Depsipeptides Featuring a Neutral P1 Are Potent Inhibitors of Kallikrein-Related Peptidase 6 with On-Target Cellular Activity
作者:Elena De Vita、Peter Schüler、Scott Lovell、Jasmin Lohbeck、Sven Kullmann、Eitan Rabinovich、Amiram Sananes、Bernd Heßling、Veronique Hamon、Niv Papo、Jochen Hess、Edward W. Tate、Nikolas Gunkel、Aubry K. Miller
DOI:10.1021/acs.jmedchem.8b01106
日期:2018.10.11
Kallikrein-related peptidase 6 (KLK6) is a secreted serine protease that belongs to the family of tissue kallikreins (KLKs). Many KLKs are investigated as potential biomarkers for cancer as well as therapeutic drug targets for a number of pathologies. KLK6, in particular, has been implicated in neurodegenerative diseases and cancer, but target validation has been hampered by a lack of selective inhibitors. This work introduces a class of depsipeptidic KLK6 inhibitors, discovered via high-throughput screening, which were found to function as substrate mimics that transiently acylate the catalytic serine of KLK6. Detailed structure-activity relationship studies, aided by in silico modeling, uncovered strict structural requirements for potency, stability, and acyl-enzyme complex half-life. An optimized scaffold, DKFZ-251, demonstrated good selectivity for KLK6 compared to other KLKs, and on-target activity in a cellular assay. Moreover, DKFZ-633, an inhibitor-derived activity based probe, could be used to pull down active endogenous KLK6.