title: Purification of serum precursor proteins to vitelline envelope (choriogenins) in masu salmon, Oncorhynchus masou.
abstract: Three vitelline envelope-related proteins (VERPs), very-high-molecular-weight VERP (vhVERP), high-molecular-weight VERP (hVERP) and low-molecular-weight VERP (lVERP) were purified from female masu salmon serum. The apparent molecular weights of vhVERP, hVERP and lVERP, in their native state, were 520, 88 and 54 kDa, respectively, by gel-filtration chromatography. Very-high-molecular-weight VERP comprises two subunits, corresponding to 175 and 126 kDa. On SDS-PAGE, hVERP and lVERP migrate at 53 and 47 kDa, respectively. Amino acid analysis of vhVERP and hVERP showed that they share a high content of glutamic acid and proline. By contrast, lVERP is rich in glutamic acid and asparatic acid. These features are in good agreement with the amino acid composition of the vitelline envelope. Immuno-biochemical analysis suggested that vhVERP is derived from hVERP by polymerization and/or aggregation. Antibodies against hVERP and lVERP specifically immunostained the vitelline envelope and liver of female masu salmon. In addition, both hVERP and lVERP were induced in the serum of estrogen-treated male fish. Taken together, it is suggested that hVERP and lVERP are homologous molecules with choriogenin H and choriogenin L in medaka, respectively. These results indicate that hVERP and lVERP are precursor proteins to the vitelline envelope (choriogenins) in masu salmon.
authors.affiliation: Division of Marine Biosciences, Graduate School of Fisheries Sciences, Hokkaido University, 3-1-1 Minato, Hakodate, Hokkaido, 041-8611, Japan.
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Fujita
authors.forename: Munetaka
authors.initials: M
authors.lastname: Shimizu
authors.forename: Naoshi
authors.initials: N
authors.lastname: Hiramatsu
authors.forename: Haruhisa
authors.initials: H
authors.lastname: Fukada
authors.forename: Akihiko
authors.initials: A
authors.lastname: Hara
mesh_terms: D000596:Amino Acids / Q000032:analysis; D000818:Animals; D000918:Antibody Specificity; D015153:Blotting, Western; D003429:Cross Reactions; D004527:Egg Proteins / Q000097:blood* / Q000737:chemistry / Q000302:isolation & purification*; D004591:Electrophoresis, Polyacrylamide Gel; D004958:Estradiol / Q000494:pharmacology; D005260:Female; D007106:Immune Sera / Q000276:immunology; D005779:Immunodiffusion; D007150:Immunohistochemistry; D008297:Male; D008565:Membrane Proteins / Q000097:blood / Q000737:chemistry / Q000302:isolation & purification; D008970:Molecular Weight; D017683:Oncorhynchus / Q000097:blood*; D011498:Protein Precursors / Q000097:blood* / Q000737:chemistry / Q000302:isolation & purification*; D011817:Rabbits; D014817:Vitelline Membrane / Q000737:chemistry*
chemical_list: D000596:Amino Acids; D004527:Egg Proteins; D007106:Immune Sera; D008565:Membrane Proteins; D011498:Protein Precursors; C035651:vitelline membrane proteins; D004958:Estradiol