1
|
Feidakis CP, Krivak R, Hoksza D, Novotny M. AHoJ-DB: A PDB-wide Assignment of apo & holo Relationships Based on Individual Protein-Ligand Interactions. J Mol Biol 2024; 436:168545. [PMID: 38508305 DOI: 10.1016/j.jmb.2024.168545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 03/12/2024] [Accepted: 03/14/2024] [Indexed: 03/22/2024]
Abstract
A single protein structure is rarely sufficient to capture the conformational variability of a protein. Both bound and unbound (holo and apo) forms of a protein are essential for understanding its geometry and making meaningful comparisons. Nevertheless, docking or drug design studies often still consider only single protein structures in their holo form, which are for the most part rigid. With the recent explosion in the field of structural biology, large, curated datasets are urgently needed. Here, we use a previously developed application (AHoJ) to perform a comprehensive search for apo-holo pairs for 468,293 biologically relevant protein-ligand interactions across 27,983 proteins. In each search, the binding pocket is captured and mapped across existing structures within the same UniProt, and the mapped pockets are annotated as apo or holo, based on the presence or absence of ligands. We assemble the results into a database, AHoJ-DB (www.apoholo.cz/db), that captures the variability of proteins with identical sequences, thereby exposing the agents responsible for the observed differences in geometry. We report several metrics for each annotated pocket, and we also include binding pockets that form at the interface of multiple chains. Analysis of the database shows that about 24% of the binding sites occur at the interface of two or more chains and that less than 50% of the total binding sites processed have an apo form in the PDB. These results can be used to train and evaluate predictors, discover potentially druggable proteins, and reveal protein- and ligand-specific relationships that were previously obscured by intermittent or partial data. Availability: www.apoholo.cz/db.
Collapse
Affiliation(s)
- Christos P Feidakis
- Department of Cell Biology, Faculty of Science, Charles University, Prague 12843, Czech Republic.
| | - Radoslav Krivak
- Department of Software Engineering, Faculty of Mathematics and Physics, Charles University, Prague 12116, Czech Republic; Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague 16000, Czech Republic
| | - David Hoksza
- Department of Software Engineering, Faculty of Mathematics and Physics, Charles University, Prague 12116, Czech Republic
| | - Marian Novotny
- Department of Cell Biology, Faculty of Science, Charles University, Prague 12843, Czech Republic.
| |
Collapse
|
2
|
Wang J, Xue N, Pan W, Tu R, Li S, Zhang Y, Mao Y, Liu Y, Cheng H, Guo Y, Yuan W, Ni X, Wang M. Repurposing conformational changes in ANL superfamily enzymes to rapidly generate biosensors for organic and amino acids. Nat Commun 2023; 14:6680. [PMID: 37865661 PMCID: PMC10590383 DOI: 10.1038/s41467-023-42431-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 10/10/2023] [Indexed: 10/23/2023] Open
Abstract
Biosensors are powerful tools for detecting, real-time imaging, and quantifying molecules, but rapidly constructing diverse genetically encoded biosensors remains challenging. Here, we report a method to rapidly convert enzymes into genetically encoded circularly permuted fluorescent protein-based indicators to detect organic acids (GECFINDER). ANL superfamily enzymes undergo hinge-mediated ligand-coupling domain movement during catalysis. We introduce a circularly permuted fluorescent protein into enzymes hinges, converting ligand-induced conformational changes into significant fluorescence signal changes. We obtain 11 GECFINDERs for detecting phenylalanine, glutamic acid and other acids. GECFINDER-Phe3 and GECFINDER-Glu can efficiently and accurately quantify target molecules in biological samples in vitro. This method simplifies amino acid quantification without requiring complex equipment, potentially serving as point-of-care testing tools for clinical applications in low-resource environments. We also develop a GECFINDER-enabled droplet-based microfluidic high-throughput screening method for obtaining high-yield industrial strains. Our method provides a foundation for using enzymes as untapped blueprint resources for biosensor design, creation, and application.
Collapse
Affiliation(s)
- Jin Wang
- University of Chinese Academy of Sciences, 100049, Beijing, China
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 300308, Tianjin, China
- Haihe Laboratory of Synthetic Biology, 300308, Tianjin, China
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, 300308, Tianjin, China
| | - Ning Xue
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 300308, Tianjin, China
- Haihe Laboratory of Synthetic Biology, 300308, Tianjin, China
- Tianjin University of Science & Technology, 300457, Tianjin, China
| | - Wenjia Pan
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 300308, Tianjin, China
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, 300308, Tianjin, China
| | - Ran Tu
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 300308, Tianjin, China
- College of Environmental and Resources, Chongqing Technology and Business University, 400067, Chongqing, China
| | - Shixin Li
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 300308, Tianjin, China
- Tianjin University of Science & Technology, 300457, Tianjin, China
| | - Yue Zhang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 300308, Tianjin, China
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, 300308, Tianjin, China
| | - Yufeng Mao
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 300308, Tianjin, China
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, 300308, Tianjin, China
| | - Ye Liu
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 300308, Tianjin, China
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, 300308, Tianjin, China
| | - Haijiao Cheng
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 300308, Tianjin, China
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, 300308, Tianjin, China
| | - Yanmei Guo
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 300308, Tianjin, China
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, 300308, Tianjin, China
| | - Wei Yuan
- University of Chinese Academy of Sciences, 100049, Beijing, China
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 300308, Tianjin, China
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, 300308, Tianjin, China
| | - Xiaomeng Ni
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 300308, Tianjin, China
| | - Meng Wang
- University of Chinese Academy of Sciences, 100049, Beijing, China.
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 300308, Tianjin, China.
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, 300308, Tianjin, China.
| |
Collapse
|
3
|
D3PM: a comprehensive database for protein motions ranging from residue to domain. BMC Bioinformatics 2022; 23:70. [PMID: 35164668 PMCID: PMC8845362 DOI: 10.1186/s12859-022-04595-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Accepted: 02/01/2022] [Indexed: 11/24/2022] Open
Abstract
Background Knowledge of protein motions is significant to understand its functions. While currently available databases for protein motions are mostly focused on overall domain motions, little attention is paid on local residue motions. Albeit with relatively small scale, the local residue motions, especially those residues in binding pockets, may play crucial roles in protein functioning and ligands binding. Results A comprehensive protein motion database, namely D3PM, was constructed in this study to facilitate the analysis of protein motions. The protein motions in the D3PM range from overall structural changes of macromolecule to local flip motions of binding pocket residues. Currently, the D3PM has collected 7679 proteins with overall motions and 3513 proteins with pocket residue motions. The motion patterns are classified into 4 types of overall structural changes and 5 types of pocket residue motions. Impressively, we found that less than 15% of protein pairs have obvious overall conformational adaptations induced by ligand binding, while more than 50% of protein pairs have significant structural changes in ligand binding sites, indicating that ligand-induced conformational changes are drastic and mainly confined around ligand binding sites. Based on the residue preference in binding pocket, we classified amino acids into “pocketphilic” and “pocketphobic” residues, which should be helpful for pocket prediction and drug design. Conclusion D3PM is a comprehensive database about protein motions ranging from residue to domain, which should be useful for exploring diverse protein motions and for understanding protein function and drug design. The D3PM is available on www.d3pharma.com/D3PM/index.php. Supplementary Information The online version contains supplementary material available at 10.1186/s12859-022-04595-0.
Collapse
|
4
|
Basciu A, Callea L, Motta S, Bonvin AM, Bonati L, Vargiu AV. No dance, no partner! A tale of receptor flexibility in docking and virtual screening. VIRTUAL SCREENING AND DRUG DOCKING 2022. [DOI: 10.1016/bs.armc.2022.08.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
5
|
Parisi G, Palopoli N, Tosatto SC, Fornasari MS, Tompa P. "Protein" no longer means what it used to. Curr Res Struct Biol 2021; 3:146-152. [PMID: 34308370 PMCID: PMC8283027 DOI: 10.1016/j.crstbi.2021.06.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 06/18/2021] [Accepted: 06/22/2021] [Indexed: 01/02/2023] Open
Abstract
Every biologist knows that the word protein describes a group of macromolecules essential to sustain life on Earth. As biologists, we are invariably trained under a protein paradigm established since the early twentieth century. However, in recent years, the term protein unveiled itself as an euphemism to describe the overwhelming heterogeneity of these compounds. Most of our current studies are targeted on carefully selected subsets of proteins, but we tend to think and write about these as representative of the whole population. Here we discuss how seeking for universal definitions and general rules in any arbitrarily segmented study would be misleading about the conclusions. Of course, it is not our purpose to discourage the use of the word protein. Instead, we suggest to embrace the extended universe of proteins to reach a deeper understanding of their full potential, realizing that the term encompasses a group of molecules very heterogeneous in terms of size, shape, chemistry and functions, i.e. the term protein no longer means what it used to.
Collapse
Affiliation(s)
- Gustavo Parisi
- Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, CONICET, Bernal, Buenos Aires, Argentina
| | - Nicolas Palopoli
- Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, CONICET, Bernal, Buenos Aires, Argentina
| | | | - María Silvina Fornasari
- Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, CONICET, Bernal, Buenos Aires, Argentina
| | - Peter Tompa
- VIB-VUB Center for Structural Biology (CSB), Brussels, Belgium
- Structural Biology Brussels (SBB), Vrije Universiteit Brussel (VUB), Brussels, Belgium
- Institute of Enzymology, Research Centre for Natural Sciences, Budapest, Hungary
| |
Collapse
|
6
|
Wu S, Liu C, Feng J, Yang A, Guo F, Qiao J. QSIdb: quorum sensing interference molecules. Brief Bioinform 2020; 22:5916938. [PMID: 33003203 DOI: 10.1093/bib/bbaa218] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 08/15/2020] [Accepted: 08/17/2020] [Indexed: 12/30/2022] Open
Abstract
Quorum sensing interference (QSI), the disruption and manipulation of quorum sensing (QS) in the dynamic control of bacteria populations could be widely applied in synthetic biology to realize dynamic metabolic control and develop potential clinical therapies. Conventionally, limited QSI molecules (QSIMs) were developed based on molecular structures or for specific QS receptors, which are in short supply for various interferences and manipulations of QS systems. In this study, we developed QSIdb (http://qsidb.lbci.net/), a specialized repository of 633 reported QSIMs and 73 073 expanded QSIMs including both QS agonists and antagonists. We have collected all reported QSIMs in literatures focused on the modifications of N-acyl homoserine lactones, natural QSIMs and synthetic QS analogues. Moreover, we developed a pipeline with SMILES-based similarity assessment algorithms and docking-based validations to mine potential QSIMs from existing 138 805 608 compounds in the PubChem database. In addition, we proposed a new measure, pocketedit, for assessing the similarities of active protein pockets or QSIMs crosstalk, and obtained 273 possible potential broad-spectrum QSIMs. We provided user-friendly browsing and searching facilities for easy data retrieval and comparison. QSIdb could assist the scientific community in understanding QS-related therapeutics, manipulating QS-based genetic circuits in metabolic engineering, developing potential broad-spectrum QSIMs and expanding new ligands for other receptors.
Collapse
Affiliation(s)
- Shengbo Wu
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
| | - Chunjiang Liu
- State Key Laboratory of Chemical Engineering, Tianjin University, Tianjin, China
| | - Jie Feng
- School of Computer Science and Technology, College of Intelligence and Computing, Tianjin University, Tianjin, China
| | - Aidong Yang
- Department of Engineering Science, University of Oxford, Oxford, UK
| | - Fei Guo
- School of Computer Science and Technology, College of Intelligence and Computing, Tianjin University, Tianjin, China
| | - Jianjun Qiao
- Key Laboratory of Systems Bioengineering, Ministry of Education (Tianjin University) and Frontiers Science Center for Synthetic Biology (Ministry of Education), Tianjin University, Tianjin, China
| |
Collapse
|
7
|
Structure dictates the mechanism of ligand recognition in the histidine and maltose binding proteins. Curr Res Struct Biol 2020; 2:180-190. [PMID: 34235478 PMCID: PMC8244415 DOI: 10.1016/j.crstbi.2020.08.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 07/26/2020] [Accepted: 08/06/2020] [Indexed: 12/21/2022] Open
Abstract
Two mechanisms, induced fit (IF) and conformational selection (CS), have been proposed to explain ligand recognition coupled conformational changes. The histidine binding protein (HisJ) adopts the CS mechanism, in which a pre-equilibrium is established between the open and the closed states with the ligand binding to the closed state. Despite being structurally similar to HisJ, the maltose binding protein (MBP) adopts the IF mechanism, in which the ligand binds the open state and induces a transition to the closed state. To understand the molecular determinants of this difference, we performed molecular dynamics (MD) simulations of coarse-grained dual structure based models. We find that intra-protein contacts unique to the closed state are sufficient to promote the conformational transition in HisJ, indicating a CS-like mechanism. In contrast, additional ligand-mimicking contacts are required to “induce” the conformational transition in MBP suggesting an IF-like mechanism. In agreement with experiments, destabilizing modifications to two structural features, the spine helix (SH) and the balancing interface (BI), present in MBP but absent in HisJ, reduce the need for ligand-mimicking contacts indicating that SH and BI act as structural restraints that keep MBP in the open state. We introduce an SH like element into HisJ and observe that this can impede the conformational transition increasing the importance of ligand-mimicking contacts. Similarly, simultaneous mutations to BI and SH in MBP reduce the barrier to conformational transitions significantly and promote a CS-like mechanism. Together, our results show that structural restraints present in the protein structure can determine the mechanism of conformational transitions and even simple models that correctly capture such structural features can predict their positions. MD simulations of such models can thus be used, in conjunction with mutational experiments, to regulate protein ligand interactions, and modulate ligand binding affinities. MBP operates by induced fit, HisJ by the conformational selection mechanism. Dual structure based models (dSBMs) encode two structures of a protein. MD simulations of dSBMs can identify the mechanism of conformational transitions. Locks, absent in HisJ, hold MBP open with ligand contacts required for closing. Binding mechanisms can be modified by altering such structural locks.
Collapse
Key Words
- BI, Balancing interface
- CS, conformational selection
- CTD, C-terminal domain
- Conformational selection
- Dual structure based models
- FEP, free energy profile
- HisJ, histidine binding protein
- IF, induced fit
- Induced fit
- MBP, maltose binding protein
- MD simulations
- MD, molecular dynamics
- NTD, N-terminal domain
- PBP, periplasmic binding protein
- Periplasmic binding proteins
- SH, spine helix
- Structural restraints
- WT, wild-type
- dSBM, dual structure-based model
- sSBM, single structure-based model
Collapse
|
8
|
Gleason PR, Kelly PI, Grisingher DW, Mills JH. An intrinsic FRET sensor of protein-ligand interactions. Org Biomol Chem 2020; 18:4079-4084. [PMID: 32427252 PMCID: PMC7313717 DOI: 10.1039/d0ob00793e] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We describe an approach for the development of fluorescent sensors of metabolite binding in which a genetically encoded fluorescent non-canonical amino acid (fNCAA) containing a 7-hydroxycoumarin moiety (7-HCAA) forms a FRET pair with native tryptophan residues. Although previous studies demonstrated the potential for using 7-HCAA as an acceptor for tryptophan, this approach has not yet been explored within a single protein containing multiple tryptophan residues. A structure-based analysis of a hexokinase enzyme with multiple native tryptophan residues identified glutamate 50 as a potential site of 7-HCAA incorporation; Glu50 moves closer to the native tryptophans upon substrate binding. Substitution of 7-HCAA at residue 50 led to an increase in FRET efficiency in the presence of the substrate; this effect was not observed in a control protein where no change in distance between 7-HCAA and the native tryptophans occurs on substrate binding. This system was then used to directly observe differences in binding affinity of the hexokinase that occur at a number of pH values. Our approach builds on previous research in that it eliminates the need for the incorporation of multiple fNCAAs or fluorescent labels within a target protein and can be used to study substrate binding with native ligands. As such, it serves to expand the versatility of FRET-based techniques.
Collapse
Affiliation(s)
- Patrick R Gleason
- School of Molecular Sciences and The Biodesign Center for Molecular Design and Biomimetics, Arizona State University, Tempe, AZ 85287, USA.
| | | | | | | |
Collapse
|
9
|
Tripathi SK, Salunke DM. Exploring the different states of wild-type T-cell receptor and mutant conformational changes towards understanding the antigen recognition. J Biomol Struct Dyn 2020; 39:188-201. [PMID: 31870204 DOI: 10.1080/07391102.2019.1708795] [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: 10/25/2022]
Abstract
Recognition of proteolytic peptide fragments presented by major histocompatibility complex (MHC) on target cells by T-cell receptor (TCR) is among the most important interactions in the adaptive immune system. Several computational studies have been performed to investigate conformational and dynamical properties of TCRs for enhanced immunogenicity. Here, we present the large-scale molecular dynamics (MD) simulation studies of the two comprehensive systems consisting of the wild-type and mutant IG4 TCR in complex with the tumor epitope NY-ESO peptide (SLLMWITQC) and analyzed for mapping conformational changes of TCR in the states prior to antigen binding, upon antigen binding and after the antigen was released. All of the simulations were performed with different states of TCRs for each 1000 ns of simulation time, providing six simulations for time duration of 6000 ns (6µs). We show that rather than undergoing most critical conformational changes upon antigen binding, the high proportion of complementarity-determining region (CDR) loops change by comparatively small amount. The hypervariable CDRα3 and CDRβ3 loops showed significant structural changes. Interestingly, the TCR β chain loops showed the least changes, which is reliable with recent implications that β domain of TCR may propel antigen interaction. The mutant shows higher rigidity than wild-type even in released state; expose an induced fit mechanism occurring from the re-structuring of CDRα3 loop and can allow enhanced binding affinity of the peptide antigen. Additionally, we show that CDRα3 loop and peptide contacts are an adaptive feature of affinity enhanced mutant TCR.Communicated by Ramaswamy H. Sarma.
Collapse
Affiliation(s)
- Sunil Kumar Tripathi
- Structural Immunology Group, Regional Centre for Biotechnology, NCR Biotech Science Cluster, Faridabad, India
| | - Dinakar M Salunke
- Structural Immunology Group, Regional Centre for Biotechnology, NCR Biotech Science Cluster, Faridabad, India.,Structural Immunology Group, International Centre for Genetic Engineering and Biotechnology (ICGEB), New Delhi, India
| |
Collapse
|
10
|
Chang KC, Salawu EO, Chang YY, Wen JD, Yang LW. Resolution-exchanged structural modeling and simulations jointly unravel that subunit rolling underlies the mechanism of programmed ribosomal frameshifting. Bioinformatics 2019; 35:945-952. [PMID: 30169551 DOI: 10.1093/bioinformatics/bty762] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Revised: 07/26/2018] [Accepted: 08/28/2018] [Indexed: 12/20/2022] Open
Abstract
MOTIVATION Programmed ribosomal frameshifting (PRF) is widely used by viruses and bacteria to produce different proteins from a single mRNA template. How steric hindrance of a PRF-stimulatory mRNA structure transiently modifies the conformational dynamics of the ribosome, and thereby allows tRNA slippage, remains elusive. RESULTS Here, we leverage linear response theories and resolution-exchanged simulations to construct a structural/dynamics model that connects and rationalizes existing structural, single-molecule and mutagenesis data by resolution-exchanged structural modelling and simulations. Our combined theoretical techniques provide a temporal and spatial description of PRF with unprecedented mechanistic details. We discover that ribosomal unfolding of the PRF-stimulating pseudoknot exerts resistant forces on the mRNA entrance of the ribosome, and thereby drives 30S subunit rolling. Such motion distorts tRNAs, leads to tRNA slippage, and in turn serves as a delicate control of cis-element's unwinding forces over PRF. AVAILABILITY AND IMPLEMENTATION All the simulation scripts and computational implementations of our methods/analyses (including linear response theory) are included in the bioStructureM suite, provided through GitHub at https://github.com/Yuan-Yu/bioStructureM. SUPPLEMENTARY INFORMATION Supplementary data are available at Bioinformatics online.
Collapse
Affiliation(s)
- Kai-Chun Chang
- Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, Taiwan
| | - Emmanuel Oluwatobi Salawu
- Institute of Bioinformatics and Structural Biology, National Tsing Hua University, Hsinchu, Taiwan.,TIGP Bioinformatics Program, Institute of Information Sciences, Academia Sinica, Taipei, Taiwan
| | - Yuan-Yu Chang
- Institute of Bioinformatics and Structural Biology, National Tsing Hua University, Hsinchu, Taiwan
| | - Jin-Der Wen
- Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, Taiwan
| | - Lee-Wei Yang
- Institute of Bioinformatics and Structural Biology, National Tsing Hua University, Hsinchu, Taiwan.,TIGP Bioinformatics Program, Institute of Information Sciences, Academia Sinica, Taipei, Taiwan.,Physics Division, National Center for Theoretical Sciences, Hsinchu, Taiwan
| |
Collapse
|
11
|
ART-RRT: As-Rigid-As-Possible search for protein conformational transition paths. J Comput Aided Mol Des 2019; 33:705-727. [PMID: 31435895 DOI: 10.1007/s10822-019-00216-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Accepted: 08/06/2019] [Indexed: 10/26/2022]
Abstract
The possible functions of a protein are strongly related to its structural rearrangements in the presence of other molecules or environmental changes. Hence, the evaluation of transition paths of proteins, which encodes conformational changes between stable states, is important since it may reveal the underlying mechanisms of the biochemical processes related to these motions. During the last few decades, different geometry-based methods have been proposed to predict such transition paths. However, in the cases where the solution requires complex motions, these methods, which typically constrain only locally the molecular structures, could produce physically irrelevant solutions involving self-intersection. Recently, we have proposed ART-RRT, an efficient method for finding ligand-unbinding pathways. It relies on the exploration of energy valleys in low-dimensional spaces, taking advantage of some mechanisms inspired from computer graphics to ensure the consistency of molecular structures. This article extends ART-RRT to the problem of finding probable conformational transition between two stable states for proteins. It relies on a bidirectional exploration rooted on the two end states and introduces an original strategy to attempt connections between the explored regions. The resulting method is able to produce at low computational cost biologically realistic paths free from self-intersection. These paths can serve as valuable input to other advanced methods for the study of proteins. A better understanding of conformational changes of proteins is important since it may reveal the underlying mechanisms of the biochemical processes related to such motions. Recently, the ART-RRT method has been introduced for finding ligand-unbinding pathways. This article presents an adaptation of the method for finding probable conformational transition between two stable states of a protein. The method is not only computationally cost-effective but also able to produce biologically realistic paths which are free from self-intersection.
Collapse
|
12
|
Ensembles from Ordered and Disordered Proteins Reveal Similar Structural Constraints during Evolution. J Mol Biol 2019; 431:1298-1307. [DOI: 10.1016/j.jmb.2019.01.031] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Revised: 01/23/2019] [Accepted: 01/24/2019] [Indexed: 01/08/2023]
|
13
|
Clark JJ, Benson ML, Smith RD, Carlson HA. Inherent versus induced protein flexibility: Comparisons within and between apo and holo structures. PLoS Comput Biol 2019; 15:e1006705. [PMID: 30699115 PMCID: PMC6370239 DOI: 10.1371/journal.pcbi.1006705] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Revised: 02/11/2019] [Accepted: 12/07/2018] [Indexed: 11/18/2022] Open
Abstract
Understanding how ligand binding influences protein flexibility is important, especially in rational drug design. Protein flexibility upon ligand binding is analyzed herein using 305 proteins with 2369 crystal structures with ligands (holo) and 1679 without (apo). Each protein has at least two apo and two holo structures for analysis. The inherent variation in structures with and without ligands is first established as a baseline. This baseline is then compared to the change in conformation in going from the apo to holo states to probe induced flexibility. The inherent backbone flexibility across the apo structures is roughly the same as the variation across holo structures. The induced backbone flexibility across apo-holo pairs is larger than that of the apo or holo states, but the increase in RMSD is less than 0.5 Å. Analysis of χ1 angles revealed a distinctly different pattern with significant influences seen for ligand binding on side-chain conformations in the binding site. Within the apo and holo states themselves, the variation of the χ1 angles is the same. However, the data combining both apo and holo states show significant displacements. Upon ligand binding, χ1 angles are frequently pushed to new orientations outside the range seen in the apo states. Influences on binding-site variation could not be easily attributed to features such as ligand size or x-ray structure resolution. By combining these findings, we find that most binding site flexibility is compatible with the common practice in flexible docking, where backbones are kept rigid and side chains are allowed some degree of flexibility.
Collapse
Affiliation(s)
- Jordan J. Clark
- Department of Medicinal Chemistry, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Mark L. Benson
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Richard D. Smith
- Department of Medicinal Chemistry, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Heather A. Carlson
- Department of Medicinal Chemistry, University of Michigan, Ann Arbor, Michigan, United States of America
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, Michigan, United States of America
- * E-mail:
| |
Collapse
|
14
|
Abstract
The native state of proteins is composed of conformers in dynamical equilibrium. In this chapter, different issues related to conformational diversity are explored using a curated and experimentally based database called CoDNaS (Conformational Diversity in the Native State). This database is a collection of redundant structures for the same sequence. CoDNaS estimates the degree of conformational diversity using different global and local structural similarity measures. It allows the user to explore how structural differences among conformers change as a function of several structural features providing further biological information. This chapter explores the measurement of conformational diversity and its relationship with sequence divergence. Also, it discusses how proteins with high conformational diversity could affect homology modeling techniques.
Collapse
Affiliation(s)
- Alexander Miguel Monzon
- Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, CONICET, Bernal, Argentina
| | - Maria Silvina Fornasari
- Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, CONICET, Bernal, Argentina
| | - Diego Javier Zea
- Structural Bioinformatics Unit, Fundación Instituto Leloir, CONICET, Buenos Aires, Argentina
| | - Gustavo Parisi
- Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, CONICET, Bernal, Argentina.
| |
Collapse
|
15
|
Marks C, Shi J, Deane CM. Predicting loop conformational ensembles. Bioinformatics 2018; 34:949-956. [PMID: 29136084 DOI: 10.1093/bioinformatics/btx718] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Accepted: 11/09/2017] [Indexed: 12/23/2022] Open
Abstract
Motivation Protein function is often facilitated by the existence of multiple stable conformations. Structure prediction algorithms need to be able to model these different conformations accurately and produce an ensemble of structures that represent a target's conformational diversity rather than just a single state. Here, we investigate whether current loop prediction algorithms are capable of this. We use the algorithms to predict the structures of loops with multiple experimentally determined conformations, and the structures of loops with only one conformation, and assess their ability to generate and select decoys that are close to any, or all, of the observed structures. Results We find that while loops with only one known conformation are predicted well, conformationally diverse loops are modelled poorly, and in most cases the predictions returned by the methods do not resemble any of the known conformers. Our results contradict the often-held assumption that multiple native conformations will be present in the decoy set, making the production of accurate conformational ensembles impossible, and hence indicating that current methodologies are not well suited to prediction of conformationally diverse, often functionally important protein regions. Contact marks@stats.ox.ac.uk. Supplementary information Supplementary data are available at Bioinformatics online.
Collapse
Affiliation(s)
- Claire Marks
- Department of Statistics, University of Oxford, Oxford OX1 3LB, UK
| | - Jiye Shi
- Department of Chemistry, UCB Pharma, Slough SL1 3WE, UK
| | | |
Collapse
|
16
|
Veevers R, Hayward S. Morphing and docking visualisation of biomolecular structures using Multi-Dimensional Scaling. J Mol Graph Model 2018; 82:108-116. [PMID: 29729647 DOI: 10.1016/j.jmgm.2018.04.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 04/20/2018] [Accepted: 04/22/2018] [Indexed: 11/28/2022]
Abstract
Protein structures are often solved at atomic resolution in two states defining a functional movement but intervening conformations are usually unknown. Morphing methods generate intervening conformations between two known structures. When viewed as an animation using molecular graphics, a smooth, direct morph enables the eye to track changes in structure that might be otherwise missed. We present a morphing method that aims to linearly interpolate interatomic distances and which uses SMACOF (Scaling by MAjorisation of COmplicated Function) and multigrid techniques with a cut-off distance based weighting that optimizes the MolProbity score of intervening structures. The all-atom morphs are smooth, move directly between the two structures, and are shown, in general, to pass closer to a set of known intermediates than those generated using other methods. The techniques are also used for docking by putting the unbound structures in a "near-approach pose" and then morphing to the bound complex. The resulting GPU-accelerated tools are available on a webserver, Morphit_Pro, at http://morphit-pro.cmp.uea.ac.uk/ and more than 5000 domains movements available at the DynDom website can now be viewed as morphs http://morphit-pro.cmp.uea.ac.uk/dyndom/.
Collapse
Affiliation(s)
- Ruth Veevers
- Computational Biology Laboratory, School of Computing Sciences, University of East Anglia, Norwich, NR4 7TJ, UK
| | - Steven Hayward
- Computational Biology Laboratory, School of Computing Sciences, University of East Anglia, Norwich, NR4 7TJ, UK.
| |
Collapse
|
17
|
Wako H, Endo S. Normal mode analysis as a method to derive protein dynamics information from the Protein Data Bank. Biophys Rev 2017; 9:877-893. [PMID: 29103094 DOI: 10.1007/s12551-017-0330-2] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Accepted: 10/04/2017] [Indexed: 11/30/2022] Open
Abstract
Normal mode analysis (NMA) can facilitate quick and systematic investigation of protein dynamics using data from the Protein Data Bank (PDB). We developed an elastic network model-based NMA program using dihedral angles as independent variables. Compared to the NMA programs that use Cartesian coordinates as independent variables, key attributes of the proposed program are as follows: (1) chain connectivity related to the folding pattern of a polypeptide chain is naturally embedded in the model; (2) the full-atom system is acceptable, and owing to a considerably smaller number of independent variables, the PDB data can be used without further manipulation; (3) the number of variables can be easily reduced by some of the rotatable dihedral angles; (4) the PDB data for any molecule besides proteins can be considered without coarse-graining; and (5) individual motions of constituent subunits and ligand molecules can be easily decomposed into external and internal motions to examine their mutual and intrinsic motions. Its performance is illustrated with an example of a DNA-binding allosteric protein, a catabolite activator protein. In particular, the focus is on the conformational change upon cAMP and DNA binding, and on the communication between their binding sites remotely located from each other. In this illustration, NMA creates a vivid picture of the protein dynamics at various levels of the structures, i.e., atoms, residues, secondary structures, domains, subunits, and the complete system, including DNA and cAMP. Comparative studies of the specific protein in different states, e.g., apo- and holo-conformations, and free and complexed configurations, provide useful information for studying structurally and functionally important aspects of the protein.
Collapse
Affiliation(s)
- Hiroshi Wako
- School of Social Sciences, Waseda University, Tokyo, 169-8050, Japan.
| | - Shigeru Endo
- Department of Physics, School of Science, Kitasato University, Sagamihara, 252-0373, Japan
| |
Collapse
|
18
|
Gao C, Desaphy J, Vieth M. Are induced fit protein conformational changes caused by ligand-binding predictable? A molecular dynamics investigation. J Comput Chem 2017; 38:1229-1237. [PMID: 28419481 DOI: 10.1002/jcc.24714] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 12/06/2016] [Accepted: 12/09/2016] [Indexed: 01/04/2023]
Abstract
In this work, the ability of molecular dynamics simulations (MD) to prospectively predict regions of ligand binding sites that could undergo induced fit effects was investigated. Conventional MD was run on 39 apo structures (no ligand), and the resulting trajectories were compared to a set of 147 holo X-ray structures (ligand-bound). It was observed from the simulations, in the absence of the ligands, that structures exhibiting large residue conformational changes indicated higher likelihood of induced fit effects. Nevertheless, the simulation results did not perform better than using the normalized crystallographic structural factors as predictors of active-site rigid residues (87% predictive power) and mobile residues (47% predictive power). While the simulations could not produce full active sites conformations similar to holo-like states, it was found that the simulations could reproduce bound state conformations of individual residues. These results suggest potential issues in the use of unligated simulation frames directly for drug design applications such as ligand docking, and an overall caution in the use of protein flexibility in docking protocols should be emphasized. © 2017 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Cen Gao
- Discovery chemistry, Lilly Research Laboratories, Eli Lilly and Company, Lilly Corporate Center, Discovery Chemistry Research and Technologies, DC 1931, Indianapolis, Indiana, 46285
| | - Jeremy Desaphy
- Discovery chemistry, Lilly Research Laboratories, Eli Lilly and Company, Lilly Corporate Center, Discovery Chemistry Research and Technologies, DC 1931, Indianapolis, Indiana, 46285
| | - Michal Vieth
- Discovery Chemistry Research, Lilly Biotechnology Center, San Diego, California 92121
| |
Collapse
|
19
|
Jian JW, Elumalai P, Pitti T, Wu CY, Tsai KC, Chang JY, Peng HP, Yang AS. Predicting Ligand Binding Sites on Protein Surfaces by 3-Dimensional Probability Density Distributions of Interacting Atoms. PLoS One 2016; 11:e0160315. [PMID: 27513851 PMCID: PMC4981321 DOI: 10.1371/journal.pone.0160315] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Accepted: 07/18/2016] [Indexed: 11/18/2022] Open
Abstract
Predicting ligand binding sites (LBSs) on protein structures, which are obtained either from experimental or computational methods, is a useful first step in functional annotation or structure-based drug design for the protein structures. In this work, the structure-based machine learning algorithm ISMBLab-LIG was developed to predict LBSs on protein surfaces with input attributes derived from the three-dimensional probability density maps of interacting atoms, which were reconstructed on the query protein surfaces and were relatively insensitive to local conformational variations of the tentative ligand binding sites. The prediction accuracy of the ISMBLab-LIG predictors is comparable to that of the best LBS predictors benchmarked on several well-established testing datasets. More importantly, the ISMBLab-LIG algorithm has substantial tolerance to the prediction uncertainties of computationally derived protein structure models. As such, the method is particularly useful for predicting LBSs not only on experimental protein structures without known LBS templates in the database but also on computationally predicted model protein structures with structural uncertainties in the tentative ligand binding sites.
Collapse
Affiliation(s)
- Jhih-Wei Jian
- Genomics Research Center, Academia Sinica, Taipei, Taiwan 115
- Institute of Biomedical Informatics, National Yang-Ming University, Taipei, Taiwan 11221
- Bioinformatics Program, Taiwan International Graduate Program, Institute of Information Science, Academia Sinica, Taipei, Taiwan 115
| | | | - Thejkiran Pitti
- Genomics Research Center, Academia Sinica, Taipei, Taiwan 115
- Bioinformatics Program, Taiwan International Graduate Program, Institute of Information Science, Academia Sinica, Taipei, Taiwan 115
- Institute of Bioinformatics and Structural Biology, National Tsing Hua University, Hsinchu, Taiwan 30013
| | - Chih Yuan Wu
- Genomics Research Center, Academia Sinica, Taipei, Taiwan 115
| | - Keng-Chang Tsai
- Genomics Research Center, Academia Sinica, Taipei, Taiwan 115
| | - Jeng-Yih Chang
- Genomics Research Center, Academia Sinica, Taipei, Taiwan 115
| | - Hung-Pin Peng
- Genomics Research Center, Academia Sinica, Taipei, Taiwan 115
| | - An-Suei Yang
- Genomics Research Center, Academia Sinica, Taipei, Taiwan 115
- * E-mail:
| |
Collapse
|
20
|
Sacquin-Mora S. Bridging Enzymatic Structure Function via Mechanics: A Coarse-Grain Approach. Methods Enzymol 2016; 578:227-48. [PMID: 27497169 DOI: 10.1016/bs.mie.2016.05.022] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Flexibility is a central aspect of protein function, and ligand binding in enzymes involves a wide range of structural changes, ranging from large-scale domain movements to small loop or side-chain rearrangements. In order to understand how the mechanical properties of enzymes, and the mechanical variations that are induced by ligand binding, relate to enzymatic activity, we carried out coarse-grain Brownian dynamics simulations on a set of enzymes whose structures in the unbound and ligand-bound forms are available in the Protein Data Bank. Our results show that enzymes are remarkably heterogeneous objects from a mechanical point of view and that the local rigidity of individual residues is tightly connected to their part in the protein's overall structure and function. The systematic comparison of the rigidity of enzymes in their unbound and bound forms highlights the fact that small conformational changes can induce large mechanical effects, leading to either more or less flexibility depending on the enzyme's architecture and the location of its ligand-biding site. These mechanical variations target a limited number of specific residues that occupy key locations for enzymatic activity, and our approach thus offers a mean to detect perturbation-sensitive sites in enzymes, where the addition or removal of a few interactions will lead to important changes in the proteins internal dynamics.
Collapse
Affiliation(s)
- S Sacquin-Mora
- Laboratoire de Biochimie Théorique, CNRS UPR9080, Institut de Biologie Physico-Chimique, Paris, France.
| |
Collapse
|
21
|
Chang CW, Chou CW, Chang DTH. CCProf: exploring conformational change profile of proteins. DATABASE-THE JOURNAL OF BIOLOGICAL DATABASES AND CURATION 2016; 2016:baw029. [PMID: 27016699 PMCID: PMC4808249 DOI: 10.1093/database/baw029] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Accepted: 02/23/2016] [Indexed: 12/18/2022]
Abstract
In many biological processes, proteins have important interactions with various molecules such as proteins, ions or ligands. Many proteins undergo conformational changes upon these interactions, where regions with large conformational changes are critical to the interactions. This work presents the CCProf platform, which provides conformational changes of entire proteins, named conformational change profile (CCP) in the context. CCProf aims to be a platform where users can study potential causes of novel conformational changes. It provides 10 biological features, including conformational change, potential binding target site, secondary structure, conservation, disorder propensity, hydropathy propensity, sequence domain, structural domain, phosphorylation site and catalytic site. All these information are integrated into a well-aligned view, so that researchers can capture important relevance between different biological features visually. The CCProf contains 986 187 protein structure pairs for 3123 proteins. In addition, CCProf provides a 3D view in which users can see the protein structures before and after conformational changes as well as binding targets that induce conformational changes. All information (e.g. CCP, binding targets and protein structures) shown in CCProf, including intermediate data are available for download to expedite further analyses. Database URL: http://zoro.ee.ncku.edu.tw/ccprof/
Collapse
Affiliation(s)
- Che-Wei Chang
- Department of Electrical Engineering, National Cheng Kung University, Tainan, 70101, Taiwan
| | - Chai-Wei Chou
- Department of Electrical Engineering, National Cheng Kung University, Tainan, 70101, Taiwan
| | - Darby Tien-Hao Chang
- Department of Electrical Engineering, National Cheng Kung University, Tainan, 70101, Taiwan
| |
Collapse
|
22
|
Fox NK, Brenner SE, Chandonia JM. The value of protein structure classification information-Surveying the scientific literature. Proteins 2015; 83:2025-38. [PMID: 26313554 PMCID: PMC4609302 DOI: 10.1002/prot.24915] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Revised: 08/06/2015] [Accepted: 08/18/2015] [Indexed: 11/08/2022]
Abstract
The Structural Classification of Proteins (SCOP) and Class, Architecture, Topology, Homology (CATH) databases have been valuable resources for protein structure classification for over 20 years. Development of SCOP (version 1) concluded in June 2009 with SCOP 1.75. The SCOPe (SCOP-extended) database offers continued development of the classic SCOP hierarchy, adding over 33,000 structures. We have attempted to assess the impact of these two decade old resources and guide future development. To this end, we surveyed recent articles to learn how structure classification data are used. Of 571 articles published in 2012-2013 that cite SCOP, 439 actually use data from the resource. We found that the type of use was fairly evenly distributed among four top categories: A) study protein structure or evolution (27% of articles), B) train and/or benchmark algorithms (28% of articles), C) augment non-SCOP datasets with SCOP classification (21% of articles), and D) examine the classification of one protein/a small set of proteins (22% of articles). Most articles described computational research, although 11% described purely experimental research, and a further 9% included both. We examined how CATH and SCOP were used in 158 articles that cited both databases: while some studies used only one dataset, the majority used data from both resources. Protein structure classification remains highly relevant for a diverse range of problems and settings.
Collapse
Affiliation(s)
- Naomi K Fox
- Lawrence Berkeley National Laboratory, Physical Biosciences Division, Berkeley, California, 94720
| | - Steven E Brenner
- Lawrence Berkeley National Laboratory, Physical Biosciences Division, Berkeley, California, 94720.,Department of Plant and Microbial Biology, University of California, Berkeley, California, 94720
| | - John-Marc Chandonia
- Lawrence Berkeley National Laboratory, Physical Biosciences Division, Berkeley, California, 94720
| |
Collapse
|
23
|
Frappier V, Chartier M, Najmanovich RJ. ENCoM server: exploring protein conformational space and the effect of mutations on protein function and stability. Nucleic Acids Res 2015; 43:W395-400. [PMID: 25883149 PMCID: PMC4489264 DOI: 10.1093/nar/gkv343] [Citation(s) in RCA: 118] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Revised: 03/27/2015] [Accepted: 04/06/2015] [Indexed: 11/24/2022] Open
Abstract
ENCoM is a coarse-grained normal mode analysis method recently introduced that unlike previous such methods is unique in that it accounts for the nature of amino acids. The inclusion of this layer of information was shown to improve conformational space sampling and apply for the first time a coarse-grained normal mode analysis method to predict the effect of single point mutations on protein dynamics and thermostability resulting from vibrational entropy changes. Here we present a web server that allows non-technical users to have access to ENCoM calculations to predict the effect of mutations on thermostability and dynamics as well as to generate geometrically realistic conformational ensembles. The server is accessible at: http://bcb.med.usherbrooke.ca/encom.
Collapse
Affiliation(s)
- Vincent Frappier
- Department of Biochemistry, Faculty of Medicine and Health Sciences, University of Sherbrooke, Sherbrooke, Quebec, J1H 5N4, Canada
| | - Matthieu Chartier
- Department of Biochemistry, Faculty of Medicine and Health Sciences, University of Sherbrooke, Sherbrooke, Quebec, J1H 5N4, Canada
| | - Rafael J Najmanovich
- Department of Biochemistry, Faculty of Medicine and Health Sciences, University of Sherbrooke, Sherbrooke, Quebec, J1H 5N4, Canada
| |
Collapse
|
24
|
Exploring the interaction between the antiallergic drug, tranilast and human serum albumin: Insights from calorimetric, spectroscopic and modeling studies. Int J Pharm 2015; 491:352-8. [PMID: 26142245 DOI: 10.1016/j.ijpharm.2015.06.042] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Revised: 06/23/2015] [Accepted: 06/23/2015] [Indexed: 11/21/2022]
Abstract
The interaction of tranilast (TRN), an antiallergic drug with the main drug transporter in human circulation, human serum albumin (HSA) was studied using isothermal titration calorimetry (ITC), fluorescence spectroscopy and in silico docking methods. ITC data revealed the binding constant and stoichiometry of binding as (3.21 ± 0.23) × 10(6)M(-1) and 0.80 ± 0.08, respectively, at 25°C. The values of the standard enthalpy change (ΔH°) and the standard entropy change (ΔS°) for the interaction were found as -25.2 ± 5.1 kJ mol(-1) and 46.9 ± 5.4 J mol(-1)K(-1), respectively. Both thermodynamic data and modeling results suggested the involvement of hydrogen bonding, hydrophobic and van der Waals forces in the complex formation. Three-dimensional fluorescence data of TRN-HSA complex demonstrated significant changes in the microenvironment around the protein fluorophores upon drug binding. Competitive drug displacement results as well as modeling data concluded the preferred binding site of TRN as Sudlow's site I on HSA.
Collapse
|
25
|
Li W, Kinch LN, Karplus PA, Grishin NV. ChSeq: A database of chameleon sequences. Protein Sci 2015; 24:1075-86. [PMID: 25970262 DOI: 10.1002/pro.2689] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Revised: 04/15/2015] [Accepted: 04/24/2015] [Indexed: 11/11/2022]
Abstract
Chameleon sequences (ChSeqs) refer to sequence strings of identical amino acids that can adopt different conformations in protein structures. Researchers have detected and studied ChSeqs to understand the interplay between local and global interactions in protein structure formation. The different secondary structures adopted by one ChSeq challenge sequence-based secondary structure predictors. With increasing numbers of available Protein Data Bank structures, we here identify a large set of ChSeqs ranging from 6 to 10 residues in length. The homologous ChSeqs discovered highlight the structural plasticity involved in biological function. When compared with previous studies, the set of unrelated ChSeqs found represents an about 20-fold increase in the number of detected sequences, as well as an increase in the longest ChSeq length from 8 to 10 residues. We applied secondary structure predictors on our ChSeqs and found that methods based on a sequence profile outperformed methods based on a single sequence. For the unrelated ChSeqs, the evolutionary information provided by the sequence profile typically allows successful prediction of the prevailing secondary structure adopted in each protein family. Our dataset will facilitate future studies of ChSeqs, as well as interpretations of the interplay between local and nonlocal interactions. A user-friendly web interface for this ChSeq database is available at prodata.swmed.edu/chseq.
Collapse
Affiliation(s)
- Wenlin Li
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas, 75390-9050.,Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas, 75390-9050
| | - Lisa N Kinch
- Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, Texas, 75390-9050
| | - P Andrew Karplus
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, Oregon, 97331
| | - Nick V Grishin
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas, 75390-9050.,Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas, 75390-9050.,Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, Texas, 75390-9050
| |
Collapse
|
26
|
Ligand-induced protein responses and mechanical signal propagation described by linear response theories. Biophys J 2015; 107:1415-25. [PMID: 25229149 DOI: 10.1016/j.bpj.2014.07.049] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Revised: 06/18/2014] [Accepted: 07/15/2014] [Indexed: 02/04/2023] Open
Abstract
In this study, a general linear response theory (LRT) is formulated to describe time-dependent and -independent protein conformational changes upon CO binding with myoglobin. Using the theory, we are able to monitor protein relaxation in two stages. The slower relaxation is found to occur from 4.4 to 81.2 picoseconds and the time constants characterized for a couple of aromatic residues agree with those observed by UV Resonance Raman (UVRR) spectrometry and time resolved x-ray crystallography. The faster "early responses", triggered as early as 400 femtoseconds, can be best described by the theory when impulse forces are used. The newly formulated theory describes the mechanical propagation following ligand-binding as a function of time, space and types of the perturbation forces. The "disseminators", defined as the residues that propagate signals throughout the molecule the fastest among all the residues in protein when perturbed, are found evolutionarily conserved and the mutations of which have been shown to largely change the CO rebinding kinetics in myoglobin.
Collapse
|
27
|
Nussinov R, Tsai CJ, Liu J. Principles of allosteric interactions in cell signaling. J Am Chem Soc 2014; 136:17692-701. [PMID: 25474128 PMCID: PMC4291754 DOI: 10.1021/ja510028c] [Citation(s) in RCA: 111] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Indexed: 02/07/2023]
Abstract
Linking cell signaling events to the fundamental physicochemical basis of the conformational behavior of single molecules and ultimately to cellular function is a key challenge facing the life sciences. Here we outline the emerging principles of allosteric interactions in cell signaling, with emphasis on the following points. (1) Allosteric efficacy is not a function of the chemical composition of the allosteric pocket but reflects the extent of the population shift between the inactive and active states. That is, the allosteric effect is determined by the extent of preferred binding, not by the overall binding affinity. (2) Coupling between the allosteric and active sites does not decide the allosteric effect; however, it does define the propagation pathways, the allosteric binding sites, and key on-path residues. (3) Atoms of allosteric effectors can act as "driver" or "anchor" and create attractive "pulling" or repulsive "pushing" interactions. Deciphering, quantifying, and integrating the multiple co-occurring events present daunting challenges to our scientific community.
Collapse
Affiliation(s)
- Ruth Nussinov
- Cancer
and Inflammation Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research,
National Cancer Institute, Frederick, Maryland 21702, United States
- Sackler
Institute of Molecular Medicine, Department of Human Genetics and
Molecular Medicine, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Chung-Jung Tsai
- Cancer
and Inflammation Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research,
National Cancer Institute, Frederick, Maryland 21702, United States
| | - Jin Liu
- Department
of Biophysics, University of Texas Southwestern
Medical Center, 5323
Harry Hines Boulevard, Dallas, Texas 75390, United
States
- Department
of Chemistry, Center for Drug Discovery, Design, and Delivery (CD4),
and Center for Scientific Computation, Southern
Methodist University, 3215 Daniel Avenue, Dallas, Texas 75275, United
States
| |
Collapse
|
28
|
Desaphy J, Bret G, Rognan D, Kellenberger E. sc-PDB: a 3D-database of ligandable binding sites--10 years on. Nucleic Acids Res 2014; 43:D399-404. [PMID: 25300483 PMCID: PMC4384012 DOI: 10.1093/nar/gku928] [Citation(s) in RCA: 146] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The sc-PDB database (available at http://bioinfo-pharma.u-strasbg.fr/scPDB/) is a comprehensive and up-to-date selection of ligandable binding sites of the Protein Data Bank. Sites are defined from complexes between a protein and a pharmacological ligand. The database provides the all-atom description of the protein, its ligand, their binding site and their binding mode. Currently, the sc-PDB archive registers 9283 binding sites from 3678 unique proteins and 5608 unique ligands. The sc-PDB database was publicly launched in 2004 with the aim of providing structure files suitable for computational approaches to drug design, such as docking. During the last 10 years we have improved and standardized the processes for (i) identifying binding sites, (ii) correcting structures, (iii) annotating protein function and ligand properties and (iv) characterizing their binding mode. This paper presents the latest enhancements in the database, specifically pertaining to the representation of molecular interaction and to the similarity between ligand/protein binding patterns. The new website puts emphasis in pictorial analysis of data.
Collapse
Affiliation(s)
- Jérémy Desaphy
- Laboratoire d'innovation thérapeutique, Medalis Drug Discovery Center, UMR7200 CNRS-Université de Strasbourg, F-67400 Illkirch, France
| | - Guillaume Bret
- Laboratoire d'innovation thérapeutique, Medalis Drug Discovery Center, UMR7200 CNRS-Université de Strasbourg, F-67400 Illkirch, France
| | - Didier Rognan
- Laboratoire d'innovation thérapeutique, Medalis Drug Discovery Center, UMR7200 CNRS-Université de Strasbourg, F-67400 Illkirch, France
| | - Esther Kellenberger
- Laboratoire d'innovation thérapeutique, Medalis Drug Discovery Center, UMR7200 CNRS-Université de Strasbourg, F-67400 Illkirch, France
| |
Collapse
|
29
|
Negami T, Shimizu K, Terada T. Coarse-grained molecular dynamics simulations of protein-ligand binding. J Comput Chem 2014; 35:1835-45. [PMID: 25043724 DOI: 10.1002/jcc.23693] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Revised: 07/06/2014] [Accepted: 07/09/2014] [Indexed: 01/25/2023]
Abstract
Coarse-grained molecular dynamics (CGMD) simulations with the MARTINI force field were performed to reproduce the protein-ligand binding processes. We chose two protein-ligand systems, the levansucrase-sugar (glucose or sucrose), and LinB-1,2-dichloroethane systems, as target systems that differ in terms of the size and shape of the ligand-binding pocket and the physicochemical properties of the pocket and the ligand. Spatial distributions of the Coarse-grained (CG) ligand molecules revealed potential ligand-binding sites on the protein surfaces other than the real ligand-binding sites. The ligands bound most strongly to the real ligand-binding sites. The binding and unbinding rate constants obtained from the CGMD simulation of the levansucrase-sucrose system were approximately 10 times greater than the experimental values; this is mainly due to faster diffusion of the CG ligand in the CG water model. We could obtain dissociation constants close to the experimental values for both systems. Analysis of the ligand fluxes demonstrated that the CG ligand molecules entered the ligand-binding pockets through specific pathways. The ligands tended to move through grooves on the protein surface. Thus, the CGMD simulations produced reasonable results for the two different systems overall and are useful for studying the protein-ligand binding processes.
Collapse
Affiliation(s)
- Tatsuki Negami
- Department of Biotechnology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
| | | | | |
Collapse
|
30
|
Frappier V, Najmanovich RJ. A coarse-grained elastic network atom contact model and its use in the simulation of protein dynamics and the prediction of the effect of mutations. PLoS Comput Biol 2014; 10:e1003569. [PMID: 24762569 PMCID: PMC3998880 DOI: 10.1371/journal.pcbi.1003569] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Accepted: 02/25/2014] [Indexed: 11/18/2022] Open
Abstract
Normal mode analysis (NMA) methods are widely used to study dynamic aspects of protein structures. Two critical components of NMA methods are coarse-graining in the level of simplification used to represent protein structures and the choice of potential energy functional form. There is a trade-off between speed and accuracy in different choices. In one extreme one finds accurate but slow molecular-dynamics based methods with all-atom representations and detailed atom potentials. On the other extreme, fast elastic network model (ENM) methods with Cα-only representations and simplified potentials that based on geometry alone, thus oblivious to protein sequence. Here we present ENCoM, an Elastic Network Contact Model that employs a potential energy function that includes a pairwise atom-type non-bonded interaction term and thus makes it possible to consider the effect of the specific nature of amino-acids on dynamics within the context of NMA. ENCoM is as fast as existing ENM methods and outperforms such methods in the generation of conformational ensembles. Here we introduce a new application for NMA methods with the use of ENCoM in the prediction of the effect of mutations on protein stability. While existing methods are based on machine learning or enthalpic considerations, the use of ENCoM, based on vibrational normal modes, is based on entropic considerations. This represents a novel area of application for NMA methods and a novel approach for the prediction of the effect of mutations. We compare ENCoM to a large number of methods in terms of accuracy and self-consistency. We show that the accuracy of ENCoM is comparable to that of the best existing methods. We show that existing methods are biased towards the prediction of destabilizing mutations and that ENCoM is less biased at predicting stabilizing mutations.
Collapse
Affiliation(s)
- Vincent Frappier
- Department of Biochemistry, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Rafael J Najmanovich
- Department of Biochemistry, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| |
Collapse
|
31
|
Koike R, Ota M, Kidera A. Hierarchical Description and Extensive Classification of Protein Structural Changes by Motion Tree. J Mol Biol 2014; 426:752-62. [DOI: 10.1016/j.jmb.2013.10.034] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Revised: 10/24/2013] [Accepted: 10/28/2013] [Indexed: 11/25/2022]
|
32
|
Taylor D, Cawley G, Hayward S. Classification of domain movements in proteins using dynamic contact graphs. PLoS One 2013; 8:e81224. [PMID: 24260562 PMCID: PMC3832408 DOI: 10.1371/journal.pone.0081224] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Accepted: 10/09/2013] [Indexed: 12/02/2022] Open
Abstract
A new method for the classification of domain movements in proteins is described and applied to 1822 pairs of structures from the Protein Data Bank that represent a domain movement in two-domain proteins. The method is based on changes in contacts between residues from the two domains in moving from one conformation to the other. We argue that there are five types of elemental contact changes and that these relate to five model domain movements called: “free”, “open-closed”, “anchored”, “sliding-twist”, and “see-saw.” A directed graph is introduced called the “Dynamic Contact Graph” which represents the contact changes in a domain movement. In many cases a graph, or part of a graph, provides a clear visual metaphor for the movement it represents and is a motif that can be easily recognised. The Dynamic Contact Graphs are often comprised of disconnected subgraphs indicating independent regions which may play different roles in the domain movement. The Dynamic Contact Graph for each domain movement is decomposed into elemental Dynamic Contact Graphs, those that represent elemental contact changes, allowing us to count the number of instances of each type of elemental contact change in the domain movement. This naturally leads to sixteen classes into which the 1822 domain movements are classified.
Collapse
Affiliation(s)
- Daniel Taylor
- D'Arcy Thompson Centre for Computational Biology, School of Computing Sciences, University of East Anglia, Norwich, United Kingdom
| | - Gavin Cawley
- D'Arcy Thompson Centre for Computational Biology, School of Computing Sciences, University of East Anglia, Norwich, United Kingdom
| | - Steven Hayward
- D'Arcy Thompson Centre for Computational Biology, School of Computing Sciences, University of East Anglia, Norwich, United Kingdom
- * E-mail:
| |
Collapse
|
33
|
Zotti MJ, De Geyter E, Swevers L, Braz ASK, Scott LPB, Rougé P, Coll J, Grutzmacher AD, Lenardão EJ, Smagghe G. A cell-based reporter assay for screening for EcR agonist/antagonist activity of natural ecdysteroids in Lepidoptera (Bm5) and Diptera (S2) cell cultures, followed by modeling of ecdysteroid-EcR interactions and normal mode analysis. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2013; 107:309-320. [PMID: 24267692 DOI: 10.1016/j.pestbp.2013.09.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2013] [Revised: 09/16/2013] [Accepted: 09/17/2013] [Indexed: 06/02/2023]
Abstract
Ecdysteroid signal transduction is a key process in insect development and therefore an important target for insecticide development. We employed an in vitro cell-based reporter bioassay for the screening of potential ecdysone receptor (EcR) agonistic and antagonistic compounds. Natural ecdysteroids were assayed with ecdysteroid-responsive cell line cultures that were transiently transfected with the reporter plasmid ERE-b.act.luc. We used the dipteran Schneider S2 cells of Drosophila melanogaster and the lepidopteran Bm5 cells of Bombyx mori, representing important pest insects in medicine and agriculture. Measurements showed an EcR agonistic activity only for cyasterone both in S2 (EC50=3.3μM) and Bm5 cells (EC50=5.3μM), which was low compared to that of the commercial dibenzoylhydrazine-based insecticide tebufenozide (EC50=0.71μM and 0.00089μM, respectively). Interestingly, a strong antagonistic activity was found for castasterone in S2 cells with an IC50 of 0.039μM; in Bm5 cells this effect only became visible at much higher concentrations (IC50=18μM). To gain more insight in the EcR interaction, three-dimensional modeling of dipteran and lepidopteran EcR-LBD was performed. In conclusion, we showed that the EcR cell-based reporter bioassay tested here is a useful and practical tool for the screening of candidate EcR agonists and antagonists. The docking experiments as well as the normal mode analysis provided evidence that the antagonist activity of castasterone may be through direct binding with the receptor with specific changes in protein flexibility. The search for new ecdysteroid-like compounds may be particularly relevant for dipterans because the activity of dibenzoylhydrazines appears to be correlated with an extension of the EcR-LBD binding pocket that is prominent in lepidopteran receptors but less so in the modeled dipteran structure.
Collapse
Affiliation(s)
- Moisés J Zotti
- Department of Crop Protection, Ghent University, Coupure links 653, 9000 Ghent, Belgium; Department of Phytosanitary, FAEM, Federal University of Pelotas, P.O. Box 354, CEP, 96010-900 Pelotas, RS, Brazil; Department of Crop Protection, Federal University of Santa Maria, Santa Maria, Brazil.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
34
|
Kanematsu Y, Koike R, Amemiya T, Ota M. Substrate-shielding and hydrolytic reaction in hydrolases. Proteins 2013; 81:926-32. [DOI: 10.1002/prot.24253] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Revised: 12/10/2012] [Accepted: 01/04/2013] [Indexed: 11/07/2022]
|
35
|
Skolnick J, Zhou H, Gao M. Are predicted protein structures of any value for binding site prediction and virtual ligand screening? Curr Opin Struct Biol 2013; 23:191-7. [PMID: 23415854 DOI: 10.1016/j.sbi.2013.01.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Revised: 01/04/2013] [Accepted: 01/23/2013] [Indexed: 01/03/2023]
Abstract
The recently developed field of ligand homology modeling (LHM) that extends the ideas of protein homology modeling to the prediction of ligand binding sites and for use in virtual ligand screening has emerged as a powerful new approach. Unlike traditional docking methodologies, LHM can be applied to low-to-moderate resolution predicted as well as experimental structures with little if any diminution in performance; thereby enabling ≈ 75% of an average proteome to have potentially significant virtual screening predictions. In large scale benchmarking, LHM is able to predict off-target ligand binding. Thus, despite the widespread belief to the contrary, low-to-moderate resolution predicted structures have considerable utility for biochemical function prediction.
Collapse
Affiliation(s)
- Jeffrey Skolnick
- Center for the Study of Systems Biology, School of Biology, Georgia Institute of Technology, 250 14th Street NW, Atlanta, GA 30318, USA.
| | | | | |
Collapse
|
36
|
Kalyaanamoorthy S, Chen YPP. Exploring inhibitor release pathways in histone deacetylases using random acceleration molecular dynamics simulations. J Chem Inf Model 2012; 52:589-603. [PMID: 22263580 DOI: 10.1021/ci200584f] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Molecular channel exploration perseveres to be the prominent solution for eliciting structure and accessibility of active site and other internal spaces of macromolecules. The volume and silhouette characterization of these channels provides answers for the issues of substrate access and ligand swapping between the obscured active site and the exterior of the protein. Histone deacetylases (HDACs) are metal-dependent enzymes that are involved in the cell growth, cell cycle regulation, and progression, and their deregulations have been linked with different types of cancers. Hence HDACs, especially the class I family, are widely recognized as the important cancer targets, and the characterizations of their structures and functions have been of special interest in cancer drug discovery. The class I HDACs are known to possess two different protein channels, an 11 Å and a 14 Å (named channels A and B1, respectively), of which the former is a ligand or substrate occupying tunnel that leads to the buried active site zinc ion and the latter is speculated to be involved in product release. In this work, we have carried out random acceleration molecular dynamics (RAMD) simulations coupled with the classical molecular dynamics to explore the release of the ligand, N-(2-aminophenyl) benzamide (LLX) from the active sites of the recently solved X-ray crystal structure of HDAC2 and the computationally modeled HDAC1 proteins. The RAMD simulations identified significant structural and dynamic features of the HDAC channels, especially the key 'gate-keeping' amino acid residues that control these channels and the ligand release events. Further, this study identified a novel and unique channel B2, a subchannel from channel B1, in the HDAC1 protein structure. The roles of water molecules in the LLX release from the HDAC1 and HDAC2 enzymes are also discussed. Such structural and dynamic properties of the HDAC protein channels that govern the ligand escape reactions will provide further mechanistic insights into the HDAC enzymes, which, in the long run, have a potential to bring new ideas for developing more promising HDAC inhibitors as well as extend our atomic level understandings on their mechanisms of action.
Collapse
Affiliation(s)
- Subha Kalyaanamoorthy
- Department of Computer Science and Computer Engineering, Faculty of Science, Technology and Engineering, La Trobe University, Melbourne, Australia
| | | |
Collapse
|