title: Structure-activity relationship, kinetic mechanism, and selectivity for a new class of ubiquitin C-terminal hydrolase-L1 (UCH-L1) inhibitors.
abstract: 3-Amino-2-keto-7H-thieno[2,3-b]pyridin-6-one derivatives were discovered as moderately potent inhibitors of ubiquitin C-terminal hydrolase-L1 (UCH-L1) utilizing an assay that measures hydrolysis of the fluorogenic substrate Ub-AMC. SAR studies revealed that both the carboxylate at the 5-position and the 6-pyridone ring were critical for inhibitory activity. Furthermore, activity was dependent on the nature of the ketone substituent at the 2-position, with 4-Me-Ph and 2-naphthyl being best. Kinetic mechanism studies revealed that these compounds were uncompetitive inhibitors of UCH-L1, binding only to the Michaelis-complex and not to free enzyme. The active compounds were selective for UCH-L1, exhibiting neither inhibition of other cysteine hydrolases (e.g., UCH-L3, papain, isopeptidase T, caspase-3, and tissue transglutaminase) nor cytotoxicity in N2A cells.
authors: Laboratory for Drug Discovery in Neurodegeneration, Harvard Center for Neurodegeneration and Repair, Brigham & Women's Hospital and Harvard Medical School, 65 Landsdowne Street, Cambridge, MA 02139, USA.
authors: Ara H
authors: AH
authors: Mermerian
authors: April
authors: A
authors: Case
authors: Ross L
authors: RL
authors: Stein
authors: Gregory D
authors: GD
authors: Cuny
mesh_terms: D045744:Cell Line, Tumor; D002626:Chemistry, Pharmaceutical / Q000379:methods*; D003545:Cysteine / Q000737:chemistry; D015195:Drug Design; D004791:Enzyme Inhibitors / Q000138:chemical synthesis* / Q000737:chemistry; D006801:Humans; D007659:Ketones / Q000737:chemistry; D007700:Kinetics; D008956:Models, Chemical; D011485:Protein Binding; D013329:Structure-Activity Relationship; D013379:Substrate Specificity; D043222:Ubiquitin Thiolesterase / Q000037:antagonists & inhibitors* / Q000737:chemistry
chemical_list: D004791:Enzyme Inhibitors; D007659:Ketones; C482860:UCHL1 protein, human; D043222:Ubiquitin Thiolesterase; D003545:Cysteine