Studies on Peptides. XLIII. Synthesis of Two Protected Peptides Related to the C-Terminal Portion of the Basic Trypsin Inhibitor from Bovine Pancreas (Kunitz and Northrop)

Abstract

The protected nonadecapeptide and the C-terminal dipeptide corresponding to positions 38 through 56 and 57-58 of the basic trypsin inhibitor from bovine pancreas were prepared. Synthesis of the protected nonadecapeptide, Z (OMe)-Cys (Bzl)-Arg (Tos)-Ala-Lys (Z)-Arg (Tos)-Asn-Asn-Phe-Lys (Z)-Ser-Ala-Glu (OBzl)-Asp (OBzl)-Cys (Bzl)-Met-Arg (Tos)-Thr-Cys (Bzl)-Gly-OH, was achieved by condensation of three subunits : Z (OMe)-Cys (Bzl)-Arg (Tos)-Ala-Lys (Z)-Arg (Tos)-NHNH₂ (positions 38-42), Z (OMe)-Asn-Asn-Phe-Lys (Z)-Ser-Ala-NHNH₂ (positions 43-48) and Z (OMe)-Glu (OBzl)-Asp (OBzl)-Cys (Bzl)-Met-Arg (Tos)-Thr-Cys (Bzl)-Gly-OH (positions 49-56). The C-terminal dipeptide was prepared in a form of Z (OMe)-Gly-Ala-OH.