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Thapa G, Bhattacharya A, Bhattacharya S. Molecular dynamics investigation of DNA fragments bound to the anti-HIV protein SAMHD1 reveals alterations in allosteric communications. J Mol Graph Model 2024; 129:108748. [PMID: 38452417 DOI: 10.1016/j.jmgm.2024.108748] [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: 12/11/2023] [Revised: 02/16/2024] [Accepted: 02/20/2024] [Indexed: 03/09/2024]
Abstract
The sterile alpha motif and histidine-aspartate domain-containing protein 1 (or SAMHD1), a human dNTP-triphosphohydrolase, contributes to HIV-1 restriction in select terminally differentiated cells of the immune system. While the prevailing hypothesis is that the catalytically active form of the protein is an allosterically triggered tetramer, whose HIV-1 restriction properties are attributed to its dNTP - triphosphohydrolase activity, it is also known to bind to ssRNA and ssDNA oligomers. A complete picture of the structure-function relationship of the enzyme is still elusive and the function corresponding to its nucleic acid binding ability is debated. In this in silico study, we investigate the stability, preference and allosteric effects of DNA oligomers bound to SAMHD1. In particular, we compare the binding of DNA and RNA oligomers of the same sequence and also consider the binding of DNA fragments with phosphorothioate bonds in the backbone. The results are compared with the canonical form with the monomers connected by GTP/dATP crossbridges. The simulations indicate that SAMHD1 dimers preferably bind to DNA and RNA oligomers compared to GTP/dATP. However, allosteric communication channels are altered in the nucleic acid acid bound complexes compared to the canonical form. All results are consistent with the hypothesis that the DNA bound form of the protein correspond to an unproductive off-pathway state where the protein is sequestered and not available for dNTP hydrolysis.
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Affiliation(s)
- Gauri Thapa
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Mumbai, 400076, India.
| | | | - Swati Bhattacharya
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Mumbai, 400076, India.
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Zhang SM, Paulin CB, Shu H, Yagüe-Capilla M, Michel M, Marttila P, Ortis F, Bwanika HC, Dirks C, Venkatram RP, Wiita E, Jemth AS, Almlöf I, Loseva O, Hormann FM, Koolmeister T, Linde E, Lee S, Llona-Minguez S, Haraldsson M, Axelsson H, Strömberg K, Homan EJ, Scobie M, Lundbäck T, Helleday T, Rudd SG. Identification and evaluation of small-molecule inhibitors against the dNTPase SAMHD1 via a comprehensive screening funnel. iScience 2024; 27:108907. [PMID: 38318365 PMCID: PMC10839966 DOI: 10.1016/j.isci.2024.108907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2022] [Revised: 09/05/2023] [Accepted: 01/10/2024] [Indexed: 02/07/2024] Open
Abstract
SAMHD1 is a dNTP triphosphohydrolase governing nucleotide pool homeostasis and can detoxify chemotherapy metabolites controlling their clinical responses. To understand SAMHD1 biology and investigate the potential of targeting SAMHD1 as neoadjuvant to current chemotherapies, we set out to discover selective small-molecule inhibitors. Here, we report a discovery pipeline encompassing a biochemical screening campaign and a set of complementary biochemical, biophysical, and cell-based readouts for rigorous characterization of the screen output. The identified small molecules, TH6342 and analogs, accompanied by inactive control TH7126, demonstrated specific, low μM potency against both physiological and oncology-drug-derived substrates. By coupling kinetic studies with thermal shift assays, we reveal the inhibitory mechanism of TH6342 and analogs, which engage pre-tetrameric SAMHD1 and deter oligomerization and allosteric activation without occupying nucleotide-binding pockets. Altogether, our study diversifies inhibitory modes against SAMHD1, and the discovery pipeline reported herein represents a thorough framework for future SAMHD1 inhibitor development.
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Affiliation(s)
- Si Min Zhang
- Science for Life Laboratory (SciLifeLab), Department of Oncology-Pathology, Karolinska Institutet, 171 65 Stockholm, Sweden
| | - Cynthia B.J. Paulin
- Science for Life Laboratory (SciLifeLab), Department of Oncology-Pathology, Karolinska Institutet, 171 65 Stockholm, Sweden
| | - Huazhang Shu
- Science for Life Laboratory (SciLifeLab), Department of Oncology-Pathology, Karolinska Institutet, 171 65 Stockholm, Sweden
| | - Miriam Yagüe-Capilla
- Science for Life Laboratory (SciLifeLab), Department of Oncology-Pathology, Karolinska Institutet, 171 65 Stockholm, Sweden
| | - Maurice Michel
- Science for Life Laboratory (SciLifeLab), Department of Oncology-Pathology, Karolinska Institutet, 171 65 Stockholm, Sweden
| | - Petra Marttila
- Science for Life Laboratory (SciLifeLab), Department of Oncology-Pathology, Karolinska Institutet, 171 65 Stockholm, Sweden
| | - Florian Ortis
- Science for Life Laboratory (SciLifeLab), Department of Oncology-Pathology, Karolinska Institutet, 171 65 Stockholm, Sweden
| | - Henri Colyn Bwanika
- Science for Life Laboratory (SciLifeLab), Department of Oncology-Pathology, Karolinska Institutet, 171 65 Stockholm, Sweden
| | - Christopher Dirks
- Science for Life Laboratory (SciLifeLab), Department of Oncology-Pathology, Karolinska Institutet, 171 65 Stockholm, Sweden
| | - Rajagopal Papagudi Venkatram
- Science for Life Laboratory (SciLifeLab), Department of Oncology-Pathology, Karolinska Institutet, 171 65 Stockholm, Sweden
| | - Elisée Wiita
- Science for Life Laboratory (SciLifeLab), Department of Oncology-Pathology, Karolinska Institutet, 171 65 Stockholm, Sweden
| | - Ann-Sofie Jemth
- Science for Life Laboratory (SciLifeLab), Department of Oncology-Pathology, Karolinska Institutet, 171 65 Stockholm, Sweden
| | - Ingrid Almlöf
- Science for Life Laboratory (SciLifeLab), Department of Oncology-Pathology, Karolinska Institutet, 171 65 Stockholm, Sweden
| | - Olga Loseva
- Science for Life Laboratory (SciLifeLab), Department of Oncology-Pathology, Karolinska Institutet, 171 65 Stockholm, Sweden
| | - Femke M. Hormann
- Science for Life Laboratory (SciLifeLab), Department of Oncology-Pathology, Karolinska Institutet, 171 65 Stockholm, Sweden
| | - Tobias Koolmeister
- Science for Life Laboratory (SciLifeLab), Department of Oncology-Pathology, Karolinska Institutet, 171 65 Stockholm, Sweden
| | - Erika Linde
- Science for Life Laboratory (SciLifeLab), Department of Oncology-Pathology, Karolinska Institutet, 171 65 Stockholm, Sweden
| | - Sun Lee
- Science for Life Laboratory (SciLifeLab), Department of Oncology-Pathology, Karolinska Institutet, 171 65 Stockholm, Sweden
| | - Sabin Llona-Minguez
- Science for Life Laboratory (SciLifeLab), Department of Oncology-Pathology, Karolinska Institutet, 171 65 Stockholm, Sweden
| | - Martin Haraldsson
- Chemical Biology Consortium Sweden, Science for Life Laboratory (SciLifeLab), Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 171 65 Stockholm, Sweden
| | - Hanna Axelsson
- Chemical Biology Consortium Sweden, Science for Life Laboratory (SciLifeLab), Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 171 65 Stockholm, Sweden
| | - Kia Strömberg
- Science for Life Laboratory (SciLifeLab), Department of Oncology-Pathology, Karolinska Institutet, 171 65 Stockholm, Sweden
| | - Evert J. Homan
- Science for Life Laboratory (SciLifeLab), Department of Oncology-Pathology, Karolinska Institutet, 171 65 Stockholm, Sweden
| | - Martin Scobie
- Science for Life Laboratory (SciLifeLab), Department of Oncology-Pathology, Karolinska Institutet, 171 65 Stockholm, Sweden
| | - Thomas Lundbäck
- Chemical Biology Consortium Sweden, Science for Life Laboratory (SciLifeLab), Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 171 65 Stockholm, Sweden
| | - Thomas Helleday
- Science for Life Laboratory (SciLifeLab), Department of Oncology-Pathology, Karolinska Institutet, 171 65 Stockholm, Sweden
- Weston Park Cancer Centre, Department of Oncology and Metabolism, University of Sheffield, Sheffield S10 2RX, UK
| | - Sean G. Rudd
- Science for Life Laboratory (SciLifeLab), Department of Oncology-Pathology, Karolinska Institutet, 171 65 Stockholm, Sweden
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