[Identification of the reactive sites of kidney bean proteinase inhibitor]

The protein proteinase inhibitor from kidney bean (isoinhibitor, pI 4.3) is a double-headed inhibitor with independent reactive sites for trypsin and chymotrypsin. The reactive site of the inhibitor for trypsin is Lys (22)- Ser (23) in the sequense ...-Lys-Ser-Ile-Pro-Ala-Glx-Cys-Arg-..., the reactive site for chymotrypsin is Leu (64)-Ser (65) in the sequence ...-Thr-Leu-Ser-Ile-Pro-Ala-Glx-Cys-Arg-... .