Carboxyl-terminal Sequence of Human Gastricsin and Pepsin

The tryptic peptides from human pepsin and gastricsin were purified and their sequences were determined. The sequence of 27 residues at the COOH-terminal end of human pepsin was found to be: -Ile-Leu-Gly-Asp-Val-Phe-Ile-Arg-Gln-Phe-Tyr-Thr-Val-Phe-Asp-Arg-Ala-Asn-Asn-Gln-Val-Gly-Leu-Ala-Pro-Val-Ala. The sequence of 19 residues at the COOH-terminal end of human gastricsin was found to be: -Gln-Phe-Tyr-Thr-Val-Phe-Asp-Arg-Ala-Asn-Asn-Lys-Glu-Gly-Leu-Ala-Pro-Val-Ala. These sequences are extensively homologous to each other and to the known COOH-terminal sequence of bovine rennin.