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Linkova N, Khavinson V, Diatlova A, Petukhov M, Vladimirova E, Sukhareva M, Ilina A. The Influence of KE and EW Dipeptides in the Composition of the Thymalin Drug on Gene Expression and Protein Synthesis Involved in the Pathogenesis of COVID-19. Int J Mol Sci 2023; 24:13377. [PMID: 37686182 PMCID: PMC10488166 DOI: 10.3390/ijms241713377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 08/17/2023] [Accepted: 08/26/2023] [Indexed: 09/10/2023] Open
Abstract
Thymalin is an immunomodulatory drug containing a polypeptide extract of thymus that has demonstrated efficacy in the therapy of acute respiratory distress syndrome and chronic obstructive pulmonary disease, as well as in complex therapy related to severe COVID-19 in middle-aged and elderly patients.. KE and EW dipeptides are active substances of Thymalin. There is evidence that KE stimulates cellular immunity and nonspecific resistance in organisms, exerting an activating effect on macrophages, blood lymphocytes, thymocytes, and neutrophils, while EW reduces angiotensin-induced vasoconstriction and preserves endothelium-dependent vascular relaxation by inhibiting ACE2, the target protein of SARS-CoV-2. However, the mechanism of the immunomodulatory action of Thymalin, KE, and EW during COVID-19 remains unclear. To identify the potential mechanism of action underlying the immunomodulatory activity of Thymalin and its active components, EW and KE dipeptides, we assessed inflammatory response in the context of COVID-19. Interactions between EW and KE dipeptides and double-stranded DNA (dsDNA) were investigated by molecular modeling and docking using ICM-Pro. Analysis of the possible effect of EW and KE dipeptides on gene expression and protein synthesis involved in the pathogenesis of COVID-19 was conducted through the use of bioinformatics methods, including a search for promoter sequences in the Eukaryotic Promoter Database, the determination of genes associated with the development of COVID-19 using the PathCards database of human biological pathways (pathway unification database), identification of the relationship between proteins through cluster analysis in the STRING database ('Search Tool for Retrieval of Interacting Genes/Proteins'), and assessment of the functional enrichment of protein-protein interaction (PPI) using the terms of gene ontology (GO) and the Markov cluster algorithm (MCL). After that, in vitro studying of a lipopolysaccharide (LPS)-induced model of inflammation using human peripheral blood mononuclear cells was performed. ELISA was applied to assess the level of cytokines (IL-1β, IL-6, TNFα) in the supernatant of cells with or without the impact of EW and KE peptides. Blood samples were obtained from four donors; for each cytokine, ELISA was performed 2-4 times, with two parallel experimental or control samples for each experiment (experiments to assess the effects of peptides on LPS-stimulated cells were repeated four times, while additional experiments with unstimulated cells were performed two times). Using molecular docking, GGAG was found to be the best dsDNA sequence in the classical B-form for binding the EW dipeptide, while GCGC is the preferred dsDNA sequence in the curved nucleosomal form for the KE dipeptide. Cluster analysis revealed that potential target genes for the EW and KE peptides encode the AKT1 and AKT2 proteins involved in the development of the cytokine storm. The specific targets for the EW peptide are the ACE2 and CYSLTR1 genes, and specific target for the KE peptide is the CHUK gene. Protein products of the ACE2, CYSLTR1, and CHUK genes are functionally associated with IL-1β, IL-6, TNF-α, IL-4, and IL-10 cytokines. An in vitro model of an inflammatory reaction demonstrated that Thymalin and EW and KE dipeptides reduced the synthesis of IL-1β, IL-6, and TNF-α cytokines in human peripheral blood mononuclear cells by 1.4-6.0 times. The immunomodulatory effect of Thymalin under the inflammatory response conditions in COVID-19 is based on the potential ability of its active components, EW and KE dipeptides, to regulate protein synthesis involved in the development of the cytokine storm.
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Affiliation(s)
- Natalia Linkova
- Saint Petersburg Institute of Bioregulation and Gerontology, 197110 Saint Petersburg, Russia
- Saint Petersburg Research Institute of Phthisiopulmonology, 191036 Saint Petersburg, Russia
| | - Vladimir Khavinson
- Saint Petersburg Institute of Bioregulation and Gerontology, 197110 Saint Petersburg, Russia
- Pavlov Institute of Physiology of Russian Academy of Sciences, 199034 Saint Petersburg, Russia
| | - Anastasiia Diatlova
- Saint Petersburg Institute of Bioregulation and Gerontology, 197110 Saint Petersburg, Russia
| | - Michael Petukhov
- Petersburg Nuclear Physics Institute Named after B.P. Konstantinov, NRC “Kurchatov Institute”, 188300 Gatchina, Russia
| | | | - Maria Sukhareva
- FSBSI Institute of Experimental Medicine, 197022 Saint Petersburg, Russia
| | - Anastasiia Ilina
- Saint Petersburg Institute of Bioregulation and Gerontology, 197110 Saint Petersburg, Russia
- FSBSI Institute of Experimental Medicine, 197022 Saint Petersburg, Russia
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2
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Shin SH, Lee JS, Zhang JM, Choi S, Boskovic ZV, Zhao R, Song M, Wang R, Tian J, Lee MH, Kim JH, Jeong M, Lee JH, Petukhov M, Lee SW, Kim SG, Zou L, Byun S. Synthetic lethality by targeting the RUVBL1/2-TTT complex in mTORC1-hyperactive cancer cells. Sci Adv 2020; 6:eaay9131. [PMID: 32789167 PMCID: PMC7399646 DOI: 10.1126/sciadv.aay9131] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Accepted: 03/19/2020] [Indexed: 05/08/2023]
Abstract
Despite considerable efforts, mTOR inhibitors have produced limited success in the clinic. To define the vulnerabilities of mTORC1-addicted cancer cells and to find previously unknown therapeutic targets, we investigated the mechanism of piperlongumine, a small molecule identified in a chemical library screen to specifically target cancer cells with a hyperactive mTORC1 phenotype. Sensitivity to piperlongumine was dependent on its ability to suppress RUVBL1/2-TTT, a complex involved in chromatin remodeling and DNA repair. Cancer cells with high mTORC1 activity are subjected to higher levels of DNA damage stress via c-Myc and displayed an increased dependency on RUVBL1/2 for survival and counteracting genotoxic stress. Examination of clinical cancer tissues also demonstrated that high mTORC1 activity was accompanied by high RUVBL2 expression. Our findings reveal a previously unknown role for RUVBL1/2 in cell survival, where it acts as a functional chaperone to mitigate stress levels induced in the mTORC1-Myc-DNA damage axis.
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Affiliation(s)
- Seung Ho Shin
- The Hormel Institute, University of Minnesota, Austin, MN 55912, USA
- Department of Food and Nutrition, Gyeongsang National University, Jinju 52828, Republic of Korea
- Institute of Agriculture and Life Science, Gyeongsang National University, Jinju 52828, Republic of Korea
| | - Ji Su Lee
- Division of Bioengineering, Incheon National University, Incheon 22012, Republic of Korea
| | - Jia-Min Zhang
- Massachusetts General Hospital Cancer Center, Building 149 13th Street, Charlestown, MA 02129, USA
| | - Sungbin Choi
- Division of Bioengineering, Incheon National University, Incheon 22012, Republic of Korea
| | - Zarko V. Boskovic
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
- Department of Medicinal Chemistry, University of Kansas, Lawrence, KS 66045, USA
| | - Ran Zhao
- School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, Henan, China
- China-US (Henan) Hormel Cancer Institute, Zhengzhou, Henan, China
| | - Mengqiu Song
- School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, Henan, China
- China-US (Henan) Hormel Cancer Institute, Zhengzhou, Henan, China
| | - Rui Wang
- School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, Henan, China
- China-US (Henan) Hormel Cancer Institute, Zhengzhou, Henan, China
| | - Jie Tian
- School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, Henan, China
- China-US (Henan) Hormel Cancer Institute, Zhengzhou, Henan, China
| | - Mee-Hyun Lee
- School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, Henan, China
- China-US (Henan) Hormel Cancer Institute, Zhengzhou, Henan, China
| | - Jae Hwan Kim
- Department of Agricultural Biotechnology, Seoul National University, Seoul 08826, Korea
| | - Minju Jeong
- Department of Agricultural Biotechnology, Seoul National University, Seoul 08826, Korea
| | - Jung Hyun Lee
- Division of Dermatology, Department of Medicine, University of Washington, Seattle, WA 98109, USA
- Cutaneous Biology Research Center, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | - Michael Petukhov
- Petersburg Nuclear Physics Institute named after B.P. Konstantinov, NRC "Kurchatov Institute", Gatchina, Russia
- Peter the Great St. Petersburg Polytechnic University, St. Petersburg, Russia
| | - Sam W. Lee
- Cutaneous Biology Research Center, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
- Yale University School of Medicine, New Haven, CT 06520, USA
| | - Sang Gyun Kim
- Department of Cell Biology, Harvard Medical School, 240 Longwood Ave, Boston, MA 02115, USA
| | - Lee Zou
- Massachusetts General Hospital Cancer Center, Building 149 13th Street, Charlestown, MA 02129, USA
- Department of Pathology, Harvard Medical School, Boston, MA 02114, USA
| | - Sanguine Byun
- Division of Bioengineering, Incheon National University, Incheon 22012, Republic of Korea
- Cutaneous Biology Research Center, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul 03722, Republic of Korea
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Kolchina N, Khavinson V, Linkova N, Yakimov A, Baitin D, Afanasyeva A, Petukhov M. Systematic search for structural motifs of peptide binding to double-stranded DNA. Nucleic Acids Res 2020; 47:10553-10563. [PMID: 31598715 PMCID: PMC6847403 DOI: 10.1093/nar/gkz850] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 09/17/2019] [Accepted: 09/29/2019] [Indexed: 01/06/2023] Open
Abstract
A large variety of short biologically active peptides possesses antioxidant, antibacterial, antitumour, anti-ageing and anti-inflammatory activity, involved in the regulation of neuro-immuno-endocrine system functions, cell apoptosis, proliferation and differentiation. Therefore, the mechanisms of their biological activity are attracting increasing attention not only in modern molecular biology, biochemistry and biophysics, but also in pharmacology and medicine. In this work, we systematically analysed the ability of dipeptides (all possible combinations of the 20 standard amino acids) to bind all possible combinations of tetra-nucleotides in the central part of dsDNA in the classic B-form using molecular docking and molecular dynamics. The vast majority of the dipeptides were found to be unable to bind dsDNA. However, we were able to identify 57 low-energy dipeptide complexes with peptide-dsDNA possessing high selectivity for DNA binding. The analysis of the dsDNA complexes with dipeptides with free and blocked N- and C-terminus showed that selective peptide binding to dsDNA can increase dramatically with the peptide length.
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Affiliation(s)
- Nina Kolchina
- Petersburg Nuclear Physics Institute named after B.P. Konstantinov, NRC "Kurchatov Institute", Gatchina, Russia.,Peter the Great St. Petersburg Polytechnic University, St. Petersburg, Russia.,Russian Scientific Center of Radiology and Surgical Technologies named after A.M. Granov, St. Petersburg, Russia
| | - Vladimir Khavinson
- Saint Petersburg Institute of Bioregulation and Gerontology, St. Petersburg, Russia.,Pavlov Institute of Physiology of RAS, St. Petersburg, Russia.,North-Western State Medical University named after I.I. Mechnikov, St. Petersburg, Russia
| | - Natalia Linkova
- Saint Petersburg Institute of Bioregulation and Gerontology, St. Petersburg, Russia.,Academy of postgraduate education under FSBU FSCC of FMBA of Russia, Moscow, Russia
| | - Alexander Yakimov
- Petersburg Nuclear Physics Institute named after B.P. Konstantinov, NRC "Kurchatov Institute", Gatchina, Russia.,Peter the Great St. Petersburg Polytechnic University, St. Petersburg, Russia
| | - Dmitry Baitin
- Petersburg Nuclear Physics Institute named after B.P. Konstantinov, NRC "Kurchatov Institute", Gatchina, Russia
| | - Arina Afanasyeva
- Petersburg Nuclear Physics Institute named after B.P. Konstantinov, NRC "Kurchatov Institute", Gatchina, Russia.,Peter the Great St. Petersburg Polytechnic University, St. Petersburg, Russia.,National Institutes of Biomedical Innovation, Health and Nutrition, Osaka, Japan
| | - Michael Petukhov
- Petersburg Nuclear Physics Institute named after B.P. Konstantinov, NRC "Kurchatov Institute", Gatchina, Russia.,Peter the Great St. Petersburg Polytechnic University, St. Petersburg, Russia.,Russian Scientific Center of Radiology and Surgical Technologies named after A.M. Granov, St. Petersburg, Russia
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Ammosova T, Pietzsch CA, Saygideger Y, Ilatovsky A, Lin X, Ivanov A, Kumari N, Jerebtsova M, Kulkarni A, Petukhov M, Üren A, Bukreyev A, Nekhai S. Protein Phosphatase 1-Targeting Small-Molecule C31 Inhibits Ebola Virus Replication. J Infect Dis 2019; 218:S627-S635. [PMID: 30169869 DOI: 10.1093/infdis/jiy422] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Background Ebola virus (EBOV) infection causes severe hemorrhagic fever. EBOV transcription is controlled by host protein phosphatase 1 (PP1), which dephosphorylates VP30 protein. We previously developed 1E7-03, a compound targeting a noncatalytic site of PP1 that induced VP30 phosphorylation and inhibited EBOV transcription. Here, we attempted to further improve 1E7-03, which was not stable in murine serum. Results High-throughput screening with EBOV-green fluorescent protein was conducted on 72 1E7-03 analogs and identified 6 best inhibitory and the least toxic compounds. A parallel in silico screening of compounds from the ZINC database by docking to PP1 identified the best-binding compound C31, which was also present among the top 6 compounds found in the viral screen. C31 showed the best EBOV inhibitory activity among the top 6 compounds and also inhibited EBOV minigenome. C31 bound to the PP1 C-terminal groove in vitro and increased VP30 phosphorylation in cultured cells. C31 demonstrated improved stability in mouse plasma and cell permeability, compared with 1E7-03. It was also detected for 24 hours after injection in mice. Conclusion C31 represents a novel PP1-targeting EBOV inhibitor with improved pharmacological properties that can be further evaluated for future antifiloviral therapy.
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Affiliation(s)
- Tatiana Ammosova
- Center for Sickle Cell Disease, Howard University.,Department of Medicine, Howard University.,Yakut Science Center for Complex Medical Problems, Yakutsk
| | - Colette A Pietzsch
- Department of Pathology, University of Texas Medical Branch at Galveston.,Department of Microbiology and Immunology, University of Texas Medical Branch at Galveston.,Galveston National Laboratory, University of Texas Medical Branch at Galveston
| | - Yasemin Saygideger
- Lombardi Comprehensive Cancer Center, Georgetown University, Washington, D. C
| | - Andrey Ilatovsky
- Division of Molecular and Radiation Biophysics, Petersburg Nuclear Physics Institute, St. Petersburg, Russia
| | - Xionghao Lin
- Center for Sickle Cell Disease, Howard University
| | | | - Namita Kumari
- Center for Sickle Cell Disease, Howard University.,Department of Medicine, Howard University
| | | | | | - Michael Petukhov
- Division of Molecular and Radiation Biophysics, Petersburg Nuclear Physics Institute, St. Petersburg, Russia
| | - Aykut Üren
- Lombardi Comprehensive Cancer Center, Georgetown University, Washington, D. C
| | - Alexander Bukreyev
- Department of Pathology, University of Texas Medical Branch at Galveston.,Department of Microbiology and Immunology, University of Texas Medical Branch at Galveston.,Galveston National Laboratory, University of Texas Medical Branch at Galveston
| | - Sergei Nekhai
- Center for Sickle Cell Disease, Howard University.,Department of Medicine, Howard University.,Department of Microbiology, Howard University
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Yakimov A, Pobegalov G, Bakhlanova I, Khodorkovskii M, Petukhov M, Baitin D. Blocking the RecA activity and SOS-response in bacteria with a short α-helical peptide. Nucleic Acids Res 2017; 45:9788-9796. [PMID: 28934502 PMCID: PMC5766188 DOI: 10.1093/nar/gkx687] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Accepted: 07/24/2017] [Indexed: 01/19/2023] Open
Abstract
The RecX protein, a very active natural RecA protein inhibitor, can completely disassemble RecA filaments at nanomolar concentrations that are two to three orders of magnitude lower than that of RecA protein. Based on the structure of RecX protein complex with the presynaptic RecA filament, we designed a short first in class α-helical peptide that both inhibits RecA protein activities in vitro and blocks the bacterial SOS-response in vivo. The peptide was designed using SEQOPT, a novel method for global sequence optimization of protein α-helices. SEQOPT produces artificial peptide sequences containing only 20 natural amino acids with the maximum possible conformational stability at a given pH, ionic strength, temperature, peptide solubility. It also accounts for restrictions due to known amino acid residues involved in stabilization of protein complexes under consideration. The results indicate that a few key intermolecular interactions inside the RecA protein presynaptic complex are enough to reproduce the main features of the RecX protein mechanism of action. Since the SOS-response provides a major mechanism of bacterial adaptation to antibiotics, these results open new ways for the development of antibiotic co-therapy that would not cause bacterial resistance.
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Affiliation(s)
- Alexander Yakimov
- Department of Molecular and Radiation Biophysics, Petersburg Nuclear Physics Institute (B.P.Konstantinov of National Research Centre 'Kurchatov Institute'), Gatchina 188300, Russia.,Peter the Great St Petersburg Polytechnic University, St Petersburg 195251, Russia
| | - Georgii Pobegalov
- Peter the Great St Petersburg Polytechnic University, St Petersburg 195251, Russia
| | - Irina Bakhlanova
- Department of Molecular and Radiation Biophysics, Petersburg Nuclear Physics Institute (B.P.Konstantinov of National Research Centre 'Kurchatov Institute'), Gatchina 188300, Russia.,Peter the Great St Petersburg Polytechnic University, St Petersburg 195251, Russia
| | | | - Michael Petukhov
- Department of Molecular and Radiation Biophysics, Petersburg Nuclear Physics Institute (B.P.Konstantinov of National Research Centre 'Kurchatov Institute'), Gatchina 188300, Russia.,Peter the Great St Petersburg Polytechnic University, St Petersburg 195251, Russia
| | - Dmitry Baitin
- Department of Molecular and Radiation Biophysics, Petersburg Nuclear Physics Institute (B.P.Konstantinov of National Research Centre 'Kurchatov Institute'), Gatchina 188300, Russia.,Peter the Great St Petersburg Polytechnic University, St Petersburg 195251, Russia
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6
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Afanasyeva A, Izmailov S, Grigoriev M, Petukhov M. AquaBridge: A novel method for systematic search of structural water molecules within the protein active sites. J Comput Chem 2015; 36:1973-7. [PMID: 26339759 DOI: 10.1002/jcc.24022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2015] [Revised: 06/26/2015] [Accepted: 06/29/2015] [Indexed: 11/12/2022]
Abstract
We have developed a novel method for calculation of the water bridges that can be formed in the active sites of proteins in the absence or in the presence of small-molecule ligands. We tested its efficiency on a representative set of human ATP-binding proteins, and show that the docking accuracy of ligands can be substantially improved when water bridges are included in the modeling of protein-ligand interactions. Our analysis of binding pocket hydration can be a useful addition to the in silico approaches of Drug Design.
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Affiliation(s)
- Arina Afanasyeva
- Institute of Nanobiotechnologies, St. Petersburg State Polytechnical University, Polytechnicheskaya, 29, Saint-Petersburg, 195251, Russia.,Division of Molecular and Radiation Biophysics, Petersburg Nuclear Physics Institute, Orlova Roscha, Gatchina, Leningrad district, 188300, Russia
| | - Sergey Izmailov
- Department of computational physics, Saint-Petersburg State University, Peterhof, Botanikaya 64/2, 198504, Russia
| | - Michel Grigoriev
- Laboratory of Molecular Biology of Eucaryotes (LBME) UMR 5099 CNRS, Toulouse, France.,Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, 660 South Euclid Ave., St. Louis, Missouri
| | - Michael Petukhov
- Institute of Nanobiotechnologies, St. Petersburg State Polytechnical University, Polytechnicheskaya, 29, Saint-Petersburg, 195251, Russia.,Division of Molecular and Radiation Biophysics, Petersburg Nuclear Physics Institute, Orlova Roscha, Gatchina, Leningrad district, 188300, Russia
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7
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Tyagi M, Iordanskiy S, Ammosova T, Kumari N, Smith K, Breuer D, Ilatovskiy AV, Kont YS, Ivanov A, Üren A, Kovalskyy D, Petukhov M, Kashanchi F, Nekhai S. Reactivation of latent HIV-1 provirus via targeting protein phosphatase-1. Retrovirology 2015; 12:63. [PMID: 26178009 PMCID: PMC4504130 DOI: 10.1186/s12977-015-0190-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2014] [Accepted: 07/09/2015] [Indexed: 11/23/2022] Open
Abstract
Background HIV-1 escapes antiretroviral drugs by integrating into the host DNA and forming a latent transcriptionally silent HIV-1 provirus. This provirus presents the major hurdle in HIV-1 eradication and cure. Transcriptional activation, which is prerequisite for reactivation and the eradication of latent proviruses, is impaired in latently infected T cells due to the lack of host transcription factors, primarily NF-κB and P-TEFb (CDK9/cyclin T1). We and others previously showed that protein phosphatase-1 (PP1) regulates HIV-1 transcription by modulating CDK9 phosphorylation. Recently we have developed a panel of small molecular compounds targeting a non-catalytic site of PP1. Results Here we generated a new class of sulfonamide-containing compounds that activated HIV-1 in acute and latently infected cells. Among the tested molecules, a small molecule activator of PP1 (SMAPP1) induced both HIV-1 replication and reactivation of latent HIV-1 in chronically infected cultured and primary cells. In vitro, SMAPP1 interacted with PP1 and increased PP1 activity toward a recombinant substrate. Treatment with SMAPP1 increased phosphorylation of CDK9’s Ser90 and Thr186 residues, but not Ser175. Proteomic analysis showed upregulation of P-TEFb and PP1 related proteins, including PP1 regulatory subunit Sds22 in SMAPP1-treated T cells. Docking analysis identified a PP1 binding site for SMAPP1 located within the C-terminal binding pocket of PP1. Conclusion We identified a novel class of PP1-targeting compounds that reactivate latent HIV-1 provirus by targeting PP1, increasing CDK9 phosphorylation and enhancing HIV transcription. This compound represents a novel candidate for anti-HIV-1 therapeutics aiming at eradication of latent HIV-1 reservoirs.
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Affiliation(s)
- Mudit Tyagi
- Department of Medicine, The George Washington University, Washington, DC, 2003, USA.
| | - Sergey Iordanskiy
- National Center for Biodefense and Infectious Diseases, George Mason University, Manassas, VA, 20110, USA.
| | - Tatyana Ammosova
- Center for Sickle Cell Disease, Howard University, 1840 7th Street, N.W. HURB1, Suite 202, Washington, DC, 20059, USA. .,Department of Medicine, Howard University, Washington, DC, 20059, USA. .,Yakut Science Center for Complex Medical Problems, Yakutsk, 677019, Russia.
| | - Namita Kumari
- Center for Sickle Cell Disease, Howard University, 1840 7th Street, N.W. HURB1, Suite 202, Washington, DC, 20059, USA.
| | - Kahli Smith
- Center for Sickle Cell Disease, Howard University, 1840 7th Street, N.W. HURB1, Suite 202, Washington, DC, 20059, USA.
| | - Denitra Breuer
- Center for Sickle Cell Disease, Howard University, 1840 7th Street, N.W. HURB1, Suite 202, Washington, DC, 20059, USA.
| | - Andrey V Ilatovskiy
- Division of Molecular and Radiation Biophysics, Petersburg Nuclear Physics Institute, Gatchina, Russia. .,Instiute of Nanobiotechnologies, St. Petersburg State Polytechnical University, St. Petersburg, Russia.
| | | | - Andrey Ivanov
- Center for Sickle Cell Disease, Howard University, 1840 7th Street, N.W. HURB1, Suite 202, Washington, DC, 20059, USA.
| | - Aykut Üren
- Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC, 20057, USA.
| | - Dmytro Kovalskyy
- Department of Biochemistry and Cancer Therapy and Research Center, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX, 78229, USA.
| | - Michael Petukhov
- Division of Molecular and Radiation Biophysics, Petersburg Nuclear Physics Institute, Gatchina, Russia. .,Instiute of Nanobiotechnologies, St. Petersburg State Polytechnical University, St. Petersburg, Russia.
| | - Fatah Kashanchi
- National Center for Biodefense and Infectious Diseases, George Mason University, Manassas, VA, 20110, USA.
| | - Sergei Nekhai
- Center for Sickle Cell Disease, Howard University, 1840 7th Street, N.W. HURB1, Suite 202, Washington, DC, 20059, USA. .,Department of Medicine, Howard University, Washington, DC, 20059, USA.
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8
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Afanasyeva A, Hirtreiter A, Schreiber A, Grohmann D, Pobegalov G, McKay AR, Tsaneva I, Petukhov M, Käs E, Grigoriev M, Werner F. Lytic water dynamics reveal evolutionarily conserved mechanisms of ATP hydrolysis by TIP49 AAA+ ATPases. Structure 2014; 22:549-59. [PMID: 24613487 PMCID: PMC3991330 DOI: 10.1016/j.str.2014.02.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Revised: 01/29/2014] [Accepted: 02/01/2014] [Indexed: 11/24/2022]
Abstract
Eukaryotic TIP49a (Pontin) and TIP49b (Reptin) AAA+ ATPases play essential roles in key cellular processes. How their weak ATPase activity contributes to their important functions remains largely unknown and difficult to analyze because of the divergent properties of TIP49a and TIP49b proteins and of their homo- and hetero-oligomeric assemblies. To circumvent these complexities, we have analyzed the single ancient TIP49 ortholog found in the archaeon Methanopyrus kandleri (mkTIP49). All-atom homology modeling and molecular dynamics simulations validated by biochemical assays reveal highly conserved organizational principles and identify key residues for ATP hydrolysis. An unanticipated crosstalk between Walker B and Sensor I motifs impacts the dynamics of water molecules and highlights a critical role of trans-acting aspartates in the lytic water activation step that is essential for the associative mechanism of ATP hydrolysis. We have studied the single TIP49 ortholog (mkTIP49) from the archaeon M. kandleri We propose a model for assembly of the pre-transition state for ATP hydrolysis Trans-aspartates downregulate ATP hydrolysis by mkTIP49 hexamers Mutational analysis confirms a highly conserved mechanism for lytic water activation
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Affiliation(s)
- Arina Afanasyeva
- Department of Biophysics, Saint Petersburg State Polytechnical University, Saint Petersburg 195251, Russia; Division of Molecular and Radiation Biophysics, Petersburg Nuclear Physics Institute, Gatchina 188300, Russia
| | - Angela Hirtreiter
- Division of Biosciences, Institute for Structural and Molecular Biology, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK
| | - Anne Schreiber
- Division of Biosciences, Institute for Structural and Molecular Biology, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK
| | - Dina Grohmann
- Physikalische und Theoretische Chemie - NanoBioSciences, Technische Universität Braunschweig, Braunschweig 38106, Germany
| | - Georgii Pobegalov
- Department of Biophysics, Saint Petersburg State Polytechnical University, Saint Petersburg 195251, Russia
| | - Adam R McKay
- Department of Chemistry, University College London, London WC1H 0AJ, UK
| | - Irina Tsaneva
- Division of Biosciences, Institute for Structural and Molecular Biology, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK
| | - Michael Petukhov
- Department of Biophysics, Saint Petersburg State Polytechnical University, Saint Petersburg 195251, Russia; Division of Molecular and Radiation Biophysics, Petersburg Nuclear Physics Institute, Gatchina 188300, Russia
| | - Emmanuel Käs
- UMR 5099, CNRS, Toulouse F-31000, France; Laboratoire de Biologie Moléculaire Eucaryote, Université de Toulouse, Toulouse F-31000, France.
| | - Mikhail Grigoriev
- UMR 5099, CNRS, Toulouse F-31000, France; Laboratoire de Biologie Moléculaire Eucaryote, Université de Toulouse, Toulouse F-31000, France.
| | - Finn Werner
- Division of Biosciences, Institute for Structural and Molecular Biology, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK
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9
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Petukhov M, Dagkessamanskaja A, Bommer M, Barrett T, Tsaneva I, Yakimov A, Quéval R, Shvetsov A, Khodorkovskiy M, Käs E, Grigoriev M. Large-scale conformational flexibility determines the properties of AAA+ TIP49 ATPases. Structure 2012; 20:1321-31. [PMID: 22748767 DOI: 10.1016/j.str.2012.05.012] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2012] [Revised: 04/26/2012] [Accepted: 05/26/2012] [Indexed: 11/19/2022]
Abstract
The TIP49a and TIP49b proteins belong to the family of AAA+ ATPases and play essential roles in vital processes such as transcription, DNA repair, snoRNP biogenesis, and chromatin remodeling. We report the crystal structure of a TIP49b hexamer and the comparative analysis of large-scale conformational flexibility of TIP49a, TIP49b, and TIP49a/TIP49b complexes using molecular modeling and molecular dynamics simulations in a water environment. Our results establish key principles of domain mobility that affect protein conformation and biochemical properties, including a mechanistic basis for the downregulation of ATPase activity upon protein hexamerization. These approaches, applied to the lik-TIP49b mutant reported to possess enhanced DNA-independent ATPase activity, help explain how a three-amino acid insertion remotely affects the structure and conformational dynamics of the ATP binding and hydrolysis pocket while uncoupling ATP hydrolysis from DNA binding. This might be similar to the effects of conformations adopted by TIP49 heterohexamers.
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Affiliation(s)
- Michael Petukhov
- Department of Biophysics, Saint Petersburg State Polytechnical University, Saint Petersburg 197376, Russia
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10
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Garmay Y, Shvetsov A, Karelov D, Lebedev D, Radulescu A, Petukhov M, Isaev-Ivanov V. Correlated motion of protein subdomains and large-scale conformational flexibility of RecA protein filament. ACTA ACUST UNITED AC 2012. [DOI: 10.1088/1742-6596/340/1/012094] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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11
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Petukhov M, Tatsu Y, Tamaki K, Murase S, Uekawa H, Yoshikawa S, Serrano L, Yumoto N. Design of stable alpha-helices using global sequence optimization. J Pept Sci 2009; 15:359-65. [PMID: 19222027 DOI: 10.1002/psc.1122] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The rational design of peptide and protein helices is not only of practical importance for protein engineering but also is a useful approach in attempts to improve our understanding of protein folding. Recent modifications of theoretical models of helix-coil transitions allow accurate predictions of the helix stability of monomeric peptides in water and provide new possibilities for protein design. We report here a new method for the design of alpha-helices in peptides and proteins using AGADIR, the statistical mechanical theory for helix-coil transitions in monomeric peptides and the tunneling algorithm of global optimization of multidimensional functions for optimization of amino acid sequences. CD measurements of helical content of peptides with optimized sequences indicate that the helical potential of protein amino acids is high enough to allow formation of stable alpha-helices in peptides as short as of 10 residues in length. The results show the maximum achievable helix content (HC) of short peptides with fully optimized sequences at 5 degrees C is expected to be approximately 70-75%. Under certain conditions the method can be a powerful practical tool for protein engineering. Unlike traditional approaches that are often used to increase protein stability by adding a few favorable interactions to the protein structure, this method deals with all possible sequences of protein helices and selects the best one from them.
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Affiliation(s)
- Michael Petukhov
- Petersburg Institute of Nuclear Physics, the Russian Academy of Sciences, 188300, Gatchina, Russia.
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12
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Affiliation(s)
- Andrey Ilatovskiy
- Division of Molecular and Radiation Biophysics, Petersburg Nuclear Physics Institute, Russian Academy of Sciences, Gatchina/St. Petersburg, and Research and Education Centre “Biophysics,” PNPI RAS and St. Petersburg State Polytecnic University, St. Petersburg, Russia
| | - Michael Petukhov
- Division of Molecular and Radiation Biophysics, Petersburg Nuclear Physics Institute, Russian Academy of Sciences, Gatchina/St. Petersburg, and Research and Education Centre “Biophysics,” PNPI RAS and St. Petersburg State Polytecnic University, St. Petersburg, Russia
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13
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Abstract
A new method for approximate analytical calculations of solvent accessible surface area (SASA) for arbitrary molecules and their gradients with respect to their atomic coordinates was developed. This method is based on the recursive procedure of pairwise joining of neighboring atoms. Unlike other available methods of approximate SASA calculations, the method has no empirical parameters, and therefore can be used with comparable accuracy in calculations of SASA in folded and unfolded conformations of macromolecules of any chemical nature. As shown by tests with globular proteins in folded conformations, average errors in absolute atomic surface area is around 1 A2, while for unfolded protein conformations it varies from 1.65 to 1.87 A2. Computational times of the method are comparable with those by GETAREA, one of the fastest exact analytical methods available today.
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Affiliation(s)
- Georgy Rychkov
- Division of Molecular and Radiation Biophysics, St. Petersburg Nuclear Physics Institute, The Russian Academy of Sciences (PNPI RAS), Gatchina, St. Petersburg 188300, Russia.
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14
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Petukhov M, Lebedev D, Shalguev V, Islamov A, Kuklin A, Lanzov V, Isaev-Ivanov V. Conformational flexibility of RecA protein filament: transitions between compressed and stretched states. Proteins 2006; 65:296-304. [PMID: 16909421 DOI: 10.1002/prot.21116] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
RecA protein is a central enzyme in homologous DNA recombination, repair and other forms of DNA metabolism in bacteria. It functions as a flexible helix-shaped filament bound on stretched single-stranded or double-stranded DNA in the presence of ATP. In this work, we present an atomic level model for conformational transitions of the RecA filament. The model describes small movements of the RecA N-terminal domain due to coordinated rotation of main chain dihedral angles of two amino acid residues (Psi/Lys23 and Phi/Gly24), while maintaining unchanged the RecA intersubunit interface. The model is able to reproduce a wide range of observed helix pitches in transitions between compressed and stretched conformations of the RecA filament. Predictions of the model are in agreement with Small Angle Neutron Scattering (SANS) measurements of the filament helix pitch in RecA::ADP-AlF(4) complex at various salt concentrations.
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Affiliation(s)
- Michael Petukhov
- Division of Molecular and Radiation Biophysics, Petersburg Nuclear Physics Institute, the Russian Academy of Sciences, Gatchina/St. Petersburg, Russia.
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15
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Petukhov M, Rychkov G, Firsov L, Serrano L. H-bonding in protein hydration revisited. Protein Sci 2004; 13:2120-9. [PMID: 15238635 PMCID: PMC2279814 DOI: 10.1110/ps.04748404] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2004] [Revised: 03/17/2004] [Accepted: 04/27/2004] [Indexed: 10/26/2022]
Abstract
H-bonding between protein surface polar/charged groups and water is one of the key factors of protein hydration. Here, we introduce an Accessible Surface Area (ASA) model for computationally efficient estimation of a free energy of water-protein H-bonding at any given protein conformation. The free energy of water-protein H-bonds is estimated using empirical formulas describing probabilities of hydrogen bond formation that were derived from molecular dynamics simulations of water molecules at the surface of a small protein, Crambin, from the Abyssinian cabbage (Crambe abyssinica) seed. The results suggest that atomic solvation parameters (ASP) widely used in continuum hydration models might be dependent on ASA for polar/charged atoms under consideration. The predictions of the model are found to be in qualitative agreement with the available experimental data on model compounds. This model combines the computational speed of ASA potential, with the high resolution of more sophisticated solvation methods.
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Affiliation(s)
- Michael Petukhov
- Division of Molecular and Radiation Biophysics (OMRB), St. Petersburg Nuclear Physics Institute, RAS, Gatchina, 188350, St. Petersburg, Russia.
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16
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Petukhov M, Uegaki K, Yumoto N, Serrano L. Amino acid intrinsic alpha-helical propensities III: positional dependence at several positions of C terminus. Protein Sci 2002; 11:766-77. [PMID: 11910021 PMCID: PMC2373540 DOI: 10.1110/ps.2610102] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
In this study, we have analyzed experimentally the helical intrinsic propensities of non-charged and non-aromatic residues at different C-terminal positions (C1, C2, C3) of an Ala-based peptide. The effect was found to be complex, resulting in extra stabilization or destabilization, depending on guest amino acid and position under consideration. Polar (Ser, Thr, Cys, Asn, and Gln) amino acids and Gly were found to have significantly larger helical propensities at several C-terminal positions compared with the alpha-helix center (-1.0 kcal/mole in some cases). Some of the nonpolar residues, especially beta-branched ones (Val and Ile) are significantly more favorable at position C3 (-0.3 to -0.4 kcal/mole), although having minor differences at other C-terminal positions compared with the alpha-helix center. Leu has moderate (-0.1 to -0.2 kcal/mole) stabilization effects at position C2 and C3, whereas being relatively neutral at C1. Finally, Met was found to be unfavorable at C1 and C2 ( +0.2 kcal/mole) and favorable at C3 (-0.2 kcal/mole). Thus, significant differences found between the intrinsic helical propensities at the C-terminal positions and those in the alpha-helix center must be accounted for in helix/coil transition theories and in protein design.
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Affiliation(s)
- Michael Petukhov
- European Molecular Biology Laboratory, Heidelberg, D-69012, Germany
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17
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Chervyakova D, Kagansky A, Petukhov M, Lanzov V. [L29M] substitution in the interface of subunit-subunit interactions enhances Escherichia coli RecA protein properties important for its recombinogenic activity. J Mol Biol 2001; 314:923-35. [PMID: 11734008 DOI: 10.1006/jmbi.2001.5170] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Genetic analysis of RecA protein chimeras and their ancestors, RecAEc (from Escherichia coli) and RecAPa (Pseudomonas aeruginosa) had allowed us to place these proteins with respect to their recombinogenic activities in the following order: RecAPa>RecAX21>RecAX20=RecAEc. While RecAX20 differs from RecAEc in five amino acid residues with two substitutions ([S25A] and [I26V]) at the interface of subunit interactions in the RecA polymer, RecAX20 and RecAX21 differ only by a single substitution [L29M] present at the interface. Here, we present an analysis of the biochemical properties considered important for the recombinogenic activity of all four RecA proteins. While RecAX20 was very similar to RecAEc by all activities analysed, RecAX21 differed from RecAEc in several respects. These differences included an increased affinity for double-stranded DNA, a more active displacement of SSB protein from single-stranded DNA (ssDNA), a decreased end-dependent RecAX21 protein dissociation from a presynaptic complex, and a greater accumulation of intermediate products relative to the final product in the strand-exchange reaction. RecAPa was more tolerant than RecAX21 only to the end-dependent RecA protein dissociation. In addition, RecAPa was more resistant to temperature and salt concentrations in its ability to form a presynaptic RecAPa::ATP::ssDNA filament. Calculations of conformational energy revealed that the [L29M] substitution in RecAX21 polymer caused an increase in its flexibility. This led us to conclude that even a small change in the flexibility of the RecA presynaptic complex could profoundly affect its recombinogenic properties.
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Affiliation(s)
- D Chervyakova
- Division of Molecular and Radiation Biophysics, Petersburg Nuclear Physics Institute, Russian Academy of Sciences, Gatchina/St. Petersburg, 188300, Russia
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18
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Petukhov M, Uegaki K, Yumoto N, Yoshikawa S, Serrano L. Position dependence of amino acid intrinsic helical propensities II: non-charged polar residues: Ser, Thr, Asn, and Gln. Protein Sci 1999; 8:2144-50. [PMID: 10548060 PMCID: PMC2144147 DOI: 10.1110/ps.8.10.2144] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
The assumption that the intrinsic alpha-helical propensities of the amino acids are position independent was critical in several helix/coil transition theories. In the first paper of these series, we reported that this is not the case for Gly and nonpolar aliphatic amino acids (Val, Leu, Met, and Ile). Here we have analyzed the helical intrinsic propensities of noncharged polar residues (Ser, Thr, Asn, and Gln) at different positions of a model polyalanine-based peptide. We found that Thr is more favorable (by approximately 0.3 kcal/mol) at positions N1 and N2 than in the helix center, although for Ser, Asn, and Gln the differences are smaller (+/-0.2 kcal/mol), and in many cases within the experimental error. There is a reasonable agreement (+/-0.2 kcal/mol) between the calculated free energies, using the ECEPP/2 force field equipped with a hydration potential, and the experimental data, except at position N1.
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Affiliation(s)
- M Petukhov
- European Molecular Biology Laboratory, Heidelberg, Germany.
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19
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Abstract
Recent studies have pointed out the important role of local water structures in protein conformational stability. Here, we present an accurate and computationally effective way to estimate the free energy contribution of the simplest water structure motif--the water bridge. Based on the combination of empirical parameters for accessible protein surface area and the explicit consideration of all possible water bridges with the protein, we introduce an improved protein solvation model. We find that accounting for water bridge formation in our model is essential to understand the conformational behavior of polypeptides in water. The model formulation, in fact, does not depend on the polypeptide nature of the solute and is therefore applicable to other flexible biomolecules (i.e., DNAs, RNAs, polysaccharides, etc.).
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Affiliation(s)
- M Petukhov
- European Molecular Biology Laboratory, Heidelberg, Germany.
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20
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Petukhov M, Kil Y, Lanzov V. Comment on a paper by Facchiano et al. (1998). Evaluation of relationship between helix stability and protein thermostability. Protein Eng 1999; 12:437-8. [PMID: 10388838 DOI: 10.1093/protein/12.6.437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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21
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Abstract
Until now and based on the success of the helix/coil transition theory it has been assumed that the alpha-helical propensities of the amino acids are position independent. This has been critical to derive the set of theoretical parameters for the 20 natural amino acids. Here, we have analyzed the behavior of several non-polar residues, Val, Ile, Leu, Met and Gly at the N-cap, at each position of the first helical turn and at a central helical position of a 16-residue peptide model system that starts with eight consecutive alanine residues. We have interpreted the results from these experiments with the model of the helix/coil transition (AGADIR), that indicates that the intrinsic helical propensity is position dependent. Gly, Val and Ile are more favorable at the first turn than in the middle of the alpha-helix, while for Leu and Met we observe the opposite behavior. The differences between the observed helical propensities are as large as 1.0 kcal/mol in some cases. Molecular modeling calculations using the ECEPP/2 force-field equipped with a hydration potential show that this effect can be explained by the combination of three factors: (a) the side-chains in the first helix turn are more solvent-exposed; (b) they have fewer intramolecular van der Waals' contacts; and (c) they posses higher configurational entropy than that in the central position of an alpha-helix. The position-dependent results of the calculations are in reasonable agreement with the experimental estimates and with the intrinsic propensities of the amino acids derived from the statistical analysis of the protein structure database.
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Affiliation(s)
- M Petukhov
- European Molecular Biology Laboratory (EMBL), Meyerhofstrasse 1, Heidelberg, D-69012, Germany
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22
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Abstract
To investigate the role of alpha helices in protein thermostability, we compared energy characteristics of alpha helices from thermophilic and mesophilic proteins belonging to four protein families of known three-dimensional structure, for at least one member of each family. The changes in intrinsic free energy of alpha-helix formation were estimated using the statistical mechanical theory for describing helix/coil transitions in peptide helices [Munoz, V., Serrano, L. Nature Struc. Biol. 1:399-409, 1994; Munoz, V., Serrano, L. J. Mol. Biol. 245:275-296, 1995; Munoz, V., Serrano, L. J. Mol. Biol. 245:297-308, 1995]. Based on known sequences of mesophilic and thermophilic RecA proteins we found that (1) a high stability of alpha helices is necessary but is not a sufficient condition for thermostability of RecA proteins, (2) the total helix stability, rather than that of individual helices, is the factor determining protein thermostability, and (3) two facets of intrahelical interactions, the intrinsic helical propensities of amino acids and the side chain-side chain interactions, are the main contributors to protein thermostability. Similar analysis applied to families of L-lactate dehydrogenases, seryl-tRNA synthetases, and aspartate amino transferases led us to conclude that an enhanced total stability of alpha helices is a general feature of many thermophilic proteins. The magnitude of the observed decrease in intrinsic free energy on alpha-helix formation of several thermoresistant proteins was found to be sufficient to explain the experimentally determined increase of their thermostability. Free energies of intrahelical interactions of different RecA proteins calculated at three temperatures that are thought to be close to its normal environmental conditions were found to be approximately equal. This indicates that certain flexibility of RecA protein structure is an essential factor for protein function. All RecA proteins analyzed fell into three temperature-dependent classes of similar alpha-helix stability (delta G(int) = 45.0 +/- 2.0 kcal/mol). These classes were consistent with the natural origin of the proteins. Based on the sequences of protein alpha helices with optimized arrangement of stabilizing interactions, a natural reserve of RecA protein thermoresistance was estimated to be sufficient for conformational stability of the protein at nearly 200 degrees C.
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Affiliation(s)
- M Petukhov
- Pacific Institute of Bioorganic Chemistry, RAS, Vladivostok, Russia.
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Petukhov M, Yumoto N, Murase S, Onmura R, Yoshikawa S. Factors that affect the stabilization of alpha-helices in short peptides by a capping box. Biochemistry 1996; 35:387-97. [PMID: 8555208 DOI: 10.1021/bi9513766] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
It was reported recently that the capping box sequences of four N-terminal residues are very important for the stabilization of alpha-helices in proteins and peptides. To elucidate factors that affect the stabilization of alpha-helices in short peptides by this motif, we analyzed conformational properties of side chains of five N-terminal residues in several analogs of neuropeptide Y (NPY). The analysis revealed three previously unreported factors that appear to be important for stabilization of an alpha-helix: (a) a second capping box hydrogen bond for the side chains of Ser, Thr, and Cys; (b) long-range electrostatic interactions between the first (N-cap) and fifth (N4) residues; and (c) capping interactions of alpha-amino groups with the N4 residue. These factors were incorporated into the parameter set of a recently published, statistical mechanics approach that showed excellent accuracy in the prediction of the helical propensities of short peptides in water [Muñoz, V., & Serrano, L. (1995) J. Mol. Biol. 245, 275-296, 297-308]. A significant improvement in the agreement between theoretical predictions and experimental data was achieved. The present results also clarify the nature of capping box stabilization of alpha-helices in peptides and proteins, indicating that the total influence of hydrogen bonding, local interactions between side chains, helix macrodipole--charge/dipole interactions, and solvation possibilities must all be taken into account. All these factors are associated with approximately the same energy, but with different residues at the N-cap position, they may have opposite effects on the helix stability of peptides. Thus, a delicate balance of interactions of different types controls the stabilization properties of N-cap residues in alpha-helices.
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Affiliation(s)
- M Petukhov
- Pacific Institute of Bioorganic Chemistry, RAS, Vladivostok, Russia
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