title: Isolation and characterization of a non sex-specific lipoprotein from hemolymph of fresh water crab Potamon potamios.
abstract: A non sex-specific high density lipoprotein (HDL) was isolated from the hemolymph of male fresh water crab Potamon potamios. Antiserum against male lipoprotein precipitated a lipoprotein from ovigerous and non ovigerous females. The lipoprotein was isolated by a combination of KBr density gradient ultracentrifugation and gel filtration on Bio-Gel A-1.5m. Two yellow bands with hydrated density of 1.08 and 1.10 g x ml-1 were observed following density gradient ultracentrifugation. Native polyacrylamide electrophoresis showed a low- and a high-mobility band, staining with Sudan black. Both native bands were resolved to a single 128 kDa band in SDS-PAGE. The relative molecular masses of the two bands, as determined by gel filtration and native gradient gel electrophoresis, were 230 and 440 kDa, respectively. Since the lipid content was 50% and the molecular mass of the apoprotein was 128 kDa, we suggest that the lipoprotein is a monomer and a dimer. Chemical cross-linking experiments support this observation. The isoelectric point of the lipoprotein was pH 5.8. The amino-acid composition was also determined. The lipoprotein contained 50% lipids, with phospholipids being the predominant species (80%). Phosphatidylcholine (66%) and phosphatidylethanolamine (16%) were the predominant phospholipids. The fatty acid content of the lipoprotein was also determined. The lipoprotein contained 68% unsaturated fatty acids with oleate being the dominant species (35%).
authors.affiliation: Department of Biology, University of Crete, Greece.
authors.forename: E
authors.initials: E
authors.lastname: Stratakis
authors.forename: G
authors.initials: G
authors.lastname: Fragkiadakis
authors.forename: E
authors.initials: E
authors.lastname: Carpeli-Moustaizi
mesh_terms: D000596:Amino Acids / Q000032:analysis; D000818:Animals; D003386:Brachyura / Q000737:chemistry*; D002850:Chromatography, Gel; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D005618:Fresh Water; D006458:Hemolymph / Q000737:chemistry*; D005779:Immunodiffusion; D008075:Lipoproteins, HDL / Q000276:immunology / Q000302:isolation & purification*; D008297:Male
chemical_list: D000596:Amino Acids; D008075:Lipoproteins, HDL