[EN] NONPEPTIDIC INHIBITORS OF CRUZAIN<br/>[FR] INHIBITEURS NON PEPTIDIQUES DE LA CRUAZÏNE
申请人:UNIV CALIFORNIA
公开号:WO2009075778A2
公开(公告)日:2009-06-18
Cruzain is the major cysteine protease of T. cruzi, which is the causative agent of Chagas' disease and is a promising target for the development of new chemotherapy. With the goal of developing potent nonpeptidic inhibitors of cruzain, the Substrate Activity Screening (SAS) method was used to screen a library of protease substrates initially designed to target the homologous human protease cathepsin S. Structure-based design was next used to further improve substrate cleavage efficiency by introducing additional binding interactions in the S3 pocket of cruzain. The optimized substrates were then converted to inhibitors by the introduction of cysteine protease mechanism-based pharmacophores. Inhibitor (38) was determined to be reversible even though it incorporated the vinyl sulfone pharmacophore that is well documented to give irreversible cruzain inhibition for peptidic inhibitors. The previously unexplored β-chloro vinyl sulfone pharmacophore provided mechanistic insight that led to the development of potent irreversible acyl- and aryl- oxymethyl ketone cruzain inhibitors. For these inhibitors, potency did not solely depend on leaving group pTa, with 2,3,5,6-tetrafluorophenoxy methyl ketone (54) identified as one of the most potent inhibitors with a second order inactivation constant of 147,000 s-1M-1. This inhibitor completely eradicated the T. cruzi parasite from mammalian cell cultures and consequently has the potential to lead to new chemo therapeutics for Chagas' disease.
Identification of a New Class of Nonpeptidic Inhibitors of Cruzain
作者:Katrien Brak、Patricia S. Doyle、James H. McKerrow、Jonathan A. Ellman
DOI:10.1021/ja710254m
日期:2008.5.1
inhibitors. The previously unexplored beta-chloro vinyl sulfone pharmacophore provided mechanisticinsight that led to the development of potent irreversible acyl- and aryl-oxymethyl ketone cruzain inhibitors. For these inhibitors, potency did not solely depend on leaving group p K a, with 2,3,5,6-tetrafluorophenoxymethyl ketone 54 identified as one of the most potent inhibitors with a second-order inactivation
Cruzain 是克氏锥虫的主要半胱氨酸蛋白酶,它是南美锥虫病的病原体,是开发新化疗的有希望的靶点。为了开发有效的 cruzain 非肽抑制剂,使用底物活性筛选 (SAS) 方法筛选最初设计用于靶向同源人蛋白酶组织蛋白酶 S 的蛋白酶底物库。接下来使用基于结构的设计来进一步改进底物通过在 cruzain 的 S3 口袋中引入额外的结合相互作用来提高切割效率。然后通过引入基于半胱氨酸蛋白酶机制的药效团将优化的底物转化为抑制剂。抑制剂 38 被确定是可逆的,即使它掺入了乙烯基砜药效团,该药效团已被充分证明可以对肽抑制剂产生不可逆的 cruzain 抑制作用。先前未探索的 β-氯乙烯基砜药效团提供了导致开发有效的不可逆酰基和芳基氧甲基酮 cruzain 抑制剂的机理洞察力。对于这些抑制剂,效力不仅仅取决于离去基团 p K a,2,3,5,6-四氟苯氧基甲基酮 54 被鉴定为最有效的抑制剂之一,其二级失活常数为