EFFICIENT METHOD FOR MODULATION OF CHOLESTEROL LEVEL IN CELL-MEMBRANES
EFFICIENT METHOD FOR MODULATION OF CHOLESTEROL LEVEL IN CELL-MEMBRANES
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DOI：
10.1016/0014-5793(78)80482-7
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发表时间：
1978-01-01
期刊：
影响因子：
3.5
通讯作者：
SHINITZKY, M
中科院分区：
文献类型：
--
作者：
SHINITZKY, M
The fluidity of lipid domains can markedly affect the lateral and rotational diffusion [l], as well as the degree of exposure [2-4], of membrane proteins. It is therefore believed that some of the control mechanisms of membrane functions involve the lipid fluidity. Under physiological conditions modulation of the fluidity of the membrane lipid domains is achieved by changes in the mole ratio of cholesterol to phospholipid (C/PL)[5, 6], changes in the mole ratio of lecithin to sphingomyelin (L/S)[6, 7], or changes in the overall degree of unsaturation of the phospholipid acyl chains.One of the main mechanisms of changing the C/PL in cell membranes is the passive partitioning of cholesterol between the serum lipoproteins and the cell plasma membrane. Under normal physiological conditions the C/PL levels in the serum and the cell membrane are at an equilibrium which is enforced by a steady-state of cholesterol exchange between these reservoirs [8]. However, alterations of the C/PL of the ambient serum will lead to translocation of cholesterol towards a new equilibrium state which will eventually alter the C/PL of the cell membrane. This mechanism is considered to be the main passive physiological process which modulates membrane fluidity in animal tissues. Essentially, all the available in vitro techniques for modulation of cellular cholesterol involve treatments with liposomes of abnormally high C/PL for cholesterol enrichment or liposomes free of cholesterol for cholesterol depletion. In most of these procedures the treated cells are incubated in the liposomes in the
