作者:G. King Farrington、Alok Kumar、Frederick C. Wedler
DOI:10.1021/jm00394a022
日期:1987.11
Inhibitors 1-4 have been shown previously to undergo enzymatic phosphorylation by glutamine synthetase (GS). Phosphonates 6-9 were designed as chemically stable analogues of these phosphorylated inhibitors, incorporating either a tetrahedral sulfur group (6-8) (-S-, -SO-, -SO2-) or phosphinate (9) adjacent to methylphosphonic acid. Phosphonates 6-8 resemble the transiently stable phosphorylated methionine
先前已经显示抑制剂1-4通过谷氨酰胺合成酶(GS)进行酶促磷酸化。膦酸酯6-9被设计为这些磷酸化抑制剂的化学稳定类似物,并结合了四面体硫基(6-8)(-S-,-SO-,-SO2-)或与甲基膦酸相邻的次膦酸酯(9)。膦酸酯6-8类似于暂时稳定的磷酸化甲硫氨酸砜(2),而9类似于磷酸化的2-氨基-4-膦酰基丁酸(4)。当作为细菌,哺乳动物和植物中谷氨酰胺合成酶的抑制剂进行测试时,类似物9被证明是最有效的,相对于大肠杆菌酶,其Ki值为7.5 X 10(-5)M。分析6-9的抑制数据表明,用疏水亚甲基取代桥接四面体硫(6-8)或次膦酸酯(9)的氧和末端磷酸酯会大大降低酶对抑制剂的亲和力。次膦酸酯上的负电荷与活性位点上的Mn2 +相互作用可导致GS对膦酸酯9的亲和力增强。