The isolation and compsotion of two phosphoproteins from hen's egg.

1. Phosvitin extracted from domestic hen's-egg yolk was resolved on Sephadex G-100 into two phosphoprotein components. 2. The major component has a molecular weight of about 3.4x10(4) and alanine as an N-terminal residue. Glucosamine is present, but tyrosine is virtually absent. 3. The minor component has a molecular weight of about 2.8x10(4) and lysine as an N-terminal residue. Missing residues are glucosamine, methionine and leucine. Lysine, histidine, threonine, glycine, phenylalanine and tyrosine contents differ significantly from those of the major component. 4. Sephadex G-100 also removes small amounts of an impurity with a much higher molecular weight.