Purification, characterization and antigenic species-specific reactivity of vitellogenin of rosy barb (Puntius conchonius Hamilton)

Abstract

Vitellogenin (Vg) was isolated using gel filtration and ion-exchange chromatography from plasma of rosy barb (Puntius conchonius) treated with estrogen (estradiol-17β). The purified Vg was stained positive for carbohydrate, lipid and phosphorus and was rich in Ala (10.58%), Asp (8.46%), Glu (10.30%), Leu (11.23%), Lys (7.22%) and Val (7.49%). It appeared as a single band of approximately 450 kDa in native PAGE and was reduced to a single band of approximately 167 kDa under SDS-PAGE, suggesting that it is probably composed of three identical polypeptide subunits. Double-immunodiffusion assay showed that the plasma from female rosy barb reacted with the mouse antisera against rosy barb Vg, forming a single immunoprecipitin line, while the plasma from male rosy barb or female zebrafish showed no such reactivity, confirming the existence of the sex- and species-specific reactivity for rosy barb Vg antisera.