High water solubility and fold in amphipols of proteins with large hydrophobic regions: Oleosins and caleosin from seed lipid bodies

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TitreHigh water solubility and fold in amphipols of proteins with large hydrophobic regions: Oleosins and caleosin from seed lipid bodies
Type de publicationJournal Article
Nouvelles publications2011
AuteursGohon, Y, Vindigni JD, Pallier A, Wien F, Celia H, Giuliani A, Tribet C, Chardot T, Briozzo P
JournalBiochimica Et Biophysica Acta-Biomembranes
Volume1808
Pagination706-716
Résumé

Seed lipid bodies constitute natural emulsions stabilized by specialized integral membrane proteins, among which the most abundant are oleosins, followed by the calcium binding caleosin. These proteins exhibit a triblock structure, with a highly hydrophobic central region comprising up to 71 residues. Little is known on their three-dimensional structure. Here we report the solubilization of caleosin and of two oleosins in aqueous solution, using various detergents or original amphiphilic polymers, amphipols. All three proteins, insoluble in water buffers, were maintained soluble either by anionic detergents or amphipols. Neutral detergents were ineffective. In complex with amphipols the oleosins and caleosin contain more beta and less alpha secondary structures than in the SDS detergent, as evaluated by synchrotron radiation circular dichroism. These are the first reported structural results on lipid bodies proteins maintained in solution with amphipols, a promising alternative to notoriously denaturing detergents. (c) 2010 Elsevier B.V. All rights reserved.

Unité de rattachement: 
UMR 8640