Inhibition of Human DNA Polymerases Eta and Kappa by Indole-Derived Molecules Occurs through Distinct Mechanisms
| العنوان: | Inhibition of Human DNA Polymerases Eta and Kappa by Indole-Derived Molecules Occurs through Distinct Mechanisms |
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| المؤلفون: | Narsimha Reddy Penthala, Amit Ketkar, Peter A. Crooks, Maroof K. Zafar, Leena Maddukuri, Robert L. Eoff, Megan R. Reed |
| المصدر: | ACS Chem Biol |
| بيانات النشر: | American Chemical Society (ACS), 2019. |
| سنة النشر: | 2019 |
| مصطلحات موضوعية: | 0301 basic medicine, Indoles, Alkylation, DNA damage, DNA-Directed DNA Polymerase, 01 natural sciences, Biochemistry, Article, Inhibitory Concentration 50, 03 medical and health sciences, chemistry.chemical_compound, Humans, Nucleotide, Enzyme Inhibitors, Ternary complex, Polymerase, chemistry.chemical_classification, biology, DNA synthesis, 010405 organic chemistry, General Medicine, Molecular biology, Footprinting, 0104 chemical sciences, 030104 developmental biology, Enzyme, chemistry, biology.protein, Molecular Medicine, DNA, DNA Damage |
| الوصف: | Overexpression of human DNA polymerase kappa (hpol κ) in glioblastoma is associated with shorter survival time and resistance to the alkylating agent temozolomide (TMZ), making it an attractive target for the development of small-molecule inhibitors. We previously reported on the development and characterization of indole barbituric acid-derived (IBA) inhibitors of translesion DNA synthesis polymerases (TLS pols). We have now identified a potent and selective inhibitor of hpol κ based on the indole-aminoguanidine (IAG) chemical scaffold. The most promising IAG analogue, IAG-10, exhibited greater inhibitory action against hpol κ than any other human Y-family member, as well as pols from the A-, B-, and X-families. Inhibition of hpol κ by IAG analogues appears to proceed through a mechanism that is distinct from inhibition of hpol η based on changes in DNA binding affinity and nucleotide insertion kinetics. By way of comparison, both IAG and IBA analogues inhibited binary complex formation by hpol κ and ternary complex formation by hpol η. Decreasing the concentration of enzyme and DNA in the reaction mixture lowered the IC(50) value of IAG-10 to submicromolar values, consistent with inhibition of binary complex formation for hpol κ. Chemical footprinting experiments revealed that IAG-10 binds to a cleft between the finger, little finger, and N-clasp domains on hpol κ and that this likely disrupts the interaction between the N-clasp and the TLS pol core. Ln cell culture, IAG-10 potentiated the antiproliferative activity and DNA damaging effects of TMZ in hpol κ-proficient cells but not in hpol κ-deficient cells, indicative of a target-dependent effect. Mutagenic replication across alkylation damage increased in hpol κ-proficient cells treated with IAG-10, while no change in mutation frequency was observed for hpol κ-deficient cells. Ln summary, we developed a potent and selective small-molecule inhibitor of hpol κ that takes advantage of structural features unique to this TLS enzyme to potentiate TMZ, a standard-of-care drug used in the treatment of malignant brain tumors. Furthermore, the IAG scaffold represents a new chemical space for the exploration of TLS pol inhibitors, which could prove useful as a strategy for improving patient response to genotoxic drugs. |
| تدمد: | 1554-8937 1554-8929 |
| الوصول الحر: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::26018f3e9d3838c0e9c18de7d9702ef6Test https://doi.org/10.1021/acschembio.9b00304Test |
| حقوق: | OPEN |
| رقم الانضمام: | edsair.doi.dedup.....26018f3e9d3838c0e9c18de7d9702ef6 |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 15548937 15548929 |
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