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Lopez DM, Castro CE, Sotomayor M. In-Silico Analyses of Molecular Force Sensors for Mechanical Characterization of Biological Systems. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.17.603923. [PMID: 39091752 PMCID: PMC11291006 DOI: 10.1101/2024.07.17.603923] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/04/2024]
Abstract
Mechanical forces play key roles in biological processes such as cell migration and sensory perception. In recent years molecular force sensors have been developed as tools for in situ force measurements. Here we use all-atom steered molecular dynamics simulations to predict and study the relationship between design parameters and mechanical properties for three types of molecular force sensors commonly used in cellular biological research: two peptide- and one DNA-based. The peptide-based sensors consist of a pair of fluorescent proteins, which can undergo Förster resonance energy transfer (FRET), linked by spider silk (GPGGA)n or synthetic (GGSGGS)n disordered regions. The DNA-based sensor consists of two fluorophore-labeled strands of DNA that can be unzipped or sheared upon force application with a FRET signal as readout of dissociation. We simulated nine sensors, three of each kind. After equilibration, flexible peptide linkers of three different lengths were stretched by applying forces to their N- and C-terminal Cα atoms in opposite directions. Similarly, we equilibrated a DNA-based sensor and pulled on the phosphate atom of the terminal guanine of one strand and a selected phosphate atom on the other strand in the opposite direction. These simulations were performed at constant velocity (0.01 nm/ns - 10 nm/ns) and constant force (10 pN - 500 pN) for all versions of the sensors. Our results show how the force response of these sensors depends on their length, sequence, configuration and loading rate. Mechanistic insights gained from simulations analyses indicate that interpretation of experimental results should consider the influence of transient formation of secondary structure in peptide-based sensors and of overstretching in DNA-based sensors. These predictions can guide optimal fluorophore choice and facilitate the rational design of new sensors for use in protein, DNA, hybrid systems, and molecular devices.
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Affiliation(s)
- Diana M. Lopez
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210
- Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus, Ohio 43210
- Biophysics Graduate Program, The Ohio State University, Columbus, Ohio 43210
| | - Carlos E. Castro
- Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus, Ohio 43210
- Biophysics Graduate Program, The Ohio State University, Columbus, Ohio 43210
| | - Marcos Sotomayor
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210
- Biophysics Graduate Program, The Ohio State University, Columbus, Ohio 43210
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2
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Pedro De-la-Torre, Wen H, Brower J, Martínez-Pérez K, Narui Y, Yeh F, Hale E, Ivanchenko MV, Corey DP, Sotomayor M, Indzhykulian AA. Elasticity and Thermal Stability are Key Determinants of Hearing Rescue by Mini-Protocadherin-15 Proteins. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.16.599132. [PMID: 38948700 PMCID: PMC11212938 DOI: 10.1101/2024.06.16.599132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/02/2024]
Abstract
Protocadherin-15 is a core protein component of inner-ear hair-cell tip links pulling on transduction channels essential for hearing and balance. Protocadherin-15 defects can result in non-syndromic deafness or Usher syndrome type 1F (USH1F) with hearing loss, balance deficits, and progressive blindness. Three rationally engineered shortened versions of protocadherin-15 (mini-PCDH15s) amenable for gene therapy have been used to rescue function in USH1F mouse models. Two can successfully or partially rescue hearing, while another one fails. Here we show that despite varying levels of hearing rescue, all three mini-PCDH15 versions can rescue hair-cell mechanotransduction. Negative-stain electron microscopy shows that all three versions form dimers like the wild-type protein, while crystal structures of some engineered fragments show that these can properly fold and bind calcium ions essential for function. In contrast, simulations predict distinct elasticities and nano differential scanning fluorimetry shows differences in melting temperature measurements. Our data suggest that elasticity and thermal stability are key determinants of sustained hearing rescue by mini-PCDH15s.
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Affiliation(s)
- Pedro De-la-Torre
- Department of Otolaryngology - Head and Neck Surgery, Harvard Medical School and Massachusetts Eye and Ear, 243 Charles St, Boston, MA, USA
| | - Haosheng Wen
- Department of Chemistry and Biochemistry, The Ohio State University, 484 W. 12th Avenue, Columbus, OH, USA
- Biophysics Program, The Ohio State University, 484 W. 12th Avenue, Columbus, OH, USA
| | - Joseph Brower
- Department of Otolaryngology - Head and Neck Surgery, Harvard Medical School and Massachusetts Eye and Ear, 243 Charles St, Boston, MA, USA
| | - Karina Martínez-Pérez
- Department of Otolaryngology - Head and Neck Surgery, Harvard Medical School and Massachusetts Eye and Ear, 243 Charles St, Boston, MA, USA
- Biology Program, Department of Basic Sciences, Universidad del Atlántico, Cra 30 # 8-49, Puerto Colombia, 081007, Colombia
| | - Yoshie Narui
- Center for Electron Microscopy and Analysis, The Ohio State University, 1275-1305 Kinnear Road, Columbus, OH, USA
| | - Frank Yeh
- Department of Otolaryngology - Head and Neck Surgery, Harvard Medical School and Massachusetts Eye and Ear, 243 Charles St, Boston, MA, USA
| | - Evan Hale
- Department of Otolaryngology - Head and Neck Surgery, Harvard Medical School and Massachusetts Eye and Ear, 243 Charles St, Boston, MA, USA
- Speech and Hearing Biosciences and Technology graduate program, Harvard University, Cambridge, MA, USA
| | - Maryna V. Ivanchenko
- Department of Neurobiology, Harvard Medical School, 200 Longwood Ave, Boston, MA, USA
| | - David P. Corey
- Department of Neurobiology, Harvard Medical School, 200 Longwood Ave, Boston, MA, USA
| | - Marcos Sotomayor
- Department of Chemistry and Biochemistry, The Ohio State University, 484 W. 12th Avenue, Columbus, OH, USA
- Biophysics Program, The Ohio State University, 484 W. 12th Avenue, Columbus, OH, USA
| | - Artur A. Indzhykulian
- Department of Otolaryngology - Head and Neck Surgery, Harvard Medical School and Massachusetts Eye and Ear, 243 Charles St, Boston, MA, USA
- Speech and Hearing Biosciences and Technology graduate program, Harvard University, Cambridge, MA, USA
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Zhang Z, Mlýnský V, Krepl M, Šponer J, Stadlbauer P. Mechanical Stability and Unfolding Pathways of Parallel Tetrameric G-Quadruplexes Probed by Pulling Simulations. J Chem Inf Model 2024; 64:3896-3911. [PMID: 38630447 PMCID: PMC11094737 DOI: 10.1021/acs.jcim.4c00227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Revised: 04/02/2024] [Accepted: 04/02/2024] [Indexed: 05/14/2024]
Abstract
Guanine quadruplex (GQ) is a noncanonical nucleic acid structure formed by guanine-rich DNA and RNA sequences. Folding of GQs is a complex process, where several aspects remain elusive, despite being important for understanding structure formation and biological functions of GQs. Pulling experiments are a common tool for acquiring insights into the folding landscape of GQs. Herein, we applied a computational pulling strategy─steered molecular dynamics (SMD) simulations─in combination with standard molecular dynamics (MD) simulations to explore the unfolding landscapes of tetrameric parallel GQs. We identified anisotropic properties of elastic conformational changes, unfolding transitions, and GQ mechanical stabilities. Using a special set of structural parameters, we found that the vertical component of pulling force (perpendicular to the average G-quartet plane) plays a significant role in disrupting GQ structures and weakening their mechanical stabilities. We demonstrated that the magnitude of the vertical force component depends on the pulling anchor positions and the number of G-quartets. Typical unfolding transitions for tetrameric parallel GQs involve base unzipping, opening of the G-stem, strand slippage, and rotation to cross-like structures. The unzipping was detected as the first and dominant unfolding event, and it usually started at the 3'-end. Furthermore, results from both SMD and standard MD simulations indicate that partial spiral conformations serve as a transient ensemble during the (un)folding of GQs.
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Affiliation(s)
- Zhengyue Zhang
- Institute
of Biophysics of the Czech Academy of Sciences, Královopolská 135, Brno 61200, Czech Republic
- CEITEC−Central
European Institute of Technology, Masaryk
University, Kamenice
5, Brno 625 00, Czech Republic
- National
Center for Biomolecular Research,
Faculty of Science, Masaryk University, Kamenice 5, Brno 625 00, Czech Republic
| | - Vojtěch Mlýnský
- Institute
of Biophysics of the Czech Academy of Sciences, Královopolská 135, Brno 61200, Czech Republic
| | - Miroslav Krepl
- Institute
of Biophysics of the Czech Academy of Sciences, Královopolská 135, Brno 61200, Czech Republic
| | - Jiří Šponer
- Institute
of Biophysics of the Czech Academy of Sciences, Královopolská 135, Brno 61200, Czech Republic
| | - Petr Stadlbauer
- Institute
of Biophysics of the Czech Academy of Sciences, Královopolská 135, Brno 61200, Czech Republic
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Bajaj M, Muddassir M, Choi B, Singh P, Park JB, Singh S, Yadav M, Kumar R, Eom K, Sharma D. Single-molecule analysis of osmolyte-mediated nanomechanical unfolding behavior of a protein domain. Int J Biol Macromol 2023; 253:126849. [PMID: 37717878 DOI: 10.1016/j.ijbiomac.2023.126849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 08/25/2023] [Accepted: 09/09/2023] [Indexed: 09/19/2023]
Abstract
The small organic molecules, known as osmolytes being ubiquitously present in different cell types, affect protein folding, stability and aggregation. However, it is unknown how the osmolytes affect the nanomechanical unfolding behavior of protein domain. Here, we show the osmolyte-dependent mechanical unfolding properties of protein titin immunoglobulin-27 (I27) domain using an atomic force microscopy (AFM)-based single-molecule force spectroscopy. We found that amines and methylamines improved the mechanical stability of I27 domain, whereas polyols had no effect. Interestingly, glycine betaine (GB) or trimethylamine-N-oxide (TMAO) increased the average unfolding force of the protein domain. The kinetic parameters analyzed at single-molecule level reveal that stabilizing effect of osmolytes is due to a decrease in the unfolding rate constant of I27, which was confirmed by molecular dynamics simulations. Our study reveals different effects that diverse osmolytes have on the mechanical properties of the protein, and suggests the potential use of osmolytes in modulating the mechanical stability of proteins required for various nano-biotechnological applications.
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Affiliation(s)
- Manish Bajaj
- Council of Scientific and Industrial Research - Institute of Microbial Technology, Sector-39A, Chandigarh, India
| | - Mohd Muddassir
- Council of Scientific and Industrial Research - Institute of Microbial Technology, Sector-39A, Chandigarh, India; Department of Chemistry, College of Science, King Saud University, Riyadh, Saudi Arabia
| | - Bumjoon Choi
- Biomechanics Laboratory, College of Sport Science, Sungkyunkwan University (SKKU), Suwon 16419, Republic of Korea; Digial Bio R&D Center, Mediazen, Seoul 07789, Republic of Korea
| | - Priyanka Singh
- Council of Scientific and Industrial Research - Institute of Microbial Technology, Sector-39A, Chandigarh, India
| | - Jong Bum Park
- Biomechanics Laboratory, College of Sport Science, Sungkyunkwan University (SKKU), Suwon 16419, Republic of Korea
| | - Surjeet Singh
- Council of Scientific and Industrial Research - Institute of Microbial Technology, Sector-39A, Chandigarh, India
| | - Manisha Yadav
- School of Basic and Applied Sciences, Central University of Punjab, Bathinda, India
| | - Rajesh Kumar
- School of Basic and Applied Sciences, Central University of Punjab, Bathinda, India
| | - Kilho Eom
- Biomechanics Laboratory, College of Sport Science, Sungkyunkwan University (SKKU), Suwon 16419, Republic of Korea.
| | - Deepak Sharma
- Council of Scientific and Industrial Research - Institute of Microbial Technology, Sector-39A, Chandigarh, India; Academy of Scientific & Innovative Research, India.
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Montecino-Garrido H, Sepúlveda M, Méndez D, Monroy-Cárdenas M, Alfaro S, González-Avendaño M, Caballero J, Urra FA, Araya-Maturana R, Fuentes E. Assessing mitochondria-targeted acyl hydroquinones on the mitochondrial platelet function and cytotoxic activity: Role of the linker length. Free Radic Biol Med 2023; 208:26-36. [PMID: 37516371 DOI: 10.1016/j.freeradbiomed.2023.07.030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 07/10/2023] [Accepted: 07/26/2023] [Indexed: 07/31/2023]
Abstract
INTRODUCTION The use of triphenylphosphonium cation (TPP+) linked to phenolic compounds by alkyl chains has a significant relevance as a mitochondrial delivery strategy in biomedicine because it affects mitochondrial bioenergetics in models of noncommunicable diseases such as cancer and cardiovascular-related conditions. Studies indicate that a long alkyl chain (10-12 carbon) increases the mitochondrial accumulation of TPP+-linked drugs. In contrast, other studies show that these compounds are consistently toxic to micromolar concentrations (as observed in platelets). In the present study, we evaluated the in vitro effect of three series of triphenylphosphonium-linked acyl hydroquinones derivates on the metabolism and function of human platelets using 3-9 carbons for the alkyl linker. Those were assessed to determine the role of the length of the alkyl chain linker on platelet toxicity. METHODS Human platelets were exposed in vitro to different concentrations (2-40 μM) of every compound; cellular viability, phosphatidylserine exposition, mitochondrial membrane potential (ΔΨm), intracellular calcium release, and intracellular ROS generation were assessed by flow cytometry. An in silico energetic profile was generated with Umbrella sampling molecular dynamics (MD). RESULTS AND CONCLUSIONS There was an increase in cytotoxic activity directly related to the length of the acyl chain and lipophilicity, as seen by three techniques, and this was consistent with a decrease in ΔΨm. The in silico energetic profiles point out that the permeability of the mitochondrial membrane may be involved in the cytotoxicity of phosphonium salts. This information may be relevant for the design of new TPP+ -based drugs with a safe cardiovascular profile.
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Affiliation(s)
- Héctor Montecino-Garrido
- Thrombosis and Healthy Aging Research Center, MIBI: Interdisciplinary Group on Mitochondrial Targeting and Bioenergetics (ACT210097), Medical Technology School, Department of Clinical Biochemistry and Immunohematology, Faculty of Health Sciences, Universidad de Talca, Talca, Chile
| | - Magdalena Sepúlveda
- Thrombosis and Healthy Aging Research Center, MIBI: Interdisciplinary Group on Mitochondrial Targeting and Bioenergetics (ACT210097), Medical Technology School, Department of Clinical Biochemistry and Immunohematology, Faculty of Health Sciences, Universidad de Talca, Talca, Chile
| | - Diego Méndez
- Thrombosis and Healthy Aging Research Center, MIBI: Interdisciplinary Group on Mitochondrial Targeting and Bioenergetics (ACT210097), Medical Technology School, Department of Clinical Biochemistry and Immunohematology, Faculty of Health Sciences, Universidad de Talca, Talca, Chile
| | - Matías Monroy-Cárdenas
- Instituto de Química de Recursos Naturales, MIBI: Interdisciplinary Group on Mitochondrial Targeting and Bioenergetics, Universidad de Talca, Talca, Chile
| | - Sergio Alfaro
- Centro de Bioinformática, Simulación y Modelado (CBSM), Facultad de Ingeniería, Universidad de Talca, Talca, 3460000, Chile
| | - Mariela González-Avendaño
- Centro de Bioinformática, Simulación y Modelado (CBSM), Facultad de Ingeniería, Universidad de Talca, Talca, 3460000, Chile
| | - Julio Caballero
- Centro de Bioinformática, Simulación y Modelado (CBSM), Facultad de Ingeniería, Universidad de Talca, Talca, 3460000, Chile
| | - Félix A Urra
- Laboratory of Metabolic Plasticity and Bioenergetics, Program of Molecular and Clinical Pharmacology, Institute of Biomedical Sciences, Faculty of Medicine, Universidad de Chile, MIBI: Interdisciplinary Group on Mitochondrial Targeting and Bioenergetics, Santiago, Chile
| | - Ramiro Araya-Maturana
- Instituto de Química de Recursos Naturales, MIBI: Interdisciplinary Group on Mitochondrial Targeting and Bioenergetics, Universidad de Talca, Talca, Chile.
| | - Eduardo Fuentes
- Thrombosis and Healthy Aging Research Center, MIBI: Interdisciplinary Group on Mitochondrial Targeting and Bioenergetics (ACT210097), Medical Technology School, Department of Clinical Biochemistry and Immunohematology, Faculty of Health Sciences, Universidad de Talca, Talca, Chile.
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6
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Zuo J, Chen H, Li H. Two molecule force spectroscopy on ligand-receptor interactions. NANOSCALE 2023; 15:16581-16589. [PMID: 37740375 DOI: 10.1039/d3nr03428c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/24/2023]
Abstract
Many biological processes involve the rupture of multiple ligand-receptors or multivalent ligand-receptors. It is challenging to study the rupture of such parallelly arranged multiple ligand-receptors due to the difficulties in engineering such systems in a well-controlled fashion. Here we report the use of two-molecule force spectroscopy to investigate the rupture of two parallelly arranged monomeric streptavidin (mSA)-biotin complexes. By using SpyCatcher-SpyTag chemistry, we successfully engineered a molecular twin of biotin, in which two biotins are arranged in parallel. By reacting mSA with twin biotin, we constructed parallelly arranged two mSA-biotin complexes for force spectroscopy experiments. The incorporation of single molecule fingerprint domains into our mSA-biotin dimers allowed us to identify and assign the rupture events of the parallelly arranged mSA-biotin complexes without any ambiguity in the two-molecule force spectroscopy experiments. Our results revealed that the rupture force of the parallel dimer mSA-biotin is 172 pN at a pulling speed of 400 nm s-1, which is about 1.6 times of that of single mSA-biotin (105 pN). Furthermore, our findings indicate that the two mSA-biotin behave as non-interacting, independent ligand-receptors. The strategy we demonstrated here can be extended to other ligand-receptors and may open up an avenue toward rigorously testing the theoretic predictions proposed in various models regarding the rupture of multiple parallel ligand-receptors.
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Affiliation(s)
- Jiacheng Zuo
- Department of Chemistry, University of British Columbia, Vancouver, BC V6T 1Z1, Canada.
| | - Hui Chen
- Department of Chemical Engineering, Nanjing Forestry University, Nanjing, Jiangsu, P. R. China
| | - Hongbin Li
- Department of Chemistry, University of British Columbia, Vancouver, BC V6T 1Z1, Canada.
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7
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Stadlbauer P, Mlýnský V, Krepl M, Šponer J. Complexity of Guanine Quadruplex Unfolding Pathways Revealed by Atomistic Pulling Simulations. J Chem Inf Model 2023; 63:4716-4731. [PMID: 37458574 PMCID: PMC10428220 DOI: 10.1021/acs.jcim.3c00171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Indexed: 08/15/2023]
Abstract
Guanine quadruplexes (GQs) are non-canonical nucleic acid structures involved in many biological processes. GQs formed in single-stranded regions often need to be unwound by cellular machinery, so their mechanochemical properties are important. Here, we performed steered molecular dynamics simulations of human telomeric GQs to study their unfolding. We examined four pulling regimes, including a very slow setup with pulling velocity and force load accessible to high-speed atomic force microscopy. We identified multiple factors affecting the unfolding mechanism, i.e.,: (i) the more the direction of force was perpendicular to the GQ channel axis (determined by GQ topology), the more the base unzipping mechanism happened, (ii) the more parallel the direction of force was, GQ opening and cross-like GQs were more likely to occur, (iii) strand slippage mechanism was possible for GQs with an all-anti pattern in a strand, and (iv) slower pulling velocity led to richer structural dynamics with sampling of more intermediates and partial refolding events. We also identified that a GQ may eventually unfold after a force drop under forces smaller than those that the GQ withstood before the drop. Finally, we found out that different unfolding intermediates could have very similar chain end-to-end distances, which reveals some limitations of structural interpretations of single-molecule spectroscopic data.
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Affiliation(s)
- Petr Stadlbauer
- Institute of Biophysics of the Czech
Academy of Sciences, Královopolská 135, Brno 612 00, Czech Republic
| | - Vojtěch Mlýnský
- Institute of Biophysics of the Czech
Academy of Sciences, Královopolská 135, Brno 612 00, Czech Republic
| | - Miroslav Krepl
- Institute of Biophysics of the Czech
Academy of Sciences, Královopolská 135, Brno 612 00, Czech Republic
| | - Jiří Šponer
- Institute of Biophysics of the Czech
Academy of Sciences, Královopolská 135, Brno 612 00, Czech Republic
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Ramos MC, Gomes DF, Mello NFD, Silva END, Barreto JOM, Shimizu HE. Big Data e Inteligência Artificial para pesquisa translacional na Covid-19: revisão rápida. SAÚDE EM DEBATE 2022. [DOI: 10.1590/0103-1104202213518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
RESUMO O objetivo deste estudo foi identificar como a Inteligência Artificial (IA) vem sendo utilizada para a pesquisa translacional no contexto da Covid-19. Foi realizada uma revisão rápida para identificar o uso de técnicas de IA na translação de tecnologias para o enfrentamento da Covid-19. Empregou-se estratégia de busca com base em termos MeSH e seus respectivos sinônimos em sete bases de dados. Dos 59 artigos identificados, oito foram incluídos. Foram identificadas 11 experiências que usaram IA para a pesquisa translacional em Covid-19: predição de eficácia medicamentosa; predição de patogenicidade do Sars-CoV-2; diagnóstico de imagem para Covid-19; predição de incidência de Covid-19; estimativas de impacto da Covid-19 na sociedade; automatização de sanitização de ambientes hospitalares e clínicos; rastreio de pessoas infectadas e possivelmente infectadas; monitoramento do uso de máscaras; predição de gravidade de pacientes; estratificação de risco do paciente; e predição de recursos hospitalares. A pesquisa translacional pode ajudar no desenvolvimento produtivo e industrial em saúde, especialmente quando apoiada em métodos de IA, uma ferramenta cada vez mais importante, sobretudo quando se discute a Quarta Revolução Industrial e suas aplicações na saúde.
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Kaneko Y, Ozawa SI, Sato Y, Kobayashi T, Matsumoto T, Miyamoto K, Kobayashi S, Harato K, Hirono S, Matsumoto M, Nakamura M, Niki Y, Miyamoto T. The Stat3 inhibitor F0648-0027 is a potential therapeutic against rheumatoid arthritis. Biochem Biophys Res Commun 2022; 636:133-140. [DOI: 10.1016/j.bbrc.2022.10.106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2022] [Accepted: 10/31/2022] [Indexed: 11/06/2022]
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10
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Chen X, Li C, Ding Y, Li Y, Li J, Sun L, Wei J, Wei X, Wang H, Zhang K, Pan L, Li Y. Fully Bio-Based and Supertough PLA Blends via a Novel Interlocking Strategy Combining Strong Dipolar Interactions and Stereocomplexation. Macromolecules 2022. [DOI: 10.1021/acs.macromol.2c00266] [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)
- Xiangjian Chen
- Tianjin Key Laboratory of Composite and Functional Materials, School of Materials Science and Engineering, Tianjin University, Tianjin 300350, China
| | - Chuanxi Li
- Advanced Materials Research Center, Petrochemical Research Institute, Petro China Company Limited, Beijing 102206, China
| | - Yingli Ding
- Tianjin Key Laboratory of Composite and Functional Materials, School of Materials Science and Engineering, Tianjin University, Tianjin 300350, China
| | - Yang Li
- Advanced Materials Research Center, Petrochemical Research Institute, Petro China Company Limited, Beijing 102206, China
| | - Jinshan Li
- Advanced Materials Research Center, Petrochemical Research Institute, Petro China Company Limited, Beijing 102206, China
| | - Liming Sun
- Advanced Materials Research Center, Petrochemical Research Institute, Petro China Company Limited, Beijing 102206, China
| | - Jie Wei
- Advanced Materials Research Center, Petrochemical Research Institute, Petro China Company Limited, Beijing 102206, China
| | - Xiaohui Wei
- Advanced Materials Research Center, Petrochemical Research Institute, Petro China Company Limited, Beijing 102206, China
| | - Hao Wang
- State Key Laboratory of Heavy Oil Processing and the Key Laboratory of Catalysis of CNPC, China University of Petroleum, Beijing 102249, China
| | - Kunyu Zhang
- Advanced Materials Research Center, Petrochemical Research Institute, Petro China Company Limited, Beijing 102206, China
| | - Li Pan
- Tianjin Key Laboratory of Composite and Functional Materials, School of Materials Science and Engineering, Tianjin University, Tianjin 300350, China
| | - Yuesheng Li
- Tianjin Key Laboratory of Composite and Functional Materials, School of Materials Science and Engineering, Tianjin University, Tianjin 300350, China
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Vanegas JAG, Pacule HB, Capitão RM, Correia CRD, Terra WC, Campos VP, Oliveira DF. Methyl Esters of ( E)-Cinnamic Acid: Activity against the Plant-Parasitic Nematode Meloidogyne incognita and In Silico Interaction with Histone Deacetylase. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2022; 70:6624-6633. [PMID: 35622462 DOI: 10.1021/acs.jafc.1c08142] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
(E)-Cinnamaldehyde is very active against Meloidogyne incognita but has low persistence in soil. To circumvent this problem, esters of cinnamic acid were evaluated as a substitute for (E)-cinnamaldehyde. The best results under assays with M. incognita second-stage juveniles (J2) were obtained for the methyl esters of (E)-p-fluoro- (13), (E)-p-chloro- (14), and (E)-p-bromocinnamic acid (15), which showed lethal concentrations to 50% (LC50) J2 of 168, 95, and 216 μg/mL, respectively. Under the same conditions, the LC50 values for the nematicides carbofuran and fluensulfone were 160 and 34 μg/mL, respectively. Substances 13-15 were also active against nematode eggs, which account for most of the M. incognita population in the field. According to an in silico study, substances 13-15 can act against the nematode through inhibition of histone deacetylase. Therefore, esters 13-15 and histone deacetylase are potentially useful for the rational design of new nematicides for the control of M. incognita.
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Affiliation(s)
- Javier A G Vanegas
- Laboratório de Produtos Naturais, Departamento de Química, Universidade Federal de Lavras, CEP 37200-900 Lavras, Minas Gerais, Brazil
| | - Horácio B Pacule
- Laboratório de Produtos Naturais, Departamento de Química, Universidade Federal de Lavras, CEP 37200-900 Lavras, Minas Gerais, Brazil
| | - Rebeca M Capitão
- Laboratório de Química Orgânica, Departamento de Química, Universidade Estadual de Campinas, CEP 13083-970, Campinas, São Paulo, Brazil
| | - Carlos R D Correia
- Laboratório de Química Orgânica, Departamento de Química, Universidade Estadual de Campinas, CEP 13083-970, Campinas, São Paulo, Brazil
| | - Willian C Terra
- Laboratório de Nematologia, Departamento de Fitopatologia, Universidade Federal de Lavras, CEP 37200-900, Lavras, Minas Gerais, Brazil
| | - Vicente P Campos
- Laboratório de Nematologia, Departamento de Fitopatologia, Universidade Federal de Lavras, CEP 37200-900, Lavras, Minas Gerais, Brazil
| | - Denilson F Oliveira
- Laboratório de Produtos Naturais, Departamento de Química, Universidade Federal de Lavras, CEP 37200-900 Lavras, Minas Gerais, Brazil
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12
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Neel BL, Nisler CR, Walujkar S, Araya-Secchi R, Sotomayor M. Elastic versus brittle mechanical responses predicted for dimeric cadherin complexes. Biophys J 2022; 121:1013-1028. [PMID: 35151631 PMCID: PMC8943749 DOI: 10.1016/j.bpj.2022.02.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 01/02/2022] [Accepted: 02/07/2022] [Indexed: 12/15/2022] Open
Abstract
Cadherins are a superfamily of adhesion proteins involved in a variety of biological processes that include the formation of intercellular contacts, the maintenance of tissue integrity, and the development of neuronal circuits. These transmembrane proteins are characterized by ectodomains composed of a variable number of extracellular cadherin (EC) repeats that are similar but not identical in sequence and fold. E-cadherin, along with desmoglein and desmocollin proteins, are three classical-type cadherins that have slightly curved ectodomains and engage in homophilic and heterophilic interactions through an exchange of conserved tryptophan residues in their N-terminal EC1 repeat. In contrast, clustered protocadherins are straighter than classical cadherins and interact through an antiparallel homophilic binding interface that involves overlapped EC1 to EC4 repeats. Here we present molecular dynamics simulations that model the adhesive domains of these cadherins using available crystal structures, with systems encompassing up to 2.8 million atoms. Simulations of complete classical cadherin ectodomain dimers predict a two-phased elastic response to force in which these complexes first softly unbend and then stiffen to unbind without unfolding. Simulated α, β, and γ clustered protocadherin homodimers lack a two-phased elastic response, are brittle and stiffer than classical cadherins and exhibit complex unbinding pathways that in some cases involve transient intermediates. We propose that these distinct mechanical responses are important for function, with classical cadherin ectodomains acting as molecular shock absorbers and with stiffer clustered protocadherin ectodomains facilitating overlap that favors binding specificity over mechanical resilience. Overall, our simulations provide insights into the molecular mechanics of single cadherin dimers relevant in the formation of cellular junctions essential for tissue function.
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Affiliation(s)
- Brandon L Neel
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio; The Ohio State Biochemistry Program, The Ohio State University, Columbus, Ohio
| | - Collin R Nisler
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio; Biophysics Graduate Program, The Ohio State University, Columbus, Ohio
| | - Sanket Walujkar
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio; Chemical Physics Graduate Program, The Ohio State University, Columbus, Ohio
| | - Raul Araya-Secchi
- Facultad de Ingeniería y Tecnología, Universidad San Sebastián, Santiago, Chile
| | - Marcos Sotomayor
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio; The Ohio State Biochemistry Program, The Ohio State University, Columbus, Ohio; Biophysics Graduate Program, The Ohio State University, Columbus, Ohio; Chemical Physics Graduate Program, The Ohio State University, Columbus, Ohio.
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13
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Neel BL, Nisler CR, Walujkar S, Araya-Secchi R, Sotomayor M. Collective mechanical responses of cadherin-based adhesive junctions as predicted by simulations. Biophys J 2022; 121:991-1012. [PMID: 35150618 PMCID: PMC8943820 DOI: 10.1016/j.bpj.2022.02.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 01/02/2022] [Accepted: 02/07/2022] [Indexed: 12/13/2022] Open
Abstract
Cadherin-based adherens junctions and desmosomes help stabilize cell-cell contacts with additional function in mechano-signaling, while clustered protocadherin junctions are responsible for directing neuronal circuits assembly. Structural models for adherens junctions formed by epithelial cadherin (CDH1) proteins indicate that their long, curved ectodomains arrange to form a periodic, two-dimensional lattice stabilized by tip-to-tip trans interactions (across junction) and lateral cis contacts. Less is known about the exact architecture of desmosomes, but desmoglein (DSG) and desmocollin (DSC) cadherin proteins are also thought to form ordered junctions. In contrast, clustered protocadherin (PCDH)-based cell-cell contacts in neuronal tissues are thought to be responsible for self-recognition and avoidance, and structural models for clustered PCDH junctions show a linear arrangement in which their long and straight ectodomains form antiparallel overlapped trans complexes. Here, we report all-atom molecular dynamics simulations testing the mechanics of minimalistic adhesive junctions formed by CDH1, DSG2 coupled to DSC1, and PCDHγB4, with systems encompassing up to 3.7 million atoms. Simulations generally predict a favored shearing pathway for the adherens junction model and a two-phased elastic response to tensile forces for the adhesive adherens junction and the desmosome models. Complexes within these junctions first unbend at low tensile force and then become stiff to unbind without unfolding. However, cis interactions in both the CDH1 and DSG2-DSC1 systems dictate varied mechanical responses of individual dimers within the junctions. Conversely, the clustered protocadherin PCDHγB4 junction lacks a distinct two-phased elastic response. Instead, applied tensile force strains trans interactions directly, as there is little unbending of monomers within the junction. Transient intermediates, influenced by new cis interactions, are observed after the main rupture event. We suggest that these collective, complex mechanical responses mediated by cis contacts facilitate distinct functions in robust cell-cell adhesion for classical cadherins and in self-avoidance signaling for clustered PCDHs.
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Affiliation(s)
- Brandon L Neel
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio; The Ohio State Biochemistry Program, The Ohio State University, Columbus, Ohio
| | - Collin R Nisler
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio; Biophysics Graduate Program, The Ohio State University, Columbus, Ohio
| | - Sanket Walujkar
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio; Chemical Physics Graduate Program, The Ohio State University, Columbus, Ohio
| | - Raul Araya-Secchi
- Facultad de Ingenieria y Tecnologia, Universidad San Sebastian, Santiago, Chile
| | - Marcos Sotomayor
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio; The Ohio State Biochemistry Program, The Ohio State University, Columbus, Ohio; Biophysics Graduate Program, The Ohio State University, Columbus, Ohio; Chemical Physics Graduate Program, The Ohio State University, Columbus, Ohio.
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14
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Patra A, Abdullah S, Pradhan RC. Optimization of ultrasound‐assisted extraction of ascorbic acid, protein and total antioxidants from cashew apple bagasse using artificial neural network‐genetic algorithm and response surface methodology. J FOOD PROCESS PRES 2022. [DOI: 10.1111/jfpp.16317] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Abhipriya Patra
- Department of Food Process Engineering National Institute of Technology Rourkela India
| | - S Abdullah
- Department of Food Process Engineering National Institute of Technology Rourkela India
| | - Rama Chandra Pradhan
- Department of Food Process Engineering National Institute of Technology Rourkela India
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15
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Moreira RA, Baker JL, Guzman HV, Poma AB. Assessing the Stability of Biological Fibrils by Molecular-Scale Simulations. Methods Mol Biol 2022; 2340:357-378. [PMID: 35167082 DOI: 10.1007/978-1-0716-1546-1_16] [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: 06/14/2023]
Abstract
The nanomechanical characterization of several biological fibrils that are the result of protein aggregation via molecular dynamics simulation is nowadays feasible, and together with atomic force microscopy experiments has widened our understanding of the forces in the regime of pN-nN and system sizes of about hundreds of nanometers. Several methodologies have been developed to achieve this target, and they range from the atomistic representation via molecular force fields to coarse-grained strategies that provide comparable results with experiments in a systematic way. In this chapter, we discuss several methodologies for the calculation of mechanical parameters, such as the elastic constants of relevant biological systems. They are presented together with details about parameterization and current limitations. Then, we discuss some of the applications of such methodologies for the description of bacterial filament and β-amyloid systems. Finally, the latest lines of development are discussed.
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Affiliation(s)
- Rodrigo A Moreira
- Soft Matter and Biosystems, Institute of Fundamental Technological Research, Polish Academy of Sciences, Warsaw, Poland
| | - Joseph L Baker
- Department of Chemistry, The College of New Jersey, Ewing, NJ, USA
| | | | - Adolfo B Poma
- Soft Matter and Biosystems, Institute of Fundamental Technological Research, Polish Academy of Sciences, Warsaw, Poland.
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16
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Kognole AA, Lee J, Park SJ, Jo S, Chatterjee P, Lemkul JA, Huang J, MacKerell AD, Im W. CHARMM-GUI Drude prepper for molecular dynamics simulation using the classical Drude polarizable force field. J Comput Chem 2021; 43:359-375. [PMID: 34874077 DOI: 10.1002/jcc.26795] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 11/10/2021] [Accepted: 11/25/2021] [Indexed: 12/18/2022]
Abstract
Explicit treatment of electronic polarizability in empirical force fields (FFs) represents an extension over a traditional additive or pairwise FF and provides a more realistic model of the variations in electronic structure in condensed phase, macromolecular simulations. To facilitate utilization of the polarizable FF based on the classical Drude oscillator model, Drude Prepper has been developed in CHARMM-GUI. Drude Prepper ingests additive CHARMM protein structures file (PSF) and pre-equilibrated coordinates in CHARMM, PDB, or NAMD format, from which the molecular components of the system are identified. These include all residues and patches connecting those residues along with water, ions, and other solute molecules. This information is then used to construct the Drude FF-based PSF using molecular generation capabilities in CHARMM, followed by minimization and equilibration. In addition, inputs are generated for molecular dynamics (MD) simulations using CHARMM, GROMACS, NAMD, and OpenMM. Validation of the Drude Prepper protocol and inputs is performed through conversion and MD simulations of various heterogeneous systems that include proteins, nucleic acids, lipids, polysaccharides, and atomic ions using the aforementioned simulation packages. Stable simulations are obtained in all studied systems, including 5 μs simulation of ubiquitin, verifying the integrity of the generated Drude PSFs. In addition, the ability of the Drude FF to model variations in electronic structure is shown through dipole moment analysis in selected systems. The capabilities and availability of Drude Prepper in CHARMM-GUI is anticipated to greatly facilitate the application of the Drude FF to a range of condensed phase, macromolecular systems.
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Affiliation(s)
- Abhishek A Kognole
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, Maryland, USA
| | - Jumin Lee
- Department of Biological Sciences, Lehigh University, Bethlehem, Pennsylvania, USA
| | - Sang-Jun Park
- Department of Biological Sciences, Lehigh University, Bethlehem, Pennsylvania, USA
| | - Sunhwan Jo
- Leadership Computing Facility, Argonne National Laboratory, Argonne, Illinois, USA
| | - Payal Chatterjee
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, Maryland, USA
| | - Justin A Lemkul
- Department of Biochemistry, Virginia Tech, Blacksburg, Virginia, USA
| | - Jing Huang
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Zhejiang, Hangzhou, China
| | - Alexander D MacKerell
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, Maryland, USA
| | - Wonpil Im
- Department of Biological Sciences, Lehigh University, Bethlehem, Pennsylvania, USA
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17
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Gray ME, Johnson ZR, Modak D, Tamilselvan E, Tyska MJ, Sotomayor M. Heterophilic and homophilic cadherin interactions in intestinal intermicrovillar links are species dependent. PLoS Biol 2021; 19:e3001463. [PMID: 34871294 PMCID: PMC8691648 DOI: 10.1371/journal.pbio.3001463] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 12/21/2021] [Accepted: 10/30/2021] [Indexed: 11/19/2022] Open
Abstract
Enterocytes are specialized epithelial cells lining the luminal surface of the small intestine that build densely packed arrays of microvilli known as brush borders. These microvilli drive nutrient absorption and are arranged in a hexagonal pattern maintained by intermicrovillar links formed by 2 nonclassical members of the cadherin superfamily of calcium-dependent cell adhesion proteins: protocadherin-24 (PCDH24, also known as CDHR2) and the mucin-like protocadherin (CDHR5). The extracellular domains of these proteins are involved in heterophilic and homophilic interactions important for intermicrovillar function, yet the structural determinants of these interactions remain unresolved. Here, we present X-ray crystal structures of the PCDH24 and CDHR5 extracellular tips and analyze their species-specific features relevant for adhesive interactions. In parallel, we use binding assays to identify the PCDH24 and CDHR5 domains involved in both heterophilic and homophilic adhesion for human and mouse proteins. Our results suggest that homophilic and heterophilic interactions involving PCDH24 and CDHR5 are species dependent with unique and distinct minimal adhesive units.
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Affiliation(s)
- Michelle E. Gray
- Ohio State Biochemistry Program, The Ohio State University, Columbus, Ohio, United States of America
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio, United States of America
| | - Zachary R. Johnson
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio, United States of America
| | - Debadrita Modak
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio, United States of America
| | - Elakkiya Tamilselvan
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio, United States of America
- Biophysics Program, The Ohio State University, Columbus, Ohio, United States of America
| | - Matthew J. Tyska
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Marcos Sotomayor
- Ohio State Biochemistry Program, The Ohio State University, Columbus, Ohio, United States of America
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio, United States of America
- Biophysics Program, The Ohio State University, Columbus, Ohio, United States of America
- * E-mail:
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18
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Radan M, Djikic T, Obradovic D, Nikolic K. Application of in vitro PAMPA technique and in silico computational methods for blood-brain barrier permeability prediction of novel CNS drug candidates. Eur J Pharm Sci 2021; 168:106056. [PMID: 34740787 DOI: 10.1016/j.ejps.2021.106056] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 10/09/2021] [Accepted: 10/31/2021] [Indexed: 11/17/2022]
Abstract
Permeability assessment of small molecules through the blood-brain barrier (BBB) plays a significant role in the development of effective central nervous system (CNS) drug candidates. Since in vivo methods for BBB permeability estimation require a lot of time and resources, in silico and in vitro approaches are becoming increasingly popular nowadays for faster and more economical predictions in early phases of drug discovery. In this work, through application of in vitro parallel artificial membrane permeability assay (PAMPA-BBB) and in silico computational methods we aimed to examine the passive permeability of eighteen compounds, which affect serotonin and dopamine levels in the CNS. The data set was consisted of novel six human dopamine transporter (hDAT) substrates that were previously identified as the most promising lead compounds for further optimisation to achieve neuroprotective effect, twelve approved CNS drugs, and their related compounds. Firstly, PAMPA methods was used to experimentally determine effective BBB permeability (Pe) for all studied compounds and obtained results were further submitted for quantitative structure permeability relationship (QSPR) analysis. QSPR models were built by using three different statistical methods: stepwise multiple linear regression (MLR), partial least square (PLS), and support-vector machine (SVM), while their predictive capability was tested through internal and external validation. Obtained statistical parameters (MLR- R2pred=-0.10; PLS- R2pred=0.64, r2m=0.69, r/2m=0.44; SVM- R2pred=0.57, r2m=0.72, r/2m=0.55) indicated that the SVM model is superior over others. The most important molecular descriptors (H0p and SolvEMt_3D) were identified and used to propose structural modifications of the examined compounds in order to improve their BBB permeability. Moreover, steered molecular dynamics (SMD) simulation was employed to comprehensively investigate the permeability pathway of compounds through a lipid bilayer. Taken together, the created QSPR model could be used as a reliable and fast pre-screening tool for BBB permeability prediction of structurally related CNS compounds, while performed MD simulations provide a good foundation for future in silico examination.
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Affiliation(s)
- Milica Radan
- University of Belgrade - Faculty of Pharmacy, Department of Pharmaceutical, Chemistry, Vojvode Stepe 450, 11000 Belgrade, Serbia
| | - Teodora Djikic
- University of Belgrade - Faculty of Pharmacy, Department of Pharmaceutical, Chemistry, Vojvode Stepe 450, 11000 Belgrade, Serbia.
| | - Darija Obradovic
- University of Belgrade - Faculty of Pharmacy, Department of Pharmaceutical, Chemistry, Vojvode Stepe 450, 11000 Belgrade, Serbia
| | - Katarina Nikolic
- University of Belgrade - Faculty of Pharmacy, Department of Pharmaceutical, Chemistry, Vojvode Stepe 450, 11000 Belgrade, Serbia.
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19
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Smirnov MA, Tolmachev DA, Glova AD, Sokolova MP, Geydt PV, Lukasheva NV, Lyulin SV. Combined Use of Atomic Force Microscopy and Molecular Dynamics in the Study of Biopolymer Systems. POLYMER SCIENCE SERIES C 2021. [DOI: 10.1134/s1811238221020089] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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20
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Su KH, Wu CT, Lin SW, Mori S, Liu WM, Yang HC. Calculation of CYP450 protein-ligand binding and dissociation free energy paths. J Chem Phys 2021; 155:025101. [PMID: 34266281 DOI: 10.1063/5.0046169] [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 function of an enzyme depends on its dynamic structure, and the catalytic mechanism has long been an active focus of research. The principle for interpreting protein selectivity and fidelity stems from optimization of the active site upon protein-substrate complexation, i.e., a lock-and-key configuration, on which most protein-substrate molecule binding recognition, and hence drug discovery, relies. Yet another thought has been to incorporate the protein folding interior tunnels for stereo- and regio-selectivity along the protein-substrate or protein-ligand/inhibitor binding process. Free energy calculations provide valuable information for molecular recognition and protein-ligand binding dynamics and kinetics. In this study, we focused on the kinetics of cytochrome P450 proteins (CYP450s) and the protein interior tunnel structure-dynamics relationship in terms of the substrate binding and leaving mechanism. A case in point is given by the prostaglandin H2 (PGH2) homologous isomerase of prostacyclin synthase. To calculate the reactant and product traversing the tunnels to and from the heme site, the free energy paths and tunnel potentials of mean force are constructed from steered molecular dynamics simulations and adaptive basing force umbrella sampling simulations. We explore the binding tunnels and critical residue lining characteristics for the ligand traverse and the underlying mechanism of CYP450 activity. Our theoretical analysis provides insights into the decisive role of the substrate tunnel binding process of the CYP450 mechanism and may be useful in drug design and protein engineering contexts.
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Affiliation(s)
- Kuan-Hsuan Su
- Department of Chemistry, Fu Jen Catholic University, New Taipei City 24205, Taiwan
| | - Chin-Teng Wu
- Department of Chemistry, Fu Jen Catholic University, New Taipei City 24205, Taiwan
| | - Shang-Wei Lin
- Department of Chemistry, Fu Jen Catholic University, New Taipei City 24205, Taiwan
| | - Seiji Mori
- Institute of Quantum Beam Science, Ibaraki University, Mito, Ibaraki 310-8512, Japan
| | - Wei-Min Liu
- Department of Chemistry, Fu Jen Catholic University, New Taipei City 24205, Taiwan
| | - Hsiao-Ching Yang
- Department of Chemistry, Fu Jen Catholic University, New Taipei City 24205, Taiwan
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21
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Horst M, Yang J, Meisner J, Kouznetsova TB, Martínez TJ, Craig SL, Xia Y. Understanding the Mechanochemistry of Ladder-Type Cyclobutane Mechanophores by Single Molecule Force Spectroscopy. J Am Chem Soc 2021; 143:12328-12334. [PMID: 34310875 DOI: 10.1021/jacs.1c05857] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
We have recently reported a series of ladder-type cyclobutane mechanophores, polymers of which can transform from nonconjugated structures to conjugated structures and change many properties at once. These multicyclic mechanophores, namely, exo-ladderane/ene, endo-benzoladderene, and exo-bicyclohexene-peri-naphthalene, have different ring structures fused to the first cyclobutane, significantly different free energy changes for ring-opening, and different stereochemistry. To better understand their mechanochemistry, we used single molecule force spectroscopy (SMFS) to characterize their force-extension behavior and measure the threshold forces. The threshold forces correlate with the activation energy of the first bond, but not with the strain of the fused rings distal to the polymer main chain, suggesting that the activation of these ladder-type mechanophores occurs with similar early transition states, which is supported by force-modified potential energy surface calculations. We further determined the stereochemistry of the mechanically generated dienes and observed significant and variable contour length elongation for these mechanophores both experimentally and computationally. The fundamental understanding of ladder-type mechanophores will facilitate future design of multicyclic mechanophores with amplified force-response and their applications as mechanically responsive materials.
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Affiliation(s)
- Matías Horst
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Jinghui Yang
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Jan Meisner
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Tatiana B Kouznetsova
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
| | - Todd J Martínez
- Department of Chemistry, Stanford University, Stanford, California 94305, United States.,SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Stephen L Craig
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
| | - Yan Xia
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
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22
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Rajput SS, Deopa SPS, Ajith VJ, Kamerkar SC, Patil S. Validity of point-mass model in off-resonance dynamic atomic force microscopy. NANOTECHNOLOGY 2021; 32:405702. [PMID: 34144547 DOI: 10.1088/1361-6528/ac0cb1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Accepted: 06/18/2021] [Indexed: 06/12/2023]
Abstract
The quantitative measurement of viscoelasticity of nano-scale entities is an important goal of nanotechnology research and there is considerable progress with advent of dynamic atomic force microscopy. The hydrodynamics of cantilever, the force sensor in AFM measurements, plays a pivotal role in quantitative estimates of nano-scale viscoelasticity. The point-mass (PM) model, wherein the AFM cantilever is approximated as a point-mass with mass-less spring is widely used in dynamic AFM analysis and its validity, particularly in liquid environments, is debated. It is suggested that the cantilever must be treated as a continuous rectangular beam to obtain accurate estimates of nano-scale viscoelasticity of materials it is probing. Here, we derived equations, which relate stiffness and damping coefficient of the material under investigation to measured parameters, by approximating cantilever as a point-mass and also considering the full geometric details. These equations are derived for both tip-excited as well as base-excited cantilevers. We have performed off-resonance dynamic atomic force spectroscopy on a single protein molecule to investigate the validity of widely used PM model. We performed measurements with AFMs equipped with different cantilever excitation methods as well as detection schemes to measure cantilever response. The data was analyzed using both, continuous beam model and the PM model. We found that both models yield same results when the experiments are performed in truly off-resonance regime with small amplitudes and the cantilever stiffness is much higher than the interaction stiffness. Our findings suggest that a simple PM approximation based model is adequate to describe the dynamics, provided care is taken while performing experiments so that the approximations used in these models are valid.
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Affiliation(s)
- Shatruhan Singh Rajput
- Department of Physics, Indian Institute of Science Education and Research Pune, Dr Homi Bhabha Road, Pashan, Pune 411008, India
| | - Surya Pratap S Deopa
- Department of Physics, Indian Institute of Science Education and Research Pune, Dr Homi Bhabha Road, Pashan, Pune 411008, India
| | - V J Ajith
- Department of Physics, Indian Institute of Science Education and Research Pune, Dr Homi Bhabha Road, Pashan, Pune 411008, India
| | - Sukrut C Kamerkar
- Department of Biology, Indian Institute of Science Education and Research Pune, Dr Homi Bhabha Road, Pashan, Pune 411008, India
| | - Shivprasad Patil
- Department of Physics, Indian Institute of Science Education and Research Pune, Dr Homi Bhabha Road, Pashan, Pune 411008, India
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23
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Li Q, Apostolidou D, Marszalek PE. Reconstruction of mechanical unfolding and refolding pathways of proteins with atomic force spectroscopy and computer simulations. Methods 2021; 197:39-53. [PMID: 34020035 DOI: 10.1016/j.ymeth.2021.05.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 05/14/2021] [Accepted: 05/15/2021] [Indexed: 12/29/2022] Open
Abstract
Most proteins in proteomes are large, typically consist of more than one domain and are structurally complex. This often makes studying their mechanical unfolding pathways challenging. Proteins composed of tandem repeat domains are a subgroup of multi-domain proteins that, when stretched, display a saw-tooth pattern in their mechanical unfolding force extension profiles due to their repetitive structure. However, the assignment of force peaks to specific repeats undergoing mechanical unraveling is complicated because all repeats are similar and they interact with their neighbors and form a contiguous tertiary structure. Here, we describe in detail a combination of experimental and computational single-molecule force spectroscopy methods that proved useful for examining the mechanical unfolding and refolding pathways of ankyrin repeat proteins. Specifically, we explain and delineate the use of atomic force microscope-based single molecule force spectroscopy (SMFS) to record the mechanical unfolding behavior of ankyrin repeat proteins and capture their unusually strong refolding propensity that is responsible for generating impressive refolding force peaks. We also describe Coarse Grain Steered Molecular Dynamic (CG-SMD) simulations which complement the experimental observations and provide insights in understanding the unfolding and refolding of these proteins. In addition, we advocate the use of novel coiled-coils-based mechanical polypeptide probes which we developed to demonstrate the vectorial character of folding and refolding of these repeat proteins. The combination of AFM-based SMFS on native and CC-equipped proteins with CG-SMD simulations is powerful not only for ankyrin repeat polypeptides, but also for other repeat proteins and more generally to various multidomain, non-repetitive proteins with complex topologies.
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Affiliation(s)
- Qing Li
- Department of Mechanical Engineering and Materials Science, Duke University, 27708 Durham, NC, United States
| | - Dimitra Apostolidou
- Department of Mechanical Engineering and Materials Science, Duke University, 27708 Durham, NC, United States
| | - Piotr E Marszalek
- Department of Mechanical Engineering and Materials Science, Duke University, 27708 Durham, NC, United States.
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24
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Oestereich M, Gauss J, Diezemann G. Force probe simulations using an adaptive resolution scheme. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2021; 33:194005. [PMID: 33690183 DOI: 10.1088/1361-648x/abed18] [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: 12/30/2020] [Accepted: 03/09/2021] [Indexed: 06/12/2023]
Abstract
Molecular simulations of the forced unfolding and refolding of biomolecules or molecular complexes allow to gain important kinetic, structural and thermodynamic information about the folding process and the underlying energy landscape. In force probe molecular dynamics (FPMD) simulations, one pulls one end of the molecule with a constant velocity in order to induce the relevant conformational transitions. Since the extended configuration of the system has to fit into the simulation box together with the solvent such simulations are very time consuming. Here, we apply a hybrid scheme in which the solute is treated with atomistic resolution and the solvent molecules far away from the solute are described in a coarse-grained manner. We use the adaptive resolution scheme (AdResS) that has very successfully been applied to various examples of equilibrium simulations. We perform FPMD simulations using AdResS on a well studied system, a dimer formed from mechanically interlocked calixarene capsules. The results of the multiscale simulations are compared to all-atom simulations of the identical system and we observe that the size of the region in which atomistic resolution is required depends on the pulling velocity, i.e. the particular non-equilibrium situation. For large pulling velocities a larger all atom region is required. Our results show that multiscale simulations can be applied also in the strong non-equilibrium situations that the system experiences in FPMD simulations.
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Affiliation(s)
- Marco Oestereich
- Department Chemie, Johannes Gutenberg-Universität Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
| | - Jürgen Gauss
- Department Chemie, Johannes Gutenberg-Universität Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
| | - Gregor Diezemann
- Department Chemie, Johannes Gutenberg-Universität Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
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25
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Motta S, Pandini A, Fornili A, Bonati L. Reconstruction of ARNT PAS-B Unfolding Pathways by Steered Molecular Dynamics and Artificial Neural Networks. J Chem Theory Comput 2021; 17:2080-2089. [PMID: 33780250 PMCID: PMC8047803 DOI: 10.1021/acs.jctc.0c01308] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
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Several experimental
studies indicated that large conformational
changes, including partial domain unfolding, have a role in the functional
mechanisms of the basic helix loop helix Per/ARNT/SIM (bHLH-PAS) transcription
factors. Recently, single-molecule atomic force microscopy (AFM) revealed
two distinct pathways for the mechanical unfolding of the ARNT PAS-B.
In this work we used steered molecular dynamics simulations to gain
new insights into this process at an atomistic level. To reconstruct
and classify pathways sampled in multiple simulations, we designed
an original approach based on the use of self-organizing maps (SOMs).
This led us to identify two types of unfolding pathways for the ARNT
PAS-B, which are in good agreement with the AFM findings. Analysis
of average forces mapped on the SOM revealed a stable conformation
of the PAS-B along one pathway, which represents a possible structural
model for the intermediate state detected by AFM. The approach here
proposed will facilitate the study of other signal transmission mechanisms
involving the folding/unfolding of PAS domains.
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Affiliation(s)
- Stefano Motta
- Department of Earth and Environmental Sciences, University of Milano-Bicocca, Milan 20126, Italy
| | - Alessandro Pandini
- Department of Computer Science, Brunel University London, Uxbridge UB8 3PH, United Kingdom.,The Thomas Young Centre for Theory and Simulation of Materials, London SW7 2AZ, United Kingdom
| | - Arianna Fornili
- School of Biological and Chemical Sciences, Queen Mary University of London, London E1 4NS, United Kingdom.,The Thomas Young Centre for Theory and Simulation of Materials, London SW7 2AZ, United Kingdom
| | - Laura Bonati
- Department of Earth and Environmental Sciences, University of Milano-Bicocca, Milan 20126, Italy
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26
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Müller DJ, Dumitru AC, Lo Giudice C, Gaub HE, Hinterdorfer P, Hummer G, De Yoreo JJ, Dufrêne YF, Alsteens D. Atomic Force Microscopy-Based Force Spectroscopy and Multiparametric Imaging of Biomolecular and Cellular Systems. Chem Rev 2020; 121:11701-11725. [PMID: 33166471 DOI: 10.1021/acs.chemrev.0c00617] [Citation(s) in RCA: 83] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
During the last three decades, a series of key technological improvements turned atomic force microscopy (AFM) into a nanoscopic laboratory to directly observe and chemically characterize molecular and cell biological systems under physiological conditions. Here, we review key technological improvements that have established AFM as an analytical tool to observe and quantify native biological systems from the micro- to the nanoscale. Native biological systems include living tissues, cells, and cellular components such as single or complexed proteins, nucleic acids, lipids, or sugars. We showcase the procedures to customize nanoscopic chemical laboratories by functionalizing AFM tips and outline the advantages and limitations in applying different AFM modes to chemically image, sense, and manipulate biosystems at (sub)nanometer spatial and millisecond temporal resolution. We further discuss theoretical approaches to extract the kinetic and thermodynamic parameters of specific biomolecular interactions detected by AFM for single bonds and extend the discussion to multiple bonds. Finally, we highlight the potential of combining AFM with optical microscopy and spectroscopy to address the full complexity of biological systems and to tackle fundamental challenges in life sciences.
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Affiliation(s)
- Daniel J Müller
- Department of Biosystems Science and Engineering, Eidgenössische Technische Hochschule (ETH) Zürich, Mattenstrasse 28, 4056 Basel, Switzerland
| | - Andra C Dumitru
- Louvain Institute of Biomolecular Science and Technology, Université Catholique de Louvain (UCLouvain), Croix du Sud, 4-5, bte L7.07.07, B-1348 Louvain-la-Neuve, Belgium
| | - Cristina Lo Giudice
- Louvain Institute of Biomolecular Science and Technology, Université Catholique de Louvain (UCLouvain), Croix du Sud, 4-5, bte L7.07.07, B-1348 Louvain-la-Neuve, Belgium
| | - Hermann E Gaub
- Applied Physics, Ludwig-Maximilians-Universität Munich, Amalienstrasse 54, 80799 München, Germany
| | - Peter Hinterdorfer
- Institute of Biophysics, Johannes Kepler University of Linz, Gruberstrasse 40, 4020 Linz, Austria
| | - Gerhard Hummer
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics and Department of Physics, Goethe University Frankfurt, 60438 Frankfurt am Main, Germany
| | - James J De Yoreo
- Physical Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, United States.,Department of Materials Science and Engineering, University of Washington, Seattle, Washington 98195, United States
| | - Yves F Dufrêne
- Louvain Institute of Biomolecular Science and Technology, Université Catholique de Louvain (UCLouvain), Croix du Sud, 4-5, bte L7.07.07, B-1348 Louvain-la-Neuve, Belgium
| | - David Alsteens
- Louvain Institute of Biomolecular Science and Technology, Université Catholique de Louvain (UCLouvain), Croix du Sud, 4-5, bte L7.07.07, B-1348 Louvain-la-Neuve, Belgium
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27
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Woo H, Choi B, Eom K. Ligand-binding alters the mechanical stability of muscle protein titin domains. J Biomol Struct Dyn 2020; 38:4938-4946. [DOI: 10.1080/07391102.2019.1688686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Hwanyoung Woo
- Biomechanics Laboratory, College of Sport Science, Sungkyunkwan University (SKKU), Suwon, Republic of Korea
| | - Bumjoon Choi
- Biomechanics Laboratory, College of Sport Science, Sungkyunkwan University (SKKU), Suwon, Republic of Korea
| | - Kilho Eom
- Biomechanics Laboratory, College of Sport Science, Sungkyunkwan University (SKKU), Suwon, Republic of Korea
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28
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Guerin J, Botos I, Zhang Z, Lundquist K, Gumbart JC, Buchanan SK. Structural insight into toxin secretion by contact-dependent growth inhibition transporters. eLife 2020; 9:58100. [PMID: 33089781 PMCID: PMC7644211 DOI: 10.7554/elife.58100] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 10/21/2020] [Indexed: 12/13/2022] Open
Abstract
Bacterial contact-dependent growth inhibition (CDI) systems use a type Vb secretion mechanism to export large CdiA toxins across the outer membrane by dedicated outer membrane transporters called CdiB. Here, we report the first crystal structures of two CdiB transporters from Acinetobacter baumannii and Escherichia coli. CdiB transporters adopt a TpsB fold, containing a 16-stranded transmembrane β-barrel connected to two periplasmic domains. The lumen of the CdiB pore is occluded by an N-terminal α-helix and the conserved extracellular loop 6; these two elements adopt different conformations in the structures. We identified a conserved DxxG motif located on strand β1 that connects loop 6 through different networks of interactions. Structural modifications of DxxG induce rearrangement of extracellular loops and alter interactions with the N-terminal α-helix, preparing the system for α-helix ejection. Using structural biology, functional assays, and molecular dynamics simulations, we show how the barrel pore is primed for CdiA toxin secretion.
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Affiliation(s)
- Jeremy Guerin
- Laboratory of Molecular Biology, NIDDK, NIH, Bethesda, United States
| | - Istvan Botos
- Laboratory of Molecular Biology, NIDDK, NIH, Bethesda, United States
| | - Zijian Zhang
- School of Physics, Georgia Institute of Technology, Atlanta, Georgia
| | - Karl Lundquist
- School of Physics, Georgia Institute of Technology, Atlanta, Georgia
| | - James C Gumbart
- School of Physics, Georgia Institute of Technology, Atlanta, Georgia
| | - Susan K Buchanan
- Laboratory of Molecular Biology, NIDDK, NIH, Bethesda, United States
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29
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Schäfer K, Diezemann G. Force-dependent folding pathways in mechanically interlocked calixarene dimers via atomistic force quench simulations. Mol Phys 2020. [DOI: 10.1080/00268976.2020.1743886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
- Ken Schäfer
- Institut für Physikalische Chemie, Universität Mainz, Mainz, Germany
| | - Gregor Diezemann
- Institut für Physikalische Chemie, Universität Mainz, Mainz, Germany
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30
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Shimizu T, Lungerich D, Stuckner J, Murayama M, Harano K, Nakamura E. Real-Time Video Imaging of Mechanical Motions of a Single Molecular Shuttle with Sub-Millisecond Sub-Angstrom Precision. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2020. [DOI: 10.1246/bcsj.20200134] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Toshiki Shimizu
- Department of Chemistry, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Dominik Lungerich
- Department of Chemistry, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Joshua Stuckner
- Materials Science and Engineering Department, Virginia Tech, Blacksburg, VA 24061, USA
| | - Mitsuhiro Murayama
- Materials Science and Engineering Department, Virginia Tech, Blacksburg, VA 24061, USA
- Reactor Materials and Mechanical Design Group, Energy and Environmental Directorate, Pacific Northwest National Laboratory, Richland, WA 99352
- Institute for Materials Chemistry and Engineering, Kyushu University, Kasuga, Fukuoka 816-8580, Japan
| | - Koji Harano
- Department of Chemistry, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Eiichi Nakamura
- Department of Chemistry, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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31
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[1-(4-chloro-3-nitrobenzenesulfonyl)-1H-indol-3-yl]-methanol, an indole-3-carbinol derivative, inhibits glutamate release in rat cerebrocortical nerve terminals by suppressing the P/Q-type Ca 2+ channels and Ca 2+/calmodulin/protein kinase A pathway. Neurochem Int 2020; 140:104845. [PMID: 32911011 DOI: 10.1016/j.neuint.2020.104845] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 08/31/2020] [Accepted: 09/04/2020] [Indexed: 11/23/2022]
Abstract
Indole-3-carbinol (I3C), found in cruciferous vegetables, has been proposed to exhibit neuroprotective effects. This study aimed to investigate the effect of the I3C derivative [1(4-chloro-3-nitrobenzenesulfonyl)-1H-indol-3-yl]-methanol (CIM), which has superior pharmacokinetic properties to I3C, on glutamate release in rat cerebrocortical nerve terminals (synaptosomes). We observed that CIM dose-dependently inhibited glutamate release evoked by the potassium channel blocker 4-aminopyridine (4-AP). CIM-mediated inhibition of glutamate release was attributed to reduced exocytosis, as it correlated with the removal of extracellular calcium and blocking of the vesicular glutamate transporter but not the glutamate transporter. In addition, CIM decreased 4-AP-evoked intrasynaptosomal Ca2+ elevation; however, it did not alter the synaptosomal membrane potential. The inhibition of P/Q-typeCa2+ channels abolished the effect of CIM on 4-AP-evoked glutamate release, and the effect was not prevented by intracellular Ca2+ release inhibitors. Moreover, the molecular docking study showed that CIM exhibited the highest binding affinity with the P/Q-type Ca2+channels. Finally, the CIM-mediated inhibition of glutamate release was sensitive to calmodulin, adenylate cyclase (AC), and protein kinase A (PKA) inhibitors. Based on these results, we propose that CIM, through the direct suppression of P/Q-type Ca2+ channels, decreases Ca2+ influx and the activation of Ca2+/calmodulin/AC/PKA signaling, thereby inhibiting glutamate release. This finding is crucial for understanding the role of CIM in the central nervous system and for exploiting its potential in therapeutic interventions.
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32
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Mohammadian H, Mahnam K, Sadeghi HM, Ganjalikhany MR, Akbari V. Rational design of a new mutant of tobacco etch virus protease in order to increase the in vitro solubility. Res Pharm Sci 2020; 15:164-173. [PMID: 32582356 PMCID: PMC7306250 DOI: 10.4103/1735-5362.283816] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 12/30/2019] [Accepted: 03/16/2020] [Indexed: 12/13/2022] Open
Abstract
Background and purpose: Tobacco etch virus (TEV) protease is a protease with high sequence specificity which is useful for the cleavage of fusion proteins. A major limitation of this enzyme is its relatively poor solubility. This study aimed to investigate the effects of some suggested mutations by online tools and molecular dynamics simulation to improve the solubility of TEV protease in vitro. Experimental approach: We designed a rational multi-stage process to determine the solubilizing mutations of TEV protease. At the first stage, all the possible mutations were predicted using online tools such as PoPMuSiC and Eris servers, in which five mutations include N23F, N23L, Q74L, Q74V, and Q74I were suggested for further studies. In the next step, the three dimensional structure of the wild type (WT) and the best mutations were subjected to molecular dynamic simulations to evaluate the dynamic behaviour of the obtained structures. The selected mutation was introduced into the structure using site-directed mutagenesis and expressed in Escherichia coli BL21DE3. After purification, solubility and activity of the purified mutant and WT-TEV proteases were assayed. Findings /Results: By considering the analysis of various factors such as structural and solubility properties, one mutant, N23F, was selected for in vitro studies which led to a 1.5 times increase in the solubility compared to the WT while its activity was decreased somewhat. Conclusion and implications: We propose N23F mutation, according to computational and experimental analyses for TEV proteases which resulted in a 150% increase in solubility compared to the WT.
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Affiliation(s)
- Hossein Mohammadian
- Department of Pharmaceutical Biotechnology, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, I.R. Iran.,Isfahan Pharmaceutical Sciences Research Center, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, I.R. Iran
| | - Karim Mahnam
- Department of Biology, Faculty of Sciences, University of Shahrekord, Shahrekord, I.R. Iran.,Nanotechnology Research Centre, Shahrekord University, Shahrekord, I.R. Iran
| | - Hamid Mirmohammad Sadeghi
- Department of Pharmaceutical Biotechnology, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, I.R. Iran.,Isfahan Pharmaceutical Sciences Research Center, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, I.R. Iran
| | | | - Vajihe Akbari
- Department of Pharmaceutical Biotechnology, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, I.R. Iran.,Isfahan Pharmaceutical Sciences Research Center, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, I.R. Iran
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33
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Wu C, Alqahtani A, Sangtarash S, Vezzoli A, Sadeghi H, Robertson CM, Cai C, Lambert CJ, Higgins SJ, Nichols RJ. In situ formation of H-bonding imidazole chains in break-junction experiments. NANOSCALE 2020; 12:7914-7920. [PMID: 32232235 DOI: 10.1039/d0nr00630k] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
As a small molecule possessing both strong H-bond donor and acceptor functions, 1H-imidazole can participate in extensive homo- or heteromolecular H-bonding networks. These properties are important in Nature, as imidazole moieties are incorporated in many biologically-relevant compounds. Imidazole also finds applications ranging from corrosion inhibition to fire retardants and photography. We have found a peculiar behaviour of imidazole during scanning tunnelling microscopy-break junction (STM-BJ) experiments, in which oligomeric chains connect the two electrodes and allow efficient charge transport. We attributed this behaviour to the formation of hydrogen-bonding networks, as no evidence of such behaviour was found in 1-methylimidazole (incapable of participating in intramolecular hydrogen bonding). The results are supported by DFT calculations, which confirmed our hypothesis. These findings pave the road to the use of hydrogen-bonding networks for the fabrication of dynamic junctions based on supramolecular interactions.
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Affiliation(s)
- Chuanli Wu
- Department of Chemistry, University of Liverpool, Crown Street, Liverpool L69 7ZD, UK.
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34
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Fontana F, Gelain F. Probing mechanical properties and failure mechanisms of fibrils of self-assembling peptides. NANOSCALE ADVANCES 2020; 2:190-198. [PMID: 36133966 PMCID: PMC9416940 DOI: 10.1039/c9na00621d] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Accepted: 12/16/2019] [Indexed: 05/08/2023]
Abstract
Self-assembling peptides (SAPs) are a promising class of biomaterials amenable to easy molecular design and functionalization. Despite their increasing usage in regenerative medicine, a detailed analysis of their biomechanics at the nanoscale level is still missing. In this work, we propose and validate, in all-atom dynamics, a coarse-grained model to elucidate strain distribution, failure mechanisms and biomechanical effects of functionalization of two SAPs when subjected to both axial stretching and bending forces. We highlight different failure mechanisms for fibril seeds and fibrils, as well as the negligible contribution of the chosen functional motif to the overall system rupture. This approach could lay the basis for the development of "more" coarse-grained models in the long pathway connecting SAP sequences and hydrogel mechanical properties.
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Affiliation(s)
- Federico Fontana
- Fondazione IRCCS Casa Sollievo della Sofferenza, Unità Ingegneria Tissutale Viale Cappuccini 1, San Giovanni Rotondo 71013 Foggia Italy
| | - Fabrizio Gelain
- Fondazione IRCCS Casa Sollievo della Sofferenza, Unità Ingegneria Tissutale Viale Cappuccini 1, San Giovanni Rotondo 71013 Foggia Italy
- Center for Nanomedicine and Tissue Engineering (CNTE), ASST Ospedale Metropolitano Niguarda Piazza dell'Ospedale Maggiore 3 20162 Milan Italy
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35
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Mechanical Unfolding of Spectrin Repeats Induces Water-Molecule Ordering. Biophys J 2020; 118:1076-1089. [PMID: 32027822 DOI: 10.1016/j.bpj.2020.01.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 12/24/2019] [Accepted: 01/02/2020] [Indexed: 02/07/2023] Open
Abstract
Mechanical processes are involved at many stages of the development of living cells, and often external forces applied to a biomolecule result in its unfolding. Although our knowledge of the unfolding mechanisms and the magnitude of the forces involved has evolved, the role that water molecules play in the mechanical unfolding of biomolecules has not yet been fully elucidated. To this end, we investigated with steered molecular dynamics simulations the mechanical unfolding of dystrophin's spectrin repeat 1 and related the changes in the protein's structure to the ordering of the surrounding water molecules. Our results indicate that upon mechanically induced unfolding of the protein, the solvent molecules become more ordered and increase their average number of hydrogen bonds. In addition, the unfolded structures originating from mechanical pulling expose an increasing amount of the hydrophobic residues to the solvent molecules, and the uncoiled regions adapt a convex surface with a small radius of curvature. As a result, the solvent molecules reorganize around the protein's small protrusions in structurally ordered waters that are characteristic of the so-called "small-molecule regime," which allows water to maintain a high hydrogen bond count at the expense of an increased structural order. We also determined that the response of water to structural changes in the protein is localized to the specific regions of the protein that undergo unfolding. These results indicate that water plays an important role in the mechanically induced unfolding of biomolecules. Our findings may prove relevant to the ever-growing interest in understanding macromolecular crowding in living cells and their effects on protein folding, and suggest that the hydration layer may be exploited as a means for short-range allosteric communication.
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36
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Limongelli V. Ligand binding free energy and kinetics calculation in 2020. WILEY INTERDISCIPLINARY REVIEWS-COMPUTATIONAL MOLECULAR SCIENCE 2020. [DOI: 10.1002/wcms.1455] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Vittorio Limongelli
- Faculty of Biomedical Sciences, Institute of Computational Science – Center for Computational Medicine in Cardiology Università della Svizzera italiana (USI) Lugano Switzerland
- Department of Pharmacy University of Naples “Federico II” Naples Italy
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37
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Kadir SR, Insall RH, Moffatt G, McGhee J, Livingstone D. Analogies in 3D molecular visualisations: development of a cell biology animation 'How cells move - a new interpretation of old data'. J Vis Commun Med 2020; 43:35-46. [PMID: 31642358 DOI: 10.1080/17453054.2019.1671814] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2019] [Accepted: 09/20/2019] [Indexed: 10/25/2022]
Abstract
Cell biology and imaging technology have vastly improved over the past decades, enabling scientists to dissect the inner workings of a cell. In addition to technical limits on spatial and temporal resolution, which obscure the picture at the molecular level, the sheer density and complexity of information impede clear understanding. 3D molecular visualisation has therefore blossomed as a way to translate molecular data in a more tangible form. Whilst the molecular machinery involved in cell locomotion has been extensively studied, existing narratives describing how cells generate the forces that drive movement remain unclear. Polymerisation of a protein called actin is clearly essential. The general belief in the cell migration field is that actin polymerisation's main role is to push the leading edge of the cell forwards, while the rest of the cell follows passively. The cell migration & chemotaxis group at the CRUK Beatson Institute propose an alternative hypothesis, in which actin filaments constitute cables. Motor proteins pull on these cables, causing them to behave like the treads of a tank and drive cell movement. This article describes the development of a 3D animation that uses analogical reasoning to contrast the 'tank' hypothesis for cell locomotion with the current dogma.
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Affiliation(s)
- Shereen R Kadir
- 3D Visualisation Aesthetics Lab, University of New South Wales Art and Design, Sydney, NSW, Australia
- The School of Simulation and Visualisation, Glasgow School of Art, Glasgow, UK
| | | | - Gillian Moffatt
- The School of Simulation and Visualisation, Glasgow School of Art, Glasgow, UK
| | - John McGhee
- 3D Visualisation Aesthetics Lab, University of New South Wales Art and Design, Sydney, NSW, Australia
| | - Daniel Livingstone
- The School of Simulation and Visualisation, Glasgow School of Art, Glasgow, UK
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38
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Lai X, Roberts E. Cytotoxicity effects and ionic diffusion of single-wall carbon nanotubes in cell membrane. ACTA ACUST UNITED AC 2019. [DOI: 10.1142/s2424913019500061] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
While carbon nanotubes have been put into massive practical industrial, environmental and biomedicine applications, the cytotoxicity effects or the effect to the ionic channels they bring into the living cells need to be thoroughly investigated. In this work, molecular dynamic simulations have been carried out to investigate the ionic diffusion through the single wall armchair carbon nanotube embedded right inside the cell membrane. By modeling a two-membrane system, we build a virtual cytoplasm environment including a cell chamber and an extracellular space, in which a certain amount of solute is dissolved. The system is first brought to its equilibrium by deployment of minimization and then simulated. The results suggested that carbon nanotubes (CNTs) with size less than (12, 12) shall be less cytotoxic since it does not bring any ionic diffusion through the CNT channel, so as to maintain active cytoplasm environment. Another phenomenon we observed is a notable shifting angle of the carbon nanotube which was normal to the surface of cell membrane initially. In general, the inclination angle of the carbon nanotube increases with its radius.
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Affiliation(s)
- Xin Lai
- Hubei Key Laboratory of Theory and Application of Advanced Materials Mechanics, Wuhan University of Technology, Wuhan 430070, P. R. China
- Department of Civil and Environmental Engineering, University of California, Berkeley, CA 94720, USA
| | - Eric Roberts
- Department of Civil and Environmental Engineering, University of California, Berkeley, CA 94720, USA
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39
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Sahoo AK, Bagchi B, Maiti PK. Understanding enhanced mechanical stability of DNA in the presence of intercalated anticancer drug: Implications for DNA associated processes. J Chem Phys 2019; 151:164902. [PMID: 31675856 DOI: 10.1063/1.5117163] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Most of the anticancer drugs bind to double-stranded DNA (dsDNA) by intercalative-binding mode. Although experimental studies have become available recently, a molecular-level understanding of the interactions between the drug and dsDNA that lead to the stability of the intercalated drug is lacking. Of particular interest are the modifications of the mechanical properties of dsDNA observed in experiments. The latter could affect many biological functions, such as DNA transcription and replication. Here, we probe, via all-atom molecular dynamics (MD) simulations, the change in the mechanical properties of intercalated drug-DNA complexes for two intercalators, daunomycin and ethidium. We find that, upon drug intercalation, the stretch modulus of DNA increases significantly, whereas its persistence length and bending modulus decrease. Steered MD simulations reveal that it requires higher forces to stretch the intercalated dsDNA complexes than the normal dsDNA. Adopting various pulling protocols to study force-induced DNA melting, we find that the dissociation of dsDNA becomes difficult in the presence of intercalators. The results obtained here provide a plausible mechanism of function of the anticancer drugs, i.e., via altering the mechanical properties of DNA. We also discuss long-time consequences of using these drugs, which require further in vivo investigations.
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Affiliation(s)
- Anil Kumar Sahoo
- Center for Condensed Matter Theory, Department of Physics, Indian Institute of Science, Bangalore 560012, India
| | - Biman Bagchi
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012, India
| | - Prabal K Maiti
- Center for Condensed Matter Theory, Department of Physics, Indian Institute of Science, Bangalore 560012, India
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40
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High-speed force spectroscopy: microsecond force measurements using ultrashort cantilevers. Biophys Rev 2019; 11:689-699. [PMID: 31588961 PMCID: PMC6815269 DOI: 10.1007/s12551-019-00585-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Accepted: 08/27/2019] [Indexed: 10/25/2022] Open
Abstract
Complete understanding of the role of mechanical forces in biological processes requires knowledge of the mechanical properties of individual proteins and living cells. Moreover, the dynamic response of biological systems at the nano- and microscales span over several orders of magnitude in time, from sub-microseconds to several minutes. Thus, access to force measurements over a wide range of length and time scales is required. High-speed atomic force microscopy (HS-AFM) using ultrashort cantilevers has emerged as a tool to study the dynamics of biomolecules and cells at video rates. The adaptation of HS-AFM to perform high-speed force spectroscopy (HS-FS) allows probing protein unfolding and receptor/ligand unbinding up to the velocity of molecular dynamics (MD) simulations with sub-microsecond time resolution. Moreover, application of HS-FS on living cells allows probing the viscoelastic response at short time scales providing deep understanding of cytoskeleton dynamics. In this mini-review, we assess the principles and recent developments and applications of HS-FS using ultrashort cantilevers to probe molecular and cellular mechanics.
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41
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Wang H, Gao X, Hu X, Hu X, Hu C, Li H. Mechanical Unfolding and Folding of a Complex Slipknot Protein Probed by Using Optical Tweezers. Biochemistry 2019; 58:4751-4760. [DOI: 10.1021/acs.biochem.9b00320] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Han Wang
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - Xiaoqing Gao
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
- State Key Laboratory of Precision Measurements Technology Instruments, School of Precision Instrument Optoelectronics Engineering, Tianjin University, Tianjin 300072, People’s Republic of China
| | - Xiaodong Hu
- State Key Laboratory of Precision Measurements Technology Instruments, School of Precision Instrument Optoelectronics Engineering, Tianjin University, Tianjin 300072, People’s Republic of China
| | - Xiaotang Hu
- State Key Laboratory of Precision Measurements Technology Instruments, School of Precision Instrument Optoelectronics Engineering, Tianjin University, Tianjin 300072, People’s Republic of China
| | - Chunguang Hu
- State Key Laboratory of Precision Measurements Technology Instruments, School of Precision Instrument Optoelectronics Engineering, Tianjin University, Tianjin 300072, People’s Republic of China
| | - Hongbin Li
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
- State Key Laboratory of Precision Measurements Technology Instruments, School of Precision Instrument Optoelectronics Engineering, Tianjin University, Tianjin 300072, People’s Republic of China
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42
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Eckels EC, Tapia-Rojo R, Rivas-Pardo JA, Fernández JM. The Work of Titin Protein Folding as a Major Driver in Muscle Contraction. Annu Rev Physiol 2019; 80:327-351. [PMID: 29433413 DOI: 10.1146/annurev-physiol-021317-121254] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Single-molecule atomic force microscopy and magnetic tweezers experiments have demonstrated that titin immunoglobulin (Ig) domains are capable of folding against a pulling force, generating mechanical work that exceeds that produced by a myosin motor. We hypothesize that upon muscle activation, formation of actomyosin cross bridges reduces the force on titin, causing entropic recoil of the titin polymer and triggering the folding of the titin Ig domains. In the physiological force range of 4-15 pN under which titin operates in muscle, the folding contraction of a single Ig domain can generate 200% of the work of entropic recoil and occurs at forces that exceed the maximum stalling force of single myosin motors. Thus, titin operates like a mechanical battery, storing elastic energy efficiently by unfolding Ig domains and delivering the charge back by folding when the motors are activated during a contraction. We advance the hypothesis that titin folding and myosin activation act as inextricable partners during muscle contraction.
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Affiliation(s)
- Edward C Eckels
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA; , .,Integrated Program in Cellular, Molecular, and Biomedical Studies, Columbia University Medical Center, New York, NY 10032, USA
| | - Rafael Tapia-Rojo
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA; ,
| | | | - Julio M Fernández
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA; ,
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43
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Gunnoo M, Cazade PA, Orlowski A, Chwastyk M, Liu H, Ta DT, Cieplak M, Nash M, Thompson D. Steered molecular dynamics simulations reveal the role of Ca 2+ in regulating mechanostability of cellulose-binding proteins. Phys Chem Chem Phys 2019; 20:22674-22680. [PMID: 30132772 DOI: 10.1039/c8cp00925b] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The conversion of cellulosic biomass into biofuels requires degradation of the biomass into fermentable sugars. The most efficient natural cellulase system for carrying out this conversion is an extracellular multi-enzymatic complex named the cellulosome. In addition to temperature and pH stability, mechanical stability is important for functioning of cellulosome domains, and experimental techniques such as Single Molecule Force Spectroscopy (SMFS) have been used to measure the mechanical strength of several cellulosomal proteins. Molecular dynamics computer simulations provide complementary atomic-resolution quantitative maps of domain mechanical stability for identification of experimental leads for protein stabilization. In this study, we used multi-scale steered molecular dynamics computer simulations, benchmarked against new SMFS measurements, to measure the intermolecular contacts that confer high mechanical stability to a family 3 Carbohydrate Binding Module protein (CBM3) derived from the archetypal Clostridium thermocellum cellulosome. Our data predicts that electrostatic interactions in the calcium binding pocket modulate the mechanostability of the cellulose-binding module, which provides an additional design rule for the rational re-engineering of designer cellulosomes for biotechnology. Our data offers new molecular insights into the origins of mechanostability in cellulose binding domains and gives leads for synthesis of more robust cellulose-binding protein modules. On the other hand, simulations predict that insertion of a flexible strand can promote alternative unfolding pathways and dramatically reduce the mechanostability of the carbohydrate binding module, which gives routes to rational design of tailormade fingerprint complexes for force spectroscopy experiments.
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Affiliation(s)
- Melissabye Gunnoo
- Department of Physics, Bernal Institute, University of Limerick, V94 T9PX, Ireland.
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Torres-Sánchez A, Vanegas JM, Purohit PK, Arroyo M. Combined molecular/continuum modeling reveals the role of friction during fast unfolding of coiled-coil proteins. SOFT MATTER 2019; 15:4961-4975. [PMID: 31172154 DOI: 10.1039/c9sm00117d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Coiled-coils are filamentous proteins that form the basic building block of important force-bearing cellular elements, such as intermediate filaments and myosin motors. In addition to their biological importance, coiled-coil proteins are increasingly used in new biomaterials including fibers, nanotubes, or hydrogels. Coiled-coils undergo a structural transition from an α-helical coil to an unfolded state upon extension, which allows them to sustain large strains and is critical for their biological function. By performing equilibrium and out-of-equilibrium all-atom molecular dynamics (MD) simulations of coiled-coils in explicit solvent, we show that two-state models based on Kramers' or Bell's theories fail to predict the rate of unfolding at high pulling rates. We further show that an atomistically informed continuum rod model accounting for phase transformations and for the hydrodynamic interactions with the solvent can reconcile two-state models with our MD results. Our results show that frictional forces, usually neglected in theories of fibrous protein unfolding, reduce the thermodynamic force acting on the interface, and thus control the dynamics of unfolding at different pulling rates. Our results may help interpret MD simulations at high pulling rates, and could be pertinent to cytoskeletal networks or protein-based artificial materials subjected to shocks or blasts.
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45
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Multivalent Binding of a Ligand-Coated Particle: Role of Shape, Size, and Ligand Heterogeneity. Biophys J 2019; 114:1830-1846. [PMID: 29694862 DOI: 10.1016/j.bpj.2018.03.007] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Revised: 03/05/2018] [Accepted: 03/06/2018] [Indexed: 01/18/2023] Open
Abstract
We utilize a multiscale modeling framework to study the effect of shape, size, and ligand composition on the efficacy of binding of a ligand-coated particle to a substrate functionalized with the target receptors. First, we show how molecular dynamics along with steered molecular dynamics calculations can be used to accurately parameterize the molecular-binding free energy and the effective spring constant for a receptor-ligand pair. We demonstrate this for two ligands that bind to the α5β1-domain of integrin. Next, we show how these effective potentials can be used to build computational models at the meso- and continuum-scales. These models incorporate the molecular nature of the receptor-ligand interactions and yet provide an inexpensive route to study the multivalent interaction of receptors and ligands through the construction of Bell potentials customized to the molecular identities. We quantify the binding efficacy of the ligand-coated-particle in terms of its multivalency, binding free-energy landscape, and the losses in the configurational entropies. We show that 1) the binding avidity for particle sizes less than 350 nm is set by the competition between the enthalpic and entropic contributions, whereas that for sizes above 350 nm is dominated by the enthalpy of binding; 2) anisotropic particles display higher levels of multivalent binding compared to those of spherical particles; and 3) variations in ligand composition can alter binding avidity without altering the average multivalency. The methods and results presented here have wide applications in the rational design of functionalized carriers and also in understanding cell adhesion.
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46
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Wang WB, Zhu JZ, Li XY, Li CH, Su JG, Li JY. Enhancement of protein mechanical stability: Correlated deformations are handcuffed by ligand binding. J Chem Phys 2019; 150:155102. [PMID: 31005084 DOI: 10.1063/1.5054932] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
As revealed by previous experiments, protein mechanical stability can be effectively regulated by ligand binding with the binding site distant from the force-bearing region. However, the mechanism for such long-range allosteric control of protein mechanics is still largely unknown. In this work, we use protein topology-based elastic network model (ENM) and all-atomic steered molecular dynamics (SMD) simulations to study the impact of ligand binding on protein mechanical stability in two systems, i.e., GB1 and CheY-binding P2-domain of CheA (CBDCheA). Both ENM and SMD results show that the ligand binding has considerable and negligible effects on the mechanical stability of these two proteins, respectively. These results are consistent with the experimental observations. A physical mechanism for the enhancement of protein mechanical stability was then proposed: the correlated deformations of the force-bearing region and the binding site are handcuffed by the binding of ligand. The handcuff effect suppresses the propagation of internal force in the force-bearing region, thus improving the resistance to the loading force. Our study indicates that ENM method can effectively identify the structure motifs allosterically related to the deformation in the force bearing region, as well as the force propagation pathway within the structure of the studied proteins. Hence, it should be helpful to understand the molecular origin of the different mechanical properties in response to ligand binding for GB1 and CBDCheA.
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Affiliation(s)
- Wei Bu Wang
- Key Laboratory for Microstructural Material Physics of Hebei Province, College of Science, Yanshan University, Qinhuangdao 066004, China
| | - Jian Zhuo Zhu
- Key Laboratory for Microstructural Material Physics of Hebei Province, College of Science, Yanshan University, Qinhuangdao 066004, China
| | - Xing Yuan Li
- Key Laboratory for Microstructural Material Physics of Hebei Province, College of Science, Yanshan University, Qinhuangdao 066004, China
| | - Chun Hua Li
- College of Life Science and Bioengineering, Beijing University of Technology, Beijing 100124, China
| | - Ji Guo Su
- Key Laboratory for Microstructural Material Physics of Hebei Province, College of Science, Yanshan University, Qinhuangdao 066004, China
| | - Jing Yuan Li
- Institute of Quantitative Biology and Department of Physics, Zhejiang University, Hangzhou 310027, China
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47
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Poma AB, Li MS, Theodorakis PE. Generalization of the elastic network model for the study of large conformational changes in biomolecules. Phys Chem Chem Phys 2019; 20:17020-17028. [PMID: 29904772 DOI: 10.1039/c8cp03086c] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The elastic network (EN) is a prime model that describes the long-time dynamics of biomolecules. However, the use of harmonic potentials renders this model insufficient for studying large conformational changes of proteins (e.g. stretching of proteins, folding and thermal unfolding). Here, we extend the capabilities of the EN model by using a harmonic approximation described by Lennard-Jones (LJ) interactions for far contacts and native contacts obtained from the standard overlap criterion as in the case of Gō-like models. While our model is validated against the EN model by reproducing the equilibrium properties for a number of proteins, we also show that the model is suitable for the study of large conformation changes by providing various examples. In particular, this is illustrated on the basis of pulling simulations that predict with high accuracy the experimental data on the rupture force of the studied proteins. Furthermore, in the case of DDFLN4 protein, our pulling simulations highlight the advantages of our model with respect to Gō-like approaches, where the latter fail to reproduce previous results obtained by all-atom simulations that predict an additional characteristic peak for this protein. In addition, folding simulations of small peptides yield different folding times for α-helix and β-hairpin, in agreement with experiment, in this way providing further opportunities for the application of our model in studying large conformational changes of proteins. In contrast to the EN model, our model is suitable for both normal mode analysis and molecular dynamics simulation. We anticipate that the proposed model will find applications in a broad range of problems in biology, including, among others, protein folding and thermal unfolding.
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Affiliation(s)
- Adolfo B Poma
- Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw, Poland.
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48
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Padhi S, Pradhan M, Bung N, Roy A, Bulusu G. TPP riboswitch aptamer: Role of Mg 2+ ions, ligand unbinding, and allostery. J Mol Graph Model 2019; 88:282-291. [PMID: 30818079 DOI: 10.1016/j.jmgm.2019.01.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 01/18/2019] [Accepted: 01/18/2019] [Indexed: 01/23/2023]
Abstract
Riboswitches are non-coding RNAs that regulate gene expression in response to the binding of metabolites. Their abundance in bacteria makes them ideal drug targets. The prokaryotic thiamine pyrophosphate (TPP) riboswitch regulates gene expression in a wide range of bacteria by undergoing conformational changes in response to the binding of TPP. Although an experimental structure for the aptamer domain of the riboswitch is now available, details of the conformational changes that occur during the binding of the ligand, and the factors that govern these conformational changes, are still not clear. This study employs microsecond-scale molecular dynamics simulations to provide insights into the functioning of the riboswitch aptamer in atomistic detail. A mechanism for the transmission of conformational changes from the ligand-binding site to the P1 switch helix is proposed. Mg2+ ions in the binding site play a critical role in anchoring the ligand to the riboswitch. Finally, modeling the egress of TPP from the binding site reveals a two-step mechanism for TPP unbinding. Findings from this study can motivate the design of future studies aimed at modulating the activity of this drug target.
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Affiliation(s)
- Siladitya Padhi
- TCS Innovation Labs - Hyderabad (Life Sciences Division), Tata Consultancy Services Limited, Hyderabad, 500081, India
| | - Meenakshi Pradhan
- TCS Innovation Labs - Hyderabad (Life Sciences Division), Tata Consultancy Services Limited, Hyderabad, 500081, India
| | - Navneet Bung
- TCS Innovation Labs - Hyderabad (Life Sciences Division), Tata Consultancy Services Limited, Hyderabad, 500081, India
| | - Arijit Roy
- TCS Innovation Labs - Hyderabad (Life Sciences Division), Tata Consultancy Services Limited, Hyderabad, 500081, India
| | - Gopalakrishnan Bulusu
- TCS Innovation Labs - Hyderabad (Life Sciences Division), Tata Consultancy Services Limited, Hyderabad, 500081, India.
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49
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Computer Simulation of Protein Materials at Multiple Length Scales: From Single Proteins to Protein Assemblies. ACTA ACUST UNITED AC 2019. [DOI: 10.1007/s42493-018-00009-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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50
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Sgouralis I, Madaan S, Djutanta F, Kha R, Hariadi RF, Pressé S. A Bayesian Nonparametric Approach to Single Molecule Förster Resonance Energy Transfer. J Phys Chem B 2019; 123:675-688. [PMID: 30571128 DOI: 10.1021/acs.jpcb.8b09752] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We develop a Bayesian nonparametric framework to analyze single molecule FRET (smFRET) data. This framework, a variation on infinite hidden Markov models, goes beyond traditional hidden Markov analysis, which already treats photon shot noise, in three critical ways: (1) it learns the number of molecular states present in a smFRET time trace (a hallmark of nonparametric approaches), (2) it accounts, simultaneously and self-consistently, for photophysical features of donor and acceptor fluorophores (blinking kinetics, spectral cross-talk, detector quantum efficiency), and (3) it treats background photons. Point 2 is essential in reducing the tendency of nonparametric approaches to overinterpret noisy single molecule time traces and so to estimate states and transition kinetics robust to photophysical artifacts. As a result, with the proposed framework, we obtain accurate estimates of single molecule properties even when the supplied traces are excessively noisy, subject to photoartifacts, and of short duration. We validate our method using synthetic data sets and demonstrate its applicability to real data sets from single molecule experiments on Holliday junctions labeled with conventional fluorescent dyes.
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Affiliation(s)
- Ioannis Sgouralis
- Center for Biological Physics, Department of Physics , Arizona State University , Tempe , Arizona 85287 , United States
| | - Shreya Madaan
- School of Computing, Informatics, and Decision Systems Engineering , Arizona State University , Tempe , Arizona 85287 , United States
| | - Franky Djutanta
- Biodesign Center for Molecular Design and Biomimetics, Biodesign Institute , Arizona State University , Tempe , Arizona 85287 , United States
| | - Rachael Kha
- School for Engineering of Matter, Transport and Energy , Arizona State University , Tempe , Arizona 85287 , United States
| | - Rizal F Hariadi
- Center for Biological Physics, Department of Physics , Arizona State University , Tempe , Arizona 85287 , United States.,Biodesign Center for Molecular Design and Biomimetics, Biodesign Institute , Arizona State University , Tempe , Arizona 85287 , United States
| | - Steve Pressé
- Center for Biological Physics, Department of Physics , Arizona State University , Tempe , Arizona 85287 , United States.,School of Molecular Sciences , Arizona State University , Tempe , Arizona 85287 , United States
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