, USA
| | - Ricardo Gómez
- W.M. Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, NY, 11724, USA
| | - Hiro Furukawa
- W.M. Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, NY, 11724, USA.
| |
Collapse
|
25
|
Nguyen JDM, da Hora GCA, Swanson JMJ. Mycolactone A vs. B: Does localization or association explain isomer-specific toxicity? BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.19.541532. [PMID: 37292660 PMCID: PMC10245786 DOI: 10.1101/2023.05.19.541532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Mycolactone is an exotoxin produced by Mycobacterium ulcerans that causes the neglected tropical skin disease Buruli ulcer. This toxin inhibits the Sec61 translocon in the endoplasmic reticulum (ER), preventing the host cell from producing many secretory and transmembrane proteins, resulting in cytotoxic and immunomodulatory effects. Interestingly, only one of the two dominant isoforms of mycolactone is cytotoxic. Here, we investigate the origin of this specificity by performing extensive molecular dynamics (MD) simulations with enhanced free energy sampling to query the association trends of the two isoforms with both the Sec61 translocon and the ER membrane, which serves as a toxin reservoir prior to association. Our results suggest that mycolactone B (the cytotoxic isoform) has a stronger association with the ER membrane than mycolactone A due to more favorable interactions with membrane lipids and water molecules. This could increase the reservoir of toxin proximal to the Sec61 translocon. Isomer B also interacts more closely with the lumenal and lateral gates of the translocon, the dynamics of which are essential for protein translocation. These interactions induce a more closed conformation, which has been suggested to block signal peptide insertion and subsequent protein translocation. Collectively, these findings suggest that isomer B's unique cytotoxicity is a consequence of both increased localization to the ER membrane and channel-locking association with the Sec61 translocon, facets that could be targeted in the development of Buruli Ulcer diagnostics and Sec61-targeted therapeutics.
Collapse
Affiliation(s)
- John D M Nguyen
- Department of Chemistry, University of Utah, Salt Lake City, UT - 84112-0850, USA
| | - Gabriel C A da Hora
- Department of Chemistry, University of Utah, Salt Lake City, UT - 84112-0850, USA
| | - Jessica M J Swanson
- Department of Chemistry, University of Utah, Salt Lake City, UT - 84112-0850, USA
| |
Collapse
|
26
|
Liu X, Zhang H, Zhou Z, Prabhakaran P, Vongsangnak W, Hu G, Xiao F. Functional insight into Cordyceps militaris sugar transporters by structure modeling, network analysis and allosteric regulation. Phys Chem Chem Phys 2023; 25:14311-14323. [PMID: 37183444 DOI: 10.1039/d2cp05611a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Insights into the structures, functions and dynamics of Cordyceps militaris (C. militaris) sugar transporters are necessary for understanding their versatile metabolic capability for fungal growth. The sequence-function relationship study of 85 C. militaris sugar transporters showed that there is a gap between phylogenetic-based subfamily classification and their functions. Beyond protein sequences, structural modeling and principal component analysis of the structural ensemble revealed the different folds of the Car and Org subfamilies. Performing channel detection and network analysis found that the Alp and Hex subfamilies can be specifically distinguished from others by the betweenness of channel residues. Signature dynamics analysis further suggested that the Hex subfamily demonstrates different dynamics, with high flexibility at the H1 region in TM11. Furthermore, the H1 region as an allosteric site was examined by network parameter calculations that guided allosteric pathways between this region and the channel cavity. Together with gene expression data of C. militaris, e.g., Hex06741 in the Hex subfamily, it was promisingly expressed when sugar utilization was altered. This work demonstrates an in silico framework for investigating C. militaris sugar transporters as an example case study of the allosteric activity of the Hex subfamily and can facilitate sugar transporter engineering design that can further optimize the preferable sugar utilization and fermentation process of C. militaris.
Collapse
Affiliation(s)
- Xin Liu
- Center for Systems Biology, Department of Bioinformatics, School of Biology and Basic Medical Sciences, Suzhou Medical College of Soochow University, Suzhou 215123, China.
- Institute of Blood and Marrow Transplantation, Medical College of Soochow University, Jiangsu Institute of Hematology, The first Affiliated Hospital of Soochow University, Collaborative Innovation Center of Hematology, National Clinical Research Center for Hematologic Diseases, Soochow University, Suzhou 215123, China
| | - Hanyang Zhang
- Center for Systems Biology, Department of Bioinformatics, School of Biology and Basic Medical Sciences, Suzhou Medical College of Soochow University, Suzhou 215123, China.
| | - Ziyun Zhou
- Center for Systems Biology, Department of Bioinformatics, School of Biology and Basic Medical Sciences, Suzhou Medical College of Soochow University, Suzhou 215123, China.
- Jiangsu Province Engineering Research Center of Precision Diagnostics and Therapeutics Development, Soochow University, Suzhou, 215123, China
| | - Pranesha Prabhakaran
- Interdisciplinary Graduate Program in Bioscience, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand
- Omics Center for Agriculture, Bioresources, Food, and Health, Kasetsart University (OmiKU), Bangkok 10900, Thailand
| | - Wanwipa Vongsangnak
- Omics Center for Agriculture, Bioresources, Food, and Health, Kasetsart University (OmiKU), Bangkok 10900, Thailand
- Department of Zoology, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand.
| | - Guang Hu
- Center for Systems Biology, Department of Bioinformatics, School of Biology and Basic Medical Sciences, Suzhou Medical College of Soochow University, Suzhou 215123, China.
- Jiangsu Province Engineering Research Center of Precision Diagnostics and Therapeutics Development, Soochow University, Suzhou, 215123, China
| | - Fei Xiao
- Center for Systems Biology, Department of Bioinformatics, School of Biology and Basic Medical Sciences, Suzhou Medical College of Soochow University, Suzhou 215123, China.
| |
Collapse
|
27
|
Kornilov FD, Shabalkina AV, Lin C, Volynsky PE, Kot EF, Kayushin AL, Lushpa VA, Goncharuk MV, Arseniev AS, Goncharuk SA, Wang X, Mineev KS. The architecture of transmembrane and cytoplasmic juxtamembrane regions of Toll-like receptors. Nat Commun 2023; 14:1503. [PMID: 36932058 PMCID: PMC10023784 DOI: 10.1038/s41467-023-37042-6] [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: 08/24/2022] [Accepted: 02/28/2023] [Indexed: 03/19/2023] Open
Abstract
Toll-like receptors (TLRs) are the important participants of the innate immune response. Their spatial organization is well studied for the ligand-binding domains, while a lot of questions remain unanswered for the membrane and cytoplasmic regions of the proteins. Here we use solution NMR spectroscopy and computer simulations to investigate the spatial structures of transmembrane and cytoplasmic juxtamembrane regions of TLR2, TLR3, TLR5, and TLR9. According to our data, all the proteins reveal the presence of a previously unreported structural element, the cytoplasmic hydrophobic juxtamembrane α-helix. As indicated by the functional tests in living cells and bioinformatic analysis, this helix is important for receptor activation and plays a role, more complicated than a linker, connecting the transmembrane and cytoplasmic parts of the proteins.
Collapse
Affiliation(s)
- F D Kornilov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, 117997, Russia
- Moscow Institute of Physics and Technology, Dolgoprudny, 141701, Russia
| | - A V Shabalkina
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, 117997, Russia
- Moscow Institute of Physics and Technology, Dolgoprudny, 141701, Russia
| | - Cong Lin
- Laboratory of Chemical Biology, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 130022, Changchun, Jilin, China
| | - P E Volynsky
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, 117997, Russia
- Institute of Cytology of Russian Academy of Sciences, Tikhoretsky 4, 194064, Saint Petersburg, Russia
| | - E F Kot
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, 117997, Russia
- Moscow Institute of Physics and Technology, Dolgoprudny, 141701, Russia
| | - A L Kayushin
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, 117997, Russia
| | - V A Lushpa
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, 117997, Russia
- Moscow Institute of Physics and Technology, Dolgoprudny, 141701, Russia
| | - M V Goncharuk
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, 117997, Russia
| | - A S Arseniev
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, 117997, Russia
| | - S A Goncharuk
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, 117997, Russia.
- Moscow Institute of Physics and Technology, Dolgoprudny, 141701, Russia.
| | - Xiaohui Wang
- Laboratory of Chemical Biology, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 130022, Changchun, Jilin, China.
- School of Applied Chemistry and Engineering, University of Science and Technology of China, 230026, Hefei, Anhui, China.
| | - K S Mineev
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, 117997, Russia.
- Moscow Institute of Physics and Technology, Dolgoprudny, 141701, Russia.
| |
Collapse
|
28
|
Matthes D, de Groot BL. Molecular dynamics simulations reveal the importance of amyloid-beta oligomer β-sheet edge conformations in membrane permeabilization. J Biol Chem 2023; 299:103034. [PMID: 36806684 PMCID: PMC10033322 DOI: 10.1016/j.jbc.2023.103034] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 02/03/2023] [Accepted: 02/13/2023] [Indexed: 02/18/2023] Open
Abstract
Oligomeric aggregates of the amyloid-beta peptide(1-42) (Aβ42) are regarded as a primary cause of cytotoxicity related to membrane damage in Alzheimer's disease. However, a dynamical and structural characterization of pore-forming Aβ42 oligomers at atomic detail has not been feasible. Here, we used Aβ42 oligomer structures previously determined in a membrane-mimicking environment as putative model systems to study the pore formation process in phospholipid bilayers with all-atom molecular dynamics simulations. Multiple Aβ42 oligomer sizes, conformations, and N-terminally truncated isoforms were investigated on the multi-μs time scale. We found that pore formation and ion permeation occur via edge conductivity and exclusively for β-sandwich structures that feature exposed side-by-side β-strand pairs formed by residues 9 to 21 of Aβ42. The extent of pore formation and ion permeation depends on the insertion depth of hydrophilic residues 13 to 16 (HHQK domain) and thus on subtle differences in the overall stability, orientation, and conformation of the aggregates in the membrane. Additionally, we determined that backbone carbonyl and polar side-chain atoms from the edge strands directly contribute to the coordination sphere of the permeating ions. Furthermore, point mutations that alter the number of favorable side-chain contacts correlate with the ability of the Aβ42 oligomer models to facilitate ion permeation in the bilayer center. Our findings suggest that membrane-inserted, layered β-sheet edges are a key structural motif in pore-forming Aβ42 oligomers independent of their size and play a pivotal role in aggregate-induced membrane permeabilization.
Collapse
Affiliation(s)
- Dirk Matthes
- Computational Biomolecular Dynamics Group, Department of Theoretical and Computational Biophysics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany.
| | - Bert L de Groot
- Computational Biomolecular Dynamics Group, Department of Theoretical and Computational Biophysics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| |
Collapse
|
29
|
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.
Collapse
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
| |
Collapse
|
30
|
Zhou Y, Li J, Baryshnikov G, Tu Y. Unraveling the Abnormal Molecular Mechanism of Suicide Inhibition of Cytochrome P450 3A4. J Chem Inf Model 2022; 62:6172-6181. [PMID: 36457253 PMCID: PMC9749025 DOI: 10.1021/acs.jcim.2c01035] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
Suicide inhibition of the CYP3A4 enzyme by a drug inactivates the enzyme in the drug biotransformation process and often shows safety concerns about the drug. Despite extensive experimental studies, the abnormal molecular mechanism of a suicide inhibitor that forms a covalent bond with the residue far away from the catalytically active center of CYP3A4 inactivating the enzyme remains elusive. Here, the authors used molecular simulation approaches to study in detail how diquinone methide (DQR), the metabolite product of raloxifene, unbinds from CYP3A4 and inactivates the enzyme at the atomistic level. The results clearly indicate that in one of the intermediate states formed in its unbinding process, DQR covalently binds to Cys239, a residue far away from the catalytically active center of CYP3A4, and hinders the substrate from entering or leaving the enzyme. This work therefore provides an unprecedented way of clarifying the abnormal mechanism of suicide inhibition of the CYP3A4 enzyme.
Collapse
Affiliation(s)
- Yang Zhou
- School of Pharmacy, Jinan University, 601 Huangpu Avenue West, Guangzhou510632, China.,Department of Theoretical Chemistry and Biology, KTH Royal Institute of Technology, 114 28Stockholm, Sweden
| | - Junhao Li
- Department of Theoretical Chemistry and Biology, KTH Royal Institute of Technology, 114 28Stockholm, Sweden
| | - Glib Baryshnikov
- Laboratory of Organic Electronics, Department of Science and Technology, Linköping University, 60174Norrköping, Sweden
| | - Yaoquan Tu
- Department of Theoretical Chemistry and Biology, KTH Royal Institute of Technology, 114 28Stockholm, Sweden
| |
Collapse
|
31
|
Membrane Lipid Reshaping Underlies Oxidative Stress Sensing by the Mitochondrial Proteins UCP1 and ANT1. Antioxidants (Basel) 2022; 11:antiox11122314. [PMID: 36552523 PMCID: PMC9774536 DOI: 10.3390/antiox11122314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 11/17/2022] [Accepted: 11/18/2022] [Indexed: 11/24/2022] Open
Abstract
Oxidative stress and ROS are important players in the pathogenesis of numerous diseases. In addition to directly altering proteins, ROS also affects lipids with negative intrinsic curvature such as phosphatidylethanolamine (PE), producing PE adducts and lysolipids. The formation of PE adducts potentiates the protonophoric activity of mitochondrial uncoupling proteins, but the molecular mechanism remains unclear. Here, we linked the ROS-mediated change in lipid shape to the mechanical properties of the membrane and the function of uncoupling protein 1 (UCP1) and adenine nucleotide translocase 1 (ANT1). We show that the increase in the protonophoric activity of both proteins occurs due to the decrease in bending modulus in lipid bilayers in the presence of lysophosphatidylcholines (OPC and MPC) and PE adducts. Moreover, MD simulations showed that modified PEs and lysolipids change the lateral pressure profile of the membrane in the same direction and by the similar amplitude, indicating that modified PEs act as lipids with positive intrinsic curvature. Both results indicate that oxidative stress decreases stored curvature elastic stress (SCES) in the lipid bilayer membrane. We demonstrated that UCP1 and ANT1 sense SCES and proposed a novel regulatory mechanism for the function of these proteins. The new findings should draw the attention of the scientific community to this important and unexplored area of redox biochemistry.
Collapse
|
32
|
Surya W, Queralt-Martin M, Mu Y, Aguilella VM, Torres J. SARS-CoV-2 accessory protein 7b forms homotetramers in detergent. Virol J 2022; 19:193. [PMID: 36414943 PMCID: PMC9680129 DOI: 10.1186/s12985-022-01920-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 11/04/2022] [Indexed: 11/23/2022] Open
Abstract
A global pandemic is underway caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The SARS-CoV-2 genome, like its predecessor SARS-CoV, contains open reading frames that encode accessory proteins involved in virus-host interactions active during infection and which likely contribute to pathogenesis. One of these accessory proteins is 7b, with only 44 (SARS-CoV) and 43 (SARS-CoV-2) residues. It has one predicted transmembrane domain fully conserved, which suggests a functional role, whereas most variability is contained in the predicted cytoplasmic C-terminus. In SARS-CoV, 7b protein is expressed in infected cells, and the transmembrane domain was necessary and sufficient for Golgi localization. Also, anti-p7b antibodies have been found in the sera of SARS-CoV convalescent patients. In the present study, we have investigated the hypothesis that SARS-2 7b protein forms oligomers with ion channel activity. We show that in both SARS viruses 7b is almost completely α-helical and has a single transmembrane domain. In SDS, 7b forms various oligomers, from monomers to tetramers, but only monomers when exposed to reductants. Combination of SDS gel electrophoresis and analytical ultracentrifugation (AUC) in both equilibrium and velocity modes suggests a dimer-tetramer equilibrium, but a monomer-dimer-tetramer equilibrium in the presence of reductant. This data suggests that although disulfide-linked dimers may be present, they are not essential to form tetramers. Inclusion of pentamers or higher oligomers in the SARS-2 7b model were detrimental to fit quality. Preliminary models of this association was generated with AlphaFold2, and two alternative models were exposed to a molecular dynamics simulation in presence of a model lipid membrane. However, neither of the two models provided any evident pathway for ions. To confirm this, SARS-2 p7b was studied using Planar Bilayer Electrophysiology. Addition of p7b to model membranes produced occasional membrane permeabilization, but this was not consistent with bona fide ion channels made of a tetrameric assembly of α-helices.
Collapse
Affiliation(s)
- Wahyu Surya
- grid.59025.3b0000 0001 2224 0361School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore, 637551 Singapore
| | - Maria Queralt-Martin
- grid.9612.c0000 0001 1957 9153Laboratory of Molecular Biophysics, Department of Physics, Universitat Jaume I, 12080 Castelló, Spain
| | - Yuguang Mu
- grid.59025.3b0000 0001 2224 0361School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore, 637551 Singapore
| | - Vicente M. Aguilella
- grid.9612.c0000 0001 1957 9153Laboratory of Molecular Biophysics, Department of Physics, Universitat Jaume I, 12080 Castelló, Spain
| | - Jaume Torres
- grid.59025.3b0000 0001 2224 0361School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore, 637551 Singapore
| |
Collapse
|
33
|
Lipid-A-dependent and cholesterol-dependent dynamics properties of liposomes from gram-negative bacteria in ESKAPE. Sci Rep 2022; 12:19474. [PMID: 36376343 PMCID: PMC9663605 DOI: 10.1038/s41598-022-22886-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 10/20/2022] [Indexed: 11/16/2022] Open
Abstract
AntiMicrobial Resistance (AMR) is a worldwide health emergency. ESKAPE pathogens include the most relevant AMR bacterial families. In particular, Gram-negative bacteria stand out due to their cell envelope complexity which exhibits strong resistance to antimicrobials. A key element for AMR is the chemical structure of lipid A, modulating the physico-chemical properties of the membrane and permeability to antibiotics. Liposomes are used as models of bacterial membrane infective vesicles. In this work, coarse-grained molecular dynamics simulations were used to model liposomes from ESKAPE Gram-negative bacteria (Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii, and Pseudomonas aeruginosa). We captured the role of lipid A, cardiolipin and cholesterol on liposome morphology and physico-chemical properties. Additionally, the reported antimicrobial peptides Cecropin B1, JB95, and PTCDA1-kf, were used to unveil their implications on membrane disruption. This study opens a promising starting point to understand molecular keys of bacterial membranes and to promote the discovery of new antimicrobials to overcome AMR.
Collapse
|
34
|
Falginella FL, Kravec M, Drabinová M, Paclíková P, Bryja V, Vácha R. Binding of DEP domain to phospholipid membranes: More than just electrostatics. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2022; 1864:183983. [PMID: 35750206 DOI: 10.1016/j.bbamem.2022.183983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 05/06/2022] [Accepted: 05/31/2022] [Indexed: 06/15/2023]
Abstract
Over the past decades an extensive effort has been made to provide a more comprehensive understanding of Wnt signaling, yet many regulatory and structural aspects remain elusive. Among these, the ability of Dishevelled (DVL) protein to relocalize at the plasma membrane is a crucial step in the activation of all Wnt pathways. The membrane binding of DVL was suggested to be mediated by the preferential interaction of its C-terminal DEP domain with phosphatidic acid (PA). However, due to the scarcity and fast turnover of PA, we investigated the role on the membrane association of other more abundant phospholipids. The combined results from computational simulations and experimental measurements with various model phospholipid membranes, demonstrate that the membrane binding of DEP/DVL constructs is governed by the concerted action of generic electrostatics and finely-tuned intermolecular interactions with individual lipid species. In particular, while we confirmed the strong preference for PA lipid, we also observed a weak but non-negligible affinity for phosphatidylserine, the most abundant anionic phospholipid in the plasma membrane, and phosphatidylinositol 4,5-bisphosphate. The obtained molecular insight into DEP-membrane interaction helps to elucidate the relation between changes in the local membrane composition and the spatiotemporal localization of DVL and, possibly, other DEP-containing proteins.
Collapse
Affiliation(s)
- Francesco L Falginella
- CEITEC - Central European Institute of Technology, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic; National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
| | - Marek Kravec
- Department of Experimental Biology, Faculty of Science, Masaryk University, Brno 62500, Czech Republic
| | - Martina Drabinová
- CEITEC - Central European Institute of Technology, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
| | - Petra Paclíková
- Department of Experimental Biology, Faculty of Science, Masaryk University, Brno 62500, Czech Republic
| | - Vítĕzslav Bryja
- Department of Experimental Biology, Faculty of Science, Masaryk University, Brno 62500, Czech Republic; Institute of Biophysics, Academy of Sciences of the Czech Republic, v.v.i., Brno 612 65, Czech Republic
| | - Robert Vácha
- CEITEC - Central European Institute of Technology, Masaryk University, Kamenice 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 2, 611 37 Brno, Czech Republic.
| |
Collapse
|
35
|
Probing effects of the SARS-CoV-2 E protein on membrane curvature and intracellular calcium. BIOCHIMICA ET BIOPHYSICA ACTA (BBA) - BIOMEMBRANES 2022; 1864:183994. [PMID: 35724739 PMCID: PMC9212275 DOI: 10.1016/j.bbamem.2022.183994] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 06/03/2022] [Accepted: 06/13/2022] [Indexed: 01/20/2023]
Abstract
SARS-CoV-2 contains four structural proteins in its genome. These proteins aid in the assembly and budding of new virions at the ER-Golgi intermediate compartment (ERGIC). Current fundamental research efforts largely focus on one of these proteins – the spike (S) protein. Since successful antiviral therapies are likely to target multiple viral components, there is considerable interest in understanding the biophysical role of its other structural proteins, in particular structural membrane proteins. Here, we have focused our efforts on the characterization of the full-length envelope (E) protein from SARS-CoV-2, combining experimental and computational approaches. Recombinant expression of the full-length E protein from SARS-CoV-2 reveals that this membrane protein is capable of independent multimerization, possibly as a tetrameric or smaller species. Fluorescence microscopy shows that the protein localizes intracellularly, and coarse-grained MD simulations indicate it causes bending of the surrounding lipid bilayer, corroborating a potential role for the E protein in viral budding. Although we did not find robust electrophysiological evidence of ion-channel activity, cells transfected with the E protein exhibited reduced intracellular Ca2+, which may further promote viral replication. However, our atomistic MD simulations revealed that previous NMR structures are relatively unstable, and result in models incapable of ion conduction. Our study highlights the importance of using high-resolution structural data obtained from a full-length protein to gain detailed molecular insights, and eventually permitting virtual drug screening.
Collapse
|
36
|
The clinical drug candidate anle138b binds in a cavity of lipidic α-synuclein fibrils. Nat Commun 2022; 13:5385. [PMID: 36104315 PMCID: PMC9474542 DOI: 10.1038/s41467-022-32797-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 08/12/2022] [Indexed: 11/09/2022] Open
Abstract
AbstractAggregation of amyloidogenic proteins is a characteristic of multiple neurodegenerative diseases. Atomic resolution of small molecule binding to such pathological protein aggregates is of interest for the development of therapeutics and diagnostics. Here we investigate the interaction between α-synuclein fibrils and anle138b, a clinical drug candidate for disease modifying therapy in neurodegeneration and a promising scaffold for positron emission tomography tracer design. We used nuclear magnetic resonance spectroscopy and the cryogenic electron microscopy structure of α-synuclein fibrils grown in the presence of lipids to locate anle138b within a cavity formed between two β-strands. We explored and quantified multiple binding modes of the compound in detail using molecular dynamics simulations. Our results reveal stable polar interactions between anle138b and backbone moieties inside the tubular cavity of the fibrils. Such cavities are common in other fibril structures as well.
Collapse
|
37
|
Kumar A, Kindig K, Rao S, Zaki AM, Basak S, Sansom MSP, Biggin PC, Chakrapani S. Structural basis for cannabinoid-induced potentiation of alpha1-glycine receptors in lipid nanodiscs. Nat Commun 2022; 13:4862. [PMID: 35982060 PMCID: PMC9388682 DOI: 10.1038/s41467-022-32594-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 08/08/2022] [Indexed: 11/23/2022] Open
Abstract
Nociception and motor coordination are critically governed by glycine receptor (GlyR) function at inhibitory synapses. Consequentially, GlyRs are attractive targets in the management of chronic pain and in the treatment of several neurological disorders. High-resolution mechanistic details of GlyR function and its modulation are just emerging. While it has been known that cannabinoids such as Δ9-tetrahydrocannabinol (THC), the principal psychoactive constituent in marijuana, potentiate GlyR in the therapeutically relevant concentration range, the molecular mechanism underlying this effect is still not understood. Here, we present Cryo-EM structures of full-length GlyR reconstituted into lipid nanodisc in complex with THC under varying concentrations of glycine. The GlyR-THC complexes are captured in multiple conformational states that reveal the basis for THC-mediated potentiation, manifested as different extents of opening at the level of the channel pore. Taken together, these structural findings, combined with molecular dynamics simulations and functional analysis, provide insights into the potential THC binding site and the allosteric coupling to the channel pore.
Collapse
Affiliation(s)
- Arvind Kumar
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Kayla Kindig
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Shanlin Rao
- Department of Biochemistry, University of Oxford, Oxford, UK
| | | | - Sandip Basak
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Mark S P Sansom
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Philip C Biggin
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Sudha Chakrapani
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH, USA.
- Cleveland Center for Membrane and Structural Biology, School of Medicine, Case Western Reserve University, Cleveland, OH, USA.
- Department of Neuroscience, School of Medicine, Case Western Reserve University, Cleveland, OH, USA.
| |
Collapse
|
38
|
Lu Y, Salsbury F, Derreumaux P. Impact of A2T and D23N mutations on C99 homodimer conformations. J Chem Phys 2022; 157:085102. [DOI: 10.1063/5.0101622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The proteolytic cleavage of C99 by γ-secretase is the last step in the production of amyloid-β (Aβ) peptides. Previous studies have shown that membrane lipid composition, cholesterol concentration, and mutation in the transmembrane helix modified the structures and fluctuations of C99. In this study, we performed atomistic molecular dynamics simulations of the homodimer of the 55-residue congener of the C-terminal domain of the amyloid protein precursor, C99(1-55), in a POPC-cholesterol lipid bilayer, and we compared the conformational ensemble of WT sequence to those of the A2T and D23N variants. These mutations are particularly interesting as the protective Alzheimer's disease (AD) A2T mutation is known to decrease Aβ production, whereas the early onset AD D23N mutation does not affect Aβ production. We found noticeable differences in the structural ensembles of the three sequences. In particular, A2T varies from both WT and D23N by having long-range effects on the population of the extracellular justamembrane helix, the interface between the G29xxx-G33xxx-G37 motifs and the fluctuations of the transmembrane helical topologies.
Collapse
Affiliation(s)
- Yan Lu
- School of Physics, Xidian University, China
| | | | | |
Collapse
|
39
|
Hou Y, Xu B, Chen SL, Gan W, Yuan Q, Lin X. Understanding the different cross-membrane transport kinetics of two charged molecules on the DOPG lipid surface with second harmonic generation and MD simulation. SOFT MATTER 2022; 18:4305-4314. [PMID: 35620962 DOI: 10.1039/d2sm00167e] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
A clear physical picture of the dynamic behavior of molecules on the surface of the lipid membrane is highly desired and has attracted great attention from researchers. In this study, a step forward in this direction based on previous studies was presented with second harmonic generation (SHG) and molecular dynamic (MD) simulation. Specifically, details on the orientation flipping and cross-membrane transport of two charged molecules, 4-(4-diethylaminostyry)-1-methyl-pyridinium iodide (D289) and malachite green (MG), on the surface of 2-dioleoyl-sn-glycero-3-phospho-rac-(1-glycerol) sodium salt (DOPG) lipids were presented. Firstly, the orientation flipping of the two molecules on the surface of lipids before their cross-membrane transport was confirmed by the MD simulation. Then, the concentration dependent rate of the cross membrane transport for MG/D289 was analyzed. It was found that a simplified model could satisfactorily interpret the faster cross-membrane transport of MG under higher bulk concentrations. A different concentration dependent dynamics was observed with D289 and the reason behind it was also discussed. With this investigation, the surface structures and dynamics of D289 and MG on the DOPG lipid surface were clearly presented.
Collapse
Affiliation(s)
- Yi Hou
- Shenzhen Key Laboratory of Flexible Printed Electronics Technology, School of Science, Harbin Institute of Technology (Shenzhen), University Town, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Shenzhen 518055, Guangdong, Harbin 150001, Heilongjiang, China.
| | - Baomei Xu
- Shenzhen Key Laboratory of Flexible Printed Electronics Technology, School of Science, Harbin Institute of Technology (Shenzhen), University Town, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Shenzhen 518055, Guangdong, Harbin 150001, Heilongjiang, China.
| | - Shun-Li Chen
- Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structure Materials of Guangdong Province, Shantou University, Shantou 515063, Guangdong, China
| | - Wei Gan
- Shenzhen Key Laboratory of Flexible Printed Electronics Technology, School of Science, Harbin Institute of Technology (Shenzhen), University Town, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Shenzhen 518055, Guangdong, Harbin 150001, Heilongjiang, China.
| | - Qunhui Yuan
- Shenzhen Key Laboratory of Flexible Printed Electronics Technology, School of Materials Science and Engineering, Harbin Institute of Technology (Shenzhen), University Town, Shenzhen 518055, Guangdong, China.
| | - Xi Lin
- School of Materials Science and Engineering, and Institute of Materials Genome & Big Data, Harbin Institute of Technology(Shenzhen), University Town, Shenzhen 518055, China.
| |
Collapse
|
40
|
Chan SY, Lee D, Meivita MP, Li L, Tan YS, Bajalovic N, Loke DK. Ultrasensitive Detection of MCF-7 Cells with a Carbon Nanotube-Based Optoelectronic-Pulse Sensor Framework. ACS OMEGA 2022; 7:18459-18470. [PMID: 35694527 PMCID: PMC9178712 DOI: 10.1021/acsomega.2c00842] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Accepted: 04/07/2022] [Indexed: 06/15/2023]
Abstract
Biosensors are of vital significance for healthcare by supporting the management of infectious diseases for preventing pandemics and the diagnosis of life-threatening conditions such as cancer. However, the advancement of the field can be limited by low sensing accuracy. Here, we altered the bioelectrical signatures of the cells using carbon nanotubes (CNTs) via structural loosening effects. Using an alternating current (AC) pulse under light irradiation, we developed a photo-assisted AC pulse sensor based on CNTs to differentiate between healthy breast epithelial cells (MCF-10A) and luminal breast cancer cells (MCF-7) within a heterogeneous cell population. We observed a previously undemonstrated increase in current contrast for MCF-7 cells with CNTs compared to MCF-10A cells with CNTs under light exposure. Moreover, we obtained a detection limit of ∼1.5 × 103 cells below a baseline of ∼1 × 104 cells for existing electrical-based sensors for an adherent, heterogeneous cell population. All-atom molecular dynamics (MD) simulations reveal that interactions between the embedded CNT and cancer cell membranes result in a less rigid lipid bilayer structure, which can facilitate CNT translocation for enhancing current. This as-yet unconsidered cancer cell-specific method based on the unique optoelectrical properties of CNTs represents a strategy for unlocking the detection of a small population of cancer cells and provides a promising route for the early diagnosis, monitoring, and staging of cancer.
Collapse
Affiliation(s)
- Sophia
S. Y. Chan
- Department
of Science, Mathematics and Technology, Singapore University of Technology and Design, Singapore487372, Singapore
| | - Denise Lee
- Department
of Science, Mathematics and Technology, Singapore University of Technology and Design, Singapore487372, Singapore
| | - Maria Prisca Meivita
- Department
of Science, Mathematics and Technology, Singapore University of Technology and Design, Singapore487372, Singapore
| | - Lunna Li
- Department
of Science, Mathematics and Technology, Singapore University of Technology and Design, Singapore487372, Singapore
- Thomas
Young Centre and Department of Chemical Engineering, University College London, LondonWC1E 6BT, U.K.
| | - Yaw Sing Tan
- Bioinformatics
Institute, Agency for Science, Technology
and Research (A*STAR), Singapore138671, Singapore
| | - Natasa Bajalovic
- Department
of Science, Mathematics and Technology, Singapore University of Technology and Design, Singapore487372, Singapore
| | - Desmond K. Loke
- Department
of Science, Mathematics and Technology, Singapore University of Technology and Design, Singapore487372, Singapore
- Office
of Innovation, Changi General Hospital, Singapore529889, Singapore
| |
Collapse
|
41
|
The lung surfactant activity probed with molecular dynamics simulations. Adv Colloid Interface Sci 2022; 304:102659. [PMID: 35421637 DOI: 10.1016/j.cis.2022.102659] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2021] [Revised: 03/18/2022] [Accepted: 03/31/2022] [Indexed: 01/17/2023]
Abstract
The surface of pulmonary alveolar subphase is covered with a mixture of lipids and proteins. This lung surfactant plays a crucial role in lung functioning. It shows a complex phase behavior which can be altered by the interaction with third molecules such as drugs or pollutants. For studying multicomponent biological systems, it is of interest to couple experimental approach with computational modelling yielding atomic-scale information. Simple two, three, or four-component model systems showed to be useful for getting more insight in the interaction between lipids, lipids and proteins or lipids and proteins with drugs and impurities. These systems were studied theoretically using molecular dynamic simulations and experimentally by means of the Langmuir technique. A better understanding of the structure and behavior of lung surfactants obtained from this research is relevant for developing new synthetic surfactants for efficient therapies, and may contribute to public health protection.
Collapse
|
42
|
Lee D, Naikar JS, Chan SSY, Meivita MP, Li L, Tan YS, Bajalovic N, Loke DK. Ultralong recovery time in nanosecond electroporation systems enabled by orientational-disordering processes. NANOSCALE 2022; 14:7934-7942. [PMID: 35603889 DOI: 10.1039/d1nr07362a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The growing importance of applications based on molecular medicine and genetic engineering is driving the need to develop high-performance electroporation technologies. The electroporation phenomenon involves disruption of the cell for increasing membrane permeability. Although there is a multitude of research focused on exploring new electroporation techniques, the engineering of programming schemes suitable for these electroporation methods remains a challenge. Nanosecond stimulations could be promising candidates for these techniques owing to their ability to generate a wide range of biological responses. Here we control the membrane permeabilization of cancer cells using different numbers of electric-field pulses through orientational disordering effects. We then report our exploration of a few-volt nanosecond alternating-current (AC) stimulation method with an increased number of pulses for developing electroporation systems. A recovery time of ∼720 min was achieved, which is above the average of ∼76 min for existing electroporation methods using medium cell populations, as well as a previously unreported increased conductance with an increase in the number of pulses using weak bias amplitudes. All-atom molecular dynamics (MD) simulations reveal the orientation-disordering-facilitated increase in the degree of permeabilization. These findings highlight the potential of few-volt nanosecond AC-stimulation with an increased number of pulse strategies for the development of next-generation low-power electroporation systems.
Collapse
Affiliation(s)
- Denise Lee
- Department of Science, Mathematics and Technology, Singapore University of Technology and Design, Singapore 487372.
| | - J Shamita Naikar
- Office of Innovation, Changi General Hospital, Singapore, 529889
| | - Sophia S Y Chan
- Department of Science, Mathematics and Technology, Singapore University of Technology and Design, Singapore 487372.
| | - Maria Prisca Meivita
- Department of Science, Mathematics and Technology, Singapore University of Technology and Design, Singapore 487372.
| | - Lunna Li
- Department of Science, Mathematics and Technology, Singapore University of Technology and Design, Singapore 487372.
| | - Yaw Sing Tan
- Bioinformatics Institute, Agency for Science, Technology and Research (A*STAR), Singapore 138671
| | - Natasa Bajalovic
- Department of Science, Mathematics and Technology, Singapore University of Technology and Design, Singapore 487372.
| | - Desmond K Loke
- Department of Science, Mathematics and Technology, Singapore University of Technology and Design, Singapore 487372.
- Office of Innovation, Changi General Hospital, Singapore, 529889
| |
Collapse
|
43
|
Ginez LD, Osorio A, Vázquez-Ramírez R, Arenas T, Mendoza L, Camarena L, Poggio S. Changes in fluidity of the E. coli outer membrane in response to temperature, divalent cations and polymyxin-B show two different mechanisms of membrane fluidity adaptation. FEBS J 2022; 289:3550-3567. [PMID: 35038363 DOI: 10.1111/febs.16358] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 11/23/2021] [Accepted: 01/13/2022] [Indexed: 12/28/2022]
Abstract
The outer membrane (OM) is an essential component of the Gram-negative bacterial cell envelope. Restricted diffusion of integral OM proteins and lipopolysaccharide (LPS) that constitute the outer leaflet of the OM support a model in which the OM is in a semi-crystalline state. The low fluidity of the OM has been suggested to be an important property of this membrane that even contributes to cell rigidity. The LPS characteristics strongly determine the properties of the OM and the LPS layer fluidity has been measured using different techniques that require specific conditions or are technically challenging. Here, we characterize the Escherichia coli LPS fluidity by evaluating the lateral diffusion of the styryl dye FM4-64FX in fluorescence recovery after photobleaching experiments. This technique allowed us to determine the effect of different conditions and genetic backgrounds on the LPS fluidity. Our results show that a fraction of the LPS can slowly diffuse and that the fluidity of the LPS layer adapts by modifying the diffusion of the LPS and the fraction of mobile LPS molecules.
Collapse
Affiliation(s)
- Luis David Ginez
- Departamento Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, México
| | - Aurora Osorio
- Departamento Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, México
| | - Ricardo Vázquez-Ramírez
- Departamento Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, México
| | - Thelma Arenas
- Departamento Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, México
| | - Luis Mendoza
- Departamento Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, México
| | - Laura Camarena
- Departamento Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, México
| | - Sebastian Poggio
- Departamento Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, México
| |
Collapse
|
44
|
Baidya ATK, Kumar A, Kumar R, Darreh-Shori T. Allosteric Binding Sites of Ab Peptides on the Acetylcholine Synthesizing Enzyme ChAT as Deduced by In Silico Molecular Modeling. Int J Mol Sci 2022; 23:ijms23116073. [PMID: 35682752 PMCID: PMC9181666 DOI: 10.3390/ijms23116073] [Citation(s) in RCA: 12] [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: 04/08/2022] [Revised: 05/23/2022] [Accepted: 05/25/2022] [Indexed: 11/16/2022] Open
Abstract
The native function of amyloid-β (Aβ) peptides is still unexplored. However, several recent reports suggest a prominent role of Aβ peptides in acetylcholine homeostasis. To clarify this role of Aβ, we have reported that Aβ peptides at physiological concentrations can directly enhance the catalytic efficiency of the key cholinergic enzyme, choline acetyltransferase (ChAT), via an allosteric interaction. In the current study, we further aimed to elucidate the underlying ChAT-Aβ interaction mechanism using in silico molecular docking and dynamics analysis. Docking analysis suggested two most probable binding clusters on ChAT for Aβ40 and three for Aβ42. Most importantly, the docking results were challenged with molecular dynamic studies of 100 ns long simulation in triplicates (100 ns × 3 = 300 ns) and were analyzed for RMSD, RMSF, RoG, H-bond number and distance, SASA, and secondary structure assessment performed together with principal component analysis and the free-energy landscape diagram, which indicated that the ChAT-Aβ complex system was stable throughout the simulation time period with no abrupt motion during the evolution of the simulation across the triplicates, which also validated the robustness of the simulation study. Finally, the free-energy landscape analysis confirmed the docking results and demonstrated that the ChAT-Aβ complexes were energetically stable despite the unstructured nature of C- and N-terminals in Aβ peptides. Overall, this study supports the reported in vitro findings that Aβ peptides, particularly Aβ42, act as endogenous ChAT-Potentiating-Ligand (CPL), and thereby supports the hypothesis that one of the native biological functions of Aβ peptides is the regulation of acetylcholine homeostasis.
Collapse
Affiliation(s)
- Anurag TK Baidya
- Department of Pharmaceutical Engineering & Technology, Indian Institute of Technology (B.H.U.), Varanasi 221005, Uttar Pradesh, India;
| | - Amit Kumar
- Division of Clinical Geriatric, Center for Alzheimer Research, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, NEO, 141 52 Stockholm, Sweden;
| | - Rajnish Kumar
- Department of Pharmaceutical Engineering & Technology, Indian Institute of Technology (B.H.U.), Varanasi 221005, Uttar Pradesh, India;
- Division of Clinical Geriatric, Center for Alzheimer Research, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, NEO, 141 52 Stockholm, Sweden;
- Correspondence: (R.K.); (T.D.-S.)
| | - Taher Darreh-Shori
- Division of Clinical Geriatric, Center for Alzheimer Research, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, NEO, 141 52 Stockholm, Sweden;
- Correspondence: (R.K.); (T.D.-S.)
| |
Collapse
|
45
|
Mancino AS, Glass WG, Yan Y, Biggin PC, Bowie D. Spliced isoforms of the cardiac Nav1.5 channel modify channel activation by distinct structural mechanisms. J Gen Physiol 2022; 154:213074. [PMID: 35297947 PMCID: PMC8939363 DOI: 10.1085/jgp.202112906] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Revised: 02/02/2022] [Accepted: 02/22/2022] [Indexed: 12/19/2022] Open
Abstract
Alternative splicing is an important cellular mechanism that fine tunes the gating properties of both voltage- and ligand-gated ion-channels. The cardiac voltage-gated sodium channel, Nav1.5, is subject to alternative splicing of the DI S3–S4 linker, which generates two types of channels with different activation properties. Here, we show that the gating differences between the adult (mH1) and neonatal (Nav1.5e) isoforms of Nav1.5 are mediated by two amino acid residues: Thr/Ser at position 207 and Asp/Lys at position 211. Electrophysiological experiments, in conjunction with molecular dynamics simulations, revealed that each residue contributes equally to the overall gating shifts in activation, but that the underlying structural mechanisms are different. Asp/Lys at position 211 acts through electrostatic interactions, whereas Thr/Ser at position 207 is predicted to alter the hydrogen bond network at the top of the S3 helix. These distinct structural mechanisms work together to modify movement of the voltage-sensitive S4 helix to bring about channel activation. Interestingly, mutation of the homologous Asp and Thr residues of the skeletal muscle isoform, Nav1.4, to Lys and Ser, respectively, confers a similar gating shift in channel activation, suggesting that these residues may fulfill a conserved role across other Nav channel family members.
Collapse
Affiliation(s)
- Adamo S Mancino
- Integrated Program in Neuroscience, McGill University, Montréal, Quebec, Canada.,Department of Pharmacology and Therapeutics, McGill University, Montréal, Quebec, Canada
| | - William G Glass
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Yuhao Yan
- Integrated Program in Neuroscience, McGill University, Montréal, Quebec, Canada.,Department of Pharmacology and Therapeutics, McGill University, Montréal, Quebec, Canada
| | - Philip C Biggin
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Derek Bowie
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Quebec, Canada
| |
Collapse
|
46
|
Liao S, Pino MJ, Deleon C, Lindner-Jackson M, Wu C. Interaction analyses of hTAAR1 and mTAAR1 with antagonist EPPTB. Life Sci 2022; 300:120553. [PMID: 35452636 DOI: 10.1016/j.lfs.2022.120553] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Revised: 04/09/2022] [Accepted: 04/11/2022] [Indexed: 11/27/2022]
Abstract
Trace amine-associated receptor 1 (TAAR1) plays a critical role in regulating monoaminergic activity. EPPTB is the only known selective potent antagonist of the mouse (m) TAAR1 presently, while it was shown to be weak at antagonizing human (h) TAAR1. The lack of high-resolution structure of TAAR1 hinders the understanding of the differences in the interaction modes between EPPTB and m/hTARR1. The purpose of this study is to probe these interaction modes using homology modeling, molecular docking, molecular dynamics (MD) simulations, and molecular mechanics-generalized Born surface area (MM-GBSA) binding energy calculations. Eight populated conformers of hTAAR1-EPPTB complex were observed during the MD simulations and could be used in structure-based virtual screening in future. The MM-GBSA binding energy of hTAAR1-EPPTB complex (-96.5 kcal/mol) is larger than that of mTAAR1-EPPTB complex (-106.7 kcal/mol), which is consistent with the experimental finding that EPPTB has weaker binding affinity to hTAAR1. The several residues in binding site of hTAAR1 (F1544.56, T1945.42 and I2907.39) are different from these of mTAAR1 (Y1534.56, A1935.42 and Y2877.39), which might contribute to the binding affinity difference. Our docking analysis on another hTAAR1 antagonist Compound 3 has found that 1). this compound binds in different pockets of our mTAAR1 and hTAAR1 homology models with a slightly stronger binding affinity to hTAAR1; 2). both antagonists bind to a very similar pocket of hTAAR1.
Collapse
Affiliation(s)
- Siyan Liao
- Key Laboratory of Molecular Target & Clinical Pharmacology, School of Pharmaceutical Sciences, Guangzhou Medical University, Guangzhou 511436, China
| | - Michael James Pino
- Department of Chemistry and Biochemistry, Rowan University, 201 Mullica Hill Rd, Glassboro, NJ 08028, United States of America
| | - Catherine Deleon
- Department of Chemistry and Biochemistry, Rowan University, 201 Mullica Hill Rd, Glassboro, NJ 08028, United States of America
| | - Maurice Lindner-Jackson
- Department of Chemistry and Biochemistry, Rowan University, 201 Mullica Hill Rd, Glassboro, NJ 08028, United States of America
| | - Chun Wu
- Department of Chemistry and Biochemistry, Rowan University, 201 Mullica Hill Rd, Glassboro, NJ 08028, United States of America.
| |
Collapse
|
47
|
Riedlová K, Dolejšová T, Fišer R, Cwiklik L. H1 helix of colicin U causes phospholipid membrane permeation. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2022; 1864:183866. [PMID: 35007517 DOI: 10.1016/j.bbamem.2022.183866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 12/29/2021] [Accepted: 01/03/2022] [Indexed: 06/14/2023]
Abstract
In light of an increasing number of antibiotic-resistant bacterial strains, it is essential to understand an action imposed by various antimicrobial agents on bacteria at the molecular level. One of the leading mechanisms of killing bacteria is related to the alteration of their plasmatic membrane. We study bio-inspired peptides originating from natural antimicrobial proteins colicins, which can disrupt membranes of bacterial cells. Namely, we focus on the α-helix H1 of colicin U, produced by bacterium Shigella boydii, and compare it with analogous peptides derived from two different colicins. To address the behavior of the peptides in biological membranes, we employ a combination of molecular simulations and experiments. We use molecular dynamics simulations to show that all three peptides are stable in model zwitterionic and negatively charged phospholipid membranes. At the molecular level, their embedment leads to the formation of membrane defects, membrane permeation for water, and, for negatively charged lipids, membrane poration. These effects are caused by the presence of polar moieties in the considered peptides. Importantly, simulations demonstrate that even monomeric H1 peptides can form toroidal pores. At the macroscopic level, we employ experimental co-sedimentation and fluorescence leakage assays. We show that the H1 peptide of colicin U incorporates into phospholipid vesicles and disrupts their membranes, causing leakage, in agreement with the molecular simulations. These insights obtained for model systems seem important for understanding the mechanisms of antimicrobial action of natural bacteriocins and for future exploration of small bio-inspired peptides able to disrupt bacterial membranes.
Collapse
Affiliation(s)
- Kamila Riedlová
- J. Heyrovský Institute of Physical Chemistry, Czech Academy of Sciences, Dolejškova 3, 18223 Prague, Czech Republic; Department of Physical and Macromolecular Chemistry, Faculty of Science, Charles University, Hlavova 8, 12800 Prague, Czech Republic
| | - Tereza Dolejšová
- J. Heyrovský Institute of Physical Chemistry, Czech Academy of Sciences, Dolejškova 3, 18223 Prague, Czech Republic; Department of Genetics and Microbiology, Faculty of Science, Charles University, Viničná 5, 12843 Prague, Czech Republic
| | - Radovan Fišer
- Department of Genetics and Microbiology, Faculty of Science, Charles University, Viničná 5, 12843 Prague, Czech Republic.
| | - Lukasz Cwiklik
- J. Heyrovský Institute of Physical Chemistry, Czech Academy of Sciences, Dolejškova 3, 18223 Prague, Czech Republic.
| |
Collapse
|
48
|
Habgood M, Seiferth D, Zaki AM, Alibay I, Biggin PC. Atomistic mechanisms of human TRPA1 activation by electrophile irritants through molecular dynamics simulation and mutual information analysis. Sci Rep 2022; 12:4929. [PMID: 35322090 PMCID: PMC8943162 DOI: 10.1038/s41598-022-08824-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 03/07/2022] [Indexed: 12/16/2022] Open
Abstract
The ion channel TRPA1 is a promiscuous chemosensor, with reported response to a wide spectrum of noxious electrophilic irritants, as well as cold, heat, and mechanosensation. It is also implicated in the inception of itch and pain and has hence been investigated as a drug target for novel analgesics. The mechanism of electrophilic activation for TRPA1 is therefore of broad interest. TRPA1 structures with the pore in both open and closed states have recently been published as well as covalent binding modes for electrophile agonists. However, the detailed mechanism of coupling between electrophile binding sites and the pore remains speculative. In addition, while two different cysteine residues (C621 and C665) have been identified as critical for electrophile bonding and activation, the bound geometry has only been resolved at C621. Here, we use molecular dynamics simulations of TRPA1 in both pore-open and pore-closed states to explore the allosteric link between the electrophile binding sites and pore stability. Our simulations reveal that an open pore is structurally stable in the presence of open ‘pockets’ in the C621/C665 region, but rapidly collapses and closes when these pockets are shut. Binding of electrophiles at either C621 or C665 provides stabilisation of the pore-open state, but molecules bound at C665 are shown to be able to rotate in and out of the pocket, allowing for immediate stabilisation of transient open states. Finally, mutual information analysis of trajectories reveals an informational path linking the electrophile binding site pocket to the pore via the voltage-sensing-like domain, giving a detailed insight into the how the pore is stabilized in the open state.
Collapse
Affiliation(s)
- Matthew Habgood
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK. .,AWE Aldermaston, Reading, Berkshire, RG7 4PR, UK.
| | - David Seiferth
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK
| | - Afroditi-Maria Zaki
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK
| | - Irfan Alibay
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK
| | - Philip C Biggin
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK.
| |
Collapse
|
49
|
Conde D, Garrido PF, Calvelo M, Piñeiro Á, Garcia-Fandino R. Molecular Dynamics Simulations of Transmembrane Cyclic Peptide Nanotubes Using Classical Force Fields, Hydrogen Mass Repartitioning, and Hydrogen Isotope Exchange Methods: A Critical Comparison. Int J Mol Sci 2022; 23:ijms23063158. [PMID: 35328578 PMCID: PMC8951607 DOI: 10.3390/ijms23063158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 03/06/2022] [Accepted: 03/07/2022] [Indexed: 12/04/2022] Open
Abstract
Self-assembled cyclic peptide nanotubes with alternating D- and L-amino acid residues in the sequence of each subunit have attracted a great deal of attention due to their potential for new nanotechnology and biomedical applications, mainly in the field of antimicrobial peptides. Molecular dynamics simulations can be used to characterize these systems with atomic resolution at different time scales, providing information that is difficult to obtain via wet lab experiments. However, the performance of classical force fields typically employed in the simulation of biomolecules has not yet been extensively tested with this kind of highly constrained peptide. Four different classical force fields (AMBER, CHARMM, OPLS, and GROMOS), using a nanotube formed by eight D,L-α-cyclic peptides inserted into a lipid bilayer as a model system, were employed here to fill this gap. Significant differences in the pseudo-cylindrical cavities formed by the nanotubes were observed, the most important being the diameter of the nanopores, the number and location of confined water molecules, and the density distribution of the solvent molecules. Furthermore, several modifications were performed on GROMOS54a7, aiming to explore acceleration strategies of the MD simulations. The hydrogen mass repartitioning (HMR) and hydrogen isotope exchange (HIE) methods were tested to slow down the fastest degrees of freedom. These approaches allowed a significant increase in the time step employed in the equation of the motion integration algorithm, from 2 fs up to 5–7 fs, with no serious changes in the structural and dynamical properties of the nanopores. Subtle differences with respect to the simulations with the unmodified force fields were observed in the concerted movements of the cyclic peptides, as well as in the lifetime of several H-bonds. All together, these results are expected to contribute to better understanding of the behavior of self-assembled cyclic peptide nanotubes, as well as to support the methods tested to speed up general MD simulations; additionally, they do provide a number of quantitative descriptors that are expected to be used as a reference to design new experiments intended to validate and complement computational studies of antimicrobial cyclic peptides.
Collapse
Affiliation(s)
- Daniel Conde
- Center for Research in Biological Chemistry and Molecular Materials, Departamento de Química Orgánica, Universidade de Santiago de Compostela, Campus Vida s/n, 15782 Santiago de Compostela, Spain; (D.C.); (M.C.)
- Departamento de Física Aplicada, Facultade de Física, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain;
| | - Pablo F. Garrido
- Departamento de Física Aplicada, Facultade de Física, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain;
| | - Martín Calvelo
- Center for Research in Biological Chemistry and Molecular Materials, Departamento de Química Orgánica, Universidade de Santiago de Compostela, Campus Vida s/n, 15782 Santiago de Compostela, Spain; (D.C.); (M.C.)
- Departament de Química Inorgánica i Orgànica and Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, 08028 Barcelona, Spain
| | - Ángel Piñeiro
- Departamento de Física Aplicada, Facultade de Física, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain;
- Correspondence: (Á.P.); (R.G.-F.)
| | - Rebeca Garcia-Fandino
- Center for Research in Biological Chemistry and Molecular Materials, Departamento de Química Orgánica, Universidade de Santiago de Compostela, Campus Vida s/n, 15782 Santiago de Compostela, Spain; (D.C.); (M.C.)
- CIQUP, Centro de Investigação em Química, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, 4196-007 Porto, Portugal
- Correspondence: (Á.P.); (R.G.-F.)
| |
Collapse
|
50
|
Wang L, Zhang J, Wang D, Song C. Membrane contact probability: An essential and predictive character for the structural and functional studies of membrane proteins. PLoS Comput Biol 2022; 18:e1009972. [PMID: 35353812 PMCID: PMC9000120 DOI: 10.1371/journal.pcbi.1009972] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 04/11/2022] [Accepted: 02/25/2022] [Indexed: 11/20/2022] Open
Abstract
One of the unique traits of membrane proteins is that a significant fraction of their hydrophobic amino acids is exposed to the hydrophobic core of lipid bilayers rather than being embedded in the protein interior, which is often not explicitly considered in the protein structure and function predictions. Here, we propose a characteristic and predictive quantity, the membrane contact probability (MCP), to describe the likelihood of the amino acids of a given sequence being in direct contact with the acyl chains of lipid molecules. We show that MCP is complementary to solvent accessibility in characterizing the outer surface of membrane proteins, and it can be predicted for any given sequence with a machine learning-based method by utilizing a training dataset extracted from MemProtMD, a database generated from molecular dynamics simulations for the membrane proteins with a known structure. As the first of many potential applications, we demonstrate that MCP can be used to systematically improve the prediction precision of the protein contact maps and structures. The distribution of residues on protein surfaces is largely determined by the surrounding environment. For soluble proteins, most of the residues on the outer surface are hydrophilic, and people use the quantity “solvent accessibility” to describe and predict these surface residues. In contrast, for membrane proteins that are embedded in a lipid bilayer, many of their surface residues are hydrophobic and membrane-contacting, but there is yet a widely-accepted quantity for the description or prediction of this characteristic property. Here, we propose a new quantity termed “membrane contact probability (MCP)”, which can be used to describe and predict the membrane-contacting surface residues of proteins. We also propose a machine learning-based method to predict MCP from protein sequences, utilizing the dataset generated by physics-based computer simulations. We demonstrate that a quantity such as MCP is helpful for protein structure prediction, and we believe that it will find broad applications in the structure and function studies of membrane proteins.
Collapse
Affiliation(s)
- Lei Wang
- Center for Quantitative Biology, Academy for Advanced Interdisciplinary studies, Peking University, Beijing, China
| | - Jiangguo Zhang
- School of Life Sciences, Peking University, Beijing, China
| | - Dali Wang
- Center for Quantitative Biology, Academy for Advanced Interdisciplinary studies, Peking University, Beijing, China
- Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
| | - Chen Song
- Center for Quantitative Biology, Academy for Advanced Interdisciplinary studies, Peking University, Beijing, China
- Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
- * E-mail:
| |
Collapse
|