Cholecystokinin octapeptide (1-4) (desulfated) H-Asp-Tyr-Met-Gly-OH is a peptide hormone that is a member of the glucagon family. It has stimulatory effects on the gastrointestinal tract, pancreas and liver, and inhibits gastric acid secretion. Cholecystokinin octapeptide (1-4) (desulfated) H-Asp-Tyr-Met-Gly-OH also stimulates the release of bile from the gallbladder, which may be due to its ability to activate aminopeptidase in the cytoplasm. Captopril is an angiotensin converting enzyme inhibitor that can inhibit cholesteryl ester transfer protein activity by binding to its catalytic site.