Subtilisin BPN'

Abstract

The diisopropylphosphoryl-derivative of subtilisin BPN' was denatured and digested with chymotrypsin. The peptides were separated initially on Dowex 1-X2 or Dowex 50-X2 and further purified by various methods. A total of 36 pure peptides was isolated and the sequences were partially or fully determined. These peptides provided many useful overlaps of peptides previously isolated from the tryptic digest. In addition, new peptides were isolated as well as others which confirmed sequences established from the tryptic digest. The sequence of the first 104 residues from the amino terminus is given.