Characterisation of the Native Lipid Moiety of Echinococcus granulosus Antigen B

摘要: Antigen B (EgAgB) is the most abundant and immunogenic antigen produced by larval stage (metacestode) of Echinococcus granulosus. It a lipoprotein, structure function which have not been completely elucidated. EgAgB apolipoprotein components well characterised; they share homology with group hydrophobic ligand binding proteins (HLBPs) present exclusively in cestode organisms, consist different isoforms 8-kDa encoded polymorphic multigene family comprising five subfamilies (EgAgB1 to EgAgB5). In vitro studies shown that apolipoproteins are capable fatty acids. However, identity native lipid remains unknown. The work was aimed at characterising ligands bound vivo. purified homogeneity from hydatid cyst fluid its fraction extracted using chloroform∶methanol mixtures. This constituted approximately 40–50% total mass. High-performance thin layer chromatography revealed moiety consists variety neutral (mainly triacylglycerides, sterols sterol esters) polar phosphatidylcholine) lipids. Gas-liquid analysis showed 16∶0, 18∶0 18∶1(n-9) acids EgAgB. Furthermore, size exclusion coupled light scattering demonstrated comprises population particles heterogeneous size, an average molecular mass 229 kDa. Our results provide first direct evidence nature vivo indicate composition lipoprotein more complex than previously thought, resembling high density plasma lipoproteins. Results discussed considering what known on metabolism cestodes, taken into account spp. genomic information regarding both gene family.