The complete amino acid sequence and the trypsin reactive (inhibitory) site of the major proteinase inhibitor from the fruits of aubergine ( Solanum melongena L.)

plants of the Solanaceae are known to be a rich source of many inhibitors of proteolytic enzymes [ 121. Although the complete ammo acid sequences of the chymotryptic inhibitor I [3-S] and a carboxypeptidase inhibitor [6] from p9tato tubers have been determined together with the partial sequences of several other inhibitors from this tissue [7-91, there are as yet no details of the structures of any inhibitors from other members of the Solanaceae . Kanamori et al. [lo] first reported the occurrence of a proteinase inhibitor in the exocarps of eggplants (aubergine, Solanum melongem L.). The inhibitor was subsequently shown to be a small protein (mol. wt 5300-6200) which inhibited the serine proteinases, and existed in the form of five isoinhibitors which were separable by ionexchange cohmm chromatography and isoelec~ofocus~g [ 1 l-14]. The present paper reports the elucidation of the complete amino acid sequence and the reactive (inhibitory) site of the major isoinhibitor (PI 4.7).