Abstract
The dialyzable proteinase inhibitor in the exocarp of the eggplant, Solanum melongena L. was partially purified by column chromatographies on DEAE-cellulose and Sephadex G-25. The inhibitor showed strong inhibitory activity on bovine trypsin [EC 3. 4. 4. 4], Pronase and Nagarse. It also weakly inhibited α-chymotrypsin [EC 3. 4. 4. 5], but, pepsin was not affected. The presence of three inhibitors in this preparation was demonstrated by isoelectrofocusing; their isoelectric points being pH 4.2, 4.7 and 6. 3. The inhibitor with a pI value of 4.7 was present significantly more than the others. The molecular weight of the inhibitor was 5300 based on Sephadex G-75 gel filtration data. It was also very stable to heat treatment. This inhibitor was not the multi-headed type, and was gradually inactivated after a 4 hr incubation with Pronase.
