Biomaterial Database

A study of the interaction of lecithin: cholesterol acyltransferase with subfractions of high density lipoproteins. 1981

M Jahani, and A G Lacko

High density lipoproteins (HDL) were isolated by a chromatographic procedure and subsequently fractionated on a DEAE cellulose (DE-52) column. Four fractions were separated and analyzed for lipid and protein composition and molecular weight. During ion exchange chromatography, one of the four fractions consistently coincided with lecithin:cholesterol acyltransferase (LCAT) activity. When the HDL fractions were incubated with highly purified LCAT preparations, the LCAT activity showed a dependence on unesterified cholesterol concentrations. The HDL subfraction eluting at the highest ionic strength was found to be the best substrate for LCAT. This subfraction exhibited apoprotein and lipid composition similar to HDL3 and contained 31% of the total apoprotein D present in all the subfractions. A positive correlation was found between LCAT activity and the cholesteryl ester/unesterified cholesterol ratio, and a negative correlation was found between LCAT substrate potential and apparent molecular weight of the HDL subfractions when these subfractions were incubated with LCAT. No correlation was apparent between LCAT activity, and the phospholipid/unesterified cholesterol ratio or with the apoA-I/apoA-II ratio.U

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D007862	Phosphatidylcholine-Sterol O-Acyltransferase	An enzyme secreted from the liver into the plasma of many mammalian species. It catalyzes the esterification of the hydroxyl group of lipoprotein cholesterol by the transfer of a fatty acid from the C-2 position of lecithin. In familial lecithin:cholesterol acyltransferase deficiency disease, the absence of the enzyme results in an excess of unesterified cholesterol in plasma.	Lecithin Cholesterol Acyltransferase,Cholesterol Ester Lysolecithin Acyltransferase,Lecithin Acyltransferase,Phosophatidylcholine-Sterol Acyltransferase,Acyltransferase, Lecithin,Acyltransferase, Lecithin Cholesterol,Acyltransferase, Phosophatidylcholine-Sterol,Cholesterol Acyltransferase, Lecithin,O-Acyltransferase, Phosphatidylcholine-Sterol,Phosophatidylcholine Sterol Acyltransferase,Phosphatidylcholine Sterol O Acyltransferase
D008075	Lipoproteins, HDL	A class of lipoproteins of small size (4-13 nm) and dense (greater than 1.063 g/ml) particles. HDL lipoproteins, synthesized in the liver without a lipid core, accumulate cholesterol esters from peripheral tissues and transport them to the liver for re-utilization or elimination from the body (the reverse cholesterol transport). Their major protein component is APOLIPOPROTEIN A-I. HDL also shuttle APOLIPOPROTEINS C and APOLIPOPROTEINS E to and from triglyceride-rich lipoproteins during their catabolism. HDL plasma level has been inversely correlated with the risk of cardiovascular diseases.	High Density Lipoprotein,High-Density Lipoprotein,High-Density Lipoproteins,alpha-Lipoprotein,alpha-Lipoproteins,Heavy Lipoproteins,alpha-1 Lipoprotein,Density Lipoprotein, High,HDL Lipoproteins,High Density Lipoproteins,Lipoprotein, High Density,Lipoprotein, High-Density,Lipoproteins, Heavy,Lipoproteins, High-Density,alpha Lipoprotein,alpha Lipoproteins
D008970	Molecular Weight	The sum of the weight of all the atoms in a molecule.	Molecular Weights,Weight, Molecular,Weights, Molecular
D010743	Phospholipids	Lipids containing one or more phosphate groups, particularly those derived from either glycerol (phosphoglycerides see GLYCEROPHOSPHOLIPIDS) or sphingosine (SPHINGOLIPIDS). They are polar lipids that are of great importance for the structure and function of cell membranes and are the most abundant of membrane lipids, although not stored in large amounts in the system.	Phosphatides,Phospholipid
D002784	Cholesterol	The principal sterol of all higher animals, distributed in body tissues, especially the brain and spinal cord, and in animal fats and oils.	Epicholesterol
D002855	Chromatography, Thin Layer	Chromatography on thin layers of adsorbents rather than in columns. The adsorbent can be alumina, silica gel, silicates, charcoals, or cellulose. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Chromatography, Thin-Layer,Thin Layer Chromatography,Chromatographies, Thin Layer,Chromatographies, Thin-Layer,Thin Layer Chromatographies,Thin-Layer Chromatographies,Thin-Layer Chromatography
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D013379	Substrate Specificity	A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.	Specificities, Substrate,Specificity, Substrate,Substrate Specificities
D014280	Triglycerides	An ester formed from GLYCEROL and three fatty acid groups.	Triacylglycerol,Triacylglycerols,Triglyceride