2-STEP CHROMATOGRAPHIC PROCEDURE FOR THE PURIFICATION OF HEN EGG-WHITE OVOMUCIN, LYSOZYME, OVOTRANSFERRIN AND OVALBUMIN AND CHARACTERIZATION OF PURIFIED PROTEINS

An improved procedure is described involving gel permeation and anion-exchange chromatography for the purification of four major hen egg white proteins. The procedure involves a first-step purification of ovomucin and lysozyme by gel permeation on a Superose 6 Prep Grade column. In the second step, anion-exchange chromatography on Q Sepharose Fast Flow led to the isolation of ovotransferrin and ovalbumin from a gel permeation chromatographic peak. The purities were estimated as ca. 80, 100, 80 and 100% for ovomucin, lysozyme, ovotransferrin and ovalbumin, respectively. The purification yield was over 60%, for each protein. Further characterization of purified lysozyme revealed that it was fully active and homogeneous in relation to the electrospray ionization mass spectrum. The electrospray ionization mass spectrum showed different ovotransferrin species. The amino acid composition of purified ovomucin was compared to those published previously.