Patterson Andrew W, Wood Warren J L, Hornsby Michael, Lesley Scott, Spraggon Glen, Ellman Jonathan A
Department of Chemistry, University of California, Berkeley, California 94720, USA.
J Med Chem. 2006 Oct 19;49(21):6298-307. doi: 10.1021/jm060701s.
The substrate activity screening method, a substrate-based fragment identification and optimization method for the development of enzyme inhibitors, was previously applied to cathepsin S to obtain low nanomolar 1,4-disubstituted-1,2,3-triazole-based aldehyde inhibitors (Wood, W. J. L.; Patterson, A. W.; Tsuruoka, H.; Jain, R. K.; Ellman, J. A. J. Am. Chem. Soc. 2005, 127, 15521-15527). Replacement of the metabolically labile aldehyde pharmacophore with the nitrile pharmacophore provided inhibitors with moderate potency for cathepsin S. The inhibitors showed good selectivity over cathepsins B and L but no selectivity over cathepsin K. X-ray structures of two crystal forms (1.5 and 1.9 A) of a complex between cathepsin S and a triazole inhibitor incorporating a chloromethyl ketone pharmacophore guided the design of triazole substrates with increased cleavage efficiency and selectivity for cathepsin S over cathepsins B, L, and K. Conversion of select substrates to nitrile inhibitors yielded a low molecular weight (414 Da) and potent (15 nM) cathepsin S inhibitor that showed >1000-fold selectivity over cathepsins B, L, and K.
底物活性筛选方法是一种基于底物的片段识别和优化方法，用于开发酶抑制剂，此前已应用于组织蛋白酶S，以获得低纳摩尔浓度的基于1,4-二取代-1,2,3-三唑的醛类抑制剂（伍德，W. J. L.；帕特森，A. W.；鹤冈，H.；贾恩，R. K.；埃尔曼，J. A.《美国化学会志》2005年，127卷，15521 - 15527页）。用腈基药效团取代代谢不稳定的醛基药效团，得到了对组织蛋白酶S具有中等效力的抑制剂。这些抑制剂对组织蛋白酶B和L表现出良好的选择性，但对组织蛋白酶K没有选择性。组织蛋白酶S与一种含有氯甲基酮药效团的三唑抑制剂形成的复合物的两种晶体形式（1.5和1.9埃）的X射线结构，指导了对三唑底物的设计，使其对组织蛋白酶S的切割效率和选择性高于组织蛋白酶B、L和K。将选定的底物转化为腈类抑制剂，得到了一种低分子量（414道尔顿）且高效（15纳摩尔）的组织蛋白酶S抑制剂，该抑制剂对组织蛋白酶B、L和K的选择性超过1000倍。
