Purification and characterization of a putative vitellogenin from the ovary of amphioxus (Branchiostoma belcheri tsingtaunese)

An oocyte-yolk protein was purified by double-step chromatography from amph ioxus ovaries. The purified protein appeared to exist as a homodimer of app roximately 320 kDa in native polyacrylamide gel electrophoresis (PAGE), and was reduced to a single monomer of approximately 160 kDa in sodium dodecyl sulfate-PAGE (SDS-PAGE). The protein was characterized as a phospholipogly coprotein by native PAGE and staining of gels for phosphorus with methyl gr een, for lipids with oil red O and Sudan black B. and for carbohydrates usi ng periodic acid/Schiff reagent. In addition, the amino acid composition of the oocyte-yolk protein was generally similar to that of vitellogenins (Vg s) isolated from different phyla of animals including both vertebrates and invertebrates. The purified phospholipoglycoprotein is thus considered as p utative amphioxus Vg. (C) 2001 Elsevier Science Inc. All rights reserved.