VITELLOGEN IN-DERIVED YOLK PROTE INS OF AMUR STURGEON, (ACIPENSER SCHRENCKI I ): PURIFICATION AND CHARACTERIZATION

Sturgeon is an ancient family (Acipenseridae) of fishes close to the divergence fish that eventually evolved into terrestrial animals and those which evolved into modern teleost species. Amour sturgeon vitellogenin (Vg) and its corresponding yolk protein (YP) products, YP., YP and YP3 were isolated from serum of female at vitellogenes is and eggs from ovulated amour sturgeon, respectively. Amour sturgeon Vg was purified from female serum by a combination of precip-itation in DW and gel filtration on sephadexG-00. Vg was confirm ed to be alipogly cophospho protein by staining with Redoi,Mo lecular ProespPro-Q Emerald 300 Glycoprotein Gel sta in and P ro-Q D iamond Phosphoprotein Gel Sta in, whichhad an apparentm olecularm ass o f4.0kD and appeared as one major band corresponding to 05kD after nat ive-PAGE andSDS-PAGE, and confirmed by western blott ing. T hree yolk prote ins derived from v itellogenin (YP1,YPandYP3). Apparentmolecular weights o fYP., YP and YP3w ere 370kD,.44kD and 66kD, respectively. After SDS-PAGE, YP. appearedas two bands of 97kD and 33kD, while YP were resolved as two bands o f94kD and 45kD under reducing cond-it ions. T he characters ofYolk prote in. is smi ilar to amur sturgeon Vg, it is a lipoglycophosphoprotein that can be stainedby Red oi,l M o lecular ProespPro-Q Emerald 300 G lycoprotein Gel stain and Pro-Q D iam ond Phosphoprote in Gel Stain,wh ileYolk protein was confirm ed to be a phospholipoprotein. Yolk protein 3 appeared as one band of 30kD, and it couldbe stained only by P ro-Q Diamond Phosphoprotein Gel Stain. Antiserum toYP and YP3 cross reacted w ith vitellogeninsuggested thatYP and YP3w ere the cleaved products of v itellogen in, while the characters of purified yo lk protein indicatedthatYP and YP3 were am ur sturgeon L ipov itellin and Phosvit in like, respectively. There are e ight subunits of v itellinof am ur sturgeon appeared in reduced SDS-PAGE, as four subunits in unreduced SDS-PAGE. The results of doub le mi munodiffusiongusing ant-iVg show ed that amur sturgeonVg w as composed ofYP. and YP, andYP3 had less antigenicity againstant-iVg.