Interaction of discoidal complexes of dimyristoyl phosphatidylcholine-cholesterol-apolipoprotein A-I with human plasma high density lipoprotein HDL3

Richard L. Jackson, Alan D. Cardin, Roger L. Barnhart, Muhammad Ashraf, J. David Johnson

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3 Scopus citations


The interaction of human plasma high density lipoproteins (HDL3) with discoidal complexes of apolipoprotein A-I (apoA-I) and dimyristoyl phosphatidylcholine (DMPC) containing 0, 10, 20 or 30 mol % cholesterol was investigated. Discoidal complexes containing various amounts of cholesterol were prepared by incubating apoA-I and DMPC-cholesterol liposomes for 12 hr at 25 C; the protein-lipid complexes were isolated by gel filtration chromatography on Bio-Gel A15m. Increasing the cholesterol content from 0 to 30 mol % caused a decrease in the fluidity of the discoidal complexes as determined by fluorescence polarization with 1,6-diphenyl-1,3,5-hexatriene; a reduced phase-transition amplitude; a decrease in the ratio of apoA-I to DMPC; and an increase in the width of the discoidal complexes as determined by electron microscopy after negative staining. Incubation of the apoA-I-lipid complexes with HDL3 resulted in a complete breakdown of the discoidal structures and a transfer of DMPC and cholesterol to HDL3. As a result of lipid transfer, there was an increase in the size of HDL3. These in vitro results may be of significance as they relate to the interconversion of HDL subfractions during lipoprotein-lipase-induced lipolysis of triglyceride-rich lipoproteins.

Original languageEnglish (US)
Pages (from-to)338-344
Number of pages7
Issue number5
Publication statusPublished - May 1 1982
Externally publishedYes


ASJC Scopus subject areas

  • Biochemistry
  • Organic Chemistry
  • Cell Biology

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