Isolation and molecular characterization of vitellin from the mature ovaries of the prawn Litopenaeus vannamei

Vitellins from ovaries in shrimp Litopenaeus vannamei were examined by polyacrylamide gel electrophoresis, sodium dodecyl sulfate polyacrylamide gel electrophoresis, crossed-immunoelectrophoresis, chromatography (Sepharose CL 213 and hydroxylapatite columns), and high-performance liquid chromatography. Using these methods, two forms of vitellin (Vt1 and Vt2) were observed in ovaries (oocyte 110 mum). The vitellins identified appear to be lipoglycoproteins. Similar vitellin polypeptide composition was observed in the two forms of vitellin, with molecular weights of approximately 60, 90, 95, 100, 140, and 160 kDa. Policlonal antibodies against the two forms of purified protein were prepared, and their specificity was demonstrated by radial immunoprecipitation and Western blotting analysis. The P1 and P2 peptides from N-terminal 100 kDa and 60 kDa polypeptides were highly similar to regions of proline 20 and glycine 635 residues of crustacean vitellogenins.