Study on the composition-structure relationship of Iipophorins

High density lipophorin (HDLp is the main lipoprotein found in resting insect hemolymph. It has, in general, two molecules of apolipoproteins: apoLp-I (250 kDa) and apoLp-II (80 kDa) and a variable lipid content which ranges from 35% to 59% (w/w). Diacylglycerols (DG), phospholipids (PL), and hydroc...

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Autores principales: Soulages, José Luis, Brenner, Rodolfo Roberto
Formato: Articulo
Lenguaje:Inglés
Publicado: 1991
Materias:
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/120454
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id I19-R120-10915-120454
record_format dspace
institution Universidad Nacional de La Plata
institution_str I-19
repository_str R-120
collection SEDICI (UNLP)
language Inglés
topic Química
Lipophorin model.
Lipoprotein structure
Insect lipoprotein
Lipid transport
Lipid-protein interaction
spellingShingle Química
Lipophorin model.
Lipoprotein structure
Insect lipoprotein
Lipid transport
Lipid-protein interaction
Soulages, José Luis
Brenner, Rodolfo Roberto
Study on the composition-structure relationship of Iipophorins
topic_facet Química
Lipophorin model.
Lipoprotein structure
Insect lipoprotein
Lipid transport
Lipid-protein interaction
description High density lipophorin (HDLp is the main lipoprotein found in resting insect hemolymph. It has, in general, two molecules of apolipoproteins: apoLp-I (250 kDa) and apoLp-II (80 kDa) and a variable lipid content which ranges from 35% to 59% (w/w). Diacylglycerols (DG), phospholipids (PL), and hydrocarbons (HC) are the main lipid components, whereas cholesterol and triacylglycerols are minor components. DG content varies from 7 to 30%, PL from 11 to 24%, and HC from 0 to 15%. In order to determine the relationship between the lipid composition and the arrangement of lipid and protein components in the lipoprotein particle, a density-composition structural model was designed. The model was established by means of 12 sets of data on lipophorin density-composition relationships, and model validity was determined throughout lipoprotein space- and surface-filling conditions. Despite the differences among the lipid compositions of lipophorins, it is concluded that there are several unifying structural restrictions that govern the molecular organization of lipophorins. Quantitative treatment of the model indicates that lipophorin structure is consistent with the following. 1) Spherical particles with a protein-rich outer layer of approximately 20-21 Å thickness, comprised of proteins, phospholipids, cholesterol, and small amounts of DG, and a lipid-rich core composed of HC, TG, and almost all the lipophorin DG. 2) Apolipophorins have a lipid-embedded localization within the lipoprotein particle. They might represent one of the few examples of proteins containing beta-shift structure, exerting strong hydrophobic interaction and having a lipid-embedded localization. 3) On the lipophorin surface, apoproteins occupy about 31 x 10³ Ų that represents from 62 to 82% of the total lipoprotein surface, depending on the size of lipophorin considered. 4) The content of PL of each lipophorin is closely proportional to the lipoprotein size. 5) Despite the importance of lipophorin as DG carrier, there are only small amounts of this component on the lipophorin surface which could reach a maximal surface lipid concentration of about 10 mol%.
format Articulo
Articulo
author Soulages, José Luis
Brenner, Rodolfo Roberto
author_facet Soulages, José Luis
Brenner, Rodolfo Roberto
author_sort Soulages, José Luis
title Study on the composition-structure relationship of Iipophorins
title_short Study on the composition-structure relationship of Iipophorins
title_full Study on the composition-structure relationship of Iipophorins
title_fullStr Study on the composition-structure relationship of Iipophorins
title_full_unstemmed Study on the composition-structure relationship of Iipophorins
title_sort study on the composition-structure relationship of iipophorins
publishDate 1991
url http://sedici.unlp.edu.ar/handle/10915/120454
work_keys_str_mv AT soulagesjoseluis studyonthecompositionstructurerelationshipofiipophorins
AT brennerrodolforoberto studyonthecompositionstructurerelationshipofiipophorins
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