7TEV

Human Ornithine Aminotransferase cocrystallized with its inhibitor, (3S,4R)-3-amino-4-(difluoromethyl)cyclopent-1-ene-1-carboxylate

7TEV の概要

• エントリーDOI: 10.2210/pdb7tev/pdb
• 分子名称: Ornithine aminotransferase, mitochondrial, (1S,3R,4S)-3-formyl-4-[({3-hydroxy-2-methyl-5-[(phosphonooxy)methyl]pyridin-4-yl}methyl)amino]cyclopentane-1-carboxylic acid (3 entities in total)
• 機能のキーワード: human ornithine aminotransferase, hoat, oat, mechanism-based inhibitor, mbi, irreversible inhibitor, inactivator, transferase, transferase-inhibitor complex, transferase/inhibitor
• 由来する生物種: Homo sapiens (human)
• タンパク質・核酸の鎖数: 3
• 化学式量合計: 135745.89

構造登録者

Butrin, A.,Zhu, W.,Silverman, R.,Liu, D. (登録日: 2022-01-05, 公開日: 2022-04-06, 最終更新日: 2023-10-18)

主引用文献

Zhu, W.,Butrin, A.,Melani, R.D.,Doubleday, P.F.,Ferreira, G.M.,Tavares, M.T.,Habeeb Mohammad, T.S.,Beaupre, B.A.,Kelleher, N.L.,Moran, G.R.,Liu, D.,Silverman, R.B.
Rational Design, Synthesis, and Mechanism of (3 S ,4 R )-3-Amino-4-(difluoromethyl)cyclopent-1-ene-1-carboxylic Acid: Employing a Second-Deprotonation Strategy for Selectivity of Human Ornithine Aminotransferase over GABA Aminotransferase.
J.Am.Chem.Soc., 144:5629-5642, 2022

PubMed Abstract: Human ornithine aminotransferase (hOAT) is a pyridoxal 5'-phosphate (PLP)-dependent enzyme that contains a similar active site to that of γ-aminobutyric acid aminotransferase (GABA-AT). Recently, pharmacological inhibition of hOAT was recognized as a potential therapeutic approach for hepatocellular carcinoma. In this work, we first studied the inactivation mechanisms of hOAT by two well-known GABA-AT inactivators ( and ). Inspired by the inactivation mechanistic difference between these two aminotransferases, a series of analogues were designed and synthesized, leading to the discovery of analogue as a highly selective and potent hOAT inhibitor. Intact protein mass spectrometry, protein crystallography, and dialysis experiments indicated that was converted to an irreversible tight-binding adduct () in the active site of hOAT, as was the unsaturated analogue (). The comparison of kinetic studies between and suggested that the active intermediate () was only generated in hOAT and not in GABA-AT. Molecular docking studies and p computational calculations highlighted the importance of chirality and the endocyclic double bond for inhibitory activity. The turnover mechanism of was supported by mass spectrometric analysis of dissociable products and fluoride ion release experiments. Notably, the stopped-flow experiments were highly consistent with the proposed mechanism, suggesting a relatively slow hydrolysis rate for hOAT. The novel second-deprotonation mechanism of contributes to its high potency and significantly enhanced selectivity for hOAT inhibition.

PubMed: 35293728
DOI: 10.1021/jacs.2c00924

実験手法

X-RAY DIFFRACTION (1.91 Å)