Ovalbumin is a Component of the Chicken Eggshell Matrix

Abstract

The protein components of biomineralized structures (matrix proteins) are believed to modulate crystal nucleation and growth, and thereby influence the shape and strength of the final structure. The chicken eggshell contains a complex array of distinct matrix proteins. One of these was found to have similar molecular weight and chromatographic properties as purified egg ovalbumin. A commercially available antibody to ovalbumin was utilized for western blotting to demonstrate that ovalbumin is one of the matrix proteins this is extracted from decalcified eggshell. Immunohistochemistry revealed that ovalbumin is found only in the mammillary bodies of decalcified shell, and is not distributed throughout the shell matrix. These results indicate that ovalbumin is present during the initial phase of shell formation and becomes incorporated into the protein matrix of the mammillary bodies. However, it is not yet clear whether ovalbumin at this site plays a specific role in shell mineralization.