Studies on the synthesis of proteinase inhibitors. II. Synthesis of cyclic nonapeptide fragments and analogs related to the reactive sites of soybean Bowman-Birk inhibitor.

Several heterodetic cyclic nonapeptides modeled after the disulfide loops of Bowman-Birk inhibitor which involve either the anti-tryptic or anti-chymotryptic region have been synthesized by the conventional method. The inhibitory properties and the stabilities of these peptides toward trypsin and chymotrypsin, as well as the properties of dimers of the above nonapeptides, were examined.