Inter-protein bonding and other molecular interactions in hen egg white

Abstract

The analysis of the SDS-polyacrylamide gel electrophoresis (SDS-PAGE) data, combined with the comparison of viscosity data corresponding to the, thin fraction of hell egg white and 2 mM purefied ovalbumin solution, showed that the thin fraction is a protein solution. Dissolution of the thick fraction of hen egg white in SDS and urea solutions followed by SDS-PAGE, in the presence or absence of P-mercaptoethanol, revealed that it is a protein gel. It was also found that the gel structure consists of the three-dimensional ovomucine-ovomucoid network (matrix) held together by SS bridges which captures the rest of the proteins (ovalbumin, conalbumin, etc). The captured proteins can also be interconnected by S-S bridges thus forming agglomerates or conglomerates, but they are predominantly held by weak electrostatic interactions, as demonstrated by the washing out and dissolving experiments. The matrix structure does not prevent denaturation of the captured proteins as indecated by the 50% decrease in turbidity following gel swelling by the addition of 1 part of an 8 M urea solution to 9 parts of the gel.