51
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Peng J, Song X, Li X, Jiang Y, Liu G, Wei Y, Xia Q. Molecular Dynamics Study on the Aggregation Behavior of Triton X Micelles with Different PEO Chain Lengths in Aqueous Solution. Molecules 2023; 28:molecules28083557. [PMID: 37110791 PMCID: PMC10146536 DOI: 10.3390/molecules28083557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Revised: 04/02/2023] [Accepted: 04/16/2023] [Indexed: 04/29/2023] Open
Abstract
The aggregation structure of Triton X (TX) amphiphilic molecules in aqueous solution plays an important role in determining the various properties and applications of surfactant solutions. In this paper, the properties of micelles formed by TX-5, TX-114, and TX-100 molecules with different poly(ethylene oxide) (PEO) chain lengths in TX series of nonionic surfactants were studied via molecular dynamics (MD) simulation. The structural characteristics of three micelles were analyzed at the molecular level, including the shape and size of micelles, the solvent accessible surface area, the radial distribution function, the micelle configuration, and the hydration numbers. With the increase of PEO chain length, the micelle size and solvent accessible surface area also increase. The distribution probability of the polar head oxygen atoms on the surface of the TX-100 micelle is higher than that in the TX-5 or TX-114 micelle. In particular, the tail quaternary carbon atoms in the hydrophobic region are mainly located at the micelle exterior. For TX-5, TX-114, and TX-100 micelles, the interactions between micelles and water molecules are also quite different. These structures and comparisons at the molecular level contribute to the further understanding of the aggregation and applications of TX series surfactants.
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Affiliation(s)
- Jin Peng
- School of Chemistry and Chemical Engineering, Linyi University, Linyi 276000, China
| | - Xiaoju Song
- School of Chemistry and Chemical Engineering, Linyi University, Linyi 276000, China
| | - Xin Li
- School of Chemistry and Chemical Engineering, Linyi University, Linyi 276000, China
| | - Yongkang Jiang
- School of Chemistry and Chemical Engineering, Linyi University, Linyi 276000, China
| | - Guokui Liu
- School of Chemistry and Chemical Engineering, Linyi University, Linyi 276000, China
| | - Yaoyao Wei
- School of Chemistry and Chemical Engineering, Linyi University, Linyi 276000, China
| | - Qiying Xia
- School of Chemistry and Chemical Engineering, Linyi University, Linyi 276000, China
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52
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Bhendale M, Singh JK. Molecular Insights on Morphology, Composition, and Stability of Mixed Micelles Formed by Ionic Surfactant and Nonionic Block Copolymer in Water Using Coarse-Grained Molecular Dynamics Simulations. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:5031-5040. [PMID: 36992607 DOI: 10.1021/acs.langmuir.3c00045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
The nanoscale association domains are the ultimate determinants of the macroscopic properties of complex fluids involving amphiphilic polymers and surfactants, and hence, it is foremost important to understand the role of polymer/surfactant concentration on these domains. We have used coarse-grained molecular dynamics simulations to investigate the effect of polymer/surfactant concentration on the morphology of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO, i.e., pluronics or poloxamers) block copolymer, and ionic surfactants sodium dodecyl sulfate (SDS), mixed micelles in aqueous solution. The proclivity of the surfactant to form the mixed micelles is also probed using umbrella sampling simulations. In this study, we observed that the core of the pluronic + SDS formed mixed micelles consists of PPO, the alkyl tail of SDS, and some water molecules, whereas the PEO, water, and sulfate headgroups of SDS form a shell, consistent with experimental observations. The micelles are spherical at high-pluronic/low-SDS compositions, ellipsoidal at high-SDS/low-pluronic compositions, and wormlike-cylindrical at high-pluronic/high-SDS compositions. The transitions in micelle morphology are governed by the solvent accessible surface area of mixed aggregates, electrostatic repulsion between SDS-headgroups, and dehydration of PEO and PPO segments. The free energy barrier for SDS escape is much higher in mixed micelles than in pure SDS micelles, indicating a stronger tendency for SDS to form pluronic-SDS mixed micelles.
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Affiliation(s)
- Mangesh Bhendale
- Department of Chemical Engineering, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh 208016, India
| | - Jayant K Singh
- Department of Chemical Engineering, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh 208016, India
- Prescience Insilico Private Limited, Fifth Floor, Novel MSR Building, Marathalli, Bengaluru, Karnataka 560037, India
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53
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Zhao L, Zhang T, Luo Y, Li L, Cheng R, Shi Z, Wang G, Ren T. Effects of temperature and microwave on the stability of the blast effector complex APikL2A/sHMA25 as determined by molecular dynamics analyses. J Mol Model 2023; 29:134. [PMID: 37041399 DOI: 10.1007/s00894-023-05550-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Accepted: 04/04/2023] [Indexed: 04/13/2023]
Abstract
Magnaporthe oryzae is the causal agent of rice blast, and understanding how abiotic stress affects the resistance of plants to this disease is useful for designing disease control strategies. In this paper, the effects of temperature and microwave irradiation on the effector complex comprising APikL2A from M. oryzae and sHMA25 from foxtail millet were investigated by molecular dynamics simulations using the GROMACS software package. While the structure of APikL2A/sHMA25 remained relatively stable in a temperature range of 290 K (16.85 °C) to 320 K (46.85 °C), the concave shape of the temperature-dependent binding free energy curve indicated that there was maximum binding affinity between APikL2A and sHMA25 at 300 K-310 K. This coincided with the optimum infectivity temperature, thus suggesting that coupling of the two polypeptides may play a role in the infection process. A strong oscillating electric field destroyed the structure of APikL2A/sHMA25, although it was stable and not susceptible to weak electric fields.
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Affiliation(s)
- Ling Zhao
- Institute of Millet Crops, Hebei Academy of Agriculture and Forestry Sciences/Key Laboratory of Genetic Improvement and Utilization for Featured Coarse Cereals (Co-construction by Ministry and Province), Ministry of Agriculture and Rural Afairs/National Foxtail Millet Improvement Center/Key Laboratory of Minor Cereal Crops of Hebei Province, Hebei Academy of Agriculture and Forestry Sciences, 050035, Shijiazhuang, China
| | - Ting Zhang
- Institute of Millet Crops, Hebei Academy of Agriculture and Forestry Sciences/Key Laboratory of Genetic Improvement and Utilization for Featured Coarse Cereals (Co-construction by Ministry and Province), Ministry of Agriculture and Rural Afairs/National Foxtail Millet Improvement Center/Key Laboratory of Minor Cereal Crops of Hebei Province, Hebei Academy of Agriculture and Forestry Sciences, 050035, Shijiazhuang, China
| | - Yanjie Luo
- Institute of Millet Crops, Hebei Academy of Agriculture and Forestry Sciences/Key Laboratory of Genetic Improvement and Utilization for Featured Coarse Cereals (Co-construction by Ministry and Province), Ministry of Agriculture and Rural Afairs/National Foxtail Millet Improvement Center/Key Laboratory of Minor Cereal Crops of Hebei Province, Hebei Academy of Agriculture and Forestry Sciences, 050035, Shijiazhuang, China
| | - Lin Li
- Institute of Millet Crops, Hebei Academy of Agriculture and Forestry Sciences/Key Laboratory of Genetic Improvement and Utilization for Featured Coarse Cereals (Co-construction by Ministry and Province), Ministry of Agriculture and Rural Afairs/National Foxtail Millet Improvement Center/Key Laboratory of Minor Cereal Crops of Hebei Province, Hebei Academy of Agriculture and Forestry Sciences, 050035, Shijiazhuang, China
| | - Ruhong Cheng
- Institute of Millet Crops, Hebei Academy of Agriculture and Forestry Sciences/Key Laboratory of Genetic Improvement and Utilization for Featured Coarse Cereals (Co-construction by Ministry and Province), Ministry of Agriculture and Rural Afairs/National Foxtail Millet Improvement Center/Key Laboratory of Minor Cereal Crops of Hebei Province, Hebei Academy of Agriculture and Forestry Sciences, 050035, Shijiazhuang, China
| | - Zhigang Shi
- Institute of Millet Crops, Hebei Academy of Agriculture and Forestry Sciences/Key Laboratory of Genetic Improvement and Utilization for Featured Coarse Cereals (Co-construction by Ministry and Province), Ministry of Agriculture and Rural Afairs/National Foxtail Millet Improvement Center/Key Laboratory of Minor Cereal Crops of Hebei Province, Hebei Academy of Agriculture and Forestry Sciences, 050035, Shijiazhuang, China
| | - Genping Wang
- Institute of Millet Crops, Hebei Academy of Agriculture and Forestry Sciences/Key Laboratory of Genetic Improvement and Utilization for Featured Coarse Cereals (Co-construction by Ministry and Province), Ministry of Agriculture and Rural Afairs/National Foxtail Millet Improvement Center/Key Laboratory of Minor Cereal Crops of Hebei Province, Hebei Academy of Agriculture and Forestry Sciences, 050035, Shijiazhuang, China.
| | - Tiancong Ren
- School of Resources and Environmental Sciences, Shijiazhuang University, Shijiazhuang, 050035, China.
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54
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Zamel J, Chen J, Zaer S, Harris PD, Drori P, Lebendiker M, Kalisman N, Dokholyan NV, Lerner E. Structural and dynamic insights into α-synuclein dimer conformations. Structure 2023; 31:411-423.e6. [PMID: 36809765 PMCID: PMC10081966 DOI: 10.1016/j.str.2023.01.011] [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: 11/20/2022] [Revised: 01/12/2023] [Accepted: 01/26/2023] [Indexed: 02/22/2023]
Abstract
Parkinson disease is associated with the aggregation of the protein α-synuclein. While α-synuclein can exist in multiple oligomeric states, the dimer has been a subject of extensive debates. Here, using an array of biophysical approaches, we demonstrate that α-synuclein in vitro exhibits primarily a monomer-dimer equilibrium in nanomolar concentrations and up to a few micromolars. We then use spatial information from hetero-isotopic cross-linking mass spectrometry experiments as restrains in discrete molecular dynamics simulations to obtain the ensemble structure of dimeric species. Out of eight structural sub-populations of dimers, we identify one that is compact, stable, abundant, and exhibits partially exposed β-sheet structures. This compact dimer is the only one where the hydroxyls of tyrosine 39 are in proximity that may promote dityrosine covalent linkage upon hydroxyl radicalization, which is implicated in α-synuclein amyloid fibrils. We propose that this α-synuclein dimer features etiological relevance to Parkinson disease.
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Affiliation(s)
- Joanna Zamel
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Faculty of Mathematics & Science, The Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Jiaxing Chen
- Department of Pharmacology, Penn State College of Medicine, Hershey, PA 17033, USA
| | - Sofia Zaer
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Faculty of Mathematics & Science, The Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Paul David Harris
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Faculty of Mathematics & Science, The Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Paz Drori
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Faculty of Mathematics & Science, The Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Mario Lebendiker
- Wolfson Centre for Applied Structural Biology, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, The Edmond J. Safra Campus, Givat Ram, Jerusalem, 9190401, Israel
| | - Nir Kalisman
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Faculty of Mathematics & Science, The Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Nikolay V Dokholyan
- Department of Pharmacology, Penn State College of Medicine, Hershey, PA 17033, USA; Department of Biochemistry & Molecular Biology, Penn State College of Medicine, Hershey, PA 17033, USA; Departments of Chemistry and Biomedical Engineering, Pennsylvania State University, University Park, PA 16802, USA.
| | - Eitan Lerner
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Faculty of Mathematics & Science, The Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel; The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel.
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55
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Razzokov J, Fazliev S, Makhkamov M, Marimuthu P, Baev A, Kurganov E. Effect of Electric Field on α-Synuclein Fibrils: Revealed by Molecular Dynamics Simulations. Int J Mol Sci 2023; 24:ijms24076312. [PMID: 37047286 PMCID: PMC10094641 DOI: 10.3390/ijms24076312] [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: 12/23/2022] [Revised: 02/24/2023] [Accepted: 03/13/2023] [Indexed: 03/30/2023] Open
Abstract
The self-association of amylogenic proteins to the fibril form is considered a pivotal factor in the pathogenesis of neurodegenerative diseases, including Parkinson’s disease (PD). PD causes unintended or uncontrollable movements in its common symptoms. α-synuclein is the major cause of PD development and thus has been the main target of numerous studies to suppress and sequester its expression or effectively degrade it. Nonetheless, to date, there are no efficient and proven ways to prevent pathological protein aggregation. Recent investigations proposed applying an external electric field to interrupt the fibrils. This method is a non-invasive approach that has a certain benefit over others. We performed molecular dynamics (MD) simulations by applying an electric field on highly toxic fibrils of α-synuclein to gain a molecular-level insight into fibril disruption mechanisms. The results revealed that the applied external electric field induces substantial changes in the conformation of the α-synuclein fibrils. Furthermore, we show the threshold value for electric field strength required to completely disrupt the α-synuclein fibrils by opening the hydrophobic core of the fibril. Thus, our findings might serve as a valuable foundation to better understand molecular-level mechanisms of the α-synuclein fibrils disaggregation process under an applied external electric field.
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Affiliation(s)
- Jamoliddin Razzokov
- Institute of Fundamental and Applied Research, National Research University TIIAME, Kori Niyoziy 39, Tashkent 100000, Uzbekistan
- R&D Center, New Uzbekistan University, Mustaqillik Avenue 54, Tashkent 100007, Uzbekistan
- Institute of Material Sciences, Academy of Sciences, Chingiz Aytmatov 2b, Tashkent 100084, Uzbekistan
- Department of Physics, National University of Uzbekistan, Universitet 4, Tashkent 100174, Uzbekistan
- Correspondence: ; Tel.: +998-90-116-23-20
| | - Sunnatullo Fazliev
- Max Planck School Matter to Life, Jahnstrasse 29, 69120 Heidelberg, Germany
- Faculty of Engineering Sciences, Heidelberg University, Im Neuenheimer Feld 205, 69120 Heidelberg, Germany
| | - Mukhriddin Makhkamov
- Laboratory of Experimental Biophysics, Centre for Advanced Technologies, Tashkent 100174, Uzbekistan
| | - Parthiban Marimuthu
- Pharmaceutical Science Laboratory (PSL–Pharmacy) and Structural Bioinformatics Laboratory (SBL–Biochemistry), Faculty of Science and Engineering, Åbo Akademi University, FI-20520 Turku, Finland
| | - Artyom Baev
- Laboratory of Experimental Biophysics, Centre for Advanced Technologies, Tashkent 100174, Uzbekistan
- Department of Biophysics, Biological Faculty, National University of Uzbekistan, Universitet 4, Tashkent 100174, Uzbekistan
| | - Erkin Kurganov
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
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56
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Rafalowski A, Hassan BA, Lou K, Nguyen MC, Taylor EA. How Single Amino Acid Substitutions Can Disrupt a Protein Hetero-Dimer Interface: Computational and Experimental Studies of the LigAB Dioxygenase from Sphingobium sp. Strain SYK-6. Int J Mol Sci 2023; 24:ijms24076319. [PMID: 37047291 PMCID: PMC10094722 DOI: 10.3390/ijms24076319] [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: 01/23/2023] [Revised: 03/17/2023] [Accepted: 03/21/2023] [Indexed: 03/30/2023] Open
Abstract
Protocatechuate 4,5-dioxygenase (LigAB) is a heterodimeric enzyme that catalyzes the dioxygenation of multiple lignin derived aromatic compounds. The active site of LigAB is at the heterodimeric interface, with specificity conferred by the alpha subunit and catalytic residues contributed by the beta subunit. Previous research has indicated that the phenylalanine at the 103 position of the alpha subunit (F103α) controls selectivity for the C5 position of the aromatic substrates, and mutations of this residue can enhance the rate of catalysis for substrates with larger functional groups at this position. While several of the mutations to this position (Valine, V; Threonine, T; Leucine, L; and Histidine, H) were catalytically active, other mutations (Alanine, A; and Serine, S) were found to have reduced dimer interface affinity, leading to challenges in copurifing the catalytically active enzyme complex under high salt conditions. In this study, we aimed to experimentally and computationally interrogate residues at the dimer interface to discern the importance of position 103α for maintaining the integrity of the heterodimer. Molecular dynamic simulations and electrophoretic mobility assays revealed a preference for nonpolar/aromatic amino acids in this position, suggesting that while substitutions to polar amino acids may produce a dioxygenase with a useful substrate utilization profile, those considerations may be off-set by potential destabilization of the catalytically active oligomer. Understanding the dimerization of LigAB provides insight into the multimeric proteins within the largely uncharacterized superfamily and characteristics to consider when engineering proteins that can degrade lignin efficiently. These results shed light on the challenges associated with engineering proteins for broader substrate specificity.
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57
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Cheng Y, Zheng D, Zhang D, Guo D, Wang Y, Liu W, Liang L, Hu J, Luo T. Molecular recognition of SARS-CoV-2 spike protein with three essential partners: exploring possible immune escape mechanisms of viral mutants. J Mol Model 2023; 29:109. [PMID: 36964244 PMCID: PMC10038388 DOI: 10.1007/s00894-023-05509-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Accepted: 03/10/2023] [Indexed: 03/26/2023]
Abstract
OBJECTIVE The COVID-19 epidemic is raging around the world, with the emergence of viral mutant strains such as Delta and Omicron, posing severe challenges to people's health and quality of life. A full understanding life cycle of the virus in host cells helps to reveal inactivation mechanism of antibody and provide inspiration for the development of a new-generation vaccines. METHODS In this work, molecular recognitions and conformational changes of SARS-CoV-2 spike protein mutants (i.e., Delta, Mu, and Omicron) and three essential partners (i.e., membrane receptor hACE2, protease TMPRSS2, and antibody C121) both were compared and analyzed using molecular simulations. RESULTS Water basin and binding free energy calculations both show that the three mutants possess higher affinity for hACE2 than WT, exhibiting stronger virus transmission. The descending order of cleavage ability by TMPRSS2 is Mu, Delta, Omicron, and WT, which is related to the new S1/S2 cutting site induced by transposition effect. The inefficient utilization of TMPRSS2 by Omicron is consistent with its primary entry into cells via the endosomal pathway. In addition, RBD-directed antibody C121 showed obvious resistance to Omicron, which may have originated from high fluctuation of approaching angles, high flexibility of I472-F490 loop, and reduced binding ability. CONCLUSIONS According to the overall characteristics of the three mutants, high infectivity, high immune escape, and low virulence may be the future evolutionary selection of SARS-CoV-2. In a word, this work not only proposes the possible resistance mechanism of SARS-CoV-2 mutants, but also provides theoretical guidance for the subsequent drug design against COVID-19 based on S protein structure.
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Affiliation(s)
- Yan Cheng
- Breast Disease Center, West China Hospital, Sichuan University, Cancer CenterChengdu, 610000, China
| | - Dan Zheng
- Breast Disease Center, West China Hospital, Sichuan University, Cancer CenterChengdu, 610000, China
| | - Derong Zhang
- School of Marxism, Chengdu Vocational & Technical College of Industry, Chengdu, China
| | - Du Guo
- Breast Disease Center, West China Hospital, Sichuan University, Cancer CenterChengdu, 610000, China
| | - Yueteng Wang
- Key Laboratory of Medicinal and Edible Plants Resources Development of Sichuan Education Department, School of Pharmacy, Chengdu University, Chengdu, China
| | - Wei Liu
- Key Laboratory of Medicinal and Edible Plants Resources Development of Sichuan Education Department, School of Pharmacy, Chengdu University, Chengdu, China
| | - Li Liang
- Key Laboratory of Medicinal and Edible Plants Resources Development of Sichuan Education Department, School of Pharmacy, Chengdu University, Chengdu, China
| | - Jianping Hu
- Key Laboratory of Medicinal and Edible Plants Resources Development of Sichuan Education Department, School of Pharmacy, Chengdu University, Chengdu, China
| | - Ting Luo
- Breast Disease Center, West China Hospital, Sichuan University, Cancer CenterChengdu, 610000, China.
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58
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Hwang IC, Rick SW. The pH Response of a Peptoid Oligomer. J Phys Chem B 2023; 127:2872-2878. [PMID: 36926948 DOI: 10.1021/acs.jpcb.3c00755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/18/2023]
Abstract
Polypeptoids are N-substituted glycine polymers, which differ from peptides in the placement of the side chain on the amide nitrogen rather than the Cα carbon. A peptoid with a chiral side chain containing both an aromatic group and carboxylic acid has a structure that responds to pH changes. All-atom molecular dynamics simulations using a force field specifically tuned for peptoids were carried out with an advanced sampling method for the peptoid (S)-N-(1-carboxy-2-phenylethyl)glycine in the high and low pH limits. The simulations show that the structure changes from mostly cis amide bonds at low pH to mostly trans bonds at high pH. The structural changes are driven by side chain-backbone hydrogen bonds at low pH and side chain repulsions and increased water contact at high pH.
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Affiliation(s)
- In Chul Hwang
- Department of Chemistry, University of New Orleans, New Orleans, Louisiana 70148, United States
| | - Steven W Rick
- Department of Chemistry, University of New Orleans, New Orleans, Louisiana 70148, United States
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59
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Agles AA, Bourg IC. Structure-Thermodynamic Relationship of a Polysaccharide Gel (Alginate) as a Function of Water Content and Counterion Type (Na vs Ca). J Phys Chem B 2023; 127:1828-1841. [PMID: 36791328 PMCID: PMC10159261 DOI: 10.1021/acs.jpcb.2c07129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
Biofilms are the predominant mode of microbial life on Earth, and so a deep understanding of microbial communities─and their impacts on environmental processes─requires a firm understanding of biofilm properties. Because of the importance of biofilms to their microbial inhabitants, microbes have evolved different ways of engineering and reconfiguring the matrix of extracellular polymeric substances (EPS) that constitute the main non-living component of biofilms. This ability makes it difficult to distinguish between the biotic and abiotic origins of biofilm properties. An important route toward establishing this distinction has been the study of simplified models of the EPS matrix. This study builds on such efforts by using atomistic simulations to predict the nanoscale (≤10 nm scale) structure of a model EPS matrix and the sensitivity of this structure to interpolymer interactions and water content. To accomplish this, we use replica exchange molecular dynamics (REMD) simulations to generate all-atom configurations of ten 3.4 kDa alginate polymers at a range of water contents and Ca-Na ratios. Simulated systems are solvated with explicitly modeled water molecules, which allows us to capture the discrete structure of the hydrating water and to examine the thermodynamic stability of water in the gels as they are progressively dehydrated. Our primary findings are that (i) the structure of the hydrogels is highly sensitive to the identity of the charge-compensating cations, (ii) the thermodynamics of water within the gels (specific enthalpy and free energy) are, surprisingly, only weakly sensitive to cation identity, and (iii) predictions of the differential enthalpy and free energy of hydration include a short-ranged enthalpic term that promotes hydration and a longer-ranged (presumably entropic) term that promotes dehydration, where short and long ranges refer to distances shorter or longer than ∼0.6 nm between alginate strands.
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Affiliation(s)
- Avery A Agles
- Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08544, United States
| | - Ian C Bourg
- Department of Civil and Environmental Engineering and High Meadows Environmental Institute, Princeton University, Princeton, New Jersey 08544, United States
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60
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Molecular dynamics simulation of ethanol electrohydrodynamic atomization: Microscopic mechanism of the operating parameter effects. J Mol Liq 2023. [DOI: 10.1016/j.molliq.2023.121602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/13/2023]
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61
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Ren E, Coudert FX. Rapid adsorption enthalpy surface sampling (RAESS) to characterize nanoporous materials. Chem Sci 2023; 14:1797-1807. [PMID: 36819873 PMCID: PMC9931060 DOI: 10.1039/d2sc05810c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Accepted: 01/02/2023] [Indexed: 01/18/2023] Open
Abstract
Molecular adsorption in nanoporous materials has many large-scale industrial applications ranging from separation to storage. To design the best materials, computational simulations are key to guiding the experimentation and engineering processes. Because nanoporous materials exist in a plethora of forms, we need to speed up the existing simulation tools to be able to screen databases of hundreds of thousands of structures. Here, we describe a new algorithm that quickly calculates adsorption enthalpies by sampling the surface of the material instead of the whole porous space. This surface sampling has been tested on the CoRE MOF 2019 database and has been proven to be more than 2 orders of magnitude faster than the gold standard method (Widom insertion), with an acceptable level of error on an enthalpy value of 0.34 kJ mol-1, and is therefore proposed as a valuable addition to the high-throughput screening toolbox.
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Affiliation(s)
- Emmanuel Ren
- CEA, DES, ISEC, DMRC, Univ. Montpellier Marcoule France.,Chimie ParisTech, PSL University, CNRS, Institut de Recherche de Chimie Paris 75005 Paris France
| | - François-Xavier Coudert
- Chimie ParisTech, PSL University, CNRS, Institut de Recherche de Chimie Paris 75005 Paris France
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62
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Cui R, Li S, Yu C, Zhou Y. The Evolution of Hydrogen Bond Network in Nafion via Molecular Dynamics Simulation. Macromolecules 2023. [DOI: 10.1021/acs.macromol.2c02106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Affiliation(s)
- Rui Cui
- School of Chemistry & Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Key Laboratory of Electrical Insulation and Thermal Aging, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Shanlong Li
- School of Chemistry & Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Key Laboratory of Electrical Insulation and Thermal Aging, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Chunyang Yu
- School of Chemistry & Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Key Laboratory of Electrical Insulation and Thermal Aging, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Yongfeng Zhou
- School of Chemistry & Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Key Laboratory of Electrical Insulation and Thermal Aging, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
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63
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Dongmo Foumthuim CJ, Giacometti A. Solvent quality and solvent polarity in polypeptides. Phys Chem Chem Phys 2023; 25:4839-4853. [PMID: 36692363 DOI: 10.1039/d2cp05214h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Using molecular dynamics and thermodynamic integration, we report on the solvation process of seven polypeptides (GLY, ALA, ILE, ASN, LYS, ARG, GLU) in water and in cyclohexane. The polypeptides are selected to cover the full hydrophobic scale while varying their chain length from tri- to undeca-homopeptides, providing indications on possible non-additivity effects as well as the role of the peptide backbone in the overall stability of the polypeptides. The use of different solvents and different polypeptides allows us to investigate the relation between solvent quality - the capacity of a given solvent to fold/unfold a given biopolymer often described on a scale ranging from "good" to "poor"; and solvent polarity - related to the specific interactions of any solvent with respect to a reference solvent. Undeca-glycine is found to be the only polypeptide to have a stable collapse in water (polar solvent), with the other hydrophobic polypeptides displaying repeated folding and unfolding events in water, with polar polypeptides presenting even more complex behavior. By contrast, all polypeptides are found to keep an extended conformation in cyclohexane, irrespective of their polarity. All considered polypeptides are also found to have favorable solvation free energy independent of the solvent polarity and their intrinsic hydrophobicity, clearly highlighting the prominent stabilizing role of the peptide backbone - with the solvation process largely enthalpically dominated in polar polypeptides and partially entropically driven for hydrophobic polypeptides. Our study thus reveals the complexity of the solvation process of polypeptides defying the common view "like dissolves like", with the solute polarity playing the most prominent role. The absence of mirror symmetry upon the inversion of polarities of both the solvent and the polypeptides is confirmed.
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Affiliation(s)
- Cedrix J Dongmo Foumthuim
- Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca' Foscari di Venezia, Campus Scientifico, Edificio Alfa, via Torino 155, 30172 Venezia Mestre, Italy.
| | - Achille Giacometti
- Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca' Foscari di Venezia, Campus Scientifico, Edificio Alfa, via Torino 155, 30172 Venezia Mestre, Italy. .,European Centre for Living Technology (ECLT) Ca Bottacin, Dorsoduro 3911, Calle Crosera 30123 Venice, Italy
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64
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Nunes Azevedo FF, Freitas de Sousa FJ, Santos de Oliveira FL, Vieira Carletti J, Zanatta G. Binding site hotspot map of PI3Kα and mTOR in the presence of selective and dual ATP-competitive inhibitors. J Biomol Struct Dyn 2023; 41:1085-1097. [PMID: 34913837 DOI: 10.1080/07391102.2021.2016487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The PI3K/Akt/mTOR signaling pathway plays a pivotal role in cellular metabolism, growth and survival. PI3Kα hyperactivation impairs downstream signaling, including mTOR regulation, and are linked to poor prognosis and refractory cancer treatment. To support multi-target drug discovery, we took advantage from existing PI3Kα and mTOR crystallographic structures to map similarities and differences in their ATP-binding pockets in the presence of selective or dual inhibitors. Molecular dynamics and MM/PBSA calculations were employed to study the binding profile and identify the relative contribution of binding site residues. Our analysis showed that while varying parameters of solute and solvent dielectric constant interfered in the absolute binding free energy, it had no effect in the relative per residue contribution. In all complexes, the most important interactions were observed within 3-3.5 Å from inhibitors, responding for ∼75-100% of the total calculated interaction energy. While closest residues are essential for the strength of the binding of all ligands, more distant residues seem to have a larger impact on the binding of the dual inhibitor, as observed for PI3Kα residues Phe934, Lys802 and Asp805 and, mTOR residues Leu2192, Phe2358, Leu2354, Lys2187 and Tyr2225. A detailed description of individual residue contribution in the presence of selective or dual inhibitors is provided as an effort to improve the understanding of molecular mechanisms controlling multi-target inhibition. This work provides key information to support further studies seeking the rational design of potent PI3K/mTOR dual inhibitors for cancer treatment.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
| | | | | | | | - Geancarlo Zanatta
- Postgraduate Programme in Biochemistry, Department of Biochemistry at Federal, University of Ceará, Fortaleza, Ceará, Brazil.,Department of Physics at Federal, University of Ceará, Fortaleza, Ceará, Brazil
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65
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Özkan AU, Tuncel D, Erbaş A. Effect of Charge State on the Equilibrium and Kinetic Properties of Mechanically Interlocked [5]Rotaxane: A Molecular Dynamics Study. J Phys Chem B 2023; 127:1254-1263. [PMID: 36716388 PMCID: PMC9923746 DOI: 10.1021/acs.jpcb.2c07645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Rotaxanes can exhibit stimuli-responsive behavior by allowing positional fluctuations of their rota groups in response to physiochemical conditions such as the changes in solution pH. However, ionic strength of the solution also affects the molecular conformation by altering the charge state of the entire molecule, coupling the stimuli-responsiveness of rotaxanes with their conformation. A molecular-scale investigation on a model system can allow the decoupling and identification of various effects and can greatly benefit applications of such molecular switches. By using atomistic molecular dynamics simulations, we study equilibrium and kinetics properties of various charge states of the [5]rotaxane, which is a supramolecular moiety with four rotaxanes bonded to a porphyrin core. We model various physiochemical charge states, each of which can be realized at various solution pH levels as well as several exotic charge distributions. By analyzing molecular configurations, hydrogen bonding, and energetics of single molecules in salt-free water and its polyrotaxanated network at the interface of water and chloroform, we demonstrate that charge-neutral and negatively charged molecules often tend to collapse in a way that they can expose their porphyrin core. Contrarily, positively charged moieties tend to take more extended molecular configurations blocking the core. Further, sudden changes in the charge states emulating the pH alterations in solution conditions lead to rapid, sub-10 ns level, changes in the molecular conformation of [5]rotaxane via shuttling motion of CB6 rings along axles. Finally, simulations of 2D [5]rotaxane network structures support our previous findings on a few nanometer-thick film formation at oil-water interfaces. Overall, our results suggest that rotaxane-based structures can exhibit a rich spectrum of molecular configurations and kinetics depending on the ionic strength of the solution.
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Affiliation(s)
- Ata Utku Özkan
- UNAM-Institute
of Materials Science and Nanotechnology, Bilkent University, Ankara06800, Turkey
| | - Dönüş Tuncel
- UNAM-Institute
of Materials Science and Nanotechnology, Bilkent University, Ankara06800, Turkey,Department
of Chemistry, Bilkent University, Ankara06800, Turkey
| | - Aykut Erbaş
- UNAM-Institute
of Materials Science and Nanotechnology, Bilkent University, Ankara06800, Turkey,E-mail:
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66
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Marciano Y, del Solar V, Nayeem N, Dave D, Son J, Contel M, Ulijn RV. Encapsulation of Gold-Based Anticancer Agents in Protease-Degradable Peptide Nanofilaments Enhances Their Potency. J Am Chem Soc 2023; 145:234-246. [PMID: 36542079 PMCID: PMC10720394 DOI: 10.1021/jacs.2c09820] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
We investigated the use of amphiphilic, protease-cleavable peptides as encapsulation moieties for hydrophobic metallodrugs, in order to enhance their bioavailability and consequent activity. Two hydrophobic, gold-containing anticancer agents varying in aromatic ligand distribution (Au(I)-N-heterocyclic carbene compounds 1 and 2) were investigated. These were encapsulated into amphiphilic decapeptides that form soluble filamentous structures with hydrophobic cores, varying supramolecular packing arrangements and surface charge. Peptide sequence strongly dictates the supramolecular packing within the aromatic core, which in turn dictates drug loading. Anionic peptide filaments can effectively load 1, and to a lesser extent 2, while their cationic counterparts could not, collectively demonstrating that loading efficiency is dictated by both aromatic and electrostatic (mis)matching between drug and peptide. Peptide nanofilaments were nontoxic to cancerous and noncancerous cells. By contrast, those loaded with 1 and 2 displayed enhanced cytotoxicity in comparison to 1 and 2 alone, when exposed to Caki-1 and MDA-MB-231 cancerous cell lines, while no cytotoxicity was observed in noncancerous lung fibroblasts, IMR-90. We propose that the enhanced in vitro activity results from the enhanced proteolytic activity in the vicinity of the cancer cells, thereby breaking the filaments into drug-bound peptide fragments that are taken up by these cells, resulting in enhanced cytotoxicity toward cancer cells.
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Affiliation(s)
- Yaron Marciano
- Nanoscience Initiative, Advanced Science Research Center at The Graduate Center of the City University of New York (CUNY), 85 Saint Nicholas Terrace, New York, NY 10031, USA
- Department of Chemistry, Brooklyn College, CUNY, 2900 Bedford Avenue, Brooklyn, NY 11210, USA
- Ph.D. Program in Chemistry, The Graduate Center of CUNY, 365 Fifth Avenue, New York, NY 10016, USA
| | - Virginia del Solar
- Department of Chemistry, Brooklyn College, CUNY, 2900 Bedford Avenue, Brooklyn, NY 11210, USA
| | - Nazia Nayeem
- Department of Chemistry, Brooklyn College, CUNY, 2900 Bedford Avenue, Brooklyn, NY 11210, USA
- Ph.D. Program inBiology, The Graduate Center of CUNY, 365 Fifth Avenue, New York, NY 10016, USA
| | - Dhwanit Dave
- Nanoscience Initiative, Advanced Science Research Center at The Graduate Center of the City University of New York (CUNY), 85 Saint Nicholas Terrace, New York, NY 10031, USA
- Ph.D. Program in Chemistry, The Graduate Center of CUNY, 365 Fifth Avenue, New York, NY 10016, USA
- Department of Chemistry, Hunter College, CUNY, 695 Park Avenue, New York, NY 10065, USA
| | - Jiye Son
- Nanoscience Initiative, Advanced Science Research Center at The Graduate Center of the City University of New York (CUNY), 85 Saint Nicholas Terrace, New York, NY 10031, USA
| | - María Contel
- Department of Chemistry, Brooklyn College, CUNY, 2900 Bedford Avenue, Brooklyn, NY 11210, USA
- Ph.D. Program in Chemistry, The Graduate Center of CUNY, 365 Fifth Avenue, New York, NY 10016, USA
- Ph.D. Program in Biochemistry, The Graduate Center of CUNY, 365 Fifth Avenue, New York, NY 10016, USA
- Ph.D. Program inBiology, The Graduate Center of CUNY, 365 Fifth Avenue, New York, NY 10016, USA
| | - Rein V. Ulijn
- Nanoscience Initiative, Advanced Science Research Center at The Graduate Center of the City University of New York (CUNY), 85 Saint Nicholas Terrace, New York, NY 10031, USA
- Ph.D. Program in Chemistry, The Graduate Center of CUNY, 365 Fifth Avenue, New York, NY 10016, USA
- Ph.D. Program in Biochemistry, The Graduate Center of CUNY, 365 Fifth Avenue, New York, NY 10016, USA
- Department of Chemistry, Hunter College, CUNY, 695 Park Avenue, New York, NY 10065, USA
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67
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Rao RM, Belloy N, Crowet JM, Dauchez M, Baud S. Modelling and Simulations of Extracellular Glycoproteins. Methods Mol Biol 2023; 2619:293-313. [PMID: 36662478 DOI: 10.1007/978-1-0716-2946-8_21] [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] [Indexed: 01/21/2023]
Abstract
While the knowledge of protein structure and function has seen vast advances in previous decades, the understanding of how their posttranslational modifications, such as glycosylations, influence their structure and function remains poor. However, advances in in silico methodologies to study glycosylations in recent past have enabled us to study this and understand the role of glycosylations in protein structure and function in ways that would not be possible by conventional experimental methods. In this chapter, we will demonstrate how to leverage these methodologies to study glycoproteins and their structural and dynamic properties using molecular modelling techniques.
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Affiliation(s)
- Rajas M Rao
- Université de Reims Champagne-Ardenne, CNRS, MEDyC UMR 7369, Reims, France
| | - Nicolas Belloy
- Université de Reims Champagne-Ardenne, CNRS, MEDyC UMR 7369, Reims, France
| | - Jean-Marc Crowet
- Université de Reims Champagne-Ardenne, CNRS, MEDyC UMR 7369, Reims, France
| | - Manuel Dauchez
- Université de Reims Champagne-Ardenne, CNRS, MEDyC UMR 7369, Reims, France
| | - Stéphanie Baud
- Université de Reims Champagne-Ardenne, CNRS, MEDyC UMR 7369, Reims, France.
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68
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Grünewald F, Punt MH, Jefferys EE, Vainikka PA, König M, Virtanen V, Meyer TA, Pezeshkian W, Gormley AJ, Karonen M, Sansom MSP, Souza PCT, Marrink SJ. Martini 3 Coarse-Grained Force Field for Carbohydrates. J Chem Theory Comput 2022; 18:7555-7569. [PMID: 36342474 DOI: 10.1021/acs.jctc.2c00757] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The Martini 3 force field is a full reparametrization of the Martini coarse-grained model for biomolecular simulations. Due to the improved interaction balance, it allows for a more accurate description of condensed phase systems. In the present work, we develop a consistent strategy to parametrize carbohydrate molecules accurately within the framework of Martini 3. In particular, we develop a canonical mapping scheme which decomposes arbitrarily large carbohydrates into a limited number of fragments. Bead types for these fragments have been assigned by matching physicochemical properties of mono- and disaccharides. In addition, guidelines for assigning bonds, angles, and dihedrals were developed. These guidelines enable a more accurate description of carbohydrate conformations than in the Martini 2 force field. We show that models obtained with this approach are able to accurately reproduce osmotic pressures of carbohydrate water solutions. Furthermore, we provide evidence that the model differentiates correctly the solubility of the polyglucoses dextran (water-soluble) and cellulose (water insoluble but soluble in ionic liquids). Finally, we demonstrate that the new building blocks can be applied to glycolipids. We show they are able to reproduce membrane properties and induce binding of peripheral membrane proteins. These test cases demonstrate the validity and transferability of our approach.
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Affiliation(s)
- Fabian Grünewald
- Groningen Biomolecular Sciences and Biotechnology Institute and Zernike Institute for Advanced Materials, University of Groningen, Groningen 9747 AG, The Netherlands
| | - Mats H Punt
- Groningen Biomolecular Sciences and Biotechnology Institute and Zernike Institute for Advanced Materials, University of Groningen, Groningen 9747 AG, The Netherlands
| | - Elizabeth E Jefferys
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, United Kingdom
| | - Petteri A Vainikka
- Groningen Biomolecular Sciences and Biotechnology Institute and Zernike Institute for Advanced Materials, University of Groningen, Groningen 9747 AG, The Netherlands
| | - Melanie König
- Groningen Biomolecular Sciences and Biotechnology Institute and Zernike Institute for Advanced Materials, University of Groningen, Groningen 9747 AG, The Netherlands
| | - Valtteri Virtanen
- Natural Chemistry Research Group, Department of Chemistry, University of Turku, FI-20014 Turku, Finland
| | - Travis A Meyer
- Department of Biomedical Engineering, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, United States
| | - Weria Pezeshkian
- Groningen Biomolecular Sciences and Biotechnology Institute and Zernike Institute for Advanced Materials, University of Groningen, Groningen 9747 AG, The Netherlands.,The Niels Bohr International Academy, Niels Bohr Institute, University of Copenhagen, Copenhagen 2100, Denmark
| | - Adam J Gormley
- Department of Biomedical Engineering, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, United States
| | - Maarit Karonen
- Natural Chemistry Research Group, Department of Chemistry, University of Turku, FI-20014 Turku, Finland
| | - Mark S P Sansom
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, United Kingdom
| | - Paulo C T Souza
- Molecular Microbiology and Structural Biochemistry, UMR 5086 CNRS and University of Lyon, Lyon 69367, France
| | - Siewert J Marrink
- Groningen Biomolecular Sciences and Biotechnology Institute and Zernike Institute for Advanced Materials, University of Groningen, Groningen 9747 AG, The Netherlands
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69
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Brasino M, Wagnell E, Hamilton S, Ranganathan S, Gomes MM, Branchaud B, Messmer B, Ibsen SD. Turning antibodies off and on again using a covalently tethered blocking peptide. Commun Biol 2022; 5:1357. [PMID: 36496512 PMCID: PMC9741643 DOI: 10.1038/s42003-022-04094-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 10/11/2022] [Indexed: 12/13/2022] Open
Abstract
In their natural form, antibodies are always in an "on-state" and are capable of binding to their targets. This leads to undesirable interactions in a wide range of therapeutic, analytical, and synthetic applications. Modulating binding kinetics of antibodies to turn them from an "off-state" to an "on-state" with temporal and spatial control can address this. Here we demonstrate a method to modulate binding activity of antibodies in a predictable and reproducible way. We designed a blocking construct that uses both covalent and non-covalent interactions with the antibody. The construct consisted of a Protein L protein attached to a flexible linker ending in a blocking-peptide designed to interact with the antibody binding site. A mutant Protein L was developed to enable photo-triggered covalent crosslinking to the antibody at a specific location. The covalent bond anchored the linker and blocking peptide to the antibody light chain keeping the blocking peptide close to the antibody binding site. This effectively put the antibody into an "off-state". We demonstrate that protease-cleavable and photocleavable moieties in the tether enable controlled antibody activation to the "on-state" for anti-FLAG and cetuximab antibodies. Protein L can bind a range of antibodies used therapeutically and in research for wide applicability.
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Affiliation(s)
- Michael Brasino
- grid.5288.70000 0000 9758 5690Cancer Early Detection Advanced Research Center, Knight Cancer Institute, Oregon Health and Science University, Portland, OR 97201 USA
| | - Eli Wagnell
- grid.5288.70000 0000 9758 5690Cancer Early Detection Advanced Research Center, Knight Cancer Institute, Oregon Health and Science University, Portland, OR 97201 USA
| | - Sean Hamilton
- grid.5288.70000 0000 9758 5690Cancer Early Detection Advanced Research Center, Knight Cancer Institute, Oregon Health and Science University, Portland, OR 97201 USA ,grid.5288.70000 0000 9758 5690Department of Biomedical Engineering, School of Medicine, Oregon Health and Science University, Portland, OR 97201 USA
| | - Srivathsan Ranganathan
- grid.5288.70000 0000 9758 5690Cancer Early Detection Advanced Research Center, Knight Cancer Institute, Oregon Health and Science University, Portland, OR 97201 USA
| | - Michelle M. Gomes
- grid.5288.70000 0000 9758 5690Cancer Early Detection Advanced Research Center, Knight Cancer Institute, Oregon Health and Science University, Portland, OR 97201 USA
| | - Bruce Branchaud
- grid.5288.70000 0000 9758 5690Cancer Early Detection Advanced Research Center, Knight Cancer Institute, Oregon Health and Science University, Portland, OR 97201 USA
| | | | - Stuart D. Ibsen
- grid.5288.70000 0000 9758 5690Cancer Early Detection Advanced Research Center, Knight Cancer Institute, Oregon Health and Science University, Portland, OR 97201 USA ,grid.5288.70000 0000 9758 5690Department of Biomedical Engineering, School of Medicine, Oregon Health and Science University, Portland, OR 97201 USA
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70
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Megariotis G, Mikaelian G, Avramopoulos A, Romanos N, Theodorou DN. Molecular simulations of fluoxetine in hydrated lipid bilayers, as well as in aqueous solutions containing β-cyclodextrin. J Mol Graph Model 2022; 117:108305. [PMID: 35987186 DOI: 10.1016/j.jmgm.2022.108305] [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: 05/09/2022] [Revised: 07/25/2022] [Accepted: 08/06/2022] [Indexed: 01/14/2023]
Abstract
Fluoxetine, which is a well-known antidepressant drug, is studied in hydrated cholesterol-free and cholesterol-containing lipid bilayers through unbiased and biased atomistic molecular dynamics simulations. The latter are conducted for the calculation of the potential of mean force (PMF) of fluoxetine along an axis perpendicular to the two leaflets of the bilayer. The PMF indicates that the drug prefers to reside inside the lipid phase and allows us to calculate important thermodynamic properties, such as the Gibbs energy difference of partitioning from the water to the lipid phase and the Gibbs energy barrier for hopping events between the two leaflets of the bilayer. The results from the biased simulations are in accord with the mass density profiles calculated from the unbiased simulations. Moreover, we estimate the effect of fluoxetine mole fraction on the order parameters of the lipid alkyl chains and on the area per lipid. It is also found that fluoxetine forms a hydrogen bond network with lipids and water molecules penetrating into the lipid phase. In addition, fluoxoetine is studied in detail in aqueous solutions containing β-cyclodextrin. It is observed from unbiased molecular dynamics simulations that the two aforementioned molecules form a noncovalent complex spontaneously and the calculated binding free energy is in agreement with the literature.
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Affiliation(s)
- Grigorios Megariotis
- School of Chemical Engineering, National Technical University of Athens (NTUA), 9 Heroon Polytechniou Street, Zografou Campus, Athens, GR, 15780, Greece.
| | - Georgios Mikaelian
- School of Chemical Engineering, National Technical University of Athens (NTUA), 9 Heroon Polytechniou Street, Zografou Campus, Athens, GR, 15780, Greece
| | - Aggelos Avramopoulos
- Department of Physics, University of Thessaly, 3rd Km Old National Road Lamia Athens, Lamia, GR, 35100, Greece
| | - Nikolaos Romanos
- School of Chemical Engineering, National Technical University of Athens (NTUA), 9 Heroon Polytechniou Street, Zografou Campus, Athens, GR, 15780, Greece
| | - Doros N Theodorou
- School of Chemical Engineering, National Technical University of Athens (NTUA), 9 Heroon Polytechniou Street, Zografou Campus, Athens, GR, 15780, Greece
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71
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Lei M, Huang W, Jin Z, Sun J, Zhang M, Zhao S. Effect of molecular structure and ionization state on aggregation of carboxymethyl chitosan: A molecular dynamics study. Carbohydr Polym 2022; 297:119993. [DOI: 10.1016/j.carbpol.2022.119993] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 08/10/2022] [Accepted: 08/11/2022] [Indexed: 11/02/2022]
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72
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Li B, Ju M, Dou X, Li N, Zhang W, Sun Z, Yu K, Wang J, Wang Z. Assessing nanoparticle-surfactant-salt synergistic effects on droplet–droplet electrocoalescence by molecular dynamics simulations. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.120570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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73
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De Sancho D. Phase separation in amino acid mixtures is governed by composition. Biophys J 2022; 121:4119-4127. [PMID: 36181270 PMCID: PMC9675019 DOI: 10.1016/j.bpj.2022.09.031] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 07/19/2022] [Accepted: 09/26/2022] [Indexed: 11/02/2022] Open
Abstract
Macromolecular phase separation has recently come to immense prominence as it is central to the formation of membraneless organelles, leading to a new paradigm of cellular organization. This type of phase transition, often termed liquid-liquid phase separation (LLPS), is mediated by molecular interactions between biomolecules, including nucleic acids and both ordered and disordered proteins. In the latter case, the separation between protein-dense and -dilute phases is often interpreted using models adapted from polymer theory. Specifically, the "stickers and spacers" model proposes that the formation of condensate-spanning networks in protein solutions originates from the interplay between two classes of residues and that the main determinants for phase separation are multivalency and sequence patterning. The duality of roles of stickers (aromatics like Phe and Tyr) and spacers (Gly and polar residues) may apply more broadly in protein-like mixtures, and the presence of these two types of components alone may suffice for LLPS to take place. In order to explore this hypothesis, we use atomistic molecular dynamics simulations of capped amino acid residues as a minimal model system. We study the behavior of pure amino acids in water for three types of residues corresponding to the spacer and sticker categories and of their multicomponent mixtures. In agreement with previous observations, we find that the spacer-type amino acids fail to phase separate on their own, while the sticker is prone to aggregation. However, ternary amino acid mixtures involving both types of amino acids phase separate into two phases that retain intermediate degrees of compaction and greater fluidity than sticker-only condensates. Our results suggest that LLPS is an emergent property of amino acid mixtures determined by composition.
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Affiliation(s)
- David De Sancho
- Polimero eta Material Aurreratuak: Fisika, Kimika eta Teknologia, Kimika Fakultatea, UPV/EHU & Donostia International Physics Center (DIPC), PK 1072, Donostia-San Sebastian, Euskadi, Spain.
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74
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Wang X, Ham S, Zhou W, Qiao R. Adsorption of rhodamine 6G and choline on gold electrodes: a molecular dynamics study. NANOTECHNOLOGY 2022; 34:025501. [PMID: 36195059 DOI: 10.1088/1361-6528/ac973b] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2022] [Accepted: 10/04/2022] [Indexed: 06/16/2023]
Abstract
The adsorption of analyte molecules on nano-optoelectrodes (e.g. a combined nanoantenna and nanoelectrode device) significantly affects the signal characteristics in surface-enhanced Raman scattering (SERS) measurements. Understanding how different molecules adsorb on electrodes and their electrical potential modulation helps interpret SERS measurements better. We use molecular dynamics simulations to investigate the adsorption of prototypical analyte molecules (rhodamine 6G and choline) on gold electrodes with negative, neutral, and positive surface charges. We show that both molecules can readily adsorb on gold surfaces at all surface charge densities studied. Nevertheless, the configurations of the adsorbed molecules can differ for different surface charge densities, and adsorption can also change a molecule's conformation. Rhodamine 6G molecules adsorb more strongly than choline molecules, and the adsorption of both molecules is affected by electrode charge in 0.25 M NaCl solutions. The mechanisms of these observations are elucidated, and their implications for voltage-modulated SERS measurements are discussed.
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Affiliation(s)
- Xin Wang
- Department of Mechanical Engineering, Virginia Tech, Blacksburg, VA 24061, United States of America
| | - Seokgyun Ham
- Department of Mechanical Engineering, Virginia Tech, Blacksburg, VA 24061, United States of America
| | - Wei Zhou
- Department of Electrical and Computer Engineering Virginia Tech, Blacksburg, VA 24061, United States of America
| | - Rui Qiao
- Department of Mechanical Engineering, Virginia Tech, Blacksburg, VA 24061, United States of America
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75
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Conformational Heterogeneity and Frustration of the Tumor Suppressor p53 as Tuned by Punctual Mutations. Int J Mol Sci 2022; 23:ijms232012636. [PMID: 36293489 PMCID: PMC9604312 DOI: 10.3390/ijms232012636] [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: 09/16/2022] [Revised: 10/14/2022] [Accepted: 10/15/2022] [Indexed: 12/02/2022] Open
Abstract
The conformational heterogeneity of the p53 tumor suppressor, the wild-type (p53wt) and mutated forms, was investigated by a computational approach, including the modeling and all atoms of the molecular dynamics (MD) simulations. Four different punctual mutations (p53R175H, p53R248Q, p53R273H, and p53R282W) which are known to affect the DNA binding and belong to the most frequent hot-spot mutations in human cancers, were taken into consideration. The MD trajectories of the wild-type and mutated p53 forms were analyzed by essential dynamics to extract the relevant collective motions and by the frustration method to evaluate the degeneracy of the energy landscape. We found that p53 is characterized by wide collective motions and its energy landscape exhibits a rather high frustration level, especially in the regions involved in the binding to physiological ligands. Punctual mutations give rise to a modulation of both the collective motions and the frustration of p53, with different effects depending on the mutation. The regions of p53wt and of the mutated forms characterized by a high frustration level are also largely involved in the collective motions. Such a correlation is discussed also in connection with the intrinsic disordered character of p53 and with its central functional role.
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76
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Workman AS. Comparative analyses and molecular videography of MD simulations on WT human SOD1. COMPUT THEOR CHEM 2022. [DOI: 10.1016/j.comptc.2022.113929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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77
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Mishra RP, Gupta S, Rathore AS, Goel G. Multi-Level High-Throughput Screening for Discovery of Ligands That Inhibit Insulin Aggregation. Mol Pharm 2022; 19:3770-3783. [PMID: 36173709 DOI: 10.1021/acs.molpharmaceut.2c00219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We have developed a multi-level virtual screening protocol to identify lead molecules from the FDA inactives database that can inhibit insulin aggregation. The method is based on the presence of structural and interaction specificity in non-native aggregation pathway protein-protein interactions. Some key challenges specific to the present problem, when compared with native protein association, include structural heterogeneity of the protein species involved, multiple association pathways, and relatively higher probability of conformational rearrangement of the association complex. In this multi-step method, the inactives database was first screened using the dominant pharmacophore features of previously identified molecules shown to significantly inhibit insulin aggregation nucleation by binding to its aggregation-prone conformers. We then performed ensemble docking of several low-energy ligand conformations on these aggregation-prone conformers followed by molecular dynamics simulations and binding affinity calculations on a subset of docked complexes to identify a final set of five potential lead molecules to inhibit insulin aggregation nucleation. Their effect on aggregation inhibition was extensively investigated by incubating insulin under aggregation-prone aqueous buffer conditions (low pH, high temperature). Aggregation kinetics were characterized using size exclusion chromatography and Thioflavin T fluorescence assay, and the secondary structure was determined using circular dichroism spectroscopy. Riboflavin provided the best aggregation inhibition, with 85% native monomer retention after 48 h incubation under aggregation-prone conditions, whereas the no-ligand formulation showed complete monomer loss after 36 h. Further, insulin incubated with two of the screened inactives (aspartame, riboflavin) had the characteristic α-helical dip in CD spectra, while the no-ligand formulation showed a change to β-sheet rich conformations.
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Affiliation(s)
- Rit Pratik Mishra
- Department of Chemical Engineering, Indian Institute Technology Delhi, New Delhi, 110016, India
| | - Surbhi Gupta
- Department of Chemical Engineering, Indian Institute Technology Delhi, New Delhi, 110016, India
| | - Anurag Singh Rathore
- Department of Chemical Engineering, Indian Institute Technology Delhi, New Delhi, 110016, India
| | - Gaurav Goel
- Department of Chemical Engineering, Indian Institute Technology Delhi, New Delhi, 110016, India
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78
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Kumar S, Ayyannan SR. Identification of new small molecule monoamine oxidase-B inhibitors through pharmacophore-based virtual screening, molecular docking and molecular dynamics simulation studies. J Biomol Struct Dyn 2022:1-22. [PMID: 35983603 DOI: 10.1080/07391102.2022.2112082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
Abstract
The discovery of a safe and efficacious drug is a complex, time-consuming, and expensive process. Computational methodologies driven by cheminformatics tools play a central role in the high-throughput lead discovery and optimization process especially when the structure of the biological target is known. Monoamine oxidases are the membrane-bound FAD-containing enzymes and the isoform monoamine oxidase-B (MAO-B) is an attractive target for treating diseases like Alzheimer's disease, Parkinson's disease, glioma, etc. In the current study, we have used a pharmacophore-based virtual screening technique for the identification of new small molecule MAO-B inhibitors. Safinamide was used for building a pharmacophore model and the developed model was used to probe the ZINC database for potential hits. The obtained hits were filtered against drug-likeness and PAINS. Out of the hit's library, two compounds ZINC02181408, ZINC08853942 (most active), and ZINC53327382 (least active) were further subjected to molecular docking and dynamics simulation studies to assess their virtual binding affinities and stability of the resultant protein-ligand complex. The docking studies revealed that active ligands were well accommodated within the active site of MAO-B and interacted with both substrate and entrance cavity residues. MD simulation studies unveiled additional hydrogen bond interactions with the substrate cavity residues, Tyr398 and Tyr435 that are crucial for the catalytic role of MAO-B. Moreover, the predicted ADMET parameters suggest that the compounds ZINC08853942 and ZINC02181408 are suitable for CNS penetration. Thus, the attempted computational campaign yielded two potential MAO-B inhibitors that merit further experimental investigation.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Sandeep Kumar
- Pharmaceutical Chemistry Research Laboratory II, Department of Pharmaceutical Engineering and Technology, Indian Institute of Technology (BHU), Varanasi, India
| | - Senthil Raja Ayyannan
- Pharmaceutical Chemistry Research Laboratory II, Department of Pharmaceutical Engineering and Technology, Indian Institute of Technology (BHU), Varanasi, India
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79
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Kovács A, Yusupov M, Cornet I, Billen P, Neyts EC. Effect of natural deep eutectic solvents of non-eutectic compositions on enzyme stability. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.120180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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80
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Mitchell W, Tamucci JD, Ng EL, Liu S, Birk AV, Szeto HH, May ER, Alexandrescu AT, Alder NN. Structure-activity relationships of mitochondria-targeted tetrapeptide pharmacological compounds. eLife 2022; 11:75531. [PMID: 35913044 PMCID: PMC9342957 DOI: 10.7554/elife.75531] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 07/03/2022] [Indexed: 11/13/2022] Open
Abstract
Mitochondria play a central role in metabolic homeostasis, and dysfunction of this organelle underpins the etiology of many heritable and aging-related diseases. Tetrapeptides with alternating cationic and aromatic residues such as SS-31 (elamipretide) show promise as therapeutic compounds for mitochondrial disorders. In this study, we conducted a quantitative structure-activity analysis of three alternative tetrapeptide analogs, benchmarked against SS-31, that differ with respect to aromatic side chain composition and sequence register. We present the first structural models for this class of compounds, obtained with Nuclear Magnetic Resonance (NMR) and molecular dynamics approaches, showing that all analogs except for SS-31 form compact reverse turn conformations in the membrane-bound state. All peptide analogs bound cardiolipin-containing membranes, yet they had significant differences in equilibrium binding behavior and membrane interactions. Notably, analogs had markedly different effects on membrane surface charge, supporting a mechanism in which modulation of membrane electrostatics is a key feature of their mechanism of action. The peptides had no strict requirement for side chain composition or sequence register to permeate cells and target mitochondria in mammalian cell culture assays. All four peptides were pharmacologically active in serum withdrawal cell stress models yet showed significant differences in their abilities to restore mitochondrial membrane potential, preserve ATP content, and promote cell survival. Within our peptide set, the analog containing tryptophan side chains, SPN10, had the strongest impact on most membrane properties and showed greatest efficacy in cell culture studies. Taken together, these results show that side chain composition and register influence the activity of these mitochondria-targeted peptides, helping provide a framework for the rational design of next-generation therapeutics with enhanced potency.
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Affiliation(s)
- Wayne Mitchell
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, United States
| | - Jeffrey D Tamucci
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, United States
| | - Emery L Ng
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, United States
| | - Shaoyi Liu
- Social Profit Network, Menlo Park, CA, United States
| | - Alexander V Birk
- Department of Biology, York College of CUNY, New York, NY, United States
| | - Hazel H Szeto
- Social Profit Network, Menlo Park, CA, United States
| | - Eric R May
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, United States
| | - Andrei T Alexandrescu
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, United States
| | - Nathan N Alder
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, United States
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81
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Tomasiak L, Karch R, Schreiner W. Conformational flexibility of a free and TCR-bound pMHC-I protein investigated by long-term molecular dynamics simulations. BMC Immunol 2022; 23:36. [PMID: 35902791 PMCID: PMC9335952 DOI: 10.1186/s12865-022-00510-7] [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: 07/04/2022] [Accepted: 07/13/2022] [Indexed: 11/10/2022] Open
Abstract
Background Major histocompatibility complexes (MHCs) play a crucial role in the cell-mediated adaptive immune response as they present antigenic peptides (p) which are recognized by host T cells through a complex formation of the T cell receptor (TCR) with pMHC. In the present study, we report on changes in conformational flexibility within a pMHC molecule upon TCR binding by looking at molecular dynamics (MD) simulations of the free and the TCR-bound pMHC-I protein of the LC13-HLA-B*44:05-pEEYLQAFTY complex. Results We performed long-term MD simulations with a total simulation time of 8 µs, employing 10 independent 400 ns replicas for the free and the TCR-bound pMHC system. Upon TCR ligation, we observed a reduced dynamic flexibility in the central residues of the peptide and the MHC α1-helix, altered occurrences of hydrogen bonds between the peptide and the MHC, a reduced conformational entropy of the peptide-binding groove, as well as a decreased solvent accessible surface area. Conclusions In summary, our results from 8 µs MD simulations indicate a restricted conformational space of the MHC peptide-binding groove upon TCR ligation and suggest a minimum simulation time of approximately 100 ns for biomolecules of comparable complexity to draw meaningful conclusions. Given the relatively long total simulation time, our results contribute to a more detailed view on conformational flexibility properties of the investigated free and TCR-bound pMHC-I system. Supplementary Information The online version contains supplementary material available at 10.1186/s12865-022-00510-7.
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Affiliation(s)
- Lisa Tomasiak
- Institute of Biosimulation and Bioinformatics, Center for Medical Statistics, Informatics and Intelligent Systems, Medical University of Vienna, Spitalgasse 23, 1090, Vienna, Austria
| | - Rudolf Karch
- Institute of Biosimulation and Bioinformatics, Center for Medical Statistics, Informatics and Intelligent Systems, Medical University of Vienna, Spitalgasse 23, 1090, Vienna, Austria.
| | - Wolfgang Schreiner
- Institute of Biosimulation and Bioinformatics, Center for Medical Statistics, Informatics and Intelligent Systems, Medical University of Vienna, Spitalgasse 23, 1090, Vienna, Austria
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82
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Zhang N, Bittner JP, Fiedler M, Beretta T, de María PD, Jakobtorweihen S, Kara S. Unraveling Alcohol Dehydrogenase Catalysis in Organic–Aqueous Biphasic Systems Combining Experiments and Molecular Dynamics Simulations. ACS Catal 2022. [DOI: 10.1021/acscatal.2c02881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ningning Zhang
- Biocatalysis and Bioprocessing Group, Department of Biological and Chemical Engineering, Aarhus University, Gustav Wieds Vej 10, 8000 Aarhus, Denmark
| | - Jan Philipp Bittner
- Institute of Thermal Separation Processes, Hamburg University of Technology, Eißendorfer Straße 38, 21073 Hamburg, Germany
| | - Marius Fiedler
- Institute of Process Systems Engineering, Hamburg University of Technology, Am Schwarzenberg-Campus 4, 21073 Hamburg, Germany
| | - Thomas Beretta
- Biocatalysis and Bioprocessing Group, Department of Biological and Chemical Engineering, Aarhus University, Gustav Wieds Vej 10, 8000 Aarhus, Denmark
| | - Pablo Domínguez de María
- Sustainable Momentum, SL, Av. Ansite 3, 4-6, 35011, Las Palmas de Gran Canaria, Canary Islands, Spain
| | - Sven Jakobtorweihen
- Institute of Thermal Separation Processes, Hamburg University of Technology, Eißendorfer Straße 38, 21073 Hamburg, Germany
- Institute of Chemical Reaction Engineering, Hamburg University of Technology, Eißendorfer Straße 38, 21073 Hamburg, Germany
| | - Selin Kara
- Biocatalysis and Bioprocessing Group, Department of Biological and Chemical Engineering, Aarhus University, Gustav Wieds Vej 10, 8000 Aarhus, Denmark
- Institute of Technical Chemistry, Leibniz University Hannover, Callinstr. 5, 30167 Hannover, Germany
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83
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Synthesis and application of a temperature sensitive poly(N-vinylcaprolactam-co-N,N-diethyl acrylamide) for low-temperature rheology control of water-based drilling fluid. Colloids Surf A Physicochem Eng Asp 2022. [DOI: 10.1016/j.colsurfa.2022.128855] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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84
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Nguyen H, Thai NQ, Nguyen PH, Li MS. SARS-CoV-2 Omicron Variant Binds to Human Cells More Strongly than the Wild Type: Evidence from Molecular Dynamics Simulation. J Phys Chem B 2022; 126:4669-4678. [PMID: 35723978 PMCID: PMC9235043 DOI: 10.1021/acs.jpcb.2c01048] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Revised: 06/06/2022] [Indexed: 12/12/2022]
Abstract
The emergence of the variant of concern Omicron (B.1.1.529) of the severe acute respiratory syndrome coronavirus 2 has aggravated the Covid-19 pandemic due to its very contagious ability. The high infection rate may be due to the high binding affinity of Omicron to human cells, but both experimental and computational studies have yielded conflicting results on this issue. Some studies have shown that the Omicron variant binds to human angiotensin-converting enzyme 2 (hACE2) more strongly than the wild type (WT), but other studies have reported comparable binding affinities. To shed light on this open problem, in this work, we calculated the binding free energy of the receptor binding domain (RBD) of the WT and Omicron spike protein to hACE2 using all-atom molecular dynamics simulation and the molecular mechanics Poisson-Boltzmann surface area method. We showed that Omicron binds to human cells more strongly than the WT due to increased RBD charge, which enhances electrostatic interaction with negatively charged hACE2. N440K, T478K, E484A, Q493R, and Q498R mutations in the RBD have been found to play a critical role in the stability of the RBD-hACE2 complex. The effect of homogeneous and heterogeneous models of glycans coating the viral RBD and the peptidyl domain of hACE2 was examined. Although the total binding free energy is not sensitive to the glycan model, the distribution of per-residue interaction energies depends on it. In addition, glycans have a little effect on the binding affinity of the WT RBD to hACE2.
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Affiliation(s)
- Hoang
Linh Nguyen
- Life
Science Lab, Institute for Computational
Science and Technology, Quang Trung
Software City, Tan Chanh Hiep Ward, District 12, Ho Chi Minh
City 700000, Vietnam
- Ho
Chi Minh City University of Technology (HCMUT), Ho Chi Minh City 700000, Vietnam
- Vietnam
National University, Ho Chi Minh
City 700000, Vietnam
| | - Nguyen Quoc Thai
- Life
Science Lab, Institute for Computational
Science and Technology, Quang Trung
Software City, Tan Chanh Hiep Ward, District 12, Ho Chi Minh
City 700000, Vietnam
- Dong
Thap University, 783 Pham Huu Lau Street, Ward 6, Cao Lanh
City, Dong Thap 8100, Vietnam
| | - Phuong H. Nguyen
- CNRS,
Universit́e de Paris, UPR9080, Laboratoire de Biochimie Th́eorique,
Paris, France; Institut de Biologie Physico-Chimique, FondationEdmond
de Rothschild, PSL Research University, Paris 75006, France
| | - Mai Suan Li
- Institute
of Physics, Polish Academy of Sciences, al. Lotnikow 32/46, Warsaw 02-668, Poland
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85
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Yu CC, Raj N, Chu JW. Edge weights in a protein elastic network reorganize collective motions and render long-range sensitivity responses. J Chem Phys 2022; 156:245105. [DOI: 10.1063/5.0095107] [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 effects of inter-residue interactions on protein collective motions are analyzed by comparing two elastic network models (ENM)—structural contact ENM (SC-ENM) and molecular dynamics (MD)-ENM—with the edge weights computed from an all-atom MD trajectory by structure-mechanics statistical learning. A theoretical framework is devised to decompose the eigenvalues of ENM Hessian into contributions from individual springs and to compute the sensitivities of positional fluctuations and covariances to spring constant variation. Our linear perturbation approach quantifies the response mechanisms as softness modulation and orientation shift. All contacts of C α positions in SC-ENM have an identical spring constant by fitting the profile of root-of-mean-squared-fluctuation calculated from an all-atom MD simulation, and the same trajectory data are also used to compute the specific spring constant of each contact as an MD-ENM edge weight. We illustrate that the soft-mode reorganization can be understood in terms of gaining weights along the structural contacts of low elastic strengths and loosing magnitude along those of high rigidities. With the diverse mechanical strengths encoded in protein dynamics, MD-ENM is found to have more pronounced long-range couplings and sensitivity responses with orientation shift identified as a key player in driving the specific residues to have high sensitivities. Furthermore, the responses of perturbing the springs of different residues are found to have asymmetry in the action–reaction relationship. In understanding the mutation effects on protein functional properties, such as long-range communications, our results point in the directions of collective motions as a major effector.
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Affiliation(s)
- Chieh Cheng Yu
- Institute of Bioinformatics and Systems Biology, National Yang Ming Chiao Tung University, 75 Bo-Ai Street, Hsinchu 30010, Taiwan
| | - Nixon Raj
- Institute of Bioinformatics and Systems Biology, National Yang Ming Chiao Tung University, 75 Bo-Ai Street, Hsinchu 30010, Taiwan
| | - Jhih-Wei Chu
- Institute of Bioinformatics and Systems Biology, Department of Biological Science and Technology, Institute of Molecular Medicine and Bioengineering, Center for Intelligent Drug Systems and Smart Bio-devices (IDS2B), National Yang Ming Chiao Tung University, Hsinchu 30010, Taiwan
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86
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Garg P, Semmler S, Baudouin C, Velde CV, Plotkin SS. Misfolding-Associated Exposure of Natively Buried Residues in Mutant SOD1 Facilitates Binding to TRAF6. J Mol Biol 2022; 434:167697. [PMID: 35753527 DOI: 10.1016/j.jmb.2022.167697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 06/14/2022] [Accepted: 06/18/2022] [Indexed: 10/17/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease primarily impacting motor neurons. Mutations in superoxide dismutase 1 (SOD1) are the second most common cause of familial ALS. Several of these mutations lead to misfolding or toxic gain of function in the SOD1 protein. Recently, we reported that misfolded SOD1 interacts with TNF receptor-associated factor 6 (TRAF6) in the SOD1G93A rat model of ALS. Further, we showed in cultured cells that several mutant SOD1 proteins, but not wildtype SOD1 protein, interact with TRAF6 via the MATH domain. Here, we sought to uncover the structural details of this interaction through molecular dynamics (MD) simulations of a dimeric model system, coarse grained using the AWSEM force field. We used direct MD simulations to identify buried residues, and predict binding poses by clustering frames from the trajectories. Metadynamics simulations were also used to deduce preferred binding regions on the protein surfaces from the potential of the mean force in orientation space. Well-folded SOD1 was found to bind TRAF6 via co-option of its native homodimer interface. However, if loops IV and VII of SOD1 were disordered, as typically occurs in the absence of stabilizing Zn2+ ion binding, these disordered loops now participated in novel interactions with TRAF6. On TRAF6, multiple interaction hot-spots were distributed around the equatorial region of the MATH domain beta barrel. Expression of TRAF6 variants with mutations in this region in cultured cells demonstrated that TRAF6T475 facilitates interaction with different SOD1 mutants. These findings contribute to our understanding of the disease mechanism and uncover potential targets for the development of therapeutics.
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Affiliation(s)
- Pranav Garg
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - Sabrina Semmler
- Department of Neurology and Neurosurgery, McGill University, Montréal, Quebec H3A 2B4, Canada; Centre de Recherche du Centre Hospitalier de Université de Montréal, Montréal, Quebec H2X 0A9, Canada
| | - Charlotte Baudouin
- Centre de Recherche du Centre Hospitalier de Université de Montréal, Montréal, Quebec H2X 0A9, Canada; Université Catholique de Louvain, 1348 Louvain-la-Neuve, Belgium
| | - Christine Vande Velde
- Centre de Recherche du Centre Hospitalier de Université de Montréal, Montréal, Quebec H2X 0A9, Canada; Department of Neurosciences, Université de Montréal, Montréal, Quebec H3T 1J4, Canada
| | - Steven S Plotkin
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada; Genome Sciences and Technology Program, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada.
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87
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Yadav HOS, Kuo AT, Urata S, Funahashi K, Imamura Y, Shinoda W. Adsorption characteristics of peptides on ω-functionalized self-assembled monolayers: a molecular dynamics study. Phys Chem Chem Phys 2022; 24:14805-14815. [PMID: 35695085 DOI: 10.1039/d2cp01348g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Molecular dynamics simulations were employed to investigate the adsorption behavior of a variety of amino-acid side-chain analogs (SCAs) and a β-hairpin (HP7) peptide on a series of liquid-like self-assembled monolayers (SAMs) with terminal functional groups of -OH, -OCH3, -CH3, and -CF3. The relationships between the adsorption free energy of the SCAs and the interfacial properties of water on the SAMs were examined to determine the acute predictors of protein adsorption on the SAM surfaces. The structural changes of HP7 on the SAM surfaces were also investigated to understand the relationship between the surface nature and protein denaturation. It was found that the adsorption free energy of the SCAs was linearly related to the surface hydrophobicity, which was computed as the free energy of cavity formation near the SAM-water interfaces. In addition, the hydrophobic -CH3 and -CF3 SAMs produced substantial conformational changes in HP7 because of the strong hydrophobic attractions to the nonpolar side chains. The hydrophilic surface terminated by -OH also promoted structural changes in HP7 resulting from the formation of hydrogen bonds between the hydrophilic tail and HP7. Consequently, the moderate amphiphilic surface terminated by -OCH3 avoided the denaturation of HP7 most efficiently, thus improving the biocompatibility of the surface. In conclusion, these results provide a deep understanding of protein adsorption for a wide range of polymeric surfaces, and they can potentially aid the design of appropriate biocompatible coatings for medical applications.
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Affiliation(s)
- Hari O S Yadav
- Department of Materials Chemistry, Nagoya University, Nagoya 464-8603, Japan
| | - An-Tsung Kuo
- Materials Integration Laboratories, AGC Inc., Yokohama, Kanagawa, 230-0045, Japan
| | - Shingo Urata
- Planning Division, AGC Inc., Yokohama, Kanagawa, 230-0045, Japan
| | - Kosuke Funahashi
- Innovative Technology Laboratories, AGC Inc., Yokohama, Kanagawa, 230-0045, Japan
| | - Yutaka Imamura
- Innovative Technology Laboratories, AGC Inc., Yokohama, Kanagawa, 230-0045, Japan
| | - Wataru Shinoda
- Department of Materials Chemistry, Nagoya University, Nagoya 464-8603, Japan.,Research Institute for Interdisciplinary Science, Okayama University, Okayama 700-8530, Japan. .,Department of Chemistry, Faculty of Science, Okayama University, Okayama 700-8530, Japan
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88
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Chear CT, Mat Ripen A, Mohamad SB. Deciphering the structural and functional impact of Q657L mutation in NLRC4 using computational methods. MOLECULAR SIMULATION 2022. [DOI: 10.1080/08927022.2022.2080822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Chai Teng Chear
- Primary Immunodeficiency Unit, Allergy and Immunology Research Centre, Institute for Medical Research, National Institutes of Health, Ministry of Health Malaysia, Selangor, Malaysia
- Institute of Biological Sciences, Faculty of Science, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Adiratna Mat Ripen
- Primary Immunodeficiency Unit, Allergy and Immunology Research Centre, Institute for Medical Research, National Institutes of Health, Ministry of Health Malaysia, Selangor, Malaysia
| | - Saharuddin Bin Mohamad
- Institute of Biological Sciences, Faculty of Science, Universiti Malaya, Kuala Lumpur, Malaysia
- Centre of Research in Systems Biology, Structural Bioinformatics and Human Digital Imaging (CRYSTAL), Universiti Malaya, Kuala Lumpur, Malaysia
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89
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Gröhs Ferrareze PA, Zimerman RA, Franceschi VB, Caldana GD, Netz PA, Thompson CE. Molecular evolution and structural analyses of the spike glycoprotein from Brazilian SARS-CoV-2 genomes: the impact of selected mutations. J Biomol Struct Dyn 2022; 41:3110-3128. [PMID: 35594172 DOI: 10.1080/07391102.2022.2076154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The COVID-19 pandemic caused by SARS-CoV-2 has reached by February 2022 more than 380 million cases and 5.5 million deaths worldwide since its beginning in late 2019, leading to enhanced concern in the scientific community and the general population. One of the most important pieces of this host-pathogen interaction is the spike protein, which binds to the hACE2 cell receptor, mediates the membrane fusion and is the major target of neutralizing antibodies against SARS-CoV-2. The multiple amino acid substitutions observed in this region, specially in RBD have enhanced the hACE2 binding affinity and led to several modifications in the mechanisms of SARS-CoV-2 pathogenesis, improving the viral fitness and/or promoting immune evasion, with potential impact in the vaccine development. In this work, we identified 48 sites under selective pressures, 17 of them with the strongest evidence by the HyPhy tests, including VOC related mutation sites 138, 142, 222, 262, 484, 681, and 845, among others. The coevolutionary analysis identified 28 sites found not to be conditionally independent, such as E484K-N501Y. The molecular dynamics and free energy estimates showed the structural stabilizing effect and the higher impact of E484K for enhanced binding affinity between the spike RBD and hACE2 in P.1 and P.2 lineages (specially with L452V). Structural changes were also identified in the hACE molecule when interacting with B.1.1.7 RDB. Despite some destabilizing substitutions, a stabilizing effect was identified for the majority of the positively selected mutations.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Patrícia Aline Gröhs Ferrareze
- Graduate Program in Health Sciences, Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA), Porto Alegre, RS, Brazil
| | | | - Vinícius Bonetti Franceschi
- Center of Biotechnology, Graduate Program in Cell and Molecular Biology (PPGBCM), Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Gabriel Dickin Caldana
- Graduate Program in Health Sciences, Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA), Porto Alegre, RS, Brazil
| | - Paulo Augusto Netz
- Graduate Program in Chemistry, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Claudia Elizabeth Thompson
- Graduate Program in Health Sciences, Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA), Porto Alegre, RS, Brazil.,Center of Biotechnology, Graduate Program in Cell and Molecular Biology (PPGBCM), Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil.,Department of Pharmacosciences, Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA), Porto Alegre, RS, Brazil
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90
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Raubenolt BA, Rick SW. Simulation studies of polypeptoids using replica exchange with dynamical scaling and dihedral biasing. J Comput Chem 2022; 43:1229-1236. [PMID: 35543334 DOI: 10.1002/jcc.26887] [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: 01/17/2022] [Revised: 03/15/2022] [Accepted: 04/22/2022] [Indexed: 11/06/2022]
Abstract
Polypeptoids differ from polypeptides in that the amide bond can more frequently adopt both cis and trans conformations. The transition between the two conformations requires overcoming a large energy barrier, making it difficult for conventional molecular simulations to adequately visit the cis and trans structures. A replica-exchange method is presented that allows for easy rotations of the amide bond and also an efficient linking to a high temperature replica. The method allows for just three replicas (one at the temperature and Hamiltonian of interest, a second high temperature replica with a biased dihedral potential, and a third connecting them) to overcome the amide bond sampling problem and also enhance sampling for other coordinates. The results indicate that for short peptoid oligomers, the conformations can range from all cis to all trans with an average cis/trans ratio that depends on side chain and potential model.
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Affiliation(s)
- Bryan A Raubenolt
- Department of Chemistry, University of New Orleans, New Orleans, Louisiana, USA
| | - Steven W Rick
- Department of Chemistry, University of New Orleans, New Orleans, Louisiana, USA
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91
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Pandit G, Sarkar T, S. R. V, Debnath S, Satpati P, Chatterjee S. Delineating the Mechanism of Action of a Protease Resistant and Salt Tolerant Synthetic Antimicrobial Peptide against Pseudomonas aeruginosa. ACS OMEGA 2022; 7:15951-15968. [PMID: 35571791 PMCID: PMC9097201 DOI: 10.1021/acsomega.2c01089] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 04/08/2022] [Indexed: 06/15/2023]
Abstract
Rapidly growing antimicrobial resistance (AMR) against antibiotics has propelled the development of synthetic antimicrobial peptides (AMPs) as potential antimicrobial agents. An antimicrobial peptide Nle-Dab-Trp-Nle-Dab-Dab-Nle-CONH2 (P36; Nle = norleucine, Dab = diaminobutyric acid, Trp = tryptophan) potent against Pseudomonas aeruginosa (P. aeruginosa) has been developed in the present study. Rational design strategy adopted in this study led to the improvisation of the therapeutic qualities such as activity, salt tolerance, cytotoxicity, and protease resistance of the template peptide P4, which was earlier reported from our group. P36 exhibited salt tolerant antimicrobial potency against P. aeruginosa, along with very low cytotoxicity against mammalian cell lines. P36 was found to be nonhemolytic and resistant toward protease degradation which qualified it as a potent antimicrobial agent. We have investigated the mechanism of action of this molecule in detail using several experimental techniques (spectroscopic, biophysical, and microscopic) and molecular dynamics simulations. P36 was a membrane active AMP with membrane destabilization and deformation abilities, leading to leakage of the intracellular materials and causing eventual cell death. The interaction between P36 and the microbial membrane/membrane mimics was primarily driven by electrostatics. P36 was unstructured in water and upon binding to the microbial membrane mimic SDS, suggesting no influence of secondary structure on its antimicrobial potency. Positive charge, optimum hydrophobic-hydrophilic balance, and chain length remained the most important concerns to be addressed while designing small cationic antimicrobial peptides.
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Affiliation(s)
- Gopal Pandit
- Department
of Chemistry, Indian Institute of Technology.
Guwahati (IITG), Guwahati, Assam 781039, India
| | - Tanumoy Sarkar
- Department
of Chemistry, Indian Institute of Technology.
Guwahati (IITG), Guwahati, Assam 781039, India
| | - Vignesh S. R.
- Department
of Biosciences and Bioengineering, Indian
Institute of Technology. Guwahati (IITG), Guwahati, Assam 781039, India
| | - Swapna Debnath
- Department
of Chemistry, Indian Institute of Technology.
Guwahati (IITG), Guwahati, Assam 781039, India
| | - Priyadarshi Satpati
- Department
of Biosciences and Bioengineering, Indian
Institute of Technology. Guwahati (IITG), Guwahati, Assam 781039, India
| | - Sunanda Chatterjee
- Department
of Chemistry, Indian Institute of Technology.
Guwahati (IITG), Guwahati, Assam 781039, India
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92
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Brosz M, Michelarakis N, Bunz UHF, Aponte-Santamaría C, Gräter F. Martini 3 coarse-grained force field for poly( para-phenylene ethynylene)s. Phys Chem Chem Phys 2022; 24:9998-10010. [PMID: 35412534 DOI: 10.1039/d1cp04237h] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Poly(para-phenylene ethynylene)s, or short PPEs, are a class of conjugated and semi-flexible polymers with a strongly delocalized π electron system and increased chain stiffness. Due to this, PPEs have a wide range of technological applications. Although the material properties of single-chains or mixtures of few PPE chains have been studied in detail, the properties of large assemblies remain to be fully explored. Here, we developed a coarse-grained model for PPEs with the Martini 3 force field to enable computational studies of PPEs in large-scale assembly. We used an optimization geometrical approach to take the shape of the π conjugated backbone into account and also applied an additional angular potential to tune the mechanical bending stiffness of the polymer. Our Martini 3 model reproduces key structural and thermodynamic observables of single PPE chains and mixtures, such as persistence length, density, packing and stacking. We show that chain entanglement increases with the expense of nematic ordering with growing PPE chain length. With the Martini 3 PPE model at hand, we are now able to cover large spatio-temporal scales and thereby to uncover key aspects for the structural organization of PPE bulk systems. The model is also predicted to be of high applicability to investigate out-of-equilibrium behavior of PPEs under mechanical force.
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Affiliation(s)
- Matthias Brosz
- Heidelberg Institute for Theoretical Studies, Am Schlosswolfsbrunnenweg 35, 69118 Heidelberg, Germany. .,Interdisciplinary Center for Scientific Computing, Heidelberg University, Im Neuenheimer Feld 205, 69120 Heidelberg, Germany
| | - Nicholas Michelarakis
- Heidelberg Institute for Theoretical Studies, Am Schlosswolfsbrunnenweg 35, 69118 Heidelberg, Germany.
| | - Uwe H F Bunz
- Institute of Organic Chemistry, Heidelberg University, Im Neuenheimer Feld 270, 69120 Heidelberg, Germany
| | - Camilo Aponte-Santamaría
- Heidelberg Institute for Theoretical Studies, Am Schlosswolfsbrunnenweg 35, 69118 Heidelberg, Germany.
| | - Frauke Gräter
- Heidelberg Institute for Theoretical Studies, Am Schlosswolfsbrunnenweg 35, 69118 Heidelberg, Germany. .,Interdisciplinary Center for Scientific Computing, Heidelberg University, Im Neuenheimer Feld 205, 69120 Heidelberg, Germany
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93
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Hsu WT, Ramirez DA, Sammakia T, Tan Z, Shirts MR. Identifying signatures of proteolytic stability and monomeric propensity in O-glycosylated insulin using molecular simulation. J Comput Aided Mol Des 2022; 36:313-328. [PMID: 35507105 DOI: 10.1007/s10822-022-00453-6] [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: 10/29/2021] [Accepted: 04/06/2022] [Indexed: 11/24/2022]
Abstract
Insulin has been commonly adopted as a peptide drug to treat diabetes as it facilitates the uptake of glucose from the blood. The development of oral insulin remains elusive over decades owing to its susceptibility to the enzymes in the gastrointestinal tract and poor permeability through the intestinal epithelium upon dimerization. Recent experimental studies have revealed that certain O-linked glycosylation patterns could enhance insulin's proteolytic stability and reduce its dimerization propensity, but understanding such phenomena at the molecular level is still difficult. To address this challenge, we proposed and tested several structural determinants that could potentially influence insulin's proteolytic stability and dimerization propensity. We used these metrics to assess the properties of interest from [Formula: see text] aggregate molecular dynamics of each of 12 targeted insulin glyco-variants from multiple wild-type crystal structures. We found that glycan-involved hydrogen bonds and glycan-dimer occlusion were useful metrics predicting the proteolytic stability and dimerization propensity of insulin, respectively, as was in part the solvent-accessible surface area of proteolytic sites. However, other plausible metrics were not generally predictive. This work helps better explain how O-linked glycosylation influences the proteolytic stability and monomeric propensity of insulin, illuminating a path towards rational molecular design of insulin glycoforms.
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Affiliation(s)
- Wei-Tse Hsu
- Department of Chemical & Biological Engineering, University of Colorado Boulder, Boulder, CO, 80309, USA
| | - Dominique A Ramirez
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO, 80309, USA
| | - Tarek Sammakia
- Department of Chemistry, University of Colorado Boulder, Boulder, CO, 80309, USA
| | - Zhongping Tan
- Institute of Materia Medica, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, 100050, China.
| | - Michael R Shirts
- Department of Chemical & Biological Engineering, University of Colorado Boulder, Boulder, CO, 80309, USA.
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94
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Tavagnacco L, Zaccarelli E, Chiessi E. Modeling Solution Behavior of Poly( N-isopropylacrylamide): A Comparison between Water Models. J Phys Chem B 2022; 126:3778-3788. [PMID: 35491838 PMCID: PMC9150113 DOI: 10.1021/acs.jpcb.2c00637] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
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Water is known to
play a fundamental role in determining the structure
and functionality of macromolecules. The same crucial contribution
is also found in the in silico description of polymer aqueous solutions.
In this work, we exploit the widely investigated synthetic polymer
poly(N-isopropylacrylamide) (PNIPAM) to understand
the effect of the adopted water model on its solution behavior and
to refine the computational setup. By means of atomistic molecular
dynamics simulations, we perform a comparative study of PNIPAM aqueous
solution using two advanced water models: TIP4P/2005 and TIP4P/Ice.
The conformation and hydration features of an atactic 30-mer at infinite
dilution are probed at a range of temperature and pressure suitable
to detect the coil-to-globule transition and to map the P–T
phase diagram. Although both water models can reproduce the temperature-induced
coil-to-globule transition at atmospheric pressure and the polymer
hydration enhancement that occurs with increasing pressure, the PNIPAM–TIP4P/Ice
solution shows better agreement with experimental findings. This result
can be attributed to a stronger interaction of TIP4P/Ice water with
both hydrophilic and hydrophobic groups of PNIPAM, as well as to a
less favorable contribution of the solvent entropy to the coil-to-globule
transition.
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Affiliation(s)
- Letizia Tavagnacco
- CNR-ISC and Department of Physics, Sapienza University of Rome, Piazzale A, Moro 2, Rome 00185, Italy
| | - Emanuela Zaccarelli
- CNR-ISC and Department of Physics, Sapienza University of Rome, Piazzale A, Moro 2, Rome 00185, Italy
| | - Ester Chiessi
- Department of Chemical Sciences and Technologies, University of Rome Tor Vergata, Via della Ricerca Scientifica I, Rome 00133, Italy
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95
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Li N, Sun Z, Pang Y, Qi Z, Liu W, Li W, Sun M, Li B, Wang Z. Microscopic mechanism for electrocoalescence of water droplets in water-in-oil emulsions containing surfactant: A molecular dynamics study. Sep Purif Technol 2022. [DOI: 10.1016/j.seppur.2022.120756] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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96
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Warmińska D, Śmiechowski M. Understanding ion–ion and ion–solvent interactions in aqueous solutions of morpholinium ionic liquids with N-acetyl-L-alaninate anion through partial molar properties and molecular dynamics simulations. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.118876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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97
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Molecular dynamics study on the aggregation behaviours of Platonic micelle in different NaCl solutions. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.118828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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98
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Guo D, Duan H, Cheng Y, Wang Y, Hu J, Shi H. Omicron-included mutation-induced changes in epitopes of SARS-CoV-2 spike protein and effectiveness assessments of current antibodies. MOLECULAR BIOMEDICINE 2022; 3:12. [PMID: 35461370 PMCID: PMC9034971 DOI: 10.1186/s43556-022-00074-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 03/25/2022] [Indexed: 02/08/2023] Open
Abstract
The COVID-19 pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is spreading globally and continues to rage, posing a serious threat to human health and life quality. Antibody therapy and vaccines both have shown great efficacy in the prevention and treatment of COVID-19, whose development progress and adaptation range have attracted wide attention. However, with the emergence of variant strains of SARS-CoV-2, the neutralization activity of therapeutic or vaccine-induced antibodies may be reduced, requiring long-term virus monitoring and drug upgrade in response to its evolution. In this paper, conformational changes including continuous epitopes (CPs), discontinuous epitopes (DPs) and recognition interfaces of the three representative SARS-CoV-2 spike protein (SP) mutants (i.e., the Delta (B.1.617.2), Mu (B.1.621) and Omicron (B.1.1.529) strains), were analyzed to evaluate the effectiveness of current mainstream antibodies. The results showed that the conformation of SP wild type (WT) and mutants both remained stable, while the local antigenic epitopes underwent significant changes. Sufficient flexibility of SP CPs is critical for effective antibody recognition. The DPs of Delta, Mu and Omicron variants have showed stronger binding to human angiotensin converting enzyme-2 (hACE2) than WT; the possible drug resistance mechanisms of antibodies against three different epitopes (i.e., NTD_DP, RBD1_DP and RBD2_DP) were also proposed, respectively; the RBD2 of Delta, NTD of Mu, NTD and RBD2 of Omicron are deserve more attention in the subsequent design of next-generation vaccines. The simulation results not only revealed structural characteristics of SP antigenic epitopes, but also provided guidance for antibody modification, vaccine design and effectiveness evaluation.
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Affiliation(s)
- Du Guo
- Laboratory of Tumor Targeted and Immune Therapy, Clinical Research Center for Breast, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University and Collaborative Innovation Center, Chengdu, 610041, China
| | - Huaichuan Duan
- Key Laboratory of Medicinal and Edible Plants Resources Development of Sichuan Education Department, School of Pharmacy, Chengdu University, Chengdu, 610106, China
| | - Yan Cheng
- Laboratory of Tumor Targeted and Immune Therapy, Clinical Research Center for Breast, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University and Collaborative Innovation Center, Chengdu, 610041, China
| | - Yueteng Wang
- Key Laboratory of Medicinal and Edible Plants Resources Development of Sichuan Education Department, School of Pharmacy, Chengdu University, Chengdu, 610106, China
| | - Jianping Hu
- Key Laboratory of Medicinal and Edible Plants Resources Development of Sichuan Education Department, School of Pharmacy, Chengdu University, Chengdu, 610106, China.
| | - Hubing Shi
- Laboratory of Tumor Targeted and Immune Therapy, Clinical Research Center for Breast, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University and Collaborative Innovation Center, Chengdu, 610041, China.
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99
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Khan MA, Siddiqui MQ, Kuligina E, Varma AK. Evaluation of conformational transitions of h-BRCA2 functional domain and unclassified variant Arg2502Cys using multimodal approach. Int J Biol Macromol 2022; 209:716-724. [PMID: 35413318 DOI: 10.1016/j.ijbiomac.2022.04.049] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 04/02/2022] [Accepted: 04/06/2022] [Indexed: 11/26/2022]
Abstract
Breast cancer type 2 susceptibility (BRCA2) protein plays an essential role in the repair mechanism of DNA double-strand breaks and interstrand cross-links by Homologous recombination. Germline mutations identified in the BRCA2 gene confer an increased risk of hereditary breast and ovarian cancer. Missense mutations are identified all over the gene, including the DNA binding region of BRCA2 that interacts with FANCD2. However, the majority of these missense mutations are classified as 'Variants of Uncertain Significance' due to a lack of structural, functional and clinical correlations. Therefore, multi-disciplinary in-silico, in-vitro and biophysical approaches have been explored to characterize an unclassified missense mutation, BRCA2 Arg2502Cys, identified from a case-control study. Circular-dichroism and Fluorescence spectroscopy show that the Arg2502Cys mutation in hBRCA2 (residues 2350-2545) decreases the α-helical/β-sheet propensity of the wild-type protein and perturb the tertiary structure conformation. Molecular dynamics simulations revealed alteration in the intramolecular H-bonds, overall compactness and stability of the hydrophobic core were observed in the mutant protein. Principle component analysis indicated that Arg2502Cys mutant exhibited comparatively large conformational transitions and periodic fluctuation. Therefore, to our conclusion, BRCA2 Arg2502Cys mutant perturbed the structural integrity and conformational dynamics of BRCA2.
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Affiliation(s)
- Mudassar Ali Khan
- Advanced Centre for Treatment, Research and Education in Cancer, Kharghar, Navi Mumbai, Maharashtra 410210, India; Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai 400094, India
| | - M Quadir Siddiqui
- Advanced Centre for Treatment, Research and Education in Cancer, Kharghar, Navi Mumbai, Maharashtra 410210, India; Present address: Alberta RNA Research and Training Institute, Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Drive, Lethbridge, AB T1K 3M4, Canada
| | - Ekaterina Kuligina
- N.N. Petrov Institute of Oncology, Laboratory of Molecular Oncology, RU-197758, Pesochny-2, St.-Petersburg, Russia
| | - Ashok K Varma
- Advanced Centre for Treatment, Research and Education in Cancer, Kharghar, Navi Mumbai, Maharashtra 410210, India; Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai 400094, India.
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100
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Polylactide nanoparticle impregnation with carbamazepine in supercritical media and its subsequent release in liquid solvents: insights from molecular simulation. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.118758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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