Synthesis of 5‘-Methylthio Coformycins: Specific Inhibitors for Malarial Adenosine Deaminase
作者:Peter C. Tyler、Erika A. Taylor、Richard F. G. Fröhlich、Vern L. Schramm
DOI:10.1021/ja0708363
日期:2007.5.1
state analogue inhibitors of adenosine deaminases (ADAs). These compounds mimic the tetrahedral geometry of the ADA transition state and bind with picomolar dissociation constants to enzymes from bovine, human, and protozoan sources. The purine salvage pathway in malaria parasites is unique in that Plasmodium falciparum ADA (PfADA) catalyzes the deamination of both adenosine and 5'-methylthioadenosine
过渡态理论表明,酶促速率加速 (kcat/knon) 与给定反应的过渡态稳定有关。预计过渡态复合物的化学稳定类似物可将催化能转化为结合能。由于过渡态稳定性是催化效率的函数,因此可以在紧密结合的过渡态类似物抑制剂的设计中利用底物特异性的差异。Coformycin 和 2'-deoxycoformycin 是腺苷脱氨酶 (ADA) 的天然产物过渡态类似物抑制剂。这些化合物模拟 ADA 过渡态的四面体几何形状,并以皮摩尔解离常数与来自牛、人类和原生动物来源的酶结合。疟疾寄生虫中嘌呤补救途径的独特之处在于恶性疟原虫 ADA (PfADA) 催化腺苷和 5'-甲基硫腺苷的脱氨基作用。相比之下,人类腺苷脱氨酶 (HsADA) 和牛酶 (BtADA) 都不能使 5'-甲基硫腺苷脱氨。5'-Methylthiocoformycin 和 5'-methylthio-2'-deoxycoformycin 被合