Distribution of the Kunitz and the Bowman-Birk family proteinase inhibitors in leguminous seeds.

Abstract

The trypsin and chymotrypsin inhibitory activities of two families of inhibitors, the Kunitz family and the Bowman-Birk family, were screened for in seeds of 34 leguminous species by gel nitration. Results were compared with the morphological classification of leguminous plants. There seemed to be a relationship between the inhibitors found and the evolution of leguminous plants. That is, the seeds of the more primitive leguminous species contained mainly the Kunitz family inhibitors and those of the more advanced ones had the Bowman-Birk family inhibitors. Results suggested that the Kunitz family inhibitors in leguminous seeds have gradually been replaced by the Bowman-Birk family inhibitors in the process of evolution.