Qualitative Studies on the Interconversion of High Density Lipoproteins Facilitated by the Plasma Lipid Transfer Complex
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Authors
Hamric, Tammy
Issue Date
1981
Type
Thesis
Language
en_US
Keywords
Alternative Title
Abstract
Human lipoprotein-free plasma contains proteins which
facilitate the movement of cholesteryl ester, phospholipid,
and triglyceride between the various lipoprotein particles.
During lipolysis of very low density lipoproteins (VLDL),
lipid and protein constituents transfer to HDL. The purpose
of the present investigation was to assess the role, if any,
of the lipid transfer complex (LTC) in this transfer process.
The LTC was isolated from lipoprotein-free plasma by column
chromatography on phenyl-Sepharose and carboxymethyl
cellulose. VLDL-remnants were prepared by the action of .
bovine milk lipoprotein lipase (LPL). HDL subfractions
were isolated by zonalultracentrifugation. The interconversions
of the HDL subfractions were monitored by
gradient gel electrophoresis. Incubation of HDL4 with
VLDL-remnants in the presence of LTC caused a breakdown
of HDL4 into smaller and larger HDL3-like particles.
This breakdown was dependent on the presence of the LTC
and did not occur with VLDL substituted for the VLDL remnants.
Plasma HDL2 and HDL3 fractions were not altered
by incubation with LTC and VLDL remnants. Preincubation
of LTC with 2mM p-chloromercuriphenyl sulfonate (PCMPS) ,
an inhibitor of the triglyceride transfer protein,
prevented the breakdown of HDL4. These in vitro studies
suggest that the lipid transfer complex, and possibly the
triglyceride transfer protein, play a role in the
reorganization of HDL during the lipolysis of VLDL.
Description
38 p.
Citation
Publisher
Kalamazoo College
License
U.S. copyright laws protect this material. Commercial use or distribution of this material is not permitted without prior written permission of the copyright holder.