The Binding Groups in Ovomucin-lysozyme Interaction

Abstract

The ovomucin-lysozyme aggregation was remarkably affected by pH or ionic strength. The extent of interaction of F-ovomucin with lysozyme was much larger than that of S-ovomucin. The ovomucin-lysozyme interaction decreased correspondingly, at a rate depending on the time at which ovomucin was modified by neuraminidase. On the other hand, the ovomucin-lysozyme interaction disappeared completely by acetylation, succinila-tion, or carbamylation of lysyl ε-amino groups in lysozyme, but it was not greatly affected by guanidination of lysyl ε-amino groups in lysozyme. From these results, it was confirmed that the electrostatic interaction between the negative charges of the terminal sialic acid in ovomucin and the positive charges of lysyl ε-amino groups in lysozyme is essential for the ovomucin-lysozyme interaction.