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

• Published in: Peptides (New York, N.Y. : 1980) N.Y. : 1980), 2002-09, Vol.23 (9), p.1567-1571
• Main Authors: Nakagomi, Kazuya, Takatsu, Kouki, Takagi, Shinobu, Ebisu, Hidetoshi, Sadakane, Yutaka, Fujii, Noriko, Akizawa, Toshifumi, Tanimura, Takenori, Hatanaka, Yasumaru
• Format: Article
• Language: English
• Subjects: Albutensin A; Cabin-A1; Cathepsin B - antagonists & inhibitors; Cathepsin B - metabolism; Cathepsin B inhibitory peptide; Chromatography, High Pressure Liquid; Chymotrypsin - pharmacology; Dose-Response Relationship, Drug; Human serum albumin; Humans; Kinetics; Oligopeptides - isolation & purification; Oligopeptides - pharmacology; Peptides - chemistry; Peptides - isolation & purification; Serum Albumin - chemistry; Serum Albumin - metabolism; Time Factors; Trypsin - pharmacology; Tryptic and chymotryptic hydrolysate
• ISSN: 0196-9781; 1873-5169
• DOI: 10.1016/S0196-9781(02)00098-0

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. Human albutensin A (Ala–Phe–Lys–Ala–Trp–Ala–Val–Ala–Arg), which corresponds to f(210–218), was also isolated as a potent cathepsin B inhibitor. Synthetic Cabin-A1, -A2, and human albutensin A showed dose-dependent inhibition of cathepsin B, with K i values of 2.4, 290, and 3.8 μM, respectively.