Bioresearch Laboratory, Faculty of Biological Sciences, Shahid Beheshti University, GC Tehran, Iran.
J Enzyme Inhib Med Chem. 2012 Aug;27(4):553-7. doi: 10.3109/14756366.2011.601414. Epub 2011 Aug 18.
Ranitidine is an antagonist of histamine-2 (H(2)) receptor. It is employed to treat peptic ulcer and other conditions in which gastric acidity must be reduced. Sucrase is a hydrolytic enzyme that catalyzes the breakdown of sucrose to its monomer content. A liquid of yeast sucrase was developed for treatment of congenital sucrase-isomaltase deficiency (CSID) in human. In this study, the effect of ranitidine on yeast sucrase activity was investigated. Our results showed that ranitidine binds to sucrase and inhibits the enzyme in a noncompetitive manner. The K(i) and IC(50) values were measured to be about 2.3 and 2.2 mM, respectively. Fluorescence measurement showed conformational changes after binding of ranitidine to the enzyme. The fluorescence spectra showed that ranitidine could bind to both free enzyme and enzyme-substrate complex, which was accompanied with reduction of emission intensity and red shift production.
雷尼替丁是一种组织胺 H2（H2）受体拮抗剂。它被用于治疗消化性溃疡和其他需要降低胃酸的疾病。蔗糖酶是一种水解酶，可催化蔗糖分解为其单体成分。一种酵母蔗糖酶的液体已被开发用于治疗人类先天性蔗糖酶-异麦芽糖酶缺乏症（CSID）。在这项研究中，研究了雷尼替丁对酵母蔗糖酶活性的影响。结果表明，雷尼替丁与蔗糖酶结合，并以非竞争性方式抑制该酶。测定的 K（i）和 IC（50）值分别约为 2.3 和 2.2 mM。荧光测量显示雷尼替丁与酶结合后构象发生变化。荧光光谱表明，雷尼替丁可以结合游离酶和酶-底物复合物，同时伴随着发射强度的降低和红移产物的产生。
