1
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Huang Y, Chang Z, Gao Y, Ren C, Lin Y, Zhang X, Wu C, Pan X, Huang Z. Overcoming the Low-Stability Bottleneck in the Clinical Translation of Liposomal Pressurized Metered-Dose Inhalers: A Shell Stabilization Strategy Inspired by Biomineralization. Int J Mol Sci 2024; 25:3261. [PMID: 38542235 PMCID: PMC10970625 DOI: 10.3390/ijms25063261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Revised: 03/07/2024] [Accepted: 03/08/2024] [Indexed: 06/25/2024] Open
Abstract
Currently, several types of inhalable liposomes have been developed. Among them, liposomal pressurized metered-dose inhalers (pMDIs) have gained much attention due to their cost-effectiveness, patient compliance, and accurate dosages. However, the clinical application of liposomal pMDIs has been hindered by the low stability, i.e., the tendency of the aggregation of the liposome lipid bilayer in hydrophobic propellant medium and brittleness under high mechanical forces. Biomineralization is an evolutionary mechanism that organisms use to resist harsh external environments in nature, providing mechanical support and protection effects. Inspired by such a concept, this paper proposes a shell stabilization strategy (SSS) to solve the problem of the low stability of liposomal pMDIs. Depending on the shell material used, the SSS can be classified into biomineralization (biomineralized using calcium, silicon, manganese, titanium, gadolinium, etc.) biomineralization-like (composite with protein), and layer-by-layer (LbL) assembly (multiple shells structured with diverse materials). This work evaluated the potential of this strategy by reviewing studies on the formation of shells deposited on liposomes or similar structures. It also covered useful synthesis strategies and active molecules/functional groups for modification. We aimed to put forward new insights to promote the stability of liposomal pMDIs and shed some light on the clinical translation of relevant products.
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Affiliation(s)
- Yeqi Huang
- College of Pharmacy, Jinan University, Guangzhou 511443, China; (Y.H.); (Y.G.); (C.R.); (Y.L.); (C.W.)
| | - Ziyao Chang
- School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou 510006, China; (Z.C.); (X.P.)
| | - Yue Gao
- College of Pharmacy, Jinan University, Guangzhou 511443, China; (Y.H.); (Y.G.); (C.R.); (Y.L.); (C.W.)
| | - Chuanyu Ren
- College of Pharmacy, Jinan University, Guangzhou 511443, China; (Y.H.); (Y.G.); (C.R.); (Y.L.); (C.W.)
| | - Yuxin Lin
- College of Pharmacy, Jinan University, Guangzhou 511443, China; (Y.H.); (Y.G.); (C.R.); (Y.L.); (C.W.)
| | - Xuejuan Zhang
- College of Pharmacy, Jinan University, Guangzhou 511443, China; (Y.H.); (Y.G.); (C.R.); (Y.L.); (C.W.)
| | - Chuanbin Wu
- College of Pharmacy, Jinan University, Guangzhou 511443, China; (Y.H.); (Y.G.); (C.R.); (Y.L.); (C.W.)
| | - Xin Pan
- School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou 510006, China; (Z.C.); (X.P.)
| | - Zhengwei Huang
- College of Pharmacy, Jinan University, Guangzhou 511443, China; (Y.H.); (Y.G.); (C.R.); (Y.L.); (C.W.)
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2
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Kharche S, Yadav M, Hande V, Prakash S, Sengupta D. Improved Protein Dynamics and Hydration in the Martini3 Coarse-Grain Model. J Chem Inf Model 2024; 64:837-850. [PMID: 38291973 DOI: 10.1021/acs.jcim.3c00802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2024]
Abstract
The Martini coarse-grain force-field has emerged as an important framework to probe cellular processes at experimentally relevant time- and length-scales. However, the recently developed version, the Martini3 force-field with the implemented Go̅ model (Martini3Go̅), as well as previous variants of the Martini model have not been benchmarked and rigorously tested for globular proteins. In this study, we consider three globular proteins, ubiquitin, lysozyme, and cofilin, and compare protein dynamics and hydration with observables from experiments and all-atom simulations. We show that the Martini3Go̅ model is able to accurately model the structural and dynamic features of small globular proteins. Overall, the structural integrity of the proteins is maintained, as validated by contact maps, radii of gyration (Rg), and SAXS profiles. The chemical shifts predicted from the ensemble sampled in the simulations are consistent with the experimental data. Further, a good match is observed in the protein-water interaction energetics, and the hydration levels of the residues are similar to atomistic simulations. However, the protein-water interaction dynamics is not accurately represented and appears to depend on the protein structural complexity, residue specificity, and water dynamics. Our work is a step toward testing and assessing the Martini3Go̅ model and provides insights into future efforts to refine Martini models with improved solvation effects and better correspondence to the underlying all-atom systems.
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Affiliation(s)
- Shalmali Kharche
- CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411008, India
| | - Manjul Yadav
- CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411008, India
| | - Vrushali Hande
- CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411008, India
| | - Shikha Prakash
- CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411008, India
| | - Durba Sengupta
- CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411008, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
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3
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Reid KM, Poudel H, Leitner DM. Dynamics of Hydrogen Bonds between Water and Intrinsically Disordered and Structured Regions of Proteins. J Phys Chem B 2023; 127:7839-7847. [PMID: 37672685 DOI: 10.1021/acs.jpcb.3c03102] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/08/2023]
Abstract
Recent studies indicate more restricted dynamics of water around intrinsically disordered proteins (IDPs) than structured proteins. We examine here the dynamics of hydrogen bonds between water molecules and two proteins, small ubiquitin-related modifier-1 (SUMO-1) and ubiquitin-conjugating enzyme E2I (UBC9), which we compare around intrinsically disordered regions (IDRs) and structured regions of these proteins. It has been recognized since some time that excluded volume effects, which influence access of water molecules to hydrogen-bonding sites, and the strength of hydrogen bonds between water and protein affect hydrogen bond lifetimes. While we find those two properties to mediate lifetimes of hydrogen bonds between water and protein residues in this study, we also find that the lifetimes are affected by the concentration of charged groups on other nearby residues. These factors are more important in determining the hydrogen bond lifetimes than whether a residue hydrogen bonding with water belongs to an IDR or to a structured region.
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Affiliation(s)
- Korey M Reid
- Department of Chemistry, University of Nevada, Reno, Nevada 89557, United States
- Department of Chemistry, Dartmouth College, Hanover, New Hampshire 03755, United States
| | - Humanath Poudel
- Department of Chemistry, University of Nevada, Reno, Nevada 89557, United States
| | - David M Leitner
- Department of Chemistry, University of Nevada, Reno, Nevada 89557, United States
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4
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Yang L, Guo S, Liao C, Hou C, Jiang S, Li J, Ma X, Shi L, Ye L, He X. Spatial Layouts of Low-Entropy Hydration Shells Guide Protein Binding. GLOBAL CHALLENGES (HOBOKEN, NJ) 2023; 7:2300022. [PMID: 37483413 PMCID: PMC10362119 DOI: 10.1002/gch2.202300022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 03/29/2023] [Indexed: 07/25/2023]
Abstract
Protein-protein binding enables orderly biological self-organization and is therefore considered a miracle of nature. Protein‒protein binding is driven by electrostatic forces, hydrogen bonding, van der Waals force, and hydrophobic interactions. Among these physical forces, only hydrophobic interactions can be considered long-range intermolecular attractions between proteins due to the electrostatic shielding of surrounding water molecules. Low-entropy hydration shells around proteins drive hydrophobic attraction among them that essentially coordinate protein‒protein binding. Here, an innovative method is developed for identifying low-entropy regions of hydration shells of proteins by screening off pseudohydrophilic groups on protein surfaces and revealing that large low-entropy regions of the hydration shells typically cover the binding sites of individual proteins. According to an analysis of determined protein complex structures, shape matching between a large low-entropy hydration shell region of a protein and that of its partner at the binding sites is revealed as a universal law. Protein‒protein binding is thus found to be mainly guided by hydrophobic collapse between the shape-matched low-entropy hydration shells that is verified by bioinformatics analyses of hundreds of structures of protein complexes, which cover four test systems. A simple algorithm is proposed to accurately predict protein binding sites.
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Affiliation(s)
- Lin Yang
- National Key Laboratory of Science and Technology on Advanced Composites in Special EnvironmentsCenter for Composite Materials and StructuresHarbin Institute of TechnologyHarbin150080P. R. China
- School of AerospaceMechanical and Mechatronic EngineeringThe University of SydneyNSW2006Australia
| | - Shuai Guo
- National Key Laboratory of Science and Technology on Advanced Composites in Special EnvironmentsCenter for Composite Materials and StructuresHarbin Institute of TechnologyHarbin150080P. R. China
| | - Chenchen Liao
- School of Electronics and Information EngineeringHarbin Institute of TechnologyHarbin150080P. R. China
| | - Chengyu Hou
- School of Electronics and Information EngineeringHarbin Institute of TechnologyHarbin150080P. R. China
| | - Shenda Jiang
- National Key Laboratory of Science and Technology on Advanced Composites in Special EnvironmentsCenter for Composite Materials and StructuresHarbin Institute of TechnologyHarbin150080P. R. China
| | - Jiacheng Li
- National Key Laboratory of Science and Technology on Advanced Composites in Special EnvironmentsCenter for Composite Materials and StructuresHarbin Institute of TechnologyHarbin150080P. R. China
| | - Xiaoliang Ma
- National Key Laboratory of Science and Technology on Advanced Composites in Special EnvironmentsCenter for Composite Materials and StructuresHarbin Institute of TechnologyHarbin150080P. R. China
| | - Liping Shi
- National Key Laboratory of Science and Technology on Advanced Composites in Special EnvironmentsCenter for Composite Materials and StructuresHarbin Institute of TechnologyHarbin150080P. R. China
| | - Lin Ye
- School of System Design and Intelligent ManufacturingSouthern University of Science and TechnologyShenzhen518055P. R. China
| | - Xiaodong He
- National Key Laboratory of Science and Technology on Advanced Composites in Special EnvironmentsCenter for Composite Materials and StructuresHarbin Institute of TechnologyHarbin150080P. R. China
- Shenzhen STRONG Advanced Materials Research Institute Co., LtdShenzhen518035P. R. China
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5
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de Bruyn E, Dorn AE, Zimmermann O, Rossetti G. SPEADI: Accelerated Analysis of IDP-Ion Interactions from MD-Trajectories. BIOLOGY 2023; 12:biology12040581. [PMID: 37106781 PMCID: PMC10135740 DOI: 10.3390/biology12040581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 04/04/2023] [Accepted: 04/05/2023] [Indexed: 04/29/2023]
Abstract
The disordered nature of Intrinsically Disordered Proteins (IDPs) makes their structural ensembles particularly susceptible to changes in chemical environmental conditions, often leading to an alteration of their normal functions. A Radial Distribution Function (RDF) is considered a standard method for characterizing the chemical environment surrounding particles during atomistic simulations, commonly averaged over an entire or part of a trajectory. Given their high structural variability, such averaged information might not be reliable for IDPs. We introduce the Time-Resolved Radial Distribution Function (TRRDF), implemented in our open-source Python package SPEADI, which is able to characterize dynamic environments around IDPs. We use SPEADI to characterize the dynamic distribution of ions around the IDPs Alpha-Synuclein (AS) and Humanin (HN) from Molecular Dynamics (MD) simulations, and some of their selected mutants, showing that local ion-residue interactions play an important role in the structures and behaviors of IDPs.
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Affiliation(s)
- Emile de Bruyn
- Jülich Supercomputing Centre, Forschungszentrum Jülich, 52425 Jülich, Germany
- Faculty of Mathematics, Computer Science and Natural Sciences, RWTH Aachen University, 52062 Aachen, Germany
| | - Anton Emil Dorn
- Faculty of Mathematics, Computer Science and Natural Sciences, RWTH Aachen University, 52062 Aachen, Germany
| | - Olav Zimmermann
- Jülich Supercomputing Centre, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Giulia Rossetti
- Jülich Supercomputing Centre, Forschungszentrum Jülich, 52425 Jülich, Germany
- Computational Biomedicine, Institute for Advanced Simulation IAS-5 and Institute of Neuroscience and Medicine INM-9, Forschungszentrum Jülich, 52425 Jülich, Germany
- Department of Neurology, RWTH Aachen University, 52062 Aachen, Germany
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6
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Doan LC, Dahanayake JN, Mitchell-Koch KR, Singh AK, Vinh NQ. Probing Adaptation of Hydration and Protein Dynamics to Temperature. ACS OMEGA 2022; 7:22020-22031. [PMID: 35785325 PMCID: PMC9245114 DOI: 10.1021/acsomega.2c02843] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Accepted: 05/31/2022] [Indexed: 06/15/2023]
Abstract
Protein dynamics is strongly influenced by the surrounding environment and physiological conditions. Here we employ broadband megahertz-to-terahertz spectroscopy to explore the dynamics of water and myoglobin protein on an extended time scale from femto- to nanosecond. The dielectric spectra reveal several relaxations corresponding to the orientational polarization mechanism, including the dynamics of loosely bound, tightly bound, and bulk water, as well as collective vibrational modes of protein in an aqueous environment. The dynamics of loosely bound and bulk water follow non-Arrhenius behavior; however, the dynamics of water molecules in the tightly bound layer obeys the Arrhenius-type relation. Combining molecular simulations and effective-medium approximation, we have determined the number of water molecules in the tightly bound hydration layer and studied the dynamics of protein as a function of temperature. The results provide the important impact of water on the biochemical functions of proteins.
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Affiliation(s)
- Luan C. Doan
- Department
of Physics and Center for Soft Matter and Biological Physics, Virginia Tech, Blacksburg, Virginia 24061, United States
- Department
of Mechanical Engineering, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Jayangika N. Dahanayake
- Department
of Chemistry, Faculty of Science, University
of Kelaniya, Kelaniya 11600, Sri Lanka
| | | | - Abhishek K. Singh
- Department
of Physics and Center for Soft Matter and Biological Physics, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Nguyen Q. Vinh
- Department
of Physics and Center for Soft Matter and Biological Physics, Virginia Tech, Blacksburg, Virginia 24061, United States
- Department
of Mechanical Engineering, Virginia Tech, Blacksburg, Virginia 24061, United States
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7
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Xue Y, Zhang XG, Lu ZP, Xu C, Xu HJ, Hu Y. Enhancing the Catalytic Performance of Candida antarctica Lipase B by Chemical Modification With Alkylated Betaine Ionic Liquids. Front Bioeng Biotechnol 2022; 10:850890. [PMID: 35265607 PMCID: PMC8899502 DOI: 10.3389/fbioe.2022.850890] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Accepted: 01/27/2022] [Indexed: 11/24/2022] Open
Abstract
Various betaine ionic liquids composed of different chain lengths and different anions were designed and synthesized to modify Candida antarctica lipase B (CALB). The results showed that the catalytic activity of all modified lipases improved under different temperature and pH conditions, while also exhibiting enhanced thermostability and tolerance to organic solvents. With an increase in ionic liquid chain length, the modification effect was greater. Overall, CALB modified by [BetaineC16][H2PO4] performed best, with the modified CALB enzyme activity increased 3-fold, thermal stability increased 1.5-fold when stored at 70°C for 30 min, with tolerance increased 2.9-fold in 50% DMSO and 2.3-fold in 30% mercaptoethanol. Fluorescence and circular dichroism (CD) spectroscopic analysis showed that the introduction of an ionic liquid caused changes in the microenvironment surrounding some fluorescent groups and the secondary structure of the CALB enzyme protein. In order to establish the enzyme activity and stability change mechanisms of the modified CALB, the structures of CALB modified with [BetaineC4][Cl] and [BetaineC16][Cl] were constructed, while the reaction mechanisms were studied by molecular dynamics simulations. Results showed that the root mean square deviation (RMSD) and total energy of modified CALB were less than those of native CALB, indicating that modified CALB has a more stable structure. Root mean square fluctuation (RMSF) calculations showed that the rigidity of modified CALB was enhanced. Solvent accessibility area (SASA) calculations exhibited that both the hydrophilicity and hydrophobicity of the modified enzyme-proteins were improved. The increase in radial distribution function (RDF) of water molecules confirmed that the number of water molecules around the active sites also increased. Therefore, modified CALB has enhanced structural stability and higher hydrolytic activity.
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Affiliation(s)
| | | | | | | | | | - Yi Hu
- *Correspondence: Hua-Jin Xu, ; Yi Hu,
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8
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Reid KM, Singh AK, Bikash CR, Wei J, Tal-Gan Y, Vinh NQ, Leitner DM. The origin and impact of bound water around intrinsically disordered proteins. Biophys J 2022; 121:540-551. [PMID: 35074392 PMCID: PMC8874019 DOI: 10.1016/j.bpj.2022.01.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2021] [Revised: 12/14/2021] [Accepted: 01/13/2022] [Indexed: 12/29/2022] Open
Abstract
Proteins and water couple dynamically over a wide range of time scales. Motivated by their central role in protein function, protein-water dynamics and thermodynamics have been extensively studied for structured proteins, where correspondence to structural features has been made. However, properties controlling intrinsically disordered protein (IDP)-water dynamics are not yet known. We report results of megahertz-to-terahertz dielectric spectroscopy and molecular dynamics simulations of a group of IDPs with varying charge content along with structured proteins of similar size. Hydration water around IDPs is found to exhibit more heterogeneous rotational and translational dynamics compared with water around structured proteins of similar size, yielding on average more restricted dynamics around individual residues of IDPs, charged or neutral, compared with structured proteins. The on-average slower water dynamics is found to arise from excess tightly bound water in the first hydration layer, which is related to greater exposure to charged groups. The more tightly bound water to IDPs correlates with the smaller hydration shell found experimentally, and affects entropy associated with protein-water interactions, the contribution of which we estimate based on the dielectric measurements and simulations. Water-IDP dynamic coupling at terahertz frequencies is characterized by the dielectric measurements and simulations.
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Affiliation(s)
- Korey M. Reid
- Department of Chemistry, University of Nevada, Reno, Nevada
| | - Abhishek K. Singh
- Department of Physics and Center for Soft Matter and Biological Physics, Virginia Tech, Blacksburg, Virginia
| | | | - Jessica Wei
- Department of Chemistry, University of Nevada, Reno, Nevada
| | - Yftah Tal-Gan
- Department of Chemistry, University of Nevada, Reno, Nevada
| | - Nguyen Q. Vinh
- Department of Physics and Center for Soft Matter and Biological Physics, Virginia Tech, Blacksburg, Virginia,Corresponding author
| | - David M. Leitner
- Department of Chemistry, University of Nevada, Reno, Nevada,Corresponding author
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9
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Dighe AV, Coliaie P, Podupu PKR, Singh MR. Selective desolvation in two-step nucleation mechanism steers crystal structure formation. NANOSCALE 2022; 14:1723-1732. [PMID: 35018395 DOI: 10.1039/d1nr06346d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The two-step nucleation (TSN) theory and crystal structure prediction (CSP) techniques are two disjointed yet popular methods to predict nucleation rate and crystal structure, respectively. The TSN theory is a well-established mechanism to describe the nucleation of a wide range of crystalline materials in different solvents. However, it has never been expanded to predict the crystal structure or polymorphism. On the contrary, the existing CSP techniques only empirically account for the solvent effects. As a result, the TSN theory and CSP techniques continue to evolve as separate methods to predict two essential attributes of nucleation - rate and structure. Here we bridge this gap and show for the first time how a crystal structure is formed within the framework of TSN theory. A sequential desolvation mechanism is proposed in TSN, where the first step involves partial desolvation to form dense clusters followed by selective desolvation of functional groups directing the formation of crystal structure. We investigate the effect of the specific interaction on the degree of solvation around different functional groups of glutamic acid molecules using molecular simulations. The simulated energy landscape and activation barriers at increasing supersaturations suggest sequential and selective desolvation. We validate computationally and experimentally that the crystal structure formation and polymorph selection are due to a previously unrecognized consequence of supersaturation-driven asymmetric desolvation of molecules.
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Affiliation(s)
- Anish V Dighe
- Department of Chemical Engineering, University of Illinois Chicago, Chicago, IL 60607, USA.
| | - Paria Coliaie
- Department of Chemical Engineering, University of Illinois Chicago, Chicago, IL 60607, USA.
| | - Prem K R Podupu
- Department of Chemical Engineering, University of Illinois Chicago, Chicago, IL 60607, USA.
| | - Meenesh R Singh
- Department of Chemical Engineering, University of Illinois Chicago, Chicago, IL 60607, USA.
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10
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Wu CH, Hua CC, Wang CI. Effects of solvation shell relaxation on chain association mechanisms in poly(3-hexylthiophene) solutions. Phys Chem Chem Phys 2021; 23:12005-12014. [PMID: 34008625 DOI: 10.1039/d1cp00869b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Using poly(3-hexylthiophene) (P3HT) as a model conjugated polymer and atomistic molecular dynamics simulations with carefully verified force fields, we performed in-depth investigations of solvation shell properties of P3HT chains (15 repeating units per chain) in two representative groups of non-polar (or aprotic) organic solvents (better solvents: ortho-dichlorobenzene, bromobenzene, and chlorobenzene; poorer solvents: chloroform, para-xylene, and toluene). We demonstrated that solvation shell relaxation properties in P3HT solutions dictate the formation of regular π-π associations and, hence, crystallinity through the initial chain association and subsequent chain sliding. In contrast, the mean features of polymer-solvent interactions, including solvation free energy and radial distribution function, present little or no difference for all solvent media investigated. Better-solvent media were revealed to bear relatively large values of the first solvation shell relaxation time (τ1 ≫ 100 ps) as well as larger ratios of relaxation times for the first two solvation shells (τ1/τ2 > 2), and vice versa for poorer-solvent media (τ1 ≪ 100 ps and τ1/τ2 < 2). The linear hexyl side-chain unit was noted to substantially enlarge both quantities while notably reducing the solvation free energy as well. As discussed herein, these findings shed new light on the mechanistic features by which solvent quality impacts the degree of π-π association crucial for modern applications with crystalline conjugated polymers.
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Affiliation(s)
- Ching H Wu
- Department of Chemical Engineering, National Chung Cheng University, Chia-Yi 62102, Taiwan.
| | - Chi C Hua
- Department of Chemical Engineering, National Chung Cheng University, Chia-Yi 62102, Taiwan.
| | - Chun I Wang
- Institute of Chemistry, Academia Sinica, Taipei 115, Taiwan
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11
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Haridasan N, Sathian SP. Rotational dynamics of proteins in nanochannels: role of solvent's local viscosity. NANOTECHNOLOGY 2021; 32:225102. [PMID: 33621966 DOI: 10.1088/1361-6528/abe906] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Accepted: 02/23/2021] [Indexed: 06/12/2023]
Abstract
Viscosity variation of solvent in local regions near a solid surface, be it a biological surface of a protein or an engineered surface of a nanoconfinement, is a direct consequence of intermolecular interactions between the solid body and the solvent. The current coarse-grained molecular dynamics study takes advantage of this phenomenon to investigate the anomaly in a solvated protein's rotational dynamics confined using a representative solid matrix. The concept of persistence time, the characteristic time of structural reordering in liquids, is used to compute the solvent's local viscosity. With an increase in the degree of confinement, the confining matrix significantly influences the solvent molecule's local viscosity present in the protein hydration layer through intermolecular interactions. This effect contributes to the enhanced drag force on protein motion, causing a reduction in the rotational diffusion coefficient. Simulation results suggest that the direct matrix-protein non-bonded interaction is responsible for the occasional jump and discontinuity in orientational motion when the protein is in very tight confinement.
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Affiliation(s)
- Navaneeth Haridasan
- Micro and Nanoscale Transport Lab, Applied Mechanics Department, Indian Institute of Technology Madras, Chennai, India
| | - Sarith P Sathian
- Micro and Nanoscale Transport Lab, Applied Mechanics Department, Indian Institute of Technology Madras, Chennai, India
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12
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Xu C, Suo H, Xue Y, Qin J, Chen H, Hu Y. Experimental and theoretical evidence of enhanced catalytic performance of lipase B from Candida antarctica acquired by the chemical modification with amino acid ionic liquids. MOLECULAR CATALYSIS 2021. [DOI: 10.1016/j.mcat.2020.111355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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13
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Voloshin V, Smolin N, Geiger A, Winter R, Medvedev NN. Dynamics of TMAO and urea in the hydration shell of the protein SNase. Phys Chem Chem Phys 2019; 21:19469-19479. [PMID: 31461098 DOI: 10.1039/c9cp03184g] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Using all-atom molecular dynamics simulations of aqueous solutions of the globular protein SNase, the dynamic behavior of water molecules and cosolvents (trimethylamine-N-oxide (TMAO) and urea) in the hydration shell of the protein was studied for different solvent compositions. TMAO is a potent protein-stabilizing osmolyte, whereas urea is known to destabilize proteins. For molecules that are initially located in successive narrow layers at a given distance from the protein, the mean displacements and the distribution of displacements for short time intervals are calculated. For molecules that are initially located in solvation shells of a given thickness around the protein, the characteristic residence times in these shells are determined to characterize the dynamic behavior of the solvent molecules as a function of the distance to the protein. A combined consideration of these characteristics allows to reveal additional features of the dynamics of the cosolvents. It is shown that TMAO molecules leave the nearest vicinity of the protein faster than urea molecules, despite the fact that the mobility of TMAO molecules, measured by their mean displacements, is lower than that of urea. Moreover, we show that the rate of release of TMAO molecules from the hydration shell is lower in ternary (TMAO + urea + H2O) solvent mixtures than in the binary ones. This is consistent with a recent observation that the fraction of TMAO near the protein decreases in the presence of urea. From the analysis of the decay of the number of particles initially located in the region of the first peak of the distribution function of solvent molecules around the protein, we estimated that about 20 water molecules and 6-7 urea molecules stay near the protein for more than 1000 ps.
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Affiliation(s)
- Vladimir Voloshin
- Institute of Chemical Kinetics and Combustion, SB RAS, 630090 Novosibirsk, Russia.
| | - Nikolai Smolin
- Department of Cell and Molecular Physiology, Loyola University Chicago, Maywood, Illinois 60153, USA
| | - Alfons Geiger
- Physikalische Chemie, Fakultät für Chemie und Chemische Biologie, Technische Universität Dortmund, Otto-Hahn-Straße 4a, 44221 Dortmund, Germany.
| | - Roland Winter
- Physikalische Chemie, Fakultät für Chemie und Chemische Biologie, Technische Universität Dortmund, Otto-Hahn-Straße 4a, 44221 Dortmund, Germany.
| | - Nikolai N Medvedev
- Institute of Chemical Kinetics and Combustion, SB RAS, 630090 Novosibirsk, Russia. and Novosibirsk State University, 630090 Novosibirsk, Russia
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Wahab HA, Amaro RE, Cournia Z. A Celebration of Women in Computational Chemistry. J Chem Inf Model 2019; 59:1683-1692. [DOI: 10.1021/acs.jcim.9b00368] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
| | - Rommie E. Amaro
- Department of Chemistry and Biochemistry, University of California, San Diego, 3234 Urey Hall, #0340, 9500 Gilman Drive, La Jolla, California 92093-0340, United States
| | - Zoe Cournia
- Biomedical Research Foundation, Academy of Athens, 11527 Athens, Greece
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