Hydroxamic Acids As a Novel Family of Serine Racemase Inhibitors: Mechanistic Analysis Reveals Different Modes of Interaction with the Pyridoxal-5′-phosphate Cofactor
作者:Hillary E. Hoffman、Jana Jirásková、Petr Cígler、Miloslav Šanda、Jan Schraml、Jan Konvalinka
DOI:10.1021/jm900775q
日期:2009.10.8
Mammalian serine racemase (SR) is a pyridoxal-5-phosphate (PLP) dependent enzyme responsible for the biosynthesis of the neurotransmitter D-Scrine, which activates N-methyl-D-aspartate (NMDA) receptors in the CNS. Aberrant regulation of NMDA receptor signaling has been implicated in a variety of neuropathologies, and inhibitors of SR would therefore be a worthwhile too] for further investigation or treatment of such conditions. Here, we identify a series of small aliphatic hydroxamic acids (HAS) that act as potent SR inhibitors. However, specificity studies showed that some of these HAS can act as nonspecific inhibitors of PLP-dependent enzymes. We employed NMR, MS, and UV/vis spectroscopic techniques to reveal that the nonspecific effect is likely due to irreversible interaction of the HA moiety with PLP to form aldoxime species. We also characterize L-aspartic acid beta-hydroxamate as a competitive and selective SR inhibitor that could be used as a scaffold for further inhibitor development.
Oxidative Dearomatization of PLP in Thiamin Pyrimidine Biosynthesis in <i>Candida albicans</i>
作者:Anushree Mondal、Rung-Yi Lai、Dmytro Fedoseyenko、Nitai Giri、Tadhg P. Begley
DOI:10.1021/jacs.2c08560
日期:2023.3.1
The yeast thiamin pyrimidine synthase THI5p catalyzes one of the most complex organic rearrangements found in primary metabolism. In this reaction, the active site His66 and PLP are converted to thiamin pyrimidine in the presence of Fe(II) and oxygen. The enzyme is a single-turnover enzyme. Here, we report the identification of an oxidatively dearomatized PLP intermediate. We utilize oxygen labeling