Biomaterial Database

A glycosaminoglycan activator of lipoprotein lipase in human plasma. 1983

J M Felts, and I Staprans, and R A Gorman

By use of ion exchange chromatography we have isolated two discrete classes of "free" glycosaminoglycans (GAG) from human plasma. The GAG fractions were tested for their effects on two lipoprotein lipase (LPL) enzyme systems containing an apolipoprotein C-II activated emulsion as the triglyceride substrate and bovine serum albumin as the free fatty acid acceptor. The lowcharge GAG (Fraction I) had essentially no effect on the LPL reaction. The high-charge GAG (Fraction II) stimulated the LPL reaction 100 to 300%. The GAG composition of each fraction was investigated with chemical and enzymatic techniques. Fraction I consisted of low-charge chondroitin sulfate noncovalently bound to protein. Fraction II consisted of a mixture of high-charge GAG non-covalently bound to protein. Degradation with nitrous acid eliminated the ability of high-charge GAG to stimulate LPL. This and other evidence suggests that the high-charge GAG in human plasma responsible for LPL activation is heparan sulfate (HS). We suggest that plasma HS may modulate triglyceride clearance mechanisms in vivo by its interaction with LPL.

UI	MeSH Term	Description	Entries
D008071	Lipoprotein Lipase	An enzyme of the hydrolase class that catalyzes the reaction of triacylglycerol and water to yield diacylglycerol and a fatty acid anion. The enzyme hydrolyzes triacylglycerols in chylomicrons, very-low-density lipoproteins, low-density lipoproteins, and diacylglycerols. It occurs on capillary endothelial surfaces, especially in mammary, muscle, and adipose tissue. Genetic deficiency of the enzyme causes familial hyperlipoproteinemia Type I. (Dorland, 27th ed) EC 3.1.1.34.	Heparin-Clearing Factor,Lipemia-Clearing Factor,Diacylglycerol Lipase,Diglyceride Lipase,Post-Heparin Lipase,Postheparin Lipase,Postheparin Lipoprotein Lipase,Factor, Heparin-Clearing,Factor, Lipemia-Clearing,Heparin Clearing Factor,Lipase, Diacylglycerol,Lipase, Diglyceride,Lipase, Lipoprotein,Lipase, Post-Heparin,Lipase, Postheparin,Lipase, Postheparin Lipoprotein,Lipemia Clearing Factor,Lipoprotein Lipase, Postheparin,Post Heparin Lipase
D002852	Chromatography, Ion Exchange	Separation technique in which the stationary phase consists of ion exchange resins. The resins contain loosely held small ions that easily exchange places with other small ions of like charge present in solutions washed over the resins.	Chromatography, Ion-Exchange,Ion-Exchange Chromatography,Chromatographies, Ion Exchange,Chromatographies, Ion-Exchange,Ion Exchange Chromatographies,Ion Exchange Chromatography,Ion-Exchange Chromatographies
D004789	Enzyme Activation	Conversion of an inactive form of an enzyme to one possessing metabolic activity. It includes 1, activation by ions (activators); 2, activation by cofactors (coenzymes); and 3, conversion of an enzyme precursor (proenzyme or zymogen) to an active enzyme.	Activation, Enzyme,Activations, Enzyme,Enzyme Activations
D006025	Glycosaminoglycans	Heteropolysaccharides which contain an N-acetylated hexosamine in a characteristic repeating disaccharide unit. The repeating structure of each disaccharide involves alternate 1,4- and 1,3-linkages consisting of either N-acetylglucosamine (see ACETYLGLUCOSAMINE) or N-acetylgalactosamine (see ACETYLGALACTOSAMINE).	Glycosaminoglycan,Mucopolysaccharides
D006497	Heparitin Sulfate	A heteropolysaccharide that is similar in structure to HEPARIN. It accumulates in individuals with MUCOPOLYSACCHARIDOSIS.	Heparan Sulfate,Sulfate, Heparan,Sulfate, Heparitin
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D001053	Apolipoproteins	Protein components on the surface of LIPOPROTEINS. They form a layer surrounding the hydrophobic lipid core. There are several classes of apolipoproteins with each playing a different role in lipid transport and LIPID METABOLISM. These proteins are synthesized mainly in the LIVER and the INTESTINES.	Apolipoprotein
D001056	Apolipoproteins C	A group of apolipoproteins that can readily exchange among the various classes of lipoproteins (HDL; VLDL; CHYLOMICRONS). After lipolysis of TRIGLYCERIDES on VLDL and chylomicrons, Apo-C proteins are normally transferred to HDL. The subtypes can modulate remnant binding to receptors, LECITHIN CHOLESTEROL ACYLTRANSFERASE, or LIPOPROTEIN LIPASE.	Apo-C,Apo C,ApoC,Apoprotein (C),Apoproteins C
D053304	Apolipoprotein C-II	A 9-kDa protein component of VERY-LOW-DENSITY LIPOPROTEINS. It contains a cofactor for LIPOPROTEIN LIPASE and activates several triacylglycerol lipases. The association of Apo C-II with plasma CHYLOMICRONS; VLDL, and HIGH-DENSITY LIPOPROTEINS is reversible and changes rapidly as a function of triglyceride metabolism. Clinically, Apo C-II deficiency is similar to lipoprotein lipase deficiency (HYPERLIPOPROTEINEMIA TYPE I) and is therefore called hyperlipoproteinemia type IB.	Apo C-II,ApoC2,Apolipoprotein C-2,Apolipoprotein CII,Apoprotein C-II,Apo C II,Apolipoprotein C 2,Apolipoprotein C II,Apoprotein C II