Isolation and partial characterization of polymorphic prealbumins from chicken egg yolk and serum

Polymorphic prealbumins (Pa A, Pa AB and Pa B) from hen's egg yolk ( Gallus gallus L.) were isolated by gel filtration. Prealbumin was homogeneous on immunoelectro-phoresis, gel filtration, and ion-exchange chromatography, but heterogeneous on starch gel electrophoresis (five bands). The heterogeneity could be removed by neuraminidase treatment. Some physical and chemical properties were determined, namely molecular weight (19,500), N-terminal amino acid (aspartic acid), isoelectric point (pH 4.6-4.7), A^1%_1cm,280nm value (18.5), absorption spectrum, solubility at different conditions, and the effect of heating. Amino acid composition was estimated too, and the presence of about 4% hexose was proved.