Studies on the Allergenic Structure of Hen Ovomucoid by Chemical and Enzymic Fragmentation

Abstract

The allergenic structure of ovomucoid was studied by fragmentation with cyanogens bromide and Staphylococcal protease. Two fragments obtained by cyanogen bromide cleavage were identified in the primary structure of ovomucoid to be peptide 1-68 and peptide 69-186 cleaved at position 84 and linked together by a disulfide bridge between 70 and 109.
Allergenic activity, assayed by a passive cutaneous anaphylaxis inhibition test using IgE antibody from mouse, was retained only in peptide 69-186. Three fragments obtained by Staphylococcal protease digestion corresponded to peptide l-130 and two peptides 131-186 differing in carbohydrate content. Only peptide 1-130 was allergenic. The trypsin binding ability remained only in the allergenic peptides. These results suggest that either the common peptide portion in 1-130 and 69-186 or a long range structure composed of these peptides is essential for allergenic activity.