1
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Nicolaou ST, Kannan S, Warwicker J, Verma CS. Activation of p53: How phosphorylated Ser15 triggers sequential phosphorylation of p53 at Thr18 by CK1δ. Proteins 2022; 90:2009-2022. [PMID: 35752942 PMCID: PMC9796392 DOI: 10.1002/prot.26393] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 06/10/2022] [Accepted: 06/21/2022] [Indexed: 01/01/2023]
Abstract
The N-terminal transactivation domain (TAD) of p53 is a disordered region with multiple phosphorylation sites. Phosphorylation at Thr18 is crucial for the release of p53 from its negative regulator, MDM2. In stressed cells, CK1δ is responsible for phosphorylating Thr18, but requires Ser15 to be phosphorylated. To understand the mechanistic underpinnings of this sequential phosphorylation, molecular modeling and molecular dynamics simulation studies of these phosphorylation events were carried out. Our models suggest that a positively charged region on CK1δ near the adenosine triphosphate (ATP) binding pocket, which is conserved across species, sequesters the negatively charged pSer15, thereby constraining the positioning of the rest of the peptide, such that the side chain of Thr18 is positioned close to the γ-phosphate of ATP. Furthermore, our studies show that the phosphorylated p53 TAD1 (p53pSer15) peptide binds more strongly to CK1δ than does p53. p53 adopts a helical structure when bound to CK1δ, which is lost upon phosphorylation at Ser15, thus gaining higher flexibility and ability to morph into the binding site. We propose that upon phosphorylation at Ser15 the p53 TAD1 peptide binds to CK1δ through an electrostatically driven induced fit mechanism resulting in a flanking fuzzy complex.
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Affiliation(s)
- Sonia T. Nicolaou
- Faculty of Biology, Medicine and Health, School of Biological SciencesManchester Institute of Biotechnology, University of ManchesterManchesterUK,Bioinformatics Institute, Agency for Science, Technology, and Research (A*STAR)SingaporeSingapore
| | - Srinivasaraghavan Kannan
- Bioinformatics Institute, Agency for Science, Technology, and Research (A*STAR)SingaporeSingapore
| | - Jim Warwicker
- Faculty of Biology, Medicine and Health, School of Biological SciencesManchester Institute of Biotechnology, University of ManchesterManchesterUK
| | - Chandra S. Verma
- Bioinformatics Institute, Agency for Science, Technology, and Research (A*STAR)SingaporeSingapore,School of Biological SciencesNanyang Technological UniversitySingaporeSingapore,Department of Biological SciencesNational University of SingaporeSingaporeSingapore
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2
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Reid LM, Guzzetti I, Svensson T, Carlsson AC, Su W, Leek T, von Sydow L, Czechtizky W, Miljak M, Verma C, De Maria L, Essex JW. How well does molecular simulation reproduce environment-specific conformations of the intrinsically disordered peptides PLP, TP2 and ONEG? Chem Sci 2022; 13:1957-1971. [PMID: 35308859 PMCID: PMC8848758 DOI: 10.1039/d1sc03496k] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2021] [Accepted: 01/03/2022] [Indexed: 12/31/2022] Open
Abstract
Understanding the conformational ensembles of intrinsically disordered proteins and peptides (IDPs) in their various biological environments is essential for understanding their mechanisms and functional roles in the proteome, leading to a greater knowledge of, and potential treatments for, a broad range of diseases. To determine whether molecular simulation is able to generate accurate conformational ensembles of IDPs, we explore the structural landscape of the PLP peptide (an intrinsically disordered region of the proteolipid membrane protein) in aqueous and membrane-mimicking solvents, using replica exchange with solute scaling (REST2), and examine the ability of four force fields (ff14SB, ff14IDPSFF, CHARMM36 and CHARMM36m) to reproduce literature circular dichroism (CD) data. Results from variable temperature (VT) 1H and Rotating frame Overhauser Effect SpectroscopY (ROESY) nuclear magnetic resonance (NMR) experiments are also presented and are consistent with the structural observations obtained from the simulations and CD. We also apply the optimum simulation protocol to TP2 and ONEG (a cell-penetrating peptide (CPP) and a negative control peptide, respectively) to gain insight into the structural differences that may account for the observed difference in their membrane-penetrating abilities. Of the tested force fields, we find that CHARMM36 and CHARMM36m are best suited to the study of IDPs, and accurately predict a disordered to helical conformational transition of the PLP peptide accompanying the change from aqueous to membrane-mimicking solvents. We also identify an α-helical structure of TP2 in the membrane-mimicking solvents and provide a discussion of the mechanistic implications of this observation with reference to the previous literature on the peptide. From these results, we recommend the use of CHARMM36m with the REST2 protocol for the study of environment-specific IDP conformations. We believe that the simulation protocol will allow the study of a broad range of IDPs that undergo conformational transitions in different biological environments.
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Affiliation(s)
- Lauren M Reid
- School of Chemistry, University of Southampton Highfield Southampton SO17 1BJ UK
- Bioinformatics Institute (ASTAR) 30 Biolpolis Street Matrix 138671 Singapore
- MedChemica Ltd Alderley Park Macclesfield Cheshire SK10 4TG UK
| | - Ileana Guzzetti
- Medical Chemistry, Research and Early Development, Respiratory & Immunology, BioPharmaceuticals R&D AstraZeneca Gothenburg Sweden
| | - Tor Svensson
- Medical Chemistry, Research and Early Development, Respiratory & Immunology, BioPharmaceuticals R&D AstraZeneca Gothenburg Sweden
| | - Anna-Carin Carlsson
- Early Chemical Development, Pharmaceutical Sciences, BioPharmaceuticals R&D AstraZeneca Gothenburg Sweden
| | - Wu Su
- Medical Chemistry, Research and Early Development, Respiratory & Immunology, BioPharmaceuticals R&D AstraZeneca Gothenburg Sweden
| | - Tomas Leek
- Medical Chemistry, Research and Early Development, Respiratory & Immunology, BioPharmaceuticals R&D AstraZeneca Gothenburg Sweden
| | - Lena von Sydow
- Medical Chemistry, Research and Early Development, Respiratory & Immunology, BioPharmaceuticals R&D AstraZeneca Gothenburg Sweden
| | - Werngard Czechtizky
- Medical Chemistry, Research and Early Development, Respiratory & Immunology, BioPharmaceuticals R&D AstraZeneca Gothenburg Sweden
| | - Marija Miljak
- School of Chemistry, University of Southampton Highfield Southampton SO17 1BJ UK
| | - Chandra Verma
- Bioinformatics Institute (ASTAR) 30 Biolpolis Street Matrix 138671 Singapore
- Department of Biological Sciences, National University of Singapore 16 Science Drive 4 117558 Singapore
- School of Biological Sciences, Nanyang Technological University 60 Nanyang Dr 637551 Singapore
| | - Leonardo De Maria
- Medical Chemistry, Research and Early Development, Respiratory & Immunology, BioPharmaceuticals R&D AstraZeneca Gothenburg Sweden
| | - Jonathan W Essex
- School of Chemistry, University of Southampton Highfield Southampton SO17 1BJ UK
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3
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Strizhak AV, Babii O, Afonin S, Bakanovich I, Pantelejevs T, Xu W, Fowler E, Eapen R, Sharma K, Platonov MO, Hurmach VV, Itzhaki L, Hyvönen M, Ulrich AS, Spring DR, Komarov IV. Diarylethene moiety as an enthalpy-entropy switch: photoisomerizable stapled peptides for modulating p53/MDM2 interaction. Org Biomol Chem 2021; 18:5359-5369. [PMID: 32390036 DOI: 10.1039/d0ob00831a] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Analogs of the known inhibitor (peptide pDI) of the p53/MDM2 protein-protein interaction are reported, which are stapled by linkers bearing a photoisomerizable diarylethene moiety. The corresponding photoisomers possess significantly different affinities to the p53-interacting domain of the human MDM2. Apparent dissociation constants are in the picomolar-to-low nanomolar range for those isomers with diarylethene in the "open" configuration, but up to eight times larger for the corresponding "closed" isomers. Spectroscopic, structural, and computational studies showed that the stapling linkers of the peptides contribute to their binding. Calorimetry revealed that the binding of the "closed" isomers is mostly enthalpy-driven, whereas the "open" photoforms bind to the protein stronger due to their increased binding entropy. The results suggest that conformational dynamics of the protein-peptide complexes may explain the differences in the thermodynamic profiles of the binding.
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Affiliation(s)
- Alexander V Strizhak
- University Chemical Laboratory, University of Cambridge, Lensfield Road, CB2 1EW Cambridge, UK. and Enamine Ltd, Vul. Chervonotkatska 78, 02094 Kyiv, Ukraine
| | - Oleg Babii
- Institute of Biological Interfaces (IBG-2), Karlsruhe Institute of Technology (KIT), POB 3640, 76021 Karlsruhe, Germany.
| | - Sergii Afonin
- Institute of Biological Interfaces (IBG-2), Karlsruhe Institute of Technology (KIT), POB 3640, 76021 Karlsruhe, Germany.
| | - Iuliia Bakanovich
- University Chemical Laboratory, University of Cambridge, Lensfield Road, CB2 1EW Cambridge, UK. and Enamine Ltd, Vul. Chervonotkatska 78, 02094 Kyiv, Ukraine
| | - Teodors Pantelejevs
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, CB2 1GA Cambridge, UK
| | - Wenshu Xu
- University Chemical Laboratory, University of Cambridge, Lensfield Road, CB2 1EW Cambridge, UK.
| | - Elaine Fowler
- University Chemical Laboratory, University of Cambridge, Lensfield Road, CB2 1EW Cambridge, UK.
| | - Rohan Eapen
- Department of Pharmacology, University of Cambridge, Tennis Court Road, CB2 1PD Cambridge, UK
| | - Krishna Sharma
- University Chemical Laboratory, University of Cambridge, Lensfield Road, CB2 1EW Cambridge, UK.
| | | | - Vasyl V Hurmach
- Enamine Ltd, Vul. Chervonotkatska 78, 02094 Kyiv, Ukraine and Taras Shevchenko National University of Kyiv, Vul. Volodymyrska 60, 01601 Kyiv, Ukraine
| | - Laura Itzhaki
- Department of Pharmacology, University of Cambridge, Tennis Court Road, CB2 1PD Cambridge, UK
| | - Marko Hyvönen
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, CB2 1GA Cambridge, UK
| | - Anne S Ulrich
- Institute of Biological Interfaces (IBG-2), Karlsruhe Institute of Technology (KIT), POB 3640, 76021 Karlsruhe, Germany. and Institute of Organic Chemistry (IOC), KIT, Fritz-Haber-Weg 6, 76131 Karlsruhe, Germany
| | - David R Spring
- University Chemical Laboratory, University of Cambridge, Lensfield Road, CB2 1EW Cambridge, UK.
| | - Igor V Komarov
- Taras Shevchenko National University of Kyiv, Vul. Volodymyrska 60, 01601 Kyiv, Ukraine and Lumobiotics GmbH, Auer Str. 2, 76227, Karlsruhe, Germany.
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4
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Wang J, Miao Y. Peptide Gaussian accelerated molecular dynamics (Pep-GaMD): Enhanced sampling and free energy and kinetics calculations of peptide binding. J Chem Phys 2021; 153:154109. [PMID: 33092378 DOI: 10.1063/5.0021399] [Citation(s) in RCA: 61] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Peptides mediate up to 40% of known protein-protein interactions in higher eukaryotes and play an important role in cellular signaling. However, it is challenging to simulate both binding and unbinding of peptides and calculate peptide binding free energies through conventional molecular dynamics, due to long biological timescales and extremely high flexibility of the peptides. Based on the Gaussian accelerated molecular dynamics (GaMD) enhanced sampling technique, we have developed a new computational method "Pep-GaMD," which selectively boosts essential potential energy of the peptide in order to effectively model its high flexibility. In addition, another boost potential is applied to the remaining potential energy of the entire system in a dual-boost algorithm. Pep-GaMD has been demonstrated on binding of three model peptides to the SH3 domains. Independent 1 µs dual-boost Pep-GaMD simulations have captured repetitive peptide dissociation and binding events, which enable us to calculate peptide binding thermodynamics and kinetics. The calculated binding free energies and kinetic rate constants agreed very well with available experimental data. Furthermore, the all-atom Pep-GaMD simulations have provided important insights into the mechanism of peptide binding to proteins that involves long-range electrostatic interactions and mainly conformational selection. In summary, Pep-GaMD provides a highly efficient, easy-to-use approach for unconstrained enhanced sampling and calculations of peptide binding free energies and kinetics.
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Affiliation(s)
- Jinan Wang
- Center for Computational Biology and Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66047, USA
| | - Yinglong Miao
- Center for Computational Biology and Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66047, USA
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5
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Protein-Protein Interactions Mediated by Intrinsically Disordered Protein Regions Are Enriched in Missense Mutations. Biomolecules 2020; 10:biom10081097. [PMID: 32722039 PMCID: PMC7463635 DOI: 10.3390/biom10081097] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Revised: 07/15/2020] [Accepted: 07/20/2020] [Indexed: 12/27/2022] Open
Abstract
Because proteins are fundamental to most biological processes, many genetic diseases can be traced back to single nucleotide variants (SNVs) that cause changes in protein sequences. However, not all SNVs that result in amino acid substitutions cause disease as each residue is under different structural and functional constraints. Influential studies have shown that protein–protein interaction interfaces are enriched in disease-associated SNVs and depleted in SNVs that are common in the general population. These studies focus primarily on folded (globular) protein domains and overlook the prevalent class of protein interactions mediated by intrinsically disordered regions (IDRs). Therefore, we investigated the enrichment patterns of missense mutation-causing SNVs that are associated with disease and cancer, as well as those present in the healthy population, in structures of IDR-mediated interactions with comparisons to classical globular interactions. When comparing the different categories of interaction interfaces, division of the interface regions into solvent-exposed rim residues and buried core residues reveal distinctive enrichment patterns for the various types of missense mutations. Most notably, we demonstrate a strong enrichment at the interface core of interacting IDRs in disease mutations and its depletion in neutral ones, which supports the view that the disruption of IDR interactions is a mechanism underlying many diseases. Intriguingly, we also found an asymmetry across the IDR interaction interface in the enrichment of certain missense mutation types, which may hint at an increased variant tolerance and urges further investigations of IDR interactions.
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6
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Das P, Mattaparthi VSK. Computational Investigation on the p53-MDM2 Interaction Using the Potential of Mean Force Study. ACS OMEGA 2020; 5:8449-8462. [PMID: 32337406 PMCID: PMC7178334 DOI: 10.1021/acsomega.9b03372] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 03/26/2020] [Indexed: 05/04/2023]
Abstract
Murine double minute 2 (MDM2) proteins are found to be overproduced by many human tumors in order to inhibit the functioning of p53 molecules, a tumor suppressor protein. Thus, reactivating p53 functioning in cancer cells by disrupting p53-MDM2 interactions may offer a significant approach in cancer treatment. However, the structural characterization of the p53-MDM2 complex at the atomistic level and the mechanism of binding/unbinding of the p53-MDM2 complex still remain unclear. Therefore, we demonstrate here the probable binding (unbinding) pathway of transactivation domain 1 of p53 during the formation (dissociation) of the p53-MDM2 complex in terms of free energy as a function of reaction coordinate from the potential of mean force (PMF) study using two different force fields: ff99SB and ff99SB-ILDN. From the PMF plot, we noticed the PMF to have a minimum value at a p53-MDM2 separation of 12 Å, with a dissociation energy of 30 kcal mol-1. We also analyzed the conformational dynamics and stability of p53 as a function of its distance of separation from MDM2. The secondary structure content (helix and turns) in p53 was found to vary with its distance of separation from MDM2. The p53-MDM2 complex structure with lowest potential energy was isolated from the ensemble at the reaction coordinate corresponding to the minimum PMF value and subjected to molecular dynamics simulation to identify the interface surface area, interacting residues at the interface, and the stability of the complex. The simulation results highlight the importance of hydrogen bonds and the salt bridge between Lys94 of MDM2 and Glu17 of p53 in the stability of the p53-MDM2 complex. We also carried out the binding free energy calculations and the per residue energy decomposition analyses of the interface residues of the p53-MDM2 complex. We found that the binding affinity between MDM2 and p53 is indeed high [ΔG bind = -7.29 kcal mol-1 from molecular mechanics/Poisson-Boltzmann surface area (MM/PBSA) and ΔG bind = -53.29 kcal mol-1 from molecular mechanics/generalized borne surface area]. The total binding energy obtained using the MM/PBSA method was noticed to be closer to the experimental values (-6.4 to -9.0 kcal mol-1). The p53-MDM2 complex binding profile was observed to follow the same trend even in the duplicate simulation run and also in the simulation carried out with different force fields. We found that Lys51, Leu54, Tyr100, and Tyr104 from MDM2 and the residues Phe19, Trp23, and Leu26 from p53 provide the highest energy contributions for the p53-MDM2 interaction. Our findings highlight the prominent structural and binding characteristics of the p53-MDM2 complex that may be useful in designing potential inhibitors to disrupt the p53-MDM2 interactions.
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7
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Zou R, Zhou Y, Wang Y, Kuang G, Ågren H, Wu J, Tu Y. Free Energy Profile and Kinetics of Coupled Folding and Binding of the Intrinsically Disordered Protein p53 with MDM2. J Chem Inf Model 2020; 60:1551-1558. [DOI: 10.1021/acs.jcim.9b00920] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- Rongfeng Zou
- Department of Theoretical Chemistry and Biology, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, 10691 Stockholm, Sweden
| | - Yang Zhou
- Department of Theoretical Chemistry and Biology, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, 10691 Stockholm, Sweden
| | - Yong Wang
- Structural Biology and NMR Laboratory, Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, DK-2200 Copenhagen N, Denmark
| | - Guanglin Kuang
- Department of Theoretical Chemistry and Biology, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, 10691 Stockholm, Sweden
| | - Hans Ågren
- Department of Theoretical Chemistry and Biology, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, 10691 Stockholm, Sweden
- College of Chemistry and Chemical Engineering, Henan University, 475004 Kaifeng, Henan, P. R. China
| | - Junchen Wu
- Key Laboratory for Advanced Materials & Institute of Fine Chemicals, School of Chemistry and Molecular Engineering, East China University of Science and Technology, 200237 Shanghai, China
| | - Yaoquan Tu
- Department of Theoretical Chemistry and Biology, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, 10691 Stockholm, Sweden
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8
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Bueren-Calabuig JA, G Bage M, Cowling VH, Pisliakov AV. Mechanism of allosteric activation of human mRNA cap methyltransferase (RNMT) by RAM: insights from accelerated molecular dynamics simulations. Nucleic Acids Res 2019; 47:8675-8692. [PMID: 31329932 PMCID: PMC7145595 DOI: 10.1093/nar/gkz613] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 07/01/2019] [Accepted: 07/08/2019] [Indexed: 02/04/2023] Open
Abstract
The RNA guanine-N7 methyltransferase (RNMT) in complex with RNMT-activating miniprotein (RAM) catalyses the formation of a N7-methylated guanosine cap structure on the 5' end of nascent RNA polymerase II transcripts. The mRNA cap protects the primary transcript from exonucleases and recruits cap-binding complexes that mediate RNA processing, export and translation. By using microsecond standard and accelerated molecular dynamics simulations, we provide for the first time a detailed molecular mechanism of allosteric regulation of RNMT by RAM. We show that RAM selects the RNMT active site conformations that are optimal for binding of substrates (AdoMet and the cap), thus enhancing their affinity. Furthermore, our results strongly suggest the likely scenario in which the cap binding promotes the subsequent AdoMet binding, consistent with the previously suggested cooperative binding model. By employing the network community analyses, we revealed the underlying long-range allosteric networks and paths that are crucial for allosteric regulation by RAM. Our findings complement and explain previous experimental data on RNMT activity. Moreover, this study provides the most complete description of the cap and AdoMet binding poses and interactions within the enzyme's active site. This information is critical for the drug discovery efforts that consider RNMT as a promising anti-cancer target.
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Affiliation(s)
- Juan A Bueren-Calabuig
- Computational Biology, School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK
| | - Marcus G Bage
- Computational Biology, School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK
| | - Victoria H Cowling
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK
| | - Andrei V Pisliakov
- Computational Biology, School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK.,Physics, School of Science and Engineering, University of Dundee, Dundee, DD1 4HN, UK
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9
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Wang J, Alekseenko A, Kozakov D, Miao Y. Improved Modeling of Peptide-Protein Binding Through Global Docking and Accelerated Molecular Dynamics Simulations. Front Mol Biosci 2019; 6:112. [PMID: 31737642 PMCID: PMC6835073 DOI: 10.3389/fmolb.2019.00112] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Accepted: 10/09/2019] [Indexed: 01/31/2023] Open
Abstract
Peptides mediate up to 40% of known protein-protein interactions in higher eukaryotes and play a key role in cellular signaling, protein trafficking, immunology, and oncology. However, it is challenging to predict peptide-protein binding with conventional computational modeling approaches, due to slow dynamics and high peptide flexibility. Here, we present a prototype of the approach which combines global peptide docking using ClusPro PeptiDock and all-atom enhanced simulations using Gaussian accelerated molecular dynamics (GaMD). For three distinct model peptides, the lowest backbone root-mean-square deviations (RMSDs) of their bound conformations relative to X-ray structures obtained from PeptiDock were 3.3–4.8 Å, being medium quality predictions according to the Critical Assessment of PRediction of Interactions (CAPRI) criteria. GaMD simulations refined the peptide-protein complex structures with significantly reduced peptide backbone RMSDs of 0.6–2.7 Å, yielding two high quality (sub-angstrom) and one medium quality models. Furthermore, the GaMD simulations identified important low-energy conformational states and revealed the mechanism of peptide binding to the target proteins. Therefore, PeptiDock+GaMD is a promising approach for exploring peptide-protein interactions.
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Affiliation(s)
- Jinan Wang
- Center for Computational Biology and Department of Molecular Biosciences, University of Kansas, Lawrence, KS, United States
| | - Andrey Alekseenko
- Laufer Center for Physical and Quantitative Biology, Stony Brook University, Stony Brook, NY, United States.,Department of Applied Mathematics and Statistics, Stony Brook University, Stony Brook, NY, United States
| | - Dima Kozakov
- Laufer Center for Physical and Quantitative Biology, Stony Brook University, Stony Brook, NY, United States.,Department of Applied Mathematics and Statistics, Stony Brook University, Stony Brook, NY, United States
| | - Yinglong Miao
- Center for Computational Biology and Department of Molecular Biosciences, University of Kansas, Lawrence, KS, United States
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10
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Kinetic and thermodynamic effects of phosphorylation on p53 binding to MDM2. Sci Rep 2019; 9:693. [PMID: 30679555 PMCID: PMC6345774 DOI: 10.1038/s41598-018-36589-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Accepted: 11/15/2018] [Indexed: 02/03/2023] Open
Abstract
p53 is frequently mutated in human cancers. Its levels are tightly regulated by the E3 ubiquitin ligase MDM2. The complex between MDM2 and p53 is largely formed by the interaction between the N-terminal domain of MDM2 and the N-terminal transactivation (TA) domain of p53 (residues 15–29). We investigated the kinetic and thermodynamic basis of the MDM2/p53 interaction by using wild-type and mutant variants of the TA domain. We focus on the effects of phosphorylation at positions Thr18 and Ser20 including their substitution with phosphomimetics. Conformational propensities of the isolated peptides were investigated using in silico methods and experimentally by circular dichroism and 1H-NMR in aqueous solution. Both experimental and computational analyses indicate that the p53 peptides are mainly disordered in aqueous solution, with evidence of nascent helix around the Ser20-Leu25 region. Both phosphorylation and the phosphomimetics at Thr18 result in a decrease in the binding affinity by ten- to twenty-fold when compared to the wild-type. Phosphorylation and phosphomimetics at Ser20 result in a smaller decrease in the affinity. Mutation of Lys24 and Leu25 also disrupts the interaction. Our results may be useful for further development of peptide-based drugs targeting the MDM2/p53 interaction.
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