Amino Acid Sequence ef Chymotrypsin variegata ( LINN . ) var . Orientads InhibitorECI from the Seeds of EVythrina

The amino acids of the chymotrypsi・n inhibitor (ECI) from the Ei:ythrina vm'iagata seeds have been sequeneed. The sequence was solyed by analysis of peptides derived from the pretein by enzymatic digestions with trypsin and &upbylocoeeus aureus V8 proteinase, as well as by chemical cleayage with o-iodosobenzoic acid. The ECI consists of 179 amine aeid residues with a pyroglutamic acid as the N-terminal residue and has a calculated molecular weight of 19,791. Comparison of this seqllence with the sequences of the two trypsin inhibitors, ETIa and ETIb, from the E variegata seeds shows that about 60% of the residues of ECI are identical to those of ETIa and ETth and that the reactiye sites, Arg63, in ETIa and ETIb change to Leu64 in ECI.