Department of Crystallography & Structural Biology, Institute of Physical Chemistry Blas Cabrera, Spanish National Research Council (CSIC), Madrid, Spain.
Department of Microbiology, University of Granada, Granada, Spain.
FEBS Lett. 2023 Nov;597(21):2687-2698. doi: 10.1002/1873-3468.14738. Epub 2023 Sep 30.
A large conformational heterogeneity of human NAD(P)H:quinone oxidoreductase 1 (NQO1), a flavoprotein associated with various human diseases, has been observed to occur in the catalytic site of the enzyme. Here, we report the X-ray structure of NQO1 with phenylmethylsulfonyl fluoride (PMSF) at 1.6 Å resolution. Activity assays confirmed that, despite being covalently bound to the Tyr128 residue at the catalytic site, PMSF did not abolish NQO1 activity. This may indicate that the PMSF molecule does not reduce the high flexibility of Tyr128, thus allowing NADH and DCPIP substrates to bind to the enzyme. Our results show that targeting Tyr128, a key residue in NQO1 function, with small covalently bound molecules could possibly not be a good drug discovery strategy to inhibit this enzyme.
已观察到与人 NAD(P)H：醌氧化还原酶 1（NQO1）相关的各种人类疾病的黄素蛋白的催化部位发生人 NAD(P)H：醌氧化还原酶 1（NQO1）的大构象异质性。在这里，我们报告了在 1.6Å 分辨率下与苯甲基磺酰氟（PMSF）结合的 NQO1 的 X 射线结构。活性测定证实，尽管 PMSF 与催化部位的 Tyr128 残基共价结合，但它并没有使 NQO1 失活。这可能表明 PMSF 分子不会降低 Tyr128 的高灵活性，从而允许 NADH 和 DCPIP 底物与酶结合。我们的结果表明，针对 NQO1 功能中的关键残基 Tyr128 的小分子共价结合可能不是抑制该酶的好的药物发现策略。
