PREPARATION AND CHARACTERIZATION OF PHOSVITIN FROM HEN EGG YOLK

Abstract

Phosvitin was precipitated from egg yolk solution in 0.4 M magnesium sulphate by adding an equal volume of water. Purification was accomplished by repeatedly precipitating and dialyzing at pH 4.0 to remove lipovitellin. Phosvitin so prepared was free of lipid, contained 9.6% phosphorus, and had a molecular weight of 3.0 × 10 4 at pH 4.0 and a frictional ratio that indicates an elongated molecule. It is a polyelectrolyte with properties that are dependent on both the concentration of the solute and the composition of the solvent. In buffer solutions containing low concentrations (0.01 to 0.05 M) of magnesium sulphate, it forms complexes having a particle weight of 14 × 10 5 and with calcium salts a particle weight of 7.5 × 10 5 .