Near to the active sites of trypsin, the DEV model could predict the functi
onal sites from which the proteolytic functional system of trypsin was defi
ned. In the case of chymotrypsin, however, the assignment of functional sit
es failed. When some appropriate portion is removed from chymotrypsin, the
functional system could be defined near the active sites. It is inferred th
at the proteolytic functional system of chymotrypsin is not independent of
other portions of the molecule.