Human serine racemase is allosterically modulated by NADH and reduced nicotinamide derivatives
作者:Stefano Bruno、Francesco Marchesani、Luca Dellafiora、Marilena Margiotta、Serena Faggiano、Barbara Campanini、Andrea Mozzarelli
DOI:10.1042/bcj20160566
日期:2016.10.15
Serine racemase catalyzes both the synthesis and the degradation of d-serine, an obligatory co-agonist of the glutamatergic NMDA receptors. It is allosterically controlled by adenosine triphosphate (ATP), which increases its activity around 7-fold through a co-operative binding mechanism. Serine racemase has been proposed as a drug target for the treatment of several neuropathologies but, so far, the
丝氨酸消旋酶催化谷氨酸能NMDA受体的必需辅助激动剂d-丝氨酸的合成和降解。它由三磷酸腺苷(ATP)进行变构控制,该ATP通过合作结合机制将其活性提高了约7倍。丝氨酸消旋酶已被提议作为治疗几种神经病理学的药物靶标,但到目前为止,已发现仅针对活性部位,并鉴定了几种低亲和力抑制剂。在最近观察到烟酰胺腺嘌呤二核苷酸(还原形式)(NADH)抑制丝氨酸消旋酶后,在这里我们显示该抑制作用是部分抑制的,IC50为246±63μM,比NADH细胞内浓度高几倍。在饱和NADH浓度下,ATP的结合亲和力降低了2倍,并且没有协同作用,表明配体竞争。在不存在ATP的情况下,NADH还可以降低人丝氨酸消旋酶的弱活性,这表明存在另一种不依赖ATP的抑制机制。通过解剖NADH分子,我们发现抑制决定簇是N-取代的1,4-二氢烟酰胺环。特别地,NADH前体1,4-二氢烟酰胺单核苷酸表现出部分混合型抑制,KI为18±7μM。对接模拟表明,所有1