Isolation of cathepsin B inhibitory peptides, Cabin-A1 and -A2, from a tryptic and chymotryptic hydrolysate of human serum albumin.

Two novel peptides that inhibit cathepsin B were isolated from a tryptic and chymotryptic hydrolysate of human serum albumin, and designated as Cabin-A1 and -A2. Cabin-A1 and -A2 were purified by reversed-phase HPLC and identified as Ser-Leu-His-Thr-Leu-Phe and Phe-Gln-Asn-Ala-Leu, respectively. These peptides correspond to f(65-70) and f(403-407) of human serum albumin.