1
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Dubanevics I, McLeish TCB. Optimising Elastic Network Models for Protein Dynamics and Allostery: Spatial and Modal Cut-offs and Backbone Stiffness. J Mol Biol 2022; 434:167696. [PMID: 35810792 DOI: 10.1016/j.jmb.2022.167696] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 06/16/2022] [Accepted: 06/19/2022] [Indexed: 01/15/2023]
Abstract
The family of coarse-grained models for protein dynamics known as Elastic Network Models (ENMs) require careful choice of parameters to represent well experimental measurements or fully-atomistic simulations. The most basic ENM that represents each protein residue by a node at the position of its C-alpha atom, all connected by springs of equal stiffness, up to a cut-off in distance. Even at this level a choice is required of the optimum cut-off distance and the upper limit of elastic normal modes taken in any sum for physical properties, such as dynamic correlation or allosteric effects on binding. Additionally, backbone-enhanced ENM (BENM) may improve the model by allocating a higher stiffness to springs that connect along the protein backbone. This work reports on the effect of varying these three parameters (distance and mode cutoffs, backbone stiffness) on the dynamical structure of three proteins, Catabolite Activator Protein (CAP), Glutathione S-transferase (GST), and the SARS-CoV-2 Main Protease (M pro ). Our main results are: (1) balancing B-factor and dispersion-relation predictions, a near-universal optimal value of 8.5 Å is advisable for ENMs; (2) inhomogeneity in elasticity brings the first mode containing spatial structure not well-resolved by the ENM typically within the first 20; (3) the BENM only affects modes in the upper third of the distribution, and, additionally to the ENM, is only able to model the dispersion curve better in this vicinity; (4) BENM does not typically affect fluctuation-allostery, which also requires careful treatment of the effector binding to the host protein to capture.
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2
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Bondos SE, Dunker AK, Uversky VN. Intrinsically disordered proteins play diverse roles in cell signaling. Cell Commun Signal 2022; 20:20. [PMID: 35177069 PMCID: PMC8851865 DOI: 10.1186/s12964-022-00821-7] [Citation(s) in RCA: 67] [Impact Index Per Article: 33.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 12/11/2021] [Indexed: 11/29/2022] Open
Abstract
Signaling pathways allow cells to detect and respond to a wide variety of chemical (e.g. Ca2+ or chemokine proteins) and physical stimuli (e.g., sheer stress, light). Together, these pathways form an extensive communication network that regulates basic cell activities and coordinates the function of multiple cells or tissues. The process of cell signaling imposes many demands on the proteins that comprise these pathways, including the abilities to form active and inactive states, and to engage in multiple protein interactions. Furthermore, successful signaling often requires amplifying the signal, regulating or tuning the response to the signal, combining information sourced from multiple pathways, all while ensuring fidelity of the process. This sensitivity, adaptability, and tunability are possible, in part, due to the inclusion of intrinsically disordered regions in many proteins involved in cell signaling. The goal of this collection is to highlight the many roles of intrinsic disorder in cell signaling. Following an overview of resources that can be used to study intrinsically disordered proteins, this review highlights the critical role of intrinsically disordered proteins for signaling in widely diverse organisms (animals, plants, bacteria, fungi), in every category of cell signaling pathway (autocrine, juxtacrine, intracrine, paracrine, and endocrine) and at each stage (ligand, receptor, transducer, effector, terminator) in the cell signaling process. Thus, a cell signaling pathway cannot be fully described without understanding how intrinsically disordered protein regions contribute to its function. The ubiquitous presence of intrinsic disorder in different stages of diverse cell signaling pathways suggest that more mechanisms by which disorder modulates intra- and inter-cell signals remain to be discovered.
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Affiliation(s)
- Sarah E. Bondos
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, TX 77843 USA
| | - A. Keith Dunker
- Center for Computational Biology and Bioinformatics, Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202 USA
| | - Vladimir N. Uversky
- Department of Molecular Medicine and USF Health Byrd Alzheimer’s Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL 33612 USA
- Institute for Biological Instrumentation of the Russian Academy of Sciences, Federal Research Center “Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences”, Pushchino, Moscow Region, Russia 142290
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3
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Sen S, Dey A, Bandhyopadhyay S, Uversky VN, Maulik U. Understanding structural malleability of the SARS-CoV-2 proteins and relation to the comorbidities. Brief Bioinform 2021; 22:6304388. [PMID: 34143202 DOI: 10.1093/bib/bbab232] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 05/13/2021] [Accepted: 05/27/2021] [Indexed: 12/11/2022] Open
Abstract
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a causative agent of the coronavirus disease (COVID-19), is a part of the $\beta $-Coronaviridae family. The virus contains five major protein classes viz., four structural proteins [nucleocapsid (N), membrane (M), envelop (E) and spike glycoprotein (S)] and replicase polyproteins (R), synthesized as two polyproteins (ORF1a and ORF1ab). Due to the severity of the pandemic, most of the SARS-CoV-2-related research are focused on finding therapeutic solutions. However, studies on the sequences and structure space throughout the evolutionary time frame of viral proteins are limited. Besides, the structural malleability of viral proteins can be directly or indirectly associated with the dysfunctionality of the host cell proteins. This dysfunctionality may lead to comorbidities during the infection and may continue at the post-infection stage. In this regard, we conduct the evolutionary sequence-structure analysis of the viral proteins to evaluate their malleability. Subsequently, intrinsic disorder propensities of these viral proteins have been studied to confirm that the short intrinsically disordered regions play an important role in enhancing the likelihood of the host proteins interacting with the viral proteins. These interactions may result in molecular dysfunctionality, finally leading to different diseases. Based on the host cell proteins, the diseases are divided in two distinct classes: (i) proteins, directly associated with the set of diseases while showing similar activities, and (ii) cytokine storm-mediated pro-inflammation (e.g. acute respiratory distress syndrome, malignancies) and neuroinflammation (e.g. neurodegenerative and neuropsychiatric diseases). Finally, the study unveils that males and postmenopausal females can be more vulnerable to SARS-CoV-2 infection due to the androgen-mediated protein transmembrane serine protease 2.
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Affiliation(s)
- Sagnik Sen
- Department of Computer Science and Engineering, Jadavpur University, Kolkata-32, West Bengal, India
| | - Ashmita Dey
- Department of Computer Science and Engineering, Jadavpur University, Kolkata-32, West Bengal, India
| | | | - Vladimir N Uversky
- Department of Molecular Medicine and Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, Tampa, Florida, United States of America.,Laboratory of New Methods in Biology, Institute for Biological Instrumentation of the Russian Academy of Sciences, Federal Research Center "Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences", Pushchino, Moscow region, 142290 Russia
| | - Ujjwal Maulik
- Department of Computer Science and Engineering, Jadavpur University, Kolkata-32, West Bengal, India
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4
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Gárate F, Dokas S, Lanfranco MF, Canavan C, Wang I, Correia JJ, Maillard RA. cAMP is an allosteric modulator of DNA-binding specificity in the cAMP receptor protein from Mycobacterium tuberculosis. J Biol Chem 2021; 296:100480. [PMID: 33640453 PMCID: PMC8026907 DOI: 10.1016/j.jbc.2021.100480] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 02/21/2021] [Accepted: 02/24/2021] [Indexed: 11/28/2022] Open
Abstract
Allosteric proteins with multiple subunits and ligand-binding sites are central in regulating biological signals. The cAMP receptor protein from Mycobacterium tuberculosis (CRPMTB) is a global regulator of transcription composed of two identical subunits, each one harboring structurally conserved cAMP- and DNA-binding sites. The mechanisms by which these four binding sites are allosterically coupled in CRPMTB remain unclear. Here, we investigate the binding mechanism between CRPMTB and cAMP, and the linkage between cAMP and DNA interactions. Using calorimetric and fluorescence-based assays, we find that cAMP binding is entropically driven and displays negative cooperativity. Fluorescence anisotropy experiments show that apo-CRPMTB forms high-order CRPMTB–DNA oligomers through interactions with nonspecific DNA sequences or preformed CRPMTB–DNA complexes. Moreover, we find that cAMP prevents and reverses the formation of CRPMTB–DNA oligomers, reduces the affinity of CRPMTB for nonspecific DNA sequences, and stabilizes a 1-to-1 CRPMTB–DNA complex, but does not increase the affinity for DNA like in the canonical CRP from Escherichia coli (CRPEcoli). DNA-binding assays as a function of cAMP concentration indicate that one cAMP molecule per homodimer dissociates high-order CRPMTB–DNA oligomers into 1-to-1 complexes. These cAMP-mediated allosteric effects are lost in the double-mutant L47P/E178K found in CRP from Mycobacterium bovis Bacille Calmette-Guérin (CRPBCG). The functional behavior, thermodynamic stability, and dimerization constant of CRPBCG are not due to additive effects of L47P and E178K, indicating long-range interactions between these two sites. Altogether, we provide a previously undescribed archetype of cAMP-mediated allosteric regulation that differs from CRPEcoli, illustrating that structural homology does not imply allosteric homology.
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Affiliation(s)
- Fernanda Gárate
- Department of Chemistry, Georgetown University, Washington, District of Columbia, USA
| | - Stephen Dokas
- Department of Chemistry, Georgetown University, Washington, District of Columbia, USA
| | - Maria Fe Lanfranco
- Department of Chemistry, Georgetown University, Washington, District of Columbia, USA
| | - Clare Canavan
- Department of Chemistry, Georgetown University, Washington, District of Columbia, USA
| | - Irina Wang
- Department of Chemistry, Georgetown University, Washington, District of Columbia, USA
| | - John J Correia
- Department of Cell and Molecular Biology, The University of Mississippi Medical Center, Jackson, Mississippi, USA
| | - Rodrigo A Maillard
- Department of Chemistry, Georgetown University, Washington, District of Columbia, USA.
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5
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Prabhakant A, Panigrahi A, Krishnan M. Allosteric Response of DNA Recognition Helices of Catabolite Activator Protein to cAMP and DNA Binding. J Chem Inf Model 2020; 60:6366-6376. [PMID: 33108170 DOI: 10.1021/acs.jcim.0c00617] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The homodimeric catabolite activator protein (CAP) regulates the transcription of several bacterial genes based on the cellular concentration of cyclic adenosine monophosphate (cAMP). The binding of cAMP to CAP triggers allosteric communication between the cAMP binding domains (CBD) and DNA binding domains (DBD) of CAP, which entails repositioning of DNA recognition helices (F-helices) in the DBD to dock favorably to the target DNA. Despite considerable progress, much remains to be understood about the mechanistic details of DNA recognition by CAP and about the map of allosteric pathways involved in CAP-mediated gene transcription. The present study uses molecular dynamics and umbrella sampling simulations to investigate the mechanism of cAMP- and DNA-induced changes in the conformation and energetics of F-helices observed during the allosteric regulation of CAP by cAMP and the subsequent binding to the DNA promoter region. Using novel collective variables, the free energy profiles associated with the orientation and dynamics of F-helices in the unliganded, cAMP-bound, and cAMP-DNA-bound states of CAP are calculated and compared. The binding-induced alterations in the resultant free energy profiles reveal important flexibility constraints imposed on DBD upon cAMP and DNA binding. A comprehensive analysis of residue-wise interaction maps reveals potential allosteric pathways between CBD and DBD that facilitate the allosteric transduction of regulatory signals in CAP. The revelation that the predicted allosteric pathways crisscross the intersubunit interface offers important clues on the microscopic origin of the intersubunit cooperativity and dimer stability of CAP.
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Affiliation(s)
- Akshay Prabhakant
- Center for Computational Natural Sciences and Bioinformatics (CCNSB), International Institute of Information Technology, Gachibowli, Hyderabad, Telangana 500032, India
| | - Abhinandan Panigrahi
- Center for Computational Natural Sciences and Bioinformatics (CCNSB), International Institute of Information Technology, Gachibowli, Hyderabad, Telangana 500032, India
| | - Marimuthu Krishnan
- Center for Computational Natural Sciences and Bioinformatics (CCNSB), International Institute of Information Technology, Gachibowli, Hyderabad, Telangana 500032, India
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6
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Wang Q, Zhang S, Han Z, Fan H, Li C. An investigation into the allosteric mechanism of GPCR A 2A adenosine receptor with trajectory-based information theory and complex network model. J Biomol Struct Dyn 2020; 39:6431-6439. [PMID: 32741308 DOI: 10.1080/07391102.2020.1799862] [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] [Indexed: 10/23/2022]
Abstract
G protein-coupled receptors (GPCRs), a large superfamily of transmembrane (TM) proteins, allosterically transduce the signal of ligand binding in the extracellular (EC) domain to couple to effector proteins in the intracellular (IC) domain, therefore forming the largest class of drug targets. The A2A adenosine receptor (A2AAR), a class-A GPCR, has been extensively studied as it offers numerous possibilities for therapeutic applications. However, the mechanism of allosteric communication between EC and IC domains is not completely clear. In this work, we utilize torsional mutual information to quantify the correlated motions of residue pairs from its molecular dynamics (MD) simulation trajectories, and further use the complex network model to obtain allosteric pipelines and hubs. The identified allosteric communication pipelines mainly transmit the signal from EC domain to the cytoplasmic ends of TM helix 5 (TM5), TM6 and TM7. The allosteric hubs, mostly located at TM5, TM6 and TM7, play an important role in mediating allosteric signal transmission to keep the receptor rigid and prevent G protein from binding to IC domain, which can explain the reason why their mutations distant from ligand-binding site do not affect the ligand binding affinity but affect the ligand efficacy. Additionally, we identify the key residues located in antagonist ZM241385 binding pocket which mediate multiple allosteric pathways and have been experimentally proven to play a critical role in affecting the ligand potency. This study is helpful for understanding the allosteric communication mechanism of A2AAR, and can provide valuable information for the structure-based drug design of GPCRs.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Qiankun Wang
- Faculty of Environmental and Life Sciences, Beijing University of Technology, Beijing, China
| | - Shan Zhang
- Faculty of Environmental and Life Sciences, Beijing University of Technology, Beijing, China
| | - Zhongjie Han
- Faculty of Environmental and Life Sciences, Beijing University of Technology, Beijing, China
| | - Huifang Fan
- Faculty of Environmental and Life Sciences, Beijing University of Technology, Beijing, China
| | - Chunhua Li
- Faculty of Environmental and Life Sciences, Beijing University of Technology, Beijing, China
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7
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Ahuja LG, Aoto PC, Kornev AP, Veglia G, Taylor SS. Dynamic allostery-based molecular workings of kinase:peptide complexes. Proc Natl Acad Sci U S A 2019; 116:15052-15061. [PMID: 31285328 PMCID: PMC6660753 DOI: 10.1073/pnas.1900163116] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
A dense interplay between structure and dynamics underlies the working of proteins, especially enzymes. Protein kinases are molecular switches that are optimized for their regulation rather than catalytic turnover rates. Using long-simulations dynamic allostery analysis, this study describes an exploration of the dynamic kinase:peptide complex. We have used protein kinase A (PKA) as a model system as a generic prototype of the protein kinase superfamily of signaling enzymes. Our results explain the role of dynamic coupling of active-site residues that must work in coherence to provide for a successful activation or inhibition response from the kinase. Amino acid networks-based community analysis allows us to ponder the conformational entropy of the kinase:nucleotide:peptide ternary complex. We use a combination of 7 peptides that include 3 types of PKA-binding partners: Substrates, products, and inhibitors. The substrate peptides provide for dynamic insights into the enzyme:substrate complex, while the product phospho-peptide allows for accessing modes of enzyme:product release. Mapping of allosteric communities onto the PKA structure allows us to locate the more unvarying and flexible dynamic regions of the kinase. These distributions, when correlated with the structural elements of the kinase core, allow for a detailed exploration of key dynamics-based signatures that could affect peptide recognition and binding at the kinase active site. These studies provide a unique dynamic allostery-based perspective to kinase:peptide complexes that have previously been explored only in a structural or thermodynamic context.
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Affiliation(s)
- Lalima G Ahuja
- Department of Pharmacology, University of California San Diego, La Jolla, CA 92093;
| | - Phillip C Aoto
- Department of Pharmacology, University of California San Diego, La Jolla, CA 92093
| | - Alexandr P Kornev
- Department of Pharmacology, University of California San Diego, La Jolla, CA 92093
| | - Gianluigi Veglia
- Department of Chemistry, University of Minnesota, Minneapolis, MN 55455
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455
| | - Susan S Taylor
- Department of Pharmacology, University of California San Diego, La Jolla, CA 92093;
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA 92093
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8
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Liem SY, Popelier PLA. The influence of water potential in simulation: a catabolite activator protein case study. J Mol Model 2019; 25:216. [PMID: 31292786 PMCID: PMC7406532 DOI: 10.1007/s00894-019-4095-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Accepted: 06/13/2019] [Indexed: 10/27/2022]
Abstract
We present a rare comparison of structures of the same protein but generated by different potentials. We used four popular water potentials (SPC, TIP3P, TIP4P, TIP5P) in conjunction with the equally popular ff99SB. However, the ff12SB protein potential was used with TI3P only. Simulations (60 ns) were run on the catabolite activator protein (CAP), which is a textbook case of allosteric interaction. Overall, all potentials generated largely similar structures but failed to reproduce a crucial structural feature determined by NMR experiment. This example shows the need to develop next-generation potentials. Graphical abstract Catabolite activator protein.
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Affiliation(s)
- Steven Y Liem
- Manchester Institute of Biotechnology (MIB), University of Manchester, 131 Princess Street, Manchester, M1 7DN, Great Britain.,School of Chemistry, University of Manchester, Oxford Road, Manchester, M13 9PL, Great Britain
| | - Paul L A Popelier
- Manchester Institute of Biotechnology (MIB), University of Manchester, 131 Princess Street, Manchester, M1 7DN, Great Britain. .,School of Chemistry, University of Manchester, Oxford Road, Manchester, M13 9PL, Great Britain.
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9
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Yu M, Ma X, Cao H, Chong B, Lai L, Liu Z. Singular value decomposition for the correlation of atomic fluctuations with arbitrary angle. Proteins 2018; 86:1075-1087. [PMID: 30019778 DOI: 10.1002/prot.25586] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Revised: 06/22/2018] [Accepted: 07/04/2018] [Indexed: 01/21/2023]
Abstract
Many proteins exhibit a critical property called allostery, which enables intra-molecular transmission of information between distal sites. Microscopically, allosteric response is closely related to correlated atomic fluctuations. Conventional correlation analysis correlates the atomic fluctuations at two sites by taking the dot product (DP) between the fluctuations, which accounts only for the parallel and antiparallel components. Here, we present a singular value decomposition (SVD) method that analyzes the correlation coefficient of fluctuation dynamics with an arbitrary angle between the correlated directions. In a model allosteric system, the second PDZ domain (PDZ2) in the human PTP1E protein, approximately one third of the strong correlations have near-perpendicular directions, which are underestimated in the conventional method. The discrimination becomes more prominent for residue pairs with larger separation. The results of the proposed SVD method are more consistent with the experimentally determined PDZ2 dynamics than those of conventional method. In addition, the SVD method improved the prediction accuracy of the allosteric sites in a dataset of 23 known allosteric monomer proteins. The proposed method may inspire extended investigation not only into allostery, but also into protein dynamics and drug design.
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Affiliation(s)
- Miao Yu
- College of Chemistry and Molecular Engineering, Peking University, Beijing, China
| | - Xiaomin Ma
- Department of Biology, Southern University of Science and Technology, Shenzhen, Guangdong Province, China
| | - Huaiqing Cao
- College of Chemistry and Molecular Engineering, Peking University, Beijing, China
| | - Bin Chong
- College of Chemistry and Molecular Engineering, Peking University, Beijing, China
| | - Luhua Lai
- College of Chemistry and Molecular Engineering, Peking University, Beijing, China.,Center for Quantitative Biology, and BNLMS, Peking University, Beijing, China.,State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Peking University, Beijing, China
| | - Zhirong Liu
- College of Chemistry and Molecular Engineering, Peking University, Beijing, China.,Center for Quantitative Biology, and BNLMS, Peking University, Beijing, China.,State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Peking University, Beijing, China
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10
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Kay M, Dehghanian F. Exploring the crizotinib resistance mechanism of NSCLC with the L1196M mutation using molecular dynamics simulation. J Mol Model 2017; 23:323. [PMID: 29067524 DOI: 10.1007/s00894-017-3495-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2017] [Accepted: 10/09/2017] [Indexed: 12/20/2022]
Abstract
Crizotinib is an anticancer tyrosine kinase inhibitor that is approved for use as a first-line treatment for some non-small-cell lung cancers. L1196M is the most frequently observed mutation in NSCLC patients. This mutation, known as the gatekeeper mutation in the ALK kinase domain, confers resistance to crizotinib by sterically blocking the binding of the drug. However, the molecular mechanism of crizotinib resistance caused by the L1196M mutation is still unclear. Molecular dynamics simulation was therefore utilized in this study to investigate the mechanism by which the L1196M mutation may affect crizotinib resistance. Our results suggest that larger fluctuations in some important regions of the mutant complex compared to the wild-type complex may contribute to the resistance of the mutant complex to crizotinib. Also, mutation-induced alterations to the secondary structure of the complex as well as unstable hydrogen-bonding patterns in the A-loop and P-loop regions decrease the total binding energy of the complex. This study therefore provides a molecular explanation for the resistance to crizotinib caused by the L1196M mutation, which could aid the design of more efficient and selective drugs.
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Affiliation(s)
- Maryam Kay
- Department of Molecular Genetics, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Islamic Republic of Iran.
| | - Fariba Dehghanian
- Division of Genetics, Department of Biology, Faculty of Science, University of Isfahan, Isfahan, Islamic Republic of Iran
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11
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F1174V mutation alters the ALK active conformation in response to Crizotinib in NSCLC: Insight from molecular simulations. J Mol Graph Model 2017. [DOI: 10.1016/j.jmgm.2017.06.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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12
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Na I, DeForte S, Stojanovski BM, Ferreira GC, Uversky VN. Molecular dynamics analysis of the structural and dynamic properties of the functionally enhanced hepta-variant of mouse 5-aminolevulinate synthase. J Biomol Struct Dyn 2017; 36:152-165. [PMID: 27928941 DOI: 10.1080/07391102.2016.1269688] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Heme biosynthesis, a complex, multistage, and tightly controlled process, starts with 5-aminolevulinate (ALA) production, which, in metazoa and certain bacteria, is a reaction catalyzed by 5-aminolevulinate synthase (ALAS), a pyridoxal 5'-phosphate (PLP)-dependent enzyme. Functional aberrations in ALAS are associated with several human diseases. ALAS can adopt open and closed conformations, with segmental rearrangements of a C-terminal, 16-amino acid loop and an α-helix regulating accessibility to the ALAS active site. Of the murine erythroid ALAS (mALAS2) forms previously engineered to assess the role of the flexible C-terminal loop versus mALAS2 function one stood out due to its impressive gain in catalytic power. To elucidate how the simultaneously introduced seven mutations of this activity-enhanced variant affected structural and dynamic properties of mALAS2, we conducted extensive molecular dynamics simulation analysis of the dimeric forms of wild-type mALAS2, hepta-variant and Rhodobacter capsulatus ALAS (aka R. capsulatus HemA). This analysis revealed that the seven simultaneous mutations in the C-terminal loop, which extends over the active site of the enzyme, caused the bacterial and murine proteins to adopt different conformations. Specifically, a new β-strand in the mutated 'loop' led to interaction with two preexisting β-strands and formation of an anti-parallel three-stranded β-sheet, which likely endowed the murine hepta-variant a more 'stable' open conformation than that of wild-type mALAS2, consistent with a kinetic mechanism involving a faster closed-to-open conformation transition and product release for the mutated than wild-type enzyme. Further, the dynamic behavior of the mALAS2 protomers was strikingly different in the two dimeric forms.
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Affiliation(s)
- Insung Na
- a Department of Molecular Medicine , Morsani College of Medicine, University of South Florida , Tampa , FL 33612 , USA
| | - Shelly DeForte
- a Department of Molecular Medicine , Morsani College of Medicine, University of South Florida , Tampa , FL 33612 , USA
| | - Bosko M Stojanovski
- a Department of Molecular Medicine , Morsani College of Medicine, University of South Florida , Tampa , FL 33612 , USA
| | - Gloria C Ferreira
- a Department of Molecular Medicine , Morsani College of Medicine, University of South Florida , Tampa , FL 33612 , USA.,b Department of Chemistry , College of Arts and Sciences, University of South Florida , Tampa , FL 33612 , USA
| | - Vladimir N Uversky
- a Department of Molecular Medicine , Morsani College of Medicine, University of South Florida , Tampa , FL 33612 , USA.,c USF Health Byrd Alzheimer's Research Institute, Morsani College of Medicine , University of South Florida , Tampa , Florida 33612 , USA.,d Laboratory of Structural Dynamics, Stability and Folding of Proteins , Institute of Cytology, Russian Academy of Sciences , St. Petersburg , Russia
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13
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Sattarinezhad E, Bordbar AK, Fani N. Virtual screening of Piperine analogs as Survivin inhibitors and their molecular interaction analysis by using consensus docking, MD simulation, MMPB/GBSA and alanine scanning techniques. J Biomol Struct Dyn 2016; 35:1824-1832. [DOI: 10.1080/07391102.2016.1196152] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
| | | | - Najmeh Fani
- Department of Chemistry, University of Isfahan, Isfahan 81746-73441, Iran
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14
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Xu D, Jalal SI, Sledge GW, Meroueh SO. Small-molecule binding sites to explore protein-protein interactions in the cancer proteome. MOLECULAR BIOSYSTEMS 2016; 12:3067-87. [PMID: 27452673 DOI: 10.1039/c6mb00231e] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The Cancer Genome Atlas (TCGA) offers an unprecedented opportunity to identify small-molecule binding sites on proteins with overexpressed mRNA levels that correlate with poor survival. Here, we analyze RNA-seq and clinical data for 10 tumor types to identify genes that are both overexpressed and correlate with patient survival. Protein products of these genes were scanned for binding sites that possess shape and physicochemical properties that can accommodate small-molecule probes or therapeutic agents (druggable). These binding sites were classified as enzyme active sites (ENZ), protein-protein interaction sites (PPI), or other sites whose function is unknown (OTH). Interestingly, the overwhelming majority of binding sites were classified as OTH. We find that ENZ, PPI, and OTH binding sites often occurred on the same structure suggesting that many of these OTH cavities can be used for allosteric modulation of enzyme activity or protein-protein interactions with small molecules. We discovered several ENZ (PYCR1, QPRT, and HSPA6) and PPI (CASC5, ZBTB32, and CSAD) binding sites on proteins that have been seldom explored in cancer. We also found proteins that have been extensively studied in cancer that have not been previously explored with small molecules that harbor ENZ (PKMYT1, STEAP3, and NNMT) and PPI (HNF4A, MEF2B, and CBX2) binding sites. All binding sites were classified by the signaling pathways to which the protein that harbors them belongs using KEGG. In addition, binding sites were mapped onto structural protein-protein interaction networks to identify promising sites for drug discovery. Finally, we identify pockets that harbor missense mutations previously identified from analysis of TCGA data. The occurrence of mutations in these binding sites provides new opportunities to develop small-molecule probes to explore their function in cancer.
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Affiliation(s)
- David Xu
- Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, Indiana 46202, USA
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15
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Abstract
Nuclear magnetic resonance (NMR) spectroscopy provides a unique toolbox of experimental probes for studying dynamic processes on a wide range of timescales, ranging from picoseconds to milliseconds and beyond. Along with NMR hardware developments, recent methodological advancements have enabled the characterization of allosteric proteins at unprecedented detail, revealing intriguing aspects of allosteric mechanisms and increasing the proportion of the conformational ensemble that can be observed by experiment. Here, we present an overview of NMR spectroscopic methods for characterizing equilibrium fluctuations in free and bound states of allosteric proteins that have been most influential in the field. By combining NMR experimental approaches with molecular simulations, atomistic-level descriptions of the mechanisms by which allosteric phenomena take place are now within reach.
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Affiliation(s)
- Sarina Grutsch
- Institute of Organic Chemistry, Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innsbruck, Austria
| | - Sven Brüschweiler
- Department of Computational & Structural Biology, Max F. Perutz Laboratories, Campus Vienna Biocenter 5, Vienna, Austria
| | - Martin Tollinger
- Institute of Organic Chemistry, Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innsbruck, Austria
- * E-mail:
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16
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Haghshenas H, Kay M, Dehghanian F, Tavakol H. Molecular dynamics study of biodegradation of azo dyes via their interactions with AzrC azoreductase. J Biomol Struct Dyn 2015; 34:453-62. [PMID: 26325128 DOI: 10.1080/07391102.2015.1039585] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Azo dyes are one of the most important class of dyes, which have been widely used in industries. Because of the environmental pollution of azo dyes, many studies have been performed to study their biodegradation using bacterial systems. In present work, the AzrC of mesophilic gram-positive Bacillus sp. B29 has been considered to study its interaction with five common azo dyes (orange G, acid red 88, Sudan I, orange I, and methyl red). The molecular dynamics simulations have been employed to study the interaction between AzrC and azo dyes. The trajectory was confirmed using root mean square deviation and the root mean square fluctuation analyses. Then, the hydrogen bond and alanine scanning analyses were performed to reveal active site residues. Phe105 (A), Phe125 (B), Phe172 (B), and Pro132 (B) have been found as the most important hydrophobic residues whereas Asn104 (A), Tyr127 (B), and Asn187 (A) have key role in making hydrogen bond. The results of molecular mechanics Poisson-Boltzmann surface area and molecular mechanics generalized Born surface area calculations proved that the hydrophobic azo dyes like Acid red 88 binds more tightly to the AzrC protein. The calculated data suggested MR A 121 (B) I as a potential candidate for improving the AzrC-MR interactions.
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Affiliation(s)
- Hamed Haghshenas
- a Division of Biochemistry, Faculty of Sciences, Department of Biology , Shahrekord University , Shahrekord , Iran
| | - Maryam Kay
- b Faculty of Biological Sciences, Department of Molecular Genetics , Tarbiat Modares University , Tehran , Iran
| | - Fariba Dehghanian
- c Division of Genetics, Faculty of Sciences, Department of Biology , University of Isfahan , Isfahan , Iran
| | - Hossein Tavakol
- d Department of Chemistry , Isfahan University of Technology , Isfahan 84156-83111 , Iran
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17
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Louet M, Seifert C, Hensen U, Gräter F. Dynamic Allostery of the Catabolite Activator Protein Revealed by Interatomic Forces. PLoS Comput Biol 2015; 11:e1004358. [PMID: 26244893 PMCID: PMC4526232 DOI: 10.1371/journal.pcbi.1004358] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Accepted: 05/28/2015] [Indexed: 11/23/2022] Open
Abstract
The Catabolite Activator Protein (CAP) is a showcase example for entropic allostery. For full activation and DNA binding, the homodimeric protein requires the binding of two cyclic AMP (cAMP) molecules in an anti-cooperative manner, the source of which appears to be largely of entropic nature according to previous experimental studies. We here study at atomic detail the allosteric regulation of CAP with Molecular dynamics (MD) simulations. We recover the experimentally observed entropic penalty for the second cAMP binding event with our recently developed force covariance entropy estimator and reveal allosteric communication pathways with Force Distribution Analyses (FDA). Our observations show that CAP binding results in characteristic changes in the interaction pathways connecting the two cAMP allosteric binding sites with each other, as well as with the DNA binding domains. We identified crucial relays in the mostly symmetric allosteric activation network, and suggest point mutants to test this mechanism. Our study suggests inter-residue forces, as opposed to coordinates, as a highly sensitive measure for structural adaptations that, even though minute, can very effectively propagate allosteric signals. The Catabolite Activator Protein (CAP) is a well-studied example for how cellular catabolite levels are integrated into the gene regulation. Its affinity for a specific stretch of DNA can be switched on by the binding of two nucleotide molecules termed cAMP to its two protomers. Even though the nucleotides occupy structurally identical binding pockets, the second cAMP binding occurs at an affinity orders of magnitude lower than the first cAMP binding. The question arises how, in the absence of structural changes, the first binding can affect the second. An answer from experiments has been that the communication is largely of entropic nature, i.e. the second cAMP binding would lead to a pronounced reduction in atomic fluctuations of the protein without affecting the atomic mean positions. We here revisited this question by performing Molecular Dynamics simulations. By measuring correlations of forces, a newly derived method outperforming the more common coordinate-based approach, we could recover the previously determined entropic penalty. In addition, however, we observed unobtrusive structural changes of side-chain interactions leading to the occlusion of the second binding pocket that add a critical ‘enthalpic’ component hitherto overlooked. Our study provides a mechanistic view onto the intriguing anti-cooperativity of CAP.
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Affiliation(s)
- Maxime Louet
- Heidelberg Institutes for Theoretical Studies gGmbH, Heidelberg, Germany
| | - Christian Seifert
- Heidelberg Institutes for Theoretical Studies gGmbH, Heidelberg, Germany
| | - Ulf Hensen
- Eidgenössische Technische Hochschule Zürich, Department of Biosystem Science and Engineering, Basel, Switzerland
| | - Frauke Gräter
- Heidelberg Institutes for Theoretical Studies gGmbH, Heidelberg, Germany; CAS-MPG Partner Institute and Key Laboratory for Computational Biology, Shanghai, China
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18
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Liu D, Zhou D, Wang B, Knabe WE, Meroueh SO. A new class of orthosteric uPAR·uPA small-molecule antagonists are allosteric inhibitors of the uPAR·vitronectin interaction. ACS Chem Biol 2015; 10:1521-34. [PMID: 25671694 DOI: 10.1021/cb500832q] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The urokinase receptor (uPAR) is a GPI-anchored cell surface receptor that is at the center of an intricate network of protein-protein interactions. Its immediate binding partners are the serine proteinase urokinase (uPA), and vitronectin (VTN), a component of the extracellular matrix. uPA and VTN bind at distinct sites on uPAR to promote extracellular matrix degradation and integrin signaling, respectively. Here, we report the discovery of a new class of pyrrolone small-molecule inhibitors of the tight ∼1 nM uPAR·uPA protein-protein interaction. These compounds were designed to bind to the uPA pocket on uPAR. The highest affinity compound, namely 7, displaced a fluorescently labeled α-helical peptide (AE147-FAM) with an inhibition constant Ki of 0.7 μM and inhibited the tight uPAR·uPAATF interaction with an IC50 of 18 μM. Biophysical studies with surface plasmon resonance showed that VTN binding is highly dependent on uPA. This cooperative binding was confirmed as 7, which binds at the uPAR·uPA interface, also inhibited the distal VTN·uPAR interaction. In cell culture, 7 blocked the uPAR·uPA interaction in uPAR-expressing human embryonic kidney (HEK-293) cells and impaired cell adhesion to VTN, a process that is mediated by integrins. As a result, 7 inhibited integrin signaling in MDA-MB-231 cancer cells as evidenced by a decrease in focal adhesion kinase (FAK) phosphorylation and Rac1 GTPase activation. Consistent with these results, 7 blocked breast MDA-MB-231 cancer cell invasion with IC50 values similar to those observed in ELISA and surface plasmon resonance competition studies. Explicit-solvent molecular dynamics simulations show that the cooperativity between uPA and VTN is attributed to stabilization of uPAR motion by uPA. In addition, free energy calculations revealed that uPA stabilizes the VTNSMB·uPAR interaction through more favorable electrostatics and entropy. Disruption of the uPAR·VTNSMB interaction by 7 is consistent with the cooperative binding to uPAR by uPA and VTN. Interestingly, the VTNSMB·uPAR interaction was less favorable in the VTNSMB·uPAR·7 complex suggesting potential cooperativity between 7 and VTN. Compound 7 provides an excellent starting point for the development of more potent derivatives to explore uPAR biology.
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Affiliation(s)
| | | | - Bo Wang
- Department
of Chemistry and Chemical Biology, Indiana University Purdue University Indianapolis (IUPUI), Indianapolis, Indiana 46202, United States
| | | | - Samy O. Meroueh
- Department
of Chemistry and Chemical Biology, Indiana University Purdue University Indianapolis (IUPUI), Indianapolis, Indiana 46202, United States
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19
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Ribeiro AAST, Ortiz V. Energy Propagation and Network Energetic Coupling in Proteins. J Phys Chem B 2015; 119:1835-46. [DOI: 10.1021/jp509906m] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Andre A. S. T. Ribeiro
- Department of Chemical Engineering, Columbia University, New York, New York 10027, United States
| | - Vanessa Ortiz
- Department of Chemical Engineering, Columbia University, New York, New York 10027, United States
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20
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Cilia E, Pancsa R, Tompa P, Lenaerts T, Vranken WF. From protein sequence to dynamics and disorder with DynaMine. Nat Commun 2014; 4:2741. [PMID: 24225580 DOI: 10.1038/ncomms3741] [Citation(s) in RCA: 109] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Accepted: 10/10/2013] [Indexed: 11/09/2022] Open
Abstract
Protein function and dynamics are closely related; however, accurate dynamics information is difficult to obtain. Here based on a carefully assembled data set derived from experimental data for proteins in solution, we quantify backbone dynamics properties on the amino-acid level and develop DynaMine--a fast, high-quality predictor of protein backbone dynamics. DynaMine uses only protein sequence information as input and shows great potential in distinguishing regions of different structural organization, such as folded domains, disordered linkers, molten globules and pre-structured binding motifs of different sizes. It also identifies disordered regions within proteins with an accuracy comparable to the most sophisticated existing predictors, without depending on prior disorder knowledge or three-dimensional structural information. DynaMine provides molecular biologists with an important new method that grasps the dynamical characteristics of any protein of interest, as we show here for human p53 and E1A from human adenovirus 5.
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Affiliation(s)
- Elisa Cilia
- 1] MLG, Département d'Informatique, Université Libre de Bruxelles, Boulevard du Triomphe, CP 212, 1050 Brussels, Belgium [2] Interuniversity Institute of Bioinformatics in Brussels, ULB-VUB, La Plaine Campus, Triomflaan, BC building, 6th floor, CP 263, 1050 Brussels, Belgium
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21
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Fancy R, Wang L, Napier T, Lin J, Jing G, Lucius AL, McDonald JM, Zhou T, Song Y. Characterization of calmodulin-Fas death domain interaction: an integrated experimental and computational study. Biochemistry 2014; 53:2680-8. [PMID: 24702583 PMCID: PMC4007977 DOI: 10.1021/bi500228h] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Revised: 03/27/2014] [Indexed: 02/05/2023]
Abstract
The Fas death receptor-activated death-inducing signaling complex (DISC) regulates apoptosis in many normal and cancer cells. Qualitative biochemical experiments demonstrate that calmodulin (CaM) binds to the death domain of Fas. The interaction between CaM and Fas regulates Fas-mediated DISC formation. A quantitative understanding of the interaction between CaM and Fas is important for the optimal design of antagonists for CaM or Fas to regulate the CaM-Fas interaction, thus modulating Fas-mediated DISC formation and apoptosis. The V254N mutation of the Fas death domain (Fas DD) is analogous to an identified mutant allele of Fas in lpr-cg mice that have a deficiency in Fas-mediated apoptosis. In this study, the interactions of CaM with the Fas DD wild type (Fas DD WT) and with the Fas DD V254N mutant were characterized using isothermal titration calorimetry (ITC), circular dichroism spectroscopy (CD), and molecular dynamics (MD) simulations. ITC results reveal an endothermic binding characteristic and an entropy-driven interaction of CaM with Fas DD WT or with Fas DD V254N. The Fas DD V254N mutation decreased the association constant (Ka) for CaM-Fas DD binding from (1.79 ± 0.20) × 10(6) to (0.88 ± 0.14) × 10(6) M(-1) and slightly increased a standard state Gibbs free energy (ΔG°) for CaM-Fas DD binding from -8.87 ± 0.07 to -8.43 ± 0.10 kcal/mol. CD secondary structure analysis and MD simulation results did not show significant secondary structural changes of the Fas DD caused by the V254N mutation. The conformational and dynamical motion analyses, the analyses of hydrogen bond formation within the CaM binding region, the contact numbers of each residue, and the electrostatic potential for the CaM binding region based on MD simulations demonstrated changes caused by the Fas DD V254N mutation. These changes caused by the Fas DD V254N mutation could affect the van der Waals interactions and electrostatic interactions between CaM and Fas DD, thereby affecting CaM-Fas DD interactions. Results from this study characterize CaM-Fas DD interactions in a quantitative way, providing structural and thermodynamic evidence of the role of the Fas DD V254N mutation in the CaM-Fas DD interaction. Furthermore, the results could help to identify novel strategies for regulating CaM-Fas DD interactions and Fas DD conformation and thus to modulate Fas-mediated DISC formation and thus Fas-mediated apoptosis.
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Affiliation(s)
- Romone
M. Fancy
- Departments
of Biomedical Engineering, Chemistry, Pathology, and Medicine and Birmingham Veterans Affairs Medical
Center, University of Alabama at Birmingham, Birmingham, Alabama 35294, United States
| | - Lingyun Wang
- Departments
of Biomedical Engineering, Chemistry, Pathology, and Medicine and Birmingham Veterans Affairs Medical
Center, University of Alabama at Birmingham, Birmingham, Alabama 35294, United States
| | - Tiara Napier
- Departments
of Biomedical Engineering, Chemistry, Pathology, and Medicine and Birmingham Veterans Affairs Medical
Center, University of Alabama at Birmingham, Birmingham, Alabama 35294, United States
| | - Jiabei Lin
- Departments
of Biomedical Engineering, Chemistry, Pathology, and Medicine and Birmingham Veterans Affairs Medical
Center, University of Alabama at Birmingham, Birmingham, Alabama 35294, United States
| | - Gu Jing
- Departments
of Biomedical Engineering, Chemistry, Pathology, and Medicine and Birmingham Veterans Affairs Medical
Center, University of Alabama at Birmingham, Birmingham, Alabama 35294, United States
| | - Aaron L. Lucius
- Departments
of Biomedical Engineering, Chemistry, Pathology, and Medicine and Birmingham Veterans Affairs Medical
Center, University of Alabama at Birmingham, Birmingham, Alabama 35294, United States
| | - Jay M. McDonald
- Departments
of Biomedical Engineering, Chemistry, Pathology, and Medicine and Birmingham Veterans Affairs Medical
Center, University of Alabama at Birmingham, Birmingham, Alabama 35294, United States
| | - Tong Zhou
- Departments
of Biomedical Engineering, Chemistry, Pathology, and Medicine and Birmingham Veterans Affairs Medical
Center, University of Alabama at Birmingham, Birmingham, Alabama 35294, United States
| | - Yuhua Song
- Departments
of Biomedical Engineering, Chemistry, Pathology, and Medicine and Birmingham Veterans Affairs Medical
Center, University of Alabama at Birmingham, Birmingham, Alabama 35294, United States
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22
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Xue W, Yang Y, Wang X, Liu H, Yao X. Computational study on the inhibitor binding mode and allosteric regulation mechanism in hepatitis C virus NS3/4A protein. PLoS One 2014; 9:e87077. [PMID: 24586263 PMCID: PMC3934852 DOI: 10.1371/journal.pone.0087077] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2013] [Accepted: 12/16/2013] [Indexed: 01/17/2023] Open
Abstract
HCV NS3/4A protein is an attractive therapeutic target responsible for harboring serine protease and RNA helicase activities during the viral replication. Small molecules binding at the interface between the protease and helicase domains can stabilize the closed conformation of the protein and thus block the catalytic function of HCV NS3/4A protein via an allosteric regulation mechanism. But the detailed mechanism remains elusive. Here, we aimed to provide some insight into the inhibitor binding mode and allosteric regulation mechanism of HCV NS3/4A protein by using computational methods. Four simulation systems were investigated. They include: apo state of HCV NS3/4A protein, HCV NS3/4A protein in complex with an allosteric inhibitor and the truncated form of the above two systems. The molecular dynamics simulation results indicate HCV NS3/4A protein in complex with the allosteric inhibitor 4VA adopts a closed conformation (inactive state), while the truncated apo protein adopts an open conformation (active state). Further residue interaction network analysis suggests the communication of the domain-domain interface play an important role in the transition from closed to open conformation of HCV NS3/4A protein. However, the inhibitor stabilizes the closed conformation through interaction with several key residues from both the protease and helicase domains, including His57, Asp79, Asp81, Asp168, Met485, Cys525 and Asp527, which blocks the information communication between the functional domains interface. Finally, a dynamic model about the allosteric regulation and conformational changes of HCV NS3/4A protein was proposed and could provide fundamental insights into the allosteric mechanism of HCV NS3/4A protein function regulation and design of new potent inhibitors.
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Affiliation(s)
- Weiwei Xue
- State Key Laboratory of Applied Organic Chemistry, Department of Chemistry, Lanzhou University, Lanzhou, China
| | - Ying Yang
- Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Xiaoting Wang
- State Key Laboratory of Applied Organic Chemistry, Department of Chemistry, Lanzhou University, Lanzhou, China
| | - Huanxiang Liu
- School of Pharmacy, Lanzhou University, Lanzhou, China
| | - Xiaojun Yao
- State Key Laboratory of Applied Organic Chemistry, Department of Chemistry, Lanzhou University, Lanzhou, China
- State Key Laboratory of Quality Research in Chinese Medicine, Macau Institute for Applied Research in Medicine and Health, Macau University of Science and Technology, Taipa, Macau, China
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23
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Wang L, Cui Q, Hou Y, Bai F, Sun J, Cao X, Liu P, Jiang M, Bai G. An integrated strategy of ultra-high-performance liquid chromatography/quadrupole-time-of-flight mass spectrometry and virtual screening for the identification of α-glucosidase inhibitors in acarviostatin-containing complex. J Chromatogr A 2013; 1319:88-96. [DOI: 10.1016/j.chroma.2013.10.035] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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24
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Mani T, Liu D, Zhou D, Li L, Knabe WE, Wang F, Oh K, Meroueh SO. Probing binding and cellular activity of pyrrolidinone and piperidinone small molecules targeting the urokinase receptor. ChemMedChem 2013; 8:1963-77. [PMID: 24115356 DOI: 10.1002/cmdc.201300340] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Indexed: 01/16/2023]
Abstract
The urokinase receptor (uPAR) is a cell-surface protein that is part of an intricate web of transient and tight protein interactions that promote cancer cell invasion and metastasis. Here, we evaluate the binding and biological activity of a new class of pyrrolidinone and piperidinone compounds, along with derivatives of previously-identified pyrazole and propylamine compounds. Competition assays revealed that the compounds displace a fluorescently labeled peptide (AE147-FAM) with inhibition constant (Ki ) values ranging from 6 to 63 μM. Structure-based computational pharmacophore analysis followed by extensive explicit-solvent molecular dynamics (MD) simulations and free energy calculations suggested the pyrazole-based and piperidinone-based compounds adopt different binding modes, despite their similar two-dimensional structures. In cells, pyrazole-based compounds showed significant inhibition of breast adenocarcinoma (MDA-MB-231) and pancreatic ductal adenocarcinoma (PDAC) cell proliferation, but piperidinone-containing compounds exhibited no cytotoxicity even at concentrations of 100 μM. One pyrazole-based compound impaired MDA-MB-231 invasion, adhesion, and migration in a concentration-dependent manner, while the piperidinone inhibited only invasion. The pyrazole derivative inhibited matrix metalloprotease-9 (gelatinase) activity in a concentration-dependent manner, while the piperidinone showed no effect suggesting different mechanisms for inhibition of cell invasion. Signaling studies further highlighted these differences, showing that pyrazole compounds completely inhibited ERK phosphorylation and impaired HIF1α and NF-κB signaling, while pyrrolidinones and piperidinones had no effect. Annexin V staining suggested that the effect of the pyrazole-based compound on proliferation was due to cell killing through an apoptotic mechanism. The compounds identified represent valuable leads in the design of further derivatives with higher affinities and potential probes to unravel the protein-protein interactions of uPAR.
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Affiliation(s)
- Timmy Mani
- Department of Biochemistry & Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202 (USA)
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25
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Aykaç Fas B, Tutar Y, Haliloğlu T. Dynamic fluctuations provide the basis of a conformational switch mechanism in apo cyclic AMP receptor protein. PLoS Comput Biol 2013; 9:e1003141. [PMID: 23874183 PMCID: PMC3715548 DOI: 10.1371/journal.pcbi.1003141] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2012] [Accepted: 05/31/2013] [Indexed: 01/09/2023] Open
Abstract
Escherichia coli cyclic AMP Receptor Protein (CRP) undergoes conformational changes with cAMP binding and allosterically promotes CRP to bind specifically to the DNA. In that, the structural and dynamic properties of apo CRP prior to cAMP binding are of interest for the comprehension of the activation mechanism. Here, the dynamics of apo CRP monomer/dimer and holo CRP dimer were studied by Molecular Dynamics (MD) simulations and Gaussian Network Model (GNM). The interplay of the inter-domain hinge with the cAMP and DNA binding domains are pre-disposed in the apo state as a conformational switch in the CRP's allosteric communication mechanism. The hinge at L134-D138 displaying intra- and inter-subunit coupled fluctuations with the cAMP and DNA binding domains leads to the emergence of stronger coupled fluctuations between the two domains and describes an on state. The flexible regions at K52-E58, P154/D155 and I175 maintain the dynamic coupling of the two domains. With a shift in the inter-domain hinge position towards the N terminus, nevertheless, the latter correlations between the domains loosen and become disordered; L134-D138 dynamically interacts only with the cAMP and DNA binding domains of its own subunit, and an off state is assumed. We present a mechanistic view on how the structural dynamic units are hierarchically built for the allosteric functional mechanism; from apo CRP monomer to apo-to-holo CRP dimers.
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Affiliation(s)
- Burcu Aykaç Fas
- Department of Chemical Engineering and Polymer Research Center, Boğaziçi University, Bebek, İstanbul, Turkey
| | - Yusuf Tutar
- Department of Chemistry, Department of Biochemistry and CUTFAM Research Center, Faculty of Medicine, Cumhuriyet University, Sivas, Turkey
| | - Türkan Haliloğlu
- Department of Chemical Engineering and Polymer Research Center, Boğaziçi University, Bebek, İstanbul, Turkey
- * E-mail:
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26
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Musiani F, Ippoliti E, Micheletti C, Carloni P, Ciurli S. Conformational fluctuations of UreG, an intrinsically disordered enzyme. Biochemistry 2013; 52:2949-54. [PMID: 23560717 DOI: 10.1021/bi4001744] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
UreG proteins are small GTP binding (G) proteins that catalyze the hydrolysis of GTP necessary for the maturation of urease, a virulence factor in bacterial pathogenesis. UreG proteins are the first documented cases of intrinsically disordered enzymes. The comprehension of the dynamics of folding-unfolding events occurring in this protein could shed light on the enzymatic mechanism of UreG. Here, we used the recently developed replica exchange with solute tempering (REST2) computational methodology to explore the conformational space of UreG from Helicobacter pylori (HpUreG) and to identify its structural fluctuations. The same simulation and analysis protocol has been applied to HypB from Methanocaldococcus jannaschii (MjHypB), which is closely related to UreG in both sequence and function, even though it is not intrinsically disordered. A comparison of the two systems reveals that both HpUreG and MjHypB feature a substantial rigidity of the protein regions involved in catalysis, justifying its residual catalytic activity. On the other hand, HpUreG tends to unfold more than MjHypB in portions involved in protein-protein interactions with metallochaperones necessary for the formation of multiprotein complexes known to be involved in urease activation.
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Affiliation(s)
- Francesco Musiani
- Laboratory of Bioinorganic Chemistry, Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy
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27
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Triple mutated antibody scFv2F3 with high GPx activity: insights from MD, docking, MDFE, and MM-PBSA simulation. Amino Acids 2012; 44:1009-19. [PMID: 23224825 DOI: 10.1007/s00726-012-1435-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2012] [Accepted: 11/27/2012] [Indexed: 12/11/2022]
Abstract
By combining computational design and site-directed mutagenesis, we have engineered a new catalytic ability into the antibody scFv2F3 by installing a catalytic triad (Trp(29)-Sec(52)-Gln(72)). The resulting abzyme, Se-scFv2F3, exhibits a high glutathione peroxidase (GPx) activity, approaching the native enzyme activity. Activity assays and a systematic computational study were performed to investigate the effect of successive replacement of residues at positions 29, 52, and 72. The results revealed that an active site Ser(52)/Sec substitution is critical for the GPx activity of Se-scFv2F3. In addition, Phe(29)/Trp-Val(72)/Gln mutations enhance the reaction rate via functional cooperation with Sec(52). Molecular dynamics simulations showed that the designed catalytic triad is very stable and the conformational flexibility caused by Tyr(101) occurs mainly in the loop of complementarity determining region 3. The docking studies illustrated the importance of this loop that favors the conformational shift of Tyr(54), Asn(55), and Gly(56) to stabilize substrate binding. Molecular dynamics free energy and molecular mechanics-Poisson Boltzmann surface area calculations estimated the pK(a) shifts of the catalytic residue and the binding free energies of docked complexes, suggesting that dipole-dipole interactions among Trp(29)-Sec(52)-Gln(72) lead to the change of free energy that promotes the residual catalytic activity and the substrate-binding capacity. The calculated results agree well with the experimental data, which should help to clarify why Se-scFv2F3 exhibits high catalytic efficiency.
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28
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Papaleo E, Renzetti G. Coupled motions during dynamics reveal a tunnel toward the active site regulated by the N-terminal α-helix in an acylaminoacyl peptidase. J Mol Graph Model 2012; 38:226-34. [PMID: 23085164 DOI: 10.1016/j.jmgm.2012.06.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2012] [Revised: 06/15/2012] [Accepted: 06/26/2012] [Indexed: 10/28/2022]
Abstract
Acylaminoacyl peptidase (AAP) subfamily belongs to the prolyl oligopeptidase (POP) family of serine-proteases. There is a great interest in the definition of molecular mechanisms related to the activity and substrate recognition of these complex multi-domain enzymes. The active site relies at the interface between the C-terminal catalytic domain and the β-propeller domain, whose N-terminal region acts as a bridge to the hydrolase domain. In AAP, the N-terminal extension is characterized by a structurally conserved α1-helix, which is known to affect thermal stability and thermal dependence of the catalytic activity. In the present contribution, results from hundreds nanosecond all-atom molecular dynamics simulations, along with analyses of the networks of cross-correlated motions of a member of the AAP subfamily are discussed. The MD investigation identifies a tunnel that from the surrounding of the N-terminal α1-helix bring to the catalytic site. This cavity seems to be regulated by conformational changes of the α1-helix itself during the dynamics. The evidence here provided can be a useful guide for a better understanding of the mechanistic aspects related to AAP activity, but also for drug design purposes.
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Affiliation(s)
- Elena Papaleo
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, P.zza della Scienza 2, 20126 Milan, Italy.
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29
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Long D, Brüschweiler R. Structural and Entropic Allosteric Signal Transduction Strength via Correlated Motions. J Phys Chem Lett 2012; 3:1722-1726. [PMID: 26285736 DOI: 10.1021/jz300488e] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Allosteric signal transduction in biomacromolecules can play an essential role in their function. Internal motional correlations in proteins provide a possible communication mechanism, but the quantitative relationship between statistical correlations and allostery is unknown. Quantitative relationships between internal motional correlations and the efficiency of propagation of allosteric structural and entropic effects are introduced and validated against conformational ensembles obtained from molecular dynamics simulations. This framework can explain a range of phenomena, such as the occurrence of an allosteric entropy change in the absence of any noticeable structural change.
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Affiliation(s)
- Dong Long
- Department of Chemistry and Biochemistry and National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32306, United States
| | - Rafael Brüschweiler
- Department of Chemistry and Biochemistry and National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32306, United States
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30
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Fedotoff O, Mikheeva LM, Chait A, Uversky VN, Zaslavsky BY. Influence of Serum Proteins on Conformation of Prostate-Specific Antigen. J Biomol Struct Dyn 2012; 29:1051-64. [DOI: 10.1080/073911012010525030] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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31
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Korkmaz EN, Nussinov R, Haliloğlu T. Conformational control of the binding of the transactivation domain of the MLL protein and c-Myb to the KIX domain of CREB. PLoS Comput Biol 2012; 8:e1002420. [PMID: 22438798 PMCID: PMC3305381 DOI: 10.1371/journal.pcbi.1002420] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2011] [Accepted: 01/24/2012] [Indexed: 11/30/2022] Open
Abstract
The KIX domain of CBP is a transcriptional coactivator. Concomitant binding to the activation domain of proto-oncogene protein c-Myb and the transactivation domain of the trithorax group protein mixed lineage leukemia (MLL) transcription factor lead to the biologically active ternary MLL∶KIX∶c-Myb complex which plays a role in Pol II-mediated transcription. The binding of the activation domain of MLL to KIX enhances c-Myb binding. Here we carried out molecular dynamics (MD) simulations for the MLL∶KIX∶c-Myb ternary complex, its binary components and KIX with the goal of providing a mechanistic explanation for the experimental observations. The dynamic behavior revealed that the MLL binding site is allosterically coupled to the c-Myb binding site. MLL binding redistributes the conformational ensemble of KIX, leading to higher populations of states which favor c-Myb binding. The key element in the allosteric communication pathways is the KIX loop, which acts as a control mechanism to enhance subsequent binding events. We tested this conclusion by in silico mutations of loop residues in the KIX∶MLL complex and by comparing wild type and mutant dynamics through MD simulations. The loop assumed MLL binding conformation similar to that observed in the KIX∶c-Myb state which disfavors the allosteric network. The coupling with c-Myb binding site faded, abolishing the positive cooperativity observed in the presence of MLL. Our major conclusion is that by eliciting a loop-mediated allosteric switch between the different states following the binding events, transcriptional activation can be regulated. The KIX system presents an example how nature makes use of conformational control in higher level regulation of transcriptional activity and thus cellular events.
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Affiliation(s)
- Elif Nihal Korkmaz
- Polymer Research Center & Chemical Engineering Department, Boğaziçi University, Istanbul, Turkey
| | - Ruth Nussinov
- Basic Science Program, SAIC-Frederick, Inc., Center for Cancer Research Nanobiology Program, NCI-Frederick, Frederick, Maryland, United States of America
- Sackler Institute of Molecular Medicine, Department of Human Genetics and Molecular Medicine, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Türkan Haliloğlu
- Polymer Research Center & Chemical Engineering Department, Boğaziçi University, Istanbul, Turkey
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32
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Melnik BS, Povarnitsyna TV, Glukhov AS, Melnik TN, Uversky VN. SS-Stabilizing Proteins Rationally: Intrinsic Disorder-Based Design of Stabilizing Disulphide Bridges in GFP. J Biomol Struct Dyn 2012; 29:815-24. [DOI: 10.1080/07391102.2012.10507414] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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33
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Daughdrill GW, Borcherds WM, Wu H. Disorder predictors also predict backbone dynamics for a family of disordered proteins. PLoS One 2011; 6:e29207. [PMID: 22195023 PMCID: PMC3240651 DOI: 10.1371/journal.pone.0029207] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2011] [Accepted: 11/22/2011] [Indexed: 01/04/2023] Open
Abstract
Several algorithms have been developed that use amino acid sequences to predict whether or not a protein or a region of a protein is disordered. These algorithms make accurate predictions for disordered regions that are 30 amino acids or longer, but it is unclear whether the predictions can be directly related to the backbone dynamics of individual amino acid residues. The nuclear Overhauser effect between the amide nitrogen and hydrogen (NHNOE) provides an unambiguous measure of backbone dynamics at single residue resolution and is an excellent tool for characterizing the dynamic behavior of disordered proteins. In this report, we show that the NHNOE values for several members of a family of disordered proteins are highly correlated with the output from three popular algorithms used to predict disordered regions from amino acid sequence. This is the first test between an experimental measure of residue specific backbone dynamics and disorder predictions. The results suggest that some disorder predictors can accurately estimate the backbone dynamics of individual amino acids in a long disordered region.
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Affiliation(s)
- Gary W Daughdrill
- Department of Cell Biology, Microbiology and Molecular Biology and Center for Drug Discovery and Innovation, University of South Florida, Tampa, Florida, United States of America.
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34
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Melnik BS, Molochkov NV, Prokhorov DA, Uversky VN, Kutyshenko VP. Molecular mechanisms of the anomalous thermal aggregation of green fluorescent protein. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2011; 1814:1930-9. [DOI: 10.1016/j.bbapap.2011.07.017] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2011] [Revised: 07/19/2011] [Accepted: 07/19/2011] [Indexed: 11/27/2022]
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35
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Carra C, Cucinotta FA. Accurate prediction of the binding free energy and analysis of the mechanism of the interaction of replication protein A (RPA) with ssDNA. J Mol Model 2011; 18:2761-83. [PMID: 22116609 DOI: 10.1007/s00894-011-1288-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2011] [Accepted: 10/19/2011] [Indexed: 10/15/2022]
Abstract
The eukaryotic replication protein A (RPA) has several pivotal functions in the cell metabolism, such as chromosomal replication, prevention of hairpin formation, DNA repair and recombination, and signaling after DNA damage. Moreover, RPA seems to have a crucial role in organizing the sequential assembly of DNA processing proteins along single stranded DNA (ssDNA). The strong RPA affinity for ssDNA, K(A) between 10(-9)-10(-10) M, is characterized by a low cooperativity with minor variation for changes on the nucleotide sequence. Recently, new data on RPA interactions was reported, including the binding free energy of the complex RPA70AB with dC(8) and dC(5), which has been estimated to be -10 ± 0.4 kcal mol(-1) and -7 ± 1 kcal mol(-1), respectively. In view of these results we performed a study based on molecular dynamics aimed to reproduce the absolute binding free energy of RPA70AB with the dC(5) and dC(8) oligonucleotides. We used several tools to analyze the binding free energy, rigidity, and time evolution of the complex. The results obtained by MM-PBSA method, with the use of ligand free geometry as a reference for the receptor in the separate trajectory approach, are in excellent agreement with the experimental data, with ±4 kcal mol(-1) error. This result shows that the MM-PB(GB)SA methods can provide accurate quantitative estimates of the binding free energy for interacting complexes when appropriate geometries are used for the receptor, ligand and complex. The decomposition of the MM-GBSA energy for each residue in the receptor allowed us to correlate the change of the affinity of the mutated protein with the ΔG(gas+sol) contribution of the residue considered in the mutation. The agreement with experiment is optimal and a strong change in the binding free energy can be considered as the dominant factor in the loss for the binding affinity resulting from mutation.
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Affiliation(s)
- Claudio Carra
- Universities Space Research Association, Houston, TX 77058, USA.
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36
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Wang X, Xu X, Zhu S, Xiao Z, Ma Z, Li Y, Wang Y. Molecular dynamics simulation of conformational heterogeneity in transportin 1. Proteins 2011; 80:382-97. [PMID: 22105828 DOI: 10.1002/prot.23193] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2011] [Revised: 08/23/2011] [Accepted: 09/04/2011] [Indexed: 11/10/2022]
Abstract
Transportin 1 (Trn1), as a typical transport receptor of the karyopherin-β family, mediates numerous RNA binding proteins into the nucleus by recognizing proline-tyrosine nuclear localization signals (PY-NLSs). Such process is regulated by RanGTP through its nucleotide cycle, which is associated with ligand dissociation. Yet a proper description including dynamic properties of Trn1 and its response on ligand/Ran binding has not been accessible so far. Here, we use molecular dynamics simulations to probe the conformational dynamics of the apo-Trn1 and Trn1 in complex with ligand and Ran. The results reveal a strikingly intrinsic flexibility and conformational heterogeneity of Trn1, identified as generally segmental architecture. The segments rotate relative to each other about a flexible hinge and thereby force Trn1 to adopt a conformation compatible with the binding of Ran or substrates. Such binding significantly suppresses the flexibility and conformational heterogeneity of Trn1 and results in a disorder-to-order transition of HR8 loop, which facilitates this loop to allosterically communicate with the C-terminal arch of Trn1. These results give insights into the disassembly and recycling of the Trn1, which has important implications for the regulation of the nuclear transport cycle and for the ligand selectivity.
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Affiliation(s)
- Xia Wang
- Center of Bioinformatics, Northwest A&F University, Yangling, Shaanxi 712100, People's Republic of China; College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, People's Republic of China
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37
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Khanna M, Wang F, Jo I, Knabe WE, Wilson SM, Li L, Bum-Erdene K, Li J, W. Sledge G, Khanna R, Meroueh SO. Targeting multiple conformations leads to small molecule inhibitors of the uPAR·uPA protein-protein interaction that block cancer cell invasion. ACS Chem Biol 2011; 6:1232-43. [PMID: 21875078 DOI: 10.1021/cb200180m] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Interaction of the urokinase receptor (uPAR) with its binding partners such as the urokinase-type plasminogen activator (uPA) at the cell surface triggers a series of proteolytic and signaling events that promote invasion and metastasis. Here, we report the discovery of a small molecule (IPR-456) and its derivatives that inhibit the tight uPAR·uPA protein-protein interaction. IPR-456 was discovered by virtual screening against multiple conformations of uPAR sampled from explicit-solvent molecular dynamics simulations. Biochemical characterization reveal that the compound binds to uPAR with submicromolar affinity (K(d) = 310 nM) and inhibits the tight protein-protein interaction with an IC(50) of 10 μM. Free energy calculations based on explicit-solvent molecular dynamics simulations suggested the importance of a carboxylate moiety on IPR-456, which was confirmed by the activity of several derivatives including IPR-803. Immunofluorescence imaging showed that IPR-456 inhibited uPA binding to uPAR of breast MDA-MB-231 tumor cells with an IC(50) of 8 μM. The compounds blocked MDA-MB-231 cell invasion, but IPR-456 showed little effect on MDA-MB-231 migration and no effect on adhesion, suggesting that uPAR mediates these processes through its other binding partners.
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Affiliation(s)
| | | | | | | | | | | | - Khuchtumur Bum-Erdene
- Department of Chemistry and Chemical Biology, Indiana University Purdue University Indianapolis (IUPUI), Indianapolis, Indiana 46202, United States
| | | | | | | | - Samy O. Meroueh
- Department of Chemistry and Chemical Biology, Indiana University Purdue University Indianapolis (IUPUI), Indianapolis, Indiana 46202, United States
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38
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Li L, Wang B, Meroueh SO. Support vector regression scoring of receptor-ligand complexes for rank-ordering and virtual screening of chemical libraries. J Chem Inf Model 2011; 51:2132-8. [PMID: 21728360 PMCID: PMC3209528 DOI: 10.1021/ci200078f] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The community structure-activity resource (CSAR) data sets are used to develop and test a support vector machine-based scoring function in regression mode (SVR). Two scoring functions (SVR-KB and SVR-EP) are derived with the objective of reproducing the trend of the experimental binding affinities provided within the two CSAR data sets. The features used to train SVR-KB are knowledge-based pairwise potentials, while SVR-EP is based on physicochemical properties. SVR-KB and SVR-EP were compared to seven other widely used scoring functions, including Glide, X-score, GoldScore, ChemScore, Vina, Dock, and PMF. Results showed that SVR-KB trained with features obtained from three-dimensional complexes of the PDBbind data set outperformed all other scoring functions, including best performing X-score, by nearly 0.1 using three correlation coefficients, namely Pearson, Spearman, and Kendall. It was interesting that higher performance in rank ordering did not translate into greater enrichment in virtual screening assessed using the 40 targets of the Directory of Useful Decoys (DUD). To remedy this situation, a variant of SVR-KB (SVR-KBD) was developed by following a target-specific tailoring strategy that we had previously employed to derive SVM-SP. SVR-KBD showed a much higher enrichment, outperforming all other scoring functions tested, and was comparable in performance to our previously derived scoring function SVM-SP.
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Affiliation(s)
- Liwei Li
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indiana University, Indianapolis, Indiana, United States
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39
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Johnson AT, Schlegel MK, Meggers E, Essen LO, Wiest O. On the structure and dynamics of duplex GNA. J Org Chem 2011; 76:7964-74. [PMID: 21838272 DOI: 10.1021/jo201469b] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Glycol nucleic acid (GNA), with a nucleotide backbone comprising of just three carbons and the stereocenter derived from propylene glycol (1,2-propanediol), is a structural analog of nucleic acids with intriguing biophysical properties, such as formation of highly stable antiparallel duplexes with high Watson-Crick base pairing fidelity. Previous crystallographic studies of double stranded GNA (dsGNA) indicated two forms of backbone conformations, an elongated M-type (containing metallo-base pairs) and the condensed N-type (containing brominated base pairs). A herein presented new crystal structure of a GNA duplex at 1.8 Å resolution from self-complementary 3'-CTC(Br)UAGAG-2' GNA oligonucleotides reveals an N-type conformation with alternating gauche-anti torsions along its (O3'-C3'-C2'-O2') backbone. To elucidate the conformational state of dsGNA in solution, molecular dynamic simulations over a period of 20 ns were performed with the now available repertoire of structural information. Interestingly, dsGNA adopts conformational states in solution intermediate between experimentally observed backbone conformations: simulated dsGNA shows the all-gauche conformation characteristic of M-type GNA with the higher helical twist common to N-type GNA structures. The so far counterintuitive, smaller loss of entropy upon duplex formation as compared to DNA can be traced back to the conformational flexibility inherent to dsGNA but missing in dsDNA. Besides extensive interstrand base stacking and conformational preorganization of single strands, this flexibility contributes to the extraordinary thermal stability of GNA.
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Affiliation(s)
- Andrew T Johnson
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556-5670, United States
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40
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Gao Z, Li F, Wu G, Zhu Y, Yu T, Yu S. Roles of hinge region, loops 3 and 4 in the activation of Escherichia coli cyclic AMP receptor protein. Int J Biol Macromol 2011; 50:1-6. [PMID: 21889533 DOI: 10.1016/j.ijbiomac.2011.08.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2011] [Revised: 08/13/2011] [Accepted: 08/17/2011] [Indexed: 10/17/2022]
Abstract
The cAMP receptor protein (CRP) requires cAMP for an allosteric change and regulates more than 150 genes in Escherichia coli. In this study, the modular half of cAMP receptor protein was used to investigate the allosteric signal transmission pathway induced by cAMP binding. The activation of CRP upon cAMP binding is indicated to be realignment of the two subunits within the CRP dimer. The interaction of loop 3 and Phe136 do not involve in signal transmission.
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Affiliation(s)
- Zhengya Gao
- Department of Chemistry, Fudan University, Shanghai 200433, China
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41
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Melnik TN, Povarnitsyna TV, Glukhov AS, Uversky VN, Melnik BS. Sequential Melting of Two Hydrophobic Clusters within the Green Fluorescent Protein GFP-cycle3. Biochemistry 2011; 50:7735-44. [DOI: 10.1021/bi2006674] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Tatiana N. Melnik
- Institute
of Protein Research, Russian Academy of Sciences, 142290 Pushchino, Moscow Region, Russia
| | - Tatiana V. Povarnitsyna
- Institute
of Protein Research, Russian Academy of Sciences, 142290 Pushchino, Moscow Region, Russia
| | - Anatoly S. Glukhov
- Institute
of Protein Research, Russian Academy of Sciences, 142290 Pushchino, Moscow Region, Russia
| | - Vladimir N. Uversky
- Department of Molecular Medicine, College of Medicine, University of South Florida, Tampa, Florida 33612,
United States
| | - Bogdan S. Melnik
- Institute
of Protein Research, Russian Academy of Sciences, 142290 Pushchino, Moscow Region, Russia
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42
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Pan D, Yan Q, Chen Y, McDonald JM, Song Y. Trifluoperazine regulation of calmodulin binding to Fas: a computational study. Proteins 2011; 79:2543-56. [PMID: 21656570 PMCID: PMC3132223 DOI: 10.1002/prot.23081] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2010] [Revised: 04/26/2011] [Accepted: 05/04/2011] [Indexed: 12/13/2022]
Abstract
Death-inducing signaling complex (DISC) formation is a critical step in Fas-mediated signaling for apoptosis. Previous experiments have demonstrated that the calmodulin (CaM) antagonist, trifluoperazine (TFP) regulates CaM-Fas binding and affects Fas-mediated DISC formation. In this study, we investigated the anti-cooperative characteristics of TFP binding to CaM and the effect of TFP on the CaM-Fas interaction from both structural and thermodynamic perspectives using combined molecular dynamics simulations and binding free energy analyses. We studied the interactions of different numbers of TFP molecules with CaM and explored the effects of the resulting conformational changes in CaM on CaM-Fas binding. Results from these analyses showed that the number of TFP molecules bound to CaM directly influenced α-helix formation and hydrogen bond occupancy within the α-helices of CaM, contributing to the conformational and motion changes in CaM. These changes affected CaM binding to Fas, resulting in secondary structural changes in Fas and conformational and motion changes of Fas in CaM-Fas complexes, potentially perturbing the recruitment of Fas-associated death domain for DISC formation. The computational results from this study reveal the structural and molecular mechanisms that underlie the role of the CaM antagonist, TFP, in regulation of CaM-Fas binding and Fas-mediated DISC formation in a concentration-dependent manner.
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Affiliation(s)
- Di Pan
- Department of Biomedical Engineering, The University of Alabama at Birmingham, AL 35294
| | - Qi Yan
- Department of Biomedical Engineering, The University of Alabama at Birmingham, AL 35294
| | - Yabing Chen
- Department of Pathology, The University of Alabama at Birmingham, AL 35294
- VA Medical Center Birmingham, AL 35294
| | - Jay M McDonald
- Department of Pathology, The University of Alabama at Birmingham, AL 35294
- VA Medical Center Birmingham, AL 35294
| | - Yuhua Song
- Department of Biomedical Engineering, The University of Alabama at Birmingham, AL 35294
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Schuyler AD, Carlson HA, Feldman EL. Computational methods for identifying a layered allosteric regulatory mechanism for ALS-causing mutations of Cu-Zn superoxide dismutase 1. Proteins 2011; 79:417-27. [PMID: 21104697 DOI: 10.1002/prot.22892] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The most prominent form of familial amyotrophic lateral sclerosis (fALS, Lou Gehrig's Disease) is caused by mutations of Cu-Zn superoxide dismutase 1 (SOD1). SOD1 maintains antioxidant activity under fALS causing mutations, suggesting that the mutations introduce a new, toxic, function. There are 100+ such known mutations that are chemically diverse and spatially distributed across the structure. The common phenotype leads us to propose an allosteric regulatory mechanism hypothesis: SOD1 mutants alter the correlated dynamics of the structure and differentially signal across an inherent allosteric network, thereby driving the disease mechanism at varying rates of efficiency. Two recently developed computational methods for identifying allosteric control sites are applied to the wild type crystal structure, 4 fALS mutant crystal structures, 20 computationally generated fALS mutants and 1 computationally generated non-fALS mutant. The ensemble of mutant structures is used to generate an ensemble of dynamics, from which two allosteric control networks are identified. One network is connected to the catalytic site and thus may be involved in the natural antioxidant function. The second allosteric control network has a locus bordering the dimer interface and thus may serve as a mechanism to modulate dimer stability. Though the toxic function of mutated SOD1 is unknown and likely due to several contributing factors, this study explains how diverse mutations give rise to a common function. This new paradigm for allostery controlled function has broad implications across allosteric systems and may lead to the identification of the key chemical activity of SOD1-linked ALS.
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Affiliation(s)
- Adam D Schuyler
- Department of Molecular, Microbial and Structural Biology, University of Connecticut Health Center, Farmington, Connecticut 06030, USA.
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44
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Pérez-Castillo Y, Froeyen M, Cabrera-Pérez MÁ, Nowé A. Molecular dynamics and docking simulations as a proof of high flexibility in E. coli FabH and its relevance for accurate inhibitor modeling. J Comput Aided Mol Des 2011; 25:371-93. [DOI: 10.1007/s10822-011-9427-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2011] [Accepted: 04/09/2011] [Indexed: 10/18/2022]
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45
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Khanna M, Chelladurai B, Gavini A, Li L, Shao M, Courtney D, Turchi JJ, Matei D, Meroueh S. Targeting ovarian tumor cell adhesion mediated by tissue transglutaminase. Mol Cancer Ther 2011; 10:626-36. [PMID: 21330459 DOI: 10.1158/1535-7163.mct-10-0912] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Tissue transglutaminase (TG2) is a transpeptidase involved in protein cross-linking through generation of ε-(γ-glutamyl)lysine isopeptide bonds. It also promotes cell adhesion through interaction with fibronectin and facilitates formation of fibronectin-integrin complexes. This interaction is involved in tumor cell adhesion to the matrix and in the process of tumor dissemination. Its inhibition by small molecules may therefore be useful in blocking metastasis. To that end, we screened more than 800,000 compounds following an in silico docking approach targeting two distinct cavities in the vicinity of the fibronectin-binding site on TG2. A total of 120 compounds were acquired and tested in cell culture-based assays for inhibition of ovarian tumor cell adhesion and proliferation. Seven compounds showed more than 50% inhibition of cell adhesion at a concentration of 25 μmol/L. A follow-up fluorescence polarization study revealed that one compound in particular (ITP-79) inhibited binding of a TG2 peptide to a 42-kDa fragment of fibronectin in a dose-dependent manner. This inhibition was confirmed in cancer cells by coimmunoprecipitation. A competition assay with surface plasmon resonance showed that ITP-79 modulated binding of TG2 to fibronectin. Direct binding of compounds that inhibited adhesion to TG2 were examined with differential scanning fluorimetry, which measures the effect of the compound on the melting temperature of the target. Two compounds, including ITP-79, reduced TG2 stabilization, mimicking the effects of GTP, a known negative allosteric regulator of TG2 enzymatic function. This suggests a potential allosteric mechanism for the compound in light of its distal target site.
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Affiliation(s)
- May Khanna
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, 535 Barnhill Drive, RT473, Indianapolis, IN 46202, USA
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46
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Wang P, Zhang JZH. Selective binding of antiinfluenza drugs and their analogues to 'open' and 'closed' conformations of H5N1 neuraminidase. J Phys Chem B 2011; 114:12958-64. [PMID: 20860351 DOI: 10.1021/jp1030224] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
It was suggested that the open conformation of the 150-loop of H5N1 avian influenza neuraminidase is intrinsically lower in energy than the closed conformation and that oseltamivir (tamiflu) favors binding to the closed conformation through a relatively slow conformational change [Russell, R. J. Nature 2006, 443, 45-49]. In the present work, a systematic computational study is performed to investigate the binding mechanism of five ligands to H5N1 neuraminidase (H5N1 NA) with the 150-loop in both open and closed conformations through molecular docking, molecular dynamics simulations, and MM/PBSA free energy calculation. Our result shows that the electrostatic interactions between polar groups on the 150-loop and the charged groups of the ligands play a key role on the binding selectivity. In particular, ligands having a small positively charged group favor binding to the closed conformation of H5N1 NA, while those having a large positively charged group generally prefer binding to the open conformation. Our analysis suggests that it may be possible to design new inhibitors with large basic groups that are selective for the open conformation and thereby have stronger binding affinity to H5N1 neuraminidase.
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Affiliation(s)
- Pei Wang
- Department of Chemistry, New York University, New York, New York 10003, USA
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47
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Tao W, Gao Z, Gao Z, Zhou J, Huang Z, Dong Y, Yu S. The 1.6Å resolution structure of activated D138L mutant of catabolite gene activator protein with two cAMP bound in each monomer. Int J Biol Macromol 2011; 48:459-65. [PMID: 21255606 DOI: 10.1016/j.ijbiomac.2011.01.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2010] [Revised: 12/27/2010] [Accepted: 01/10/2011] [Indexed: 11/17/2022]
Abstract
The X-ray crystal structure of the cAMP-liganded D138L mutant of Escherichia coli catabolite gene activator protein (CAP) was determined at a resolution of 1.66Å. This high resolution crystal structure reveals four cAMP binding sites in the homodimer. Two anti conformations of cAMPs (anti-cAMP) locate between the β-barrel and the C-helix of each subunit; two syn conformations of cAMPs (syn-cAMP) bind on the surface of the C-terminal domain. With two syn-cAMP molecules bound, the D138L CAP is highly symmetrical with both subunits assuming a "closed" conformation. These differences make the hinge region of the mutant more flexible. Protease susceptibility measurements indicate that D138L is more susceptible to proteases than that of wild type (WT) CAP. The results of protein dynamic experiments (H/D exchange measurements) indicate that the structure of D138L mutant is more dynamic than that of WT CAP, which may impact the recognition of specific DNA sequences.
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Affiliation(s)
- Wenbing Tao
- Department of Chemistry and Institutes of Biomedical Science, Fudan University, Shanghai 200433, China
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48
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Yan Q, Murphy-Ullrich JE, Song Y. Structural insight into the role of thrombospondin-1 binding to calreticulin in calreticulin-induced focal adhesion disassembly. Biochemistry 2010; 49:3685-94. [PMID: 20337411 DOI: 10.1021/bi902067f] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Thrombospondin-1 (TSP1) binding to calreticulin (CRT) on the cell surface stimulates association of CRT with LDL receptor-related protein (LRP1) to signal focal adhesion disassembly and engagement of cellular activities. The structural basis for this phenomenon is unknown. We studied the binding thermodynamics of the TSP1-CRT complex and the conformational changes in CRT induced by binding to TSP1 with combined binding free energy analysis, molecular dynamics simulation, and anisotropic network model restrained molecular dynamics simulation. Results showed that mutations of Lys 24 and Lys 32 in TSP1 to Ala and of amino acids 24-26 and 32-34 in CRT to Ala significantly weakened the binding of TSP1 and CRT, which is consistent with experimental results. Upon validation of the calculated binding affinity changes of the TSP1-CRT complex by mutations in key residues in TSP1 and CRT with the experimental results, we performed conformational analyses to understand the role of TSP1 binding to CRT in the induction of conformational changes in CRT. Conformational analyses showed that TSP1 binding to CRT resulted in a more "open" conformation and a significant rotational change for the CRT N-domain with respect to the CRT P-domain, which could expose the potential binding site(s) in CRT for binding to LRP1 to signal focal adhesion disassembly. Results offer structural insight into the role of TSP1 binding to CRT in CRT-induced focal adhesion disassembly.
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Affiliation(s)
- Qi Yan
- Department of Biomedical Engineering, The University of Alabama at Birmingham,Birmingham, Alabama 35294, USA
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49
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Toncrova H, McLeish TCB. Substrate-modulated thermal fluctuations affect long-range allosteric signaling in protein homodimers: exemplified in CAP. Biophys J 2010; 98:2317-26. [PMID: 20483341 PMCID: PMC2872212 DOI: 10.1016/j.bpj.2010.01.039] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2009] [Revised: 01/14/2010] [Accepted: 01/22/2010] [Indexed: 11/30/2022] Open
Abstract
The role of conformational dynamics in allosteric signaling of proteins is increasingly recognized as an important and subtle aspect of this ubiquitous phenomenon. Cooperative binding is commonly observed in proteins with twofold symmetry that bind two identical ligands. We construct a coarse-grained model of an allosteric coupled dimer and show how the signal can be propagated between the distant binding sites via change in slow global vibrational modes alone. We demonstrate that modulation on substrate binding of as few as 5-10 slow modes can give rise to cooperativity observed in biological systems and that the type of cooperativity is given by change of interaction between the two monomers upon ligand binding. To illustrate the application of the model, we apply it to a challenging test case: the catabolite activator protein (CAP). CAP displays negative cooperativity upon association with two identical ligands. The conformation of CAP is not affected by the binding, but its vibrational spectrum undergoes a strong modification. Intriguingly, the first binding enhances thermal fluctuations, yet the second quenches them. We show that this counterintuitive behavior is, in fact, necessary for an optimal anticooperative system, and captured within a well-defined region of the model's parameter space. From analyzing the experimental results, we conclude that fast local modes take an active part in the allostery of CAP, coupled to the more-global slow modes. By including them into the model, we elucidate the role of the modes on different timescales. We conclude that such dynamic control of allostery in homodimers may be a general phenomenon and that our model framework can be used for extended interpretation of thermodynamic parameters in other systems.
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50
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Pino-Angeles A, Morreale A, Negri A, Sánchez-Jiménez F, Moya-García AA. Substrate uptake and protein stability relationship in mammalian histidine decarboxylase. Proteins 2010; 78:154-61. [PMID: 19790266 DOI: 10.1002/prot.22587] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
There is some evidence linking the substrate entrance in the active site of mammalian histidine decarboxylase and an increased stability against proteolytic degradation. In this work, we study the basis of this relationship by means of protein structure network analysis and molecular dynamics simulations. We find that the substrate binding to the active site influences the conformation of a flexible region sensible to proteolytic degradation and observe how formation of the Michaelis-Menten complex increases stability in the conformation of this region.
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Affiliation(s)
- A Pino-Angeles
- Departamento de Biología Molecular y Bioquímica, Facultad de Ciencias, Universidad de Málaga, Campus de Teatinos, Málaga, Spain
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