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Characterisation of the Native Lipid Moiety of Echinococcus granulosus Antigen B

Antigen B (EgAgB) is the most abundant and immunogenic antigen produced by the larval stage (metacestode) of Echinococcus granulosus. It is a lipoprotein, the structure and function of which have not been completely elucidated. EgAgB apolipoprotein components have been well characterised; they share...

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Autores principales: Obal, Gonzalo, Ramos, Ana Lía, Silva, Valeria, Lima, Analía, Batthyany, Carlos, Bessio, María Inés, Ferreira, Fernando, Salinas, Gustavo, Ferreira, Ana María
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2012
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3352830/
https://www.ncbi.nlm.nih.gov/pubmed/22616019
http://dx.doi.org/10.1371/journal.pntd.0001642
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author Obal, Gonzalo
Ramos, Ana Lía
Silva, Valeria
Lima, Analía
Batthyany, Carlos
Bessio, María Inés
Ferreira, Fernando
Salinas, Gustavo
Ferreira, Ana María
author_facet Obal, Gonzalo
Ramos, Ana Lía
Silva, Valeria
Lima, Analía
Batthyany, Carlos
Bessio, María Inés
Ferreira, Fernando
Salinas, Gustavo
Ferreira, Ana María
author_sort Obal, Gonzalo
collection PubMed
description Antigen B (EgAgB) is the most abundant and immunogenic antigen produced by the larval stage (metacestode) of Echinococcus granulosus. It is a lipoprotein, the structure and function of which have not been completely elucidated. EgAgB apolipoprotein components have been well characterised; they share homology with a group of hydrophobic ligand binding proteins (HLBPs) present exclusively in cestode organisms, and consist of different isoforms of 8-kDa proteins encoded by a polymorphic multigene family comprising five subfamilies (EgAgB1 to EgAgB5). In vitro studies have shown that EgAgB apolipoproteins are capable of binding fatty acids. However, the identity of the native lipid components of EgAgB remains unknown. The present work was aimed at characterising the lipid ligands bound to EgAgB in vivo. EgAgB was purified to homogeneity from hydatid cyst fluid and its lipid fraction was extracted using chloroform∶methanol mixtures. This fraction constituted approximately 40–50% of EgAgB total mass. High-performance thin layer chromatography revealed that the native lipid moiety of EgAgB consists of a variety of neutral (mainly triacylglycerides, sterols and sterol esters) and polar (mainly phosphatidylcholine) lipids. Gas-liquid chromatography analysis showed that 16∶0, 18∶0 and 18∶1(n-9) are the most abundant fatty acids in EgAgB. Furthermore, size exclusion chromatography coupled to light scattering demonstrated that EgAgB comprises a population of particles heterogeneous in size, with an average molecular mass of 229 kDa. Our results provide the first direct evidence of the nature of the hydrophobic ligands bound to EgAgB in vivo and indicate that the structure and composition of EgAgB lipoprotein particles are more complex than previously thought, resembling high density plasma lipoproteins. Results are discussed considering what is known on lipid metabolism in cestodes, and taken into account the Echinococcus spp. genomic information regarding both lipid metabolism and the EgAgB gene family.
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spelling pubmed-33528302012-05-21 Characterisation of the Native Lipid Moiety of Echinococcus granulosus Antigen B Obal, Gonzalo Ramos, Ana Lía Silva, Valeria Lima, Analía Batthyany, Carlos Bessio, María Inés Ferreira, Fernando Salinas, Gustavo Ferreira, Ana María PLoS Negl Trop Dis Research Article Antigen B (EgAgB) is the most abundant and immunogenic antigen produced by the larval stage (metacestode) of Echinococcus granulosus. It is a lipoprotein, the structure and function of which have not been completely elucidated. EgAgB apolipoprotein components have been well characterised; they share homology with a group of hydrophobic ligand binding proteins (HLBPs) present exclusively in cestode organisms, and consist of different isoforms of 8-kDa proteins encoded by a polymorphic multigene family comprising five subfamilies (EgAgB1 to EgAgB5). In vitro studies have shown that EgAgB apolipoproteins are capable of binding fatty acids. However, the identity of the native lipid components of EgAgB remains unknown. The present work was aimed at characterising the lipid ligands bound to EgAgB in vivo. EgAgB was purified to homogeneity from hydatid cyst fluid and its lipid fraction was extracted using chloroform∶methanol mixtures. This fraction constituted approximately 40–50% of EgAgB total mass. High-performance thin layer chromatography revealed that the native lipid moiety of EgAgB consists of a variety of neutral (mainly triacylglycerides, sterols and sterol esters) and polar (mainly phosphatidylcholine) lipids. Gas-liquid chromatography analysis showed that 16∶0, 18∶0 and 18∶1(n-9) are the most abundant fatty acids in EgAgB. Furthermore, size exclusion chromatography coupled to light scattering demonstrated that EgAgB comprises a population of particles heterogeneous in size, with an average molecular mass of 229 kDa. Our results provide the first direct evidence of the nature of the hydrophobic ligands bound to EgAgB in vivo and indicate that the structure and composition of EgAgB lipoprotein particles are more complex than previously thought, resembling high density plasma lipoproteins. Results are discussed considering what is known on lipid metabolism in cestodes, and taken into account the Echinococcus spp. genomic information regarding both lipid metabolism and the EgAgB gene family. Public Library of Science 2012-05-15 /pmc/articles/PMC3352830/ /pubmed/22616019 http://dx.doi.org/10.1371/journal.pntd.0001642 Text en Obal et al. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited.
spellingShingle Research Article
Obal, Gonzalo
Ramos, Ana Lía
Silva, Valeria
Lima, Analía
Batthyany, Carlos
Bessio, María Inés
Ferreira, Fernando
Salinas, Gustavo
Ferreira, Ana María
Characterisation of the Native Lipid Moiety of Echinococcus granulosus Antigen B
title Characterisation of the Native Lipid Moiety of Echinococcus granulosus Antigen B
title_full Characterisation of the Native Lipid Moiety of Echinococcus granulosus Antigen B
title_fullStr Characterisation of the Native Lipid Moiety of Echinococcus granulosus Antigen B
title_full_unstemmed Characterisation of the Native Lipid Moiety of Echinococcus granulosus Antigen B
title_short Characterisation of the Native Lipid Moiety of Echinococcus granulosus Antigen B
title_sort characterisation of the native lipid moiety of echinococcus granulosus antigen b
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3352830/
https://www.ncbi.nlm.nih.gov/pubmed/22616019
http://dx.doi.org/10.1371/journal.pntd.0001642
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