α-Cyclodextrin extracts diacylglycerol from insect high density lipoproteins

Zeina E. Jouni, Jorge Zamora, Marcus Snyder, William R. Montfort, Andrzej Weichsel, Michael A. Wells

Research output: Contribution to journalArticle

8 Scopus citations

Abstract

α-Cyclodextrins are water-soluble cyclic hexamers of glucose units with hydrophobic cavities capable of solubilizing lipophiles. Incubating α- cyclodextrin with high density lipophorin from Manduca sexta or Bombyx mori resulted in a cloudy, turbid solution. Centrifugation separated a pale yellowish precipitate. Thin-layer chromatography analysis of the lipid extract of the precipitate showed that the major lipid was diacylglycerol, while KBr density gradient analysis of the supernatant demonstrated the presence of a lipid-depleted very high density lipophorin. Transfer of diacylglycerol from lipophorin to cyclodextrin was specific to α- cyclodextrin and was not observed with β- or γ-cyclodextrins. pH had no effect on diacylglycerol transfer to α-cyclodextrin. However, the transfer was strongly dependent on the concentration of α-cyclodextrin and temperature. Increasing the concentration of α-cyclodextrin in the incubation mixture was associated with the formation of increasingly higher density lipophorins. Thus, at 20, 30, and 40 mMand α-cyclodextrin, the density of B. mori lipophorin increased from 1.107 g/ml to 1.123, 1.148, and 1.181 g/ml, respectively. At concentrations greater than 40 mM, α- cyclodextrin had no further effect on the density of lipophorin. α- Cyclodextrin removed at most 83-87% of the diacylglycerol present in lipophorin. Temperature played an important role in altering the amount of diacylglycerols transferred to α-cyclodextrin. At 30 mM α-cyclodextrin, the amount of diacylglycerol transferred at different temperatures was 50% at 4°C, 41% at 15°C, 20% at 28°C, and less than 3% at 37°C. We propose that diacylglycerol transfers to α-cyclodextrin via an aqueons diffusion pathway and that the driving force for the transfer is the formation of an insoluble α-cyclodextrin-diacylglycerol complex.

Original languageEnglish (US)
Pages (from-to)933-939
Number of pages7
JournalJournal of Lipid Research
Volume41
Issue number6
StatePublished - Jun 2000

Keywords

  • Bombyx mori
  • Fluid-phase transfer
  • Lipophorin
  • Manduca sexta

ASJC Scopus subject areas

  • Biochemistry
  • Endocrinology
  • Cell Biology

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  • Cite this

    Jouni, Z. E., Zamora, J., Snyder, M., Montfort, W. R., Weichsel, A., & Wells, M. A. (2000). α-Cyclodextrin extracts diacylglycerol from insect high density lipoproteins. Journal of Lipid Research, 41(6), 933-939.