Isolation of HIV-1 protease-inhibiting peptides from thermolysin hydrolysate of oyster proteins

The peptides inhibiting HIV-1 protease were isolated from the hydrolysate o f oyster (Crassostrea gigas) proteins prepared with thermolysin. The amino acid sequences of the peptides were determined as Leu-Leu-Glu-Tyr-Ser-Ile a nd Leu-Leu-Glu-Tyr-Ser-Leu. These sequences exist in some proteins of vario la major virus or human cytomegalovirus. Chemically synthesized Leu-Leu-Glu -Tyr-Ser-Ile and Leu-Leu-Glu-Tyr-Ser-Leu showed IC,, values of 20 and 15 nM , respectively, and behaved as competitive inhibitors for HIV-1 protease wi th K-i values of 13 and 10 nM, respectively. These peptides were more poten t as an HIV-1 protease inhibitor than pepstatin A. (C) 1998 Academic Press.