Penn Center for Molecular Discovery, University of Pennsylvania, 1024 Vagelos Research Laboratories, Philadelphia, PA 19104-6383, USA.
Recently, we identified a thiocarbazate that exhibits potent inhibitory activity against human cathepsin L. Since this structure represents a novel chemotype with potential for activity against the entire cysteine protease family, we designed, synthesized, and assayed a series of analogs to probe the mechanism of action, as well as the structural requirements for cathepsin L activity. Molecular docking studies using coordinates of a papain-inhibitor complex as a model for cathepsin L provided useful insights.