SEPARATION AND CHARACTERIZATION OF OVOINHIBITORS FROM CHICKEN EGG WHITE

Chicken ovoinhibitor is heterogeneous with respect to carbohydrate content. Separation from egg white by ammonium sulfate fractionation and gel filtration followed by chromatography on DEAE-cellulose yields five fractions that contain from 2300 to 4800 g of carbohydrate per mole. The purified fractions do not differ in amino acid content or in inhibitory activity. They contain glucosamine and hexose but no galactosamine, sialic acid, or tryptophan. Two moles of trypsin or chymotrypsin are bound per mole of ovoinhibitor. Nagarse and Pronase are inhibited by all fractions tested but papain is not. Sedimentation equilibrium in D2O and H2O gives a weight-average molecular weight of 49,000 and a ̅v of 0.71. Since the molecular weight is unchanged in a denaturing reducing solvent, these ovoinhibitors contain only one polypeptide chain. © 1969, American Chemical Society. All rights reserved.