Lipoprotein a diet
Plasma lipoproteins can be separated by ultracentrifugation, electrophoresis, or immunoelectrophoresis. Dictionary Thesaurus Medical Dictionary Legal Dictionary Financial Dictionary Acronyms Idioms Encyclopedia Wikipedia Encyclopedia. Unlike the larger lipoprotein particles which deliver fat molecules to cells, HDL particles remove fat molecules from cells which need to export fat molecules. The concentration of these other components, which may cause atheroma, is known as the non-HDL-C. Protein makes up more than 50% of some HDLs but only 1% of chylomicrons. The concentrations of certain serum lipoproteins correlate closely with the risk of atherosclerosis. Related to lipoprotein: lipoprotein lipase, Low density lipoprotein. Increasing concentrations of HDL particles are strongly associated with decreasing accumulation of atherosclerosis within the walls of arteries. HDL is the smallest of the lipoprotein particles. The remainder of the serum cholesterol after subtracting the HDL is the non-HDL cholesterol. High-density lipoproteins ( HDL ) are one of the five major groups of lipoproteins. HDL is removed by HDL receptors such as scavenger receptor BI (SR-BI), which mediate the selective uptake of cholesterol from HDL. Although dietary factors are important in some people with hyperlipidemia, basal levels of lipoprotein, cholesterol, and triglycerides depend chiefly on heredity. The protein moiety of a lipoprotein is called an apolipoprotein (or apoprotein). Lipoproteins are complex particles composed of multiple proteins which transport all fat molecules ( lipids ) around the body within the water outside cells.
HDL particles increase in size as they circulate through the bloodstream and incorporate more cholesterol and phospholipid molecules from cells and other lipoproteins, for example by the interaction with the ABCG1 transporter and the phospholipid transport protein (PLTP). In humans, probably the most relevant pathway is the indirect one, which is mediated by cholesteryl ester transfer protein (CETP). As the proportion of lipid in a lipoprotein increases, its density decreases. Dictionary, Encyclopedia and Thesaurus - The Free Dictionary. Conjugation with protein facilitates transport of lipids, which are hydrophobic, in the aqueous medium of the plasma. The apolipoproteins of plasma lipoproteins are synthesized by the liver and intestinal mucosal cells and vary in molecular weight from 7,000 to 500,000. Several phenotypes of familial hyperlipoproteinemia associated with risk of premature cardiovascular disease and death have been identified. Besides rendering lipids soluble in an aqueous solution, some apolipoproteins perform biochemical functions such as enzyme activation. Lipoproteins are important constituents of biologic membranes and of myelin. The properties of these and other plasma lipoproteins are set forth in the accompanying table (see this page). HDL transports cholesterol mostly to the liver or steroidogenic organs such as adrenals, ovary, and testes by both direct and indirect pathways. It is the densest because it contains the highest proportion of protein to lipids. This protein exchanges triglycerides of VLDL against cholesteryl esters of HDL. This is important because atherosclerosis eventually results in sudden plaque ruptures, cardiovascular disease, stroke and other vascular diseases. A plasma lipoprotein particle is typically spheric, with a hydrophobic core of triacylglycerol, cholesteryl esters, and apolar amino acid residues surrounded by hydrophilic protein structures and phospholipids.
