ISOLATION AND PARTIAL CHARACTERIZATION OF VITELLIN FROM THE EGG OF THE GIANT TIGER PRAWN, PENAEUS-MONODON

1. The results obtained from the present study show that vitellin (yolk protein), a glycolipoprotein derived from the giant tiger prawn, Penaeus monodon, consists of four polypeptides, Ep1, Ep2, Ep3 and Ep4, with molecular weights of 168, 104, 83 and 74 kDa, respectively. This protein was purified using SDS-PAGE and gel-elution. 2. Antisera against Ep2, Ep3 and Ep4 fractions showed very strong specific binding reactivity when reacted with shrimp ovaries at developing stages. 3. No crossreaction was observed among Ep2, Ep3 and Ep4 fractions of vitellin. However, anti-Ep2 and anti-Ep3 were demonstrated to be able to react with Ep1 fraction. The homogenates obtained from ripe ovaries and hemolymph of vitllogenesis females showed an immuno-identical pattern to those obtained from egg extracts. 4. The proteolysis mapping for each fraction showed that Ep1, the high molecular weight fraction, contained Ep2 and Ep3 fragments. These results suggest that Ep1 may be a precursor for Ep2 and Ep3.