Purification of Avidin by Cation Exchange, Gel Filtration, Metal Chelate Interaction and Hydrophobic Interaction Chromatography

Abstract

Avidin is commonly recovered in crude form from egg albumen by treatment with a cation exchange resin or by solvent or salt precipitation. Many methods are available for subsequent avidin purification. In this study, carboxymethyl cellulose (CMC) cation exchange, gel filtration, metal chelate interaction, aliphatic hydrophobic interaction and aromatic hydrophobic (Phenyl Sepharose) interaction chromatography each resulted in a substantial increase in avidin purity. In terms of resin capacity, yields and avidin purity, however, CMC cation exchange chromatography was superior. A comparison of sodium dodecyl sulfate polyacrylamide gel electrophoresis and native protein electrophoresis profiles gave evidence of protein-protein interaction between avidin and lysozyme in partially-purified avidin preparations. This interaction may also occur between the native proteins in the egg white, but this has not been demonstrated with certainty.