[Interaction of ovomucoid from duck egg white with serine proteinases]

The interaction of highly purified duck egg white ovomucoid with trypsin and chymotrypsin was studied. It was found that the ovomucoid molecule contains two equally effective trypsin-binding sites which, in their turn, comprise lysine residues and one independent chymotrypsin-binding site. The values of inhibition constants were determined and the changes in free energy, enthalpy and entropy during the ovomucoid interaction with trypsin and chymotrypsin were established. It was shown that the inhibitor affinity for the enzymes does not change at low degrees of free amino groups modification.