Collect. Czech. Chem. Commun. 1981, 46, 640-654

Investigation of subtilisin digest of pepsin chain between half-cystines II and III

Vladimír Kostka

Institute of Organic Chemistry and Biochemistry, Czechoslovak Academy of Sciences, 166 10 Prague 6


Aminoethylated hog pepsin was subjected to tryptic digestion and the longest fragment, arising from cleavage at S-(β-aminoethyl)-cysteine residue No II and III was isolated from the digest. This fragment was subjected to additional cleavage with subtilisin and the digest resolved into crude fractions by chromatography on Dowex 1. The isolation and final purification of the peptides was carried out by paper electrophoreses and paper chromatography. By these methods 55 peptides were obtained which were subjected to sequential analysis by stepwise degradation. The amino acid sequences of these peptides and their position in the pepsin chain are given. These sequences provided overlaps for peptides obtained by hydrolysis of this part of the pepsin chain by other enzymes.