1
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Mukherjee S, Ramos S, Pezzotti S, Kalarikkal A, Prass TM, Galazzo L, Gendreizig D, Barbosa N, Bordignon E, Havenith M, Schäfer LV. Entropy Tug-of-War Determines Solvent Effects in the Liquid-Liquid Phase Separation of a Globular Protein. J Phys Chem Lett 2024; 15:4047-4055. [PMID: 38580324 PMCID: PMC11033941 DOI: 10.1021/acs.jpclett.3c03421] [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: 02/15/2024] [Accepted: 03/19/2024] [Indexed: 04/07/2024]
Abstract
Liquid-liquid phase separation (LLPS) plays a key role in the compartmentalization of cells via the formation of biomolecular condensates. Here, we combined atomistic molecular dynamics (MD) simulations and terahertz (THz) spectroscopy to determine the solvent entropy contribution to the formation of condensates of the human eye lens protein γD-Crystallin. The MD simulations reveal an entropy tug-of-war between water molecules that are released from the protein droplets and those that are retained within the condensates, two categories of water molecules that were also assigned spectroscopically. A recently developed THz-calorimetry method enables quantitative comparison of the experimental and computational entropy changes of the released water molecules. The strong correlation mutually validates the two approaches and opens the way to a detailed atomic-level understanding of the different driving forces underlying the LLPS.
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Affiliation(s)
- Saumyak Mukherjee
- Center
for Theoretical Chemistry, Ruhr University
Bochum, D-44780 Bochum, Germany
| | - Sashary Ramos
- Department
of Physical Chemistry II, Ruhr University
Bochum, D-44780 Bochum, Germany
| | - Simone Pezzotti
- Department
of Physical Chemistry II, Ruhr University
Bochum, D-44780 Bochum, Germany
| | - Abhishek Kalarikkal
- Faculty
of Chemistry and Biochemistry, Ruhr University
Bochum, D-44780 Bochum, Germany
| | - Tobias M. Prass
- Center
for Theoretical Chemistry, Ruhr University
Bochum, D-44780 Bochum, Germany
| | - Laura Galazzo
- Faculty
of Chemistry and Biochemistry, Ruhr University
Bochum, D-44780 Bochum, Germany
| | - Dominik Gendreizig
- Department
of Physical Chemistry, University of Geneva, Quai Ernest Ansermet 30, 1211 Geneva, Switzerland
| | - Natercia Barbosa
- Department
of Physical Chemistry, University of Geneva, Quai Ernest Ansermet 30, 1211 Geneva, Switzerland
| | - Enrica Bordignon
- Faculty
of Chemistry and Biochemistry, Ruhr University
Bochum, D-44780 Bochum, Germany
- Department
of Physical Chemistry, University of Geneva, Quai Ernest Ansermet 30, 1211 Geneva, Switzerland
| | - Martina Havenith
- Department
of Physical Chemistry II, Ruhr University
Bochum, D-44780 Bochum, Germany
| | - Lars V. Schäfer
- Center
for Theoretical Chemistry, Ruhr University
Bochum, D-44780 Bochum, Germany
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2
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Roccatano D. A molecular dynamics simulation study of glycine/serine octapeptides labeled with 2,3-diazabicyclo[2.2.2]oct-2-ene fluorophore. J Chem Phys 2024; 160:145101. [PMID: 38587229 DOI: 10.1063/5.0190073] [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: 12/03/2023] [Accepted: 03/19/2024] [Indexed: 04/09/2024] Open
Abstract
The compound 2,3-diazabicyclo[2.2.2]oct-2-ene (DBO) is a versatile fluorophore widely used in Förster resonance energy transfer (FRET) spectroscopy studies due to its remarkable sensitivity, enabling precise donor-acceptor distance measurements, even for short peptides. Integrating time-resolved and FRET spectroscopies with molecular dynamics simulations provides a robust approach to unravel the structure and dynamics of biopolymers in a solution. This study investigates the structural behavior of three octapeptide variants: Trp-(Gly-Ser)3-Dbo, Trp-(GlyGly)3-Dbo, and Trp-(SerSer)3-Dbo, where Dbo represents the DBO-containing modified aspartic acid, using molecular dynamics simulations. Glycine- and serine-rich amino acid fragments, common in flexible protein regions, play essential roles in functional properties. Results show excellent agreement between end-to-end distances, orientational factors from simulations, and the available experimental and theoretical data, validating the reliability of the GROMOS force field model. The end-to-end distribution, modeled using three Gaussian distributions, reveals a complex shape, confirmed by cluster analysis highlighting a limited number of significant conformations dominating the peptide landscape. All peptides predominantly adopt a disordered state in the solvent, yet exhibit a compact shape, aligning with the model of disordered polypeptide chains in poor solvents. Conformations show marginal dependence on chain composition, with Ser-only chains exhibiting slightly more elongation. This study enhances our understanding of peptide behavior, providing valuable insights into their structural dynamics in solution.
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Affiliation(s)
- Danilo Roccatano
- School of Mathematics and Physics, University of Lincoln, Brayford Pool, Lincoln LN6 7TS, United Kingdom
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3
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Mukherjee S, Schäfer LV. Thermodynamic forces from protein and water govern condensate formation of an intrinsically disordered protein domain. Nat Commun 2023; 14:5892. [PMID: 37735186 PMCID: PMC10514047 DOI: 10.1038/s41467-023-41586-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Accepted: 09/08/2023] [Indexed: 09/23/2023] Open
Abstract
Liquid-liquid phase separation (LLPS) can drive a multitude of cellular processes by compartmentalizing biological cells via the formation of dense liquid biomolecular condensates, which can function as membraneless organelles. Despite its importance, the molecular-level understanding of the underlying thermodynamics of this process remains incomplete. In this study, we use atomistic molecular dynamics simulations of the low complexity domain (LCD) of human fused in sarcoma (FUS) protein to investigate the contributions of water and protein molecules to the free energy changes that govern LLPS. Both protein and water components are found to have comparably sizeable thermodynamic contributions to the formation of FUS condensates. Moreover, we quantify the counteracting effects of water molecules that are released into the bulk upon condensate formation and the waters retained within the protein droplets. Among the various factors considered, solvation entropy and protein interaction enthalpy are identified as the most important contributions, while solvation enthalpy and protein entropy changes are smaller. These results provide detailed molecular insights on the intricate thermodynamic interplay between protein- and solvation-related forces underlying the formation of biomolecular condensates.
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Affiliation(s)
- Saumyak Mukherjee
- Center for Theoretical Chemistry, Ruhr University Bochum, D-44780, Bochum, Germany
| | - Lars V Schäfer
- Center for Theoretical Chemistry, Ruhr University Bochum, D-44780, Bochum, Germany.
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4
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Maiti S, Heyden M. Model-Dependent Solvation of the K-18 Domain of the Intrinsically Disordered Protein Tau. J Phys Chem B 2023; 127:7220-7230. [PMID: 37556237 DOI: 10.1021/acs.jpcb.3c01726] [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: 08/11/2023]
Abstract
A known imbalance between intra-protein and protein-water interactions in many empirical force fields results in collapsed conformational ensembles of intrinsically disordered proteins in explicit solvent simulations that disagree with experiments. Multiple strategies have been introduced in the literature to modify protein-water interactions, which improve agreement between experiments and simulations. In this work, we combine simulations with standard and modified force fields with a spatially resolved analysis of solvation free energy contributions and compare the consequences of each strategy. We find that enhanced Lennard-Jones (LJ) interactions between protein atoms and water oxygens primarily improve the solvation of nonpolar functional groups of the protein. In contrast, modified electrostatics in the water model or strengthened LJ interactions between the protein and water hydrogens mainly affect the hydration of polar functional groups. Modified electrostatics further impact the average orientation of water molecules in the hydration shell. As a result, protein-water interactions with the first hydration layers are strengthened, while interactions with water molecules in higher hydration shells are weakened. Hence, distinct strategies to balance intra-protein and protein-water interactions in simulations have qualitatively different effects on protein solvation. These differences are not necessarily captured by comparisons to experiments that report on global parameters describing protein conformational ensembles, e.g., the radius of gyration, but will influence the tendency of a protein to form aggregates or phase-separated droplets.
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Affiliation(s)
- Sthitadhi Maiti
- School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, United States
| | - Matthias Heyden
- School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, United States
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5
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Fu G, Yan S, Khoo CJ, Chao VC, Liu Z, Mukhi M, Hervas R, Li XD, Ti SC. Integrated regulation of tubulin tyrosination and microtubule stability by human α-tubulin isotypes. Cell Rep 2023; 42:112653. [PMID: 37379209 DOI: 10.1016/j.celrep.2023.112653] [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: 07/28/2022] [Revised: 05/03/2023] [Accepted: 05/31/2023] [Indexed: 06/30/2023] Open
Abstract
Tubulin isotypes are critical for the functions of cellular microtubules, which exhibit different stability and harbor various post-translational modifications. However, how tubulin isotypes determine the activities of regulators for microtubule stability and modifications remains unknown. Here, we show that human α4A-tubulin, a conserved genetically detyrosinated α-tubulin isotype, is a poor substrate for enzymatic tyrosination. To examine the stability of microtubules reconstituted with defined tubulin compositions, we develop a strategy to site-specifically label recombinant human tubulin for single-molecule TIRF microscopy-based in vitro assays. The incorporation of α4A-tubulin into the microtubule lattice stabilizes the polymers from passive and MCAK-stimulated depolymerization. Further characterization reveals that the compositions of α-tubulin isotypes and tyrosination/detyrosination states allow graded control for the microtubule binding and the depolymerization activities of MCAK. Together, our results uncover the tubulin isotype-dependent enzyme activity for an integrated regulation of α-tubulin tyrosination/detyrosination states and microtubule stability, two well-correlated features of cellular microtubules.
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Affiliation(s)
- Guoling Fu
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong SAR, China
| | - Shan Yan
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong SAR, China
| | - Chen Jing Khoo
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong SAR, China
| | - Victor C Chao
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong SAR, China
| | - Zheng Liu
- Department of Chemistry, The University of Hong Kong, Hong Kong SAR, China
| | - Mayur Mukhi
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong SAR, China
| | - Rubén Hervas
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong SAR, China
| | - Xiang David Li
- Department of Chemistry, The University of Hong Kong, Hong Kong SAR, China
| | - Shih-Chieh Ti
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong SAR, China.
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6
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Conti Nibali V, Maiti S, Saija F, Heyden M, Cassone G. Electric-field induced entropic effects in liquid water. J Chem Phys 2023; 158:2889002. [PMID: 37154276 DOI: 10.1063/5.0139460] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Accepted: 03/13/2023] [Indexed: 05/10/2023] Open
Abstract
Externally applied electric fields in liquid water can induce a plethora of effects with wide implications in electrochemistry and hydrogen-based technologies. Although some effort has been made to elucidate the thermodynamics associated with the application of electric fields in aqueous systems, to the best of our knowledge, field-induced effects on the total and local entropy of bulk water have never been presented so far. Here, we report on classical TIP4P/2005 and ab initio molecular dynamics simulations measuring entropic contributions carried by diverse field intensities in liquid water at room temperature. We find that strong fields are capable of aligning large fractions of molecular dipoles. Nevertheless, the order-maker action of the field leads to quite modest entropy reductions in classical simulations. Albeit more significant variations are recorded during first-principles simulations, the associated entropy modifications are small compared to the entropy change involved in the freezing phenomenon, even at intense fields slightly beneath the molecular dissociation threshold. This finding further corroborates the idea that electrofreezing (i.e., the electric-field-induced crystallization) cannot take place in bulk water at room temperature. In addition, here, we propose a molecular-dynamics-based analysis (3D-2PT) that spatially resolves the local entropy and the number density of bulk water under an electric field, which enables us to map their field-induced changes in the environment of reference H2O molecules. By returning detailed spatial maps of the local order, the proposed approach is capable of establishing a link between entropic and structural modifications with atomistic resolution.
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Affiliation(s)
- Valeria Conti Nibali
- Department of Mathematical and Computer Sciences, Physical Sciences and Earth Sciences, University of Messina, 98166 Messina, Italy
- Institute for Chemical-Physical Processes, National Research Council of Italy (IPCF-CNR), 98158 Messina, Italy
| | - Sthitadhi Maiti
- School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, USA
| | - Franz Saija
- Institute for Chemical-Physical Processes, National Research Council of Italy (IPCF-CNR), 98158 Messina, Italy
| | - Matthias Heyden
- School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, USA
| | - Giuseppe Cassone
- Institute for Chemical-Physical Processes, National Research Council of Italy (IPCF-CNR), 98158 Messina, Italy
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7
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Lazaric A, Pattni V, Fuegner K, Ben-Naim A, Heyden M. Solvation free energy arithmetic for small organic molecules. J Comput Chem 2023; 44:1263-1277. [PMID: 36866644 DOI: 10.1002/jcc.27081] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2022] [Revised: 11/21/2022] [Accepted: 12/29/2022] [Indexed: 03/04/2023]
Abstract
Solvent-mediated interactions contribute to ligand binding affinities in computational drug design and provide a challenge for theoretical predictions. In this study, we analyze the solvation free energy of benzene derivatives in water to guide the development of predictive models for solvation free energies and solvent-mediated interactions. We use a spatially resolved analysis of local solvation free energy contributions and define solvation free energy arithmetic, which enable us to construct additive models to describe the solvation of complex compounds. The substituents analyzed in this study are carboxyl and nitro-groups due to their similar sterical requirements but distinct interactions with water. We find that nonadditive solvation free energy contributions are primarily attributed to electrostatics, which are qualitatively reproduced with computationally efficient continuum models. This suggests a promising route for the development of efficient and accurate models for the solvation of complex molecules with varying substitution patterns using solvation arithmetic.
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Affiliation(s)
- Aleksandar Lazaric
- School of Molecular Sciences, Arizona State University, Tempe, Arizona, USA
| | - Viren Pattni
- School of Molecular Sciences, Arizona State University, Tempe, Arizona, USA
| | - Kaprao Fuegner
- School of Molecular Sciences, Arizona State University, Tempe, Arizona, USA
| | - Arieh Ben-Naim
- Department of Physical Chemistry, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Matthias Heyden
- School of Molecular Sciences, Arizona State University, Tempe, Arizona, USA
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8
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Kalayan J, Chakravorty A, Warwicker J, Henchman RH. Total free energy analysis of fully hydrated proteins. Proteins 2023; 91:74-90. [PMID: 35964252 PMCID: PMC10087023 DOI: 10.1002/prot.26411] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 08/04/2022] [Accepted: 08/09/2022] [Indexed: 12/15/2022]
Abstract
The total free energy of a hydrated biomolecule and its corresponding decomposition of energy and entropy provides detailed information about regions of thermodynamic stability or instability. The free energies of four hydrated globular proteins with different net charges are calculated from a molecular dynamics simulation, with the energy coming from the system Hamiltonian and entropy using multiscale cell correlation. Water is found to be most stable around anionic residues, intermediate around cationic and polar residues, and least stable near hydrophobic residues, especially when more buried, with stability displaying moderate entropy-enthalpy compensation. Conversely, anionic residues in the proteins are energetically destabilized relative to singly solvated amino acids, while trends for other residues are less clear-cut. Almost all residues lose intraresidue entropy when in the protein, enthalpy changes are negative on average but may be positive or negative, and the resulting overall stability is moderate for some proteins and negligible for others. The free energy of water around single amino acids is found to closely match existing hydrophobicity scales. Regarding the effect of secondary structure, water is slightly more stable around loops, of intermediate stability around β strands and turns, and least stable around helices. An interesting asymmetry observed is that cationic residues stabilize a residue when bonded to its N-terminal side but destabilize it when on the C-terminal side, with a weaker reversed trend for anionic residues.
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Affiliation(s)
- Jas Kalayan
- Division of Pharmacy and Optometry, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Arghya Chakravorty
- Department of Chemistry and Biophysics, University of Michigan, Ann Arbor, Michigan, USA
| | - Jim Warwicker
- Manchester Institute of Biotechnology and School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Richard H Henchman
- Sydney Medical School, Faculty of Medicine and Health, University of Sydney, Sydney, Australia
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9
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Abstract
![]()
Water is essential
for the structure, dynamics, energetics, and
thus the function of biomolecules. It is a formidable challenge to
elicit, in microscopic detail, the role of the solvation-related driving
forces of biomolecular processes, such as the enthalpy and entropy
contributions to the underlying free-energy landscape. In this Perspective,
we discuss recent developments and applications of computational methods
that provide a spatially resolved map of hydration thermodynamics
in biomolecular systems and thus yield atomic-level insights to guide
the interpretation of experimental observations. An emphasis is on
the challenge of quantifying the hydration entropy, which requires
characterization of both the motions of the biomolecules and of the
water molecules in their surrounding.
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Affiliation(s)
- Saumyak Mukherjee
- Theoretical Chemistry, Ruhr University Bochum, 44801 Bochum, Germany
| | - Lars V Schäfer
- Theoretical Chemistry, Ruhr University Bochum, 44801 Bochum, Germany
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10
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Hsueh SCC, Nijland M, Peng X, Hilton B, Plotkin SS. First Principles Calculation of Protein-Protein Dimer Affinities of ALS-Associated SOD1 Mutants. Front Mol Biosci 2022; 9:845013. [PMID: 35402516 PMCID: PMC8988244 DOI: 10.3389/fmolb.2022.845013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 02/08/2022] [Indexed: 01/03/2023] Open
Abstract
Cu,Zn superoxide dismutase (SOD1) is a 32 kDa homodimer that converts toxic oxygen radicals in neurons to less harmful species. The dimerization of SOD1 is essential to the stability of the protein. Monomerization increases the likelihood of SOD1 misfolding into conformations associated with aggregation, cellular toxicity, and neuronal death in familial amyotrophic lateral sclerosis (fALS). The ubiquity of disease-associated mutations throughout the primary sequence of SOD1 suggests an important role of physicochemical processes, including monomerization of SOD1, in the pathology of the disease. Herein, we use a first-principles statistical mechanics method to systematically calculate the free energy of dimer binding for SOD1 using molecular dynamics, which involves sequentially computing conformational, orientational, and separation distance contributions to the binding free energy. We consider the effects of two ALS-associated mutations in SOD1 protein on dimer stability, A4V and D101N, as well as the role of metal binding and disulfide bond formation. We find that the penalty for dimer formation arising from the conformational entropy of disordered loops in SOD1 is significantly larger than that for other protein–protein interactions previously considered. In the case of the disulfide-reduced protein, this leads to a bound complex whose formation is energetically disfavored. Somewhat surprisingly, the loop free energy penalty upon dimerization is still significant for the holoprotein, despite the increased structural order induced by the bound metal cations. This resulted in a surprisingly modest increase in dimer binding free energy of only about 1.5 kcal/mol upon metalation of the protein, suggesting that the most significant stabilizing effects of metalation are on folding stability rather than dimer binding stability. The mutant A4V has an unstable dimer due to weakened monomer-monomer interactions, which are manifested in the calculation by a separation free energy surface with a lower barrier. The mutant D101N has a stable dimer partially due to an unusually rigid β-barrel in the free monomer. D101N also exhibits anticooperativity in loop folding upon dimerization. These computational calculations are, to our knowledge, the most quantitatively accurate calculations of dimer binding stability in SOD1 to date.
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Affiliation(s)
- Shawn C C Hsueh
- Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada
| | - Mark Nijland
- Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada.,Laboratory of Organic Chemistry, Wageningen University and Research, Wageningen, Netherlands.,Laboratory of Physical Chemistry and Soft Matter, Wageningen University and Research, Wageningen, Netherlands
| | - Xubiao Peng
- Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada.,Center for Quantum Technology Research, School of Physics, Beijing Institute of Technology, Beijing, China
| | - Benjamin Hilton
- Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada.,Imperial College London, London, United Kingdom
| | - Steven S Plotkin
- Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada.,Genome Science and Technology Program, University of British Columbia, Vancouver, BC, Canada
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11
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Behzadi M, Amininasab M, Eghtedardoost M, Bagheri M. Turn-folded magainin lipopeptide analog induces cytoplasmic vacuoles in MDA-MB-231 cells through G2-phase arrest. Biochem Biophys Res Commun 2021; 583:199-205. [PMID: 34752987 DOI: 10.1016/j.bbrc.2021.10.076] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Accepted: 10/30/2021] [Indexed: 02/04/2023]
Abstract
Selective induced non-canonical programmed deaths in the lipid raft type 1-enriched MDA-MB-231 is a promising treatment approach. Cationic amphiphilic peptides conjugated to relatively long fatty acyl chains that tend to self-aggregate are prone to upregulate necroptotic and paraptotic signaling. We investigated the toxic effects of an N-terminally palmitoylated magainin derivate (P1MK5E) in the MDA-MB-231 cells in relation to its structure at molecular level. The modeling showed that the palmitoylation reinforces a turn-like structural motif in the lipopeptide which is likely required for its activity. P1MK5E triggered intracellular generation of reactive oxygen species (ROS), G2-phase arrest, mitochondrial membrane potential (ΔΨmt) disturbance and presumable flopping of phosphatidylserine (PtdSer) to the cancer cell membrane outer surface in a comparable manner to doxorubicin (DOX) that induces apoptotic signaling. Despite forming extensive congregates of different sizes at the cell surface, P1MK5E had little impacts on the MDA-MB-231 membrane integrity. The cell death upon exposure to the lipopeptide was, however, caspase 3 independent and characterized by cytoplasmic vacuolation and no distinct nuclear fragmentation that is to be privileged in the treatment of apoptotic resistance pathways in triple-negative breast cancers (TNBCs).
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Affiliation(s)
- Malihe Behzadi
- Peptide Chemistry Laboratory, Institute of Biochemistry and Biophysics, University of Tehran, 16 Azar Street, 14176-14335, Tehran, Iran
| | - Mehriar Amininasab
- Department of Cell and Molecular Biology, School of Biology, College of Science, University of Tehran, 16 Azar Street, 14174-66191, Tehran, Iran
| | - Marzieh Eghtedardoost
- Department of Immunology, Faculty of Medical Sciences, Tarbiat Modares University, 14115-111, Tehran, Tehran, Iran
| | - Mojtaba Bagheri
- Peptide Chemistry Laboratory, Institute of Biochemistry and Biophysics, University of Tehran, 16 Azar Street, 14176-14335, Tehran, Iran.
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