Biomaterial Database

GPI-specific phospholipase D as an apolipoprotein. 1994

M A Deeg

Department of Medicine, University of Washington, Seattle 98195.

Glycosylphosphatidylinositol-specific phospholipase D (GPI-PLD) has recently been shown to be associated with high-density lipoproteins (HDL) in bovine serum. To determine the distribution of GPI-PLD among lipoproteins and characterize the GPI-PLD-containing lipoproteins in human plasma, we used dextran sulfate and immunoaffinity chromatography to isolate apolipoprotein-specific lipoproteins. This procedure allowed fractionation of lipoprotein particles into those containing apolipoprotein B (Lp B), apolipoproteins AI and AII (Lp AI/AII), or apolipoprotein AI only (Lp AI). In five plasma samples with HDL cholesterol ranging from 40 to 129 mg/dl, 75 +/- 12% (mean +/- SD) of the GPI-PLD activity was associated with Lp AI, 11 +/- 13% with Lp AI/AII, while only 13 +/- 9% was present in plasma devoid of these lipoproteins, suggesting that most of the GPI-PLD in human plasma is associated with apolipoprotein AI. No GPI-PLD activity was detected in Lp B. Further characterization of the GPI-PLD-containing lipoproteins by gel filtration chromatography, nondenaturing poly-acrylamide and agarose gel electrophoresis revealed that GPI-PLD was restricted to an apolipoprotein AI-containing particle or complex that was small (apparent mean Mw of 140 kDa) and distinct from the bulk of HDL. Thus, the majority of plasma GPI-PLD appears to be specifically associated with a small, minor fraction of apolipoprotein AI.

UI	MeSH Term	Description	Entries
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
D010739	Phospholipase D	An enzyme found mostly in plant tissue. It hydrolyzes glycerophosphatidates with the formation of a phosphatidic acid and a nitrogenous base such as choline. This enzyme also catalyzes transphosphatidylation reactions. EC 3.1.4.4.	Lecithinase D,Phosphatidylcholine Phosphohydrolase
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001055	Apolipoproteins B	Major structural proteins of triacylglycerol-rich LIPOPROTEINS. There are two forms, apolipoprotein B-100 and apolipoprotein B-48, both derived from a single gene. ApoB-100 expressed in the liver is found in low-density lipoproteins (LIPOPROTEINS, LDL; LIPOPROTEINS, VLDL). ApoB-48 expressed in the intestine is found in CHYLOMICRONS. They are important in the biosynthesis, transport, and metabolism of triacylglycerol-rich lipoproteins. Plasma Apo-B levels are high in atherosclerotic patients but non-detectable in ABETALIPOPROTEINEMIA.	Apo-B,Apo B,ApoB,Apoprotein (B),Apoproteins B
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
D016632	Apolipoprotein A-I	The most abundant protein component of HIGH DENSITY LIPOPROTEINS or HDL. This protein serves as an acceptor for CHOLESTEROL released from cells thus promoting efflux of cholesterol to HDL then to the LIVER for excretion from the body (reverse cholesterol transport). It also acts as a cofactor for LECITHIN CHOLESTEROL ACYLTRANSFERASE that forms CHOLESTEROL ESTERS on the HDL particles. Mutations of this gene APOA1 cause HDL deficiency, such as in FAMILIAL ALPHA LIPOPROTEIN DEFICIENCY DISEASE and in some patients with TANGIER DISEASE.	Apo A-I,Apo A-1,Apo A-I Isoproteins,Apo A1,Apo AI,ApoA-1,ApoA-I,Apolipoprotein A-1,Apolipoprotein A-I Isoprotein-2,Apolipoprotein A-I Isoprotein-4,Apolipoprotein A-I Isoproteins,Apolipoprotein A1,Apolipoprotein AI,Apolipoprotein AI Propeptide,Pro-Apo A-I,Pro-Apolipoprotein A-I,Proapolipoprotein AI,Apo A I Isoproteins,Apolipoprotein A 1,Apolipoprotein A I,Apolipoprotein A I Isoprotein 2,Apolipoprotein A I Isoprotein 4,Apolipoprotein A I Isoproteins,Pro Apo A I,Pro Apolipoprotein A I
D016633	Apolipoprotein A-II	The second most abundant protein component of HIGH DENSITY LIPOPROTEINS or HDL. It has a high lipid affinity and is known to displace APOLIPOPROTEIN A-I from HDL particles and generates a stable HDL complex. ApoA-II can modulate the activation of LECITHIN CHOLESTEROL ACYLTRANSFERASE in the presence of APOLIPOPROTEIN A-I, thus affecting HDL metabolism.	Apo A-II,Apo A-2,Apo A-II Isoproteins,Apo A2,Apo AII,ApoA-2,ApoA-II,Apolipoprotein A-2,Apolipoprotein A-II Isoproteins,Apolipoprotein A2,Apolipoprotein AII,Pro-Apo A-II,Pro-Apolipoprotein A-II,Proapolipoprotein A-II,Apo A II Isoproteins,Apolipoprotein A 2,Apolipoprotein A II,Apolipoprotein A II Isoproteins,Pro Apo A II,Pro Apolipoprotein A II,Proapolipoprotein A II
D017261	Glycosylphosphatidylinositols	Compounds containing carbohydrate or glycosyl groups linked to phosphatidylinositols. They anchor GPI-LINKED PROTEINS or polysaccharides to cell membranes.	GPI Membrane Anchor,GPI Membrane Anchors,Glycosyl-Phosphatidylinositol Membrane Protein Anchor,Glycosylated Phosphatidylinositol,Glycosylphosphatidylinositol Anchor,Glycosylphosphatidylinositol Anchors,Phosphatidylinositol Glycan,Gly-PtdIns,Glycoinositol Phospholipid Membrane Anchor,Glycosyl-Phosphatidylinositol,Glycosyl-Phosphatidylinositol Membrane Protein Anchors,Glycosylated Phosphatidylinositols,Glycosylphosphatidylinositol,Glycosylphosphatidylinositol Linkage,PI-Glycan,Anchor, GPI Membrane,Anchor, Glycosylphosphatidylinositol,Anchors, GPI Membrane,Anchors, Glycosylphosphatidylinositol,Glycan, Phosphatidylinositol,Glycosyl Phosphatidylinositol,Glycosyl Phosphatidylinositol Membrane Protein Anchor,Glycosyl Phosphatidylinositol Membrane Protein Anchors,Linkage, Glycosylphosphatidylinositol,Membrane Anchor, GPI,Membrane Anchors, GPI,PI Glycan,Phosphatidylinositol, Glycosylated,Phosphatidylinositols, Glycosylated