181769-57-3Relevant articles and documents
Novel peptidyl α-keto amide inhibitors of calpains and other cysteine proteases
Li, Zhaozhao,Ortega-Vilain, Anne-Cécile,Patil, Girish S.,Chu, Der-Lun,Foreman,Eveleth, David D.,Powers, James C.
, p. 4089 - 4098 (2007/10/03)
A series of new dipeptidyl α-keto amides of the general structure R1- L-Leu-D,L-AA-CONH-R2 were synthesized and evaluated as inhibitors for the cysteine proteases calpain I, calpain II, and cathepsin B. They combine 10 different N-protecting groups (R1), 3 amino acids residues in P1 (AA), and 44 distinct substituents on the α-keto amide nitrogen (R2). In general, calpain II was more sensitive to these inhibitors than calpain I, with a large number of inhibitors displaying dissociation constants (K(i)) in the 10-100 nM range. Calpain I was also effectively inhibited, but very low K(i) values were observed with a smaller number of inhibitors than with calpain II. Cathepsin B was weakly inhibited by most compounds in this study. The best inhibitors for calpain II were Z-Leu-Abu-CONH-CH2-CHOH-C6H5 (K(i) = 15 nM), Z-Leu-Abu-CONH-CH2-2-pyridyl (K(i) = 17 nM), and Z-Leu-Abu-CONH- CH2-C6H3(3,5(OMe)2) (K(i) = 22 nM). The best calpain I inhibitor in this study was Z-Leu-Nva-CONH-CH2-2-pyridyl (K(i) = 19 nM). The peptide α-keto amide Z-Leu-Abu-CONH-(CH2)2-3-indoly] was the best inhibitor for cathepsin B (K(i) = 31 nM). Some compounds acted as specific calpain inhibitors, with comparable activity on both calpains I and II and a lack of activity on cathepsin B (e.g., 40, 42, 48, 70). Others were specific inhibitors for calpain I (e.g., 73) or calpain II (e.g., 18, 19, 33, 35, 56). Such inhibitors may be useful in elucidating the physiological and pathological events involving these proteases and may become possible therapeutic agents.
