Complete Amino Acid Sequence of Chitinase - A from Leaves ef

peptides were put in order. Of seyen cysteine residues, six were linked by disulfide bonds (between Cys25 alld Cys74, Cys89 and Cys98, and Cys195 and Cys208); Cys176 was free. The enzyme consisted of 208 amino acid residues and had a molecular weight of 22,391. It consisted of only one polypeptide chain withellt a chitin-binding domai". The length of the chain was almost the same as that of the catalytic demains of class IL chitinases. These findings suggested that this enzyme is a new kind ef class IIL chitinase, altheugh its seqllence resembles that of catalytic demains of class IL chitinases more than that ef the class IIL chitinases reported so far. Discussion on the inyo}yement of specMc tryptophan residue in the actiye site of PLC-A is also giyen based on the sequence similarity with rye seed chitinase-c.