Linked Life Data

6830831

Source:http://linkedlifedata.com/resource/pubmed/id/6830831

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1983-5-5
pubmed:abstractText
Rat liver cytosol contains proteins which in the presence of low-molecular-weight metabolites modulate activities of membrane-bound enzymes of cholesterol biosynthesis. In the preceding paper, we identified Z-protein as a mediator in fatty acyl-CoA modulation of microsomal cholesterol synthetic and metabolizing enzymes. In this communication, we describe a second cytosolic protein which displays cholesterol-exchange activity. Purification of the protein to over 10000-fold and homogeneity has been achieved by gel permeation HPLC on an analytical Spherogel TSK-2000 SW column. Elution of both a single peak of active protein and one SDS-polyacrylamide gel electrophoresis species upon HPLC-purification suggests that homogeneous protein aggregates, with loss of exchange activity. In addition to stimulating microsomal enzymes of sterol synthesis, incubations of microsomes with cholesterol-containing liposomes and the protein consistently yields a 2-3-fold stimulation of microsomal acyl CoA: cholesterol acyltransferase activity. Under similar incubation conditions the protein enhances only slightly the extent of inhibition of microsomal hydroxymethylglutaryl-CoA reductase by liposomal cholesterol. The protein also catalyzes net transfer of cholesterol between membranes of different cholesterol content. The lipid-transfer protein and another cytosolic protein, also implicated in the regulation of sterol synthetic enzymes, appear identical. Regulation of activities of several membrane-bound enzymes of cholesterol metabolism in which the lipid-transfer protein and cytosolic Z-protein modulate uptake of lower-molecular-weight water-insoluble and water-soluble effectors, respectively, is discussed.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:day
22
pubmed:volume
751
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
52-65
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1983
pubmed:articleTitle
Cytosolic modulators of activities of microsomal enzymes of cholesterol biosynthesis. Purification and characterization of a non-specific lipid-transfer protein.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't