Interaction of δ-Chymotrypsin with Proflavine

Abstract

A 1:1 molar stoichiometry has been found for the noncovalent bonding of proflavine with δ-chymotrypsin. The dissociation constant at pH 7.6 is 0.025 mM which is similar to that found by Glazer for the reaction of proflavine with α-chymotrypsin. The difference spectrum produced by the proflavine–δ-chymotrypsin interaction has been studied as a function of pH. It would appear that a group with pK of approximately 6.5 is involved.