Biology of enterostatin. II. Development of enzyme-linked immunosorbentassay (ELISA) for enterostatin (Val-Pro-Asp-Pro-Arg), the procolipase activation peptide.

Enterostatins belong to a family of pentapeptides (e.g., Val-Pro-Asp-Pro-Arg in pig, horse, dog, and rat; Ala-Pro-Gly-Pro-Arg in human and chicken; and Val-Pro-Gly-Pro-Arg in rat) derived from the amino-terminus of procolipase after the action of trypsin. Pharmacologic studies with Val-Pro-Asp-Pro-Arg have suggested a role for this peptide in appetite regulation and pancreatic insulin secretion. Studies into the distribution of enterostatins or the role of endogenous peptides have not been possible due to the lack of a suitable method for enterostatin assay. To this end, we raised a highly specific antibody and developed an enzyme-linked immunosorbent assay for Val-Pro-Asp-Pro-Arg. Using the newly developed assay we have shown the presence of Val-Pro-Asp-Pro-Arg-like immunoreactivity (2455 +/- 440 pmol/g) in the rat brain.