Subtilisin Amylosacchariticus III. ISOLATION AND SEQUENCE OF THE CHYMOTRYPTIC PEPTIDES AND THE COMPLETE AMINO ACID SEQUENCE

Abstract The denatured diisopropylphosphoryl derivative of subtilisin Amylosacchariticus was digested with chymotrypsin and the peptides resolved by ion exchange chromatography on Dowex 50-X2. The 44 peptides obtained in pure form accounted for 259 of the 275 residues in the protein. Sequence studies were performed on some of these peptides. This information combined with that previously obtained from tryptic and cyanogen bromide peptides and, in some cases, from comparisons of the sequence to that in subtilisin BPN' has provided enough evidence for the complete amino acid sequence of subtilisin Amylosacchariticus. There are 35 differences in sequence between subtilisins Amylosacchariticus and BPN' with most of these being conservative in nature.