Interaction of cholesterol with various glycerophospholipids and sphingomyelin.
Interaction of cholesterol with various glycerophospholipids and sphingomyelin.
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DOI：
10.1021/bi00499a014
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发表时间：
1990-11
期刊：
影响因子：
2.9
通讯作者：
M. Sankaram;T. E. Thompson
中科院分区：
文献类型：
--
作者：
M. Sankaram;T. E. Thompson
用自旋标记电子自旋共振（ESR）技术研究了胆固醇对甘油磷脂和鞘磷脂相行为的影响。4-（4，4-二甲基-3-氧基-2-十三烷基-2-恶唑烷基）丁酸（5-SASL）和1-硬脂酰基-2-[4-（4，4-二甲基-3-氧基-2-十三烷基-2-恶唑烷基）丁酰基]-sn-甘油基-3-磷酸胆碱（5-PCSL）自旋标记物用于此目的。外超精细分裂常数，Amax，测量从自旋标记ESR光谱作为温度的函数，作为胆固醇诱导的变化的酰基链运动在流体状态下的经验指标。5-PCSL的Amax值对磷脂酰胆碱和牛脑鞘磷脂的胆固醇浓度表现出三相依赖性。我们解释这种依赖性，反映了存在的液体无序，LD，液体有序，LO和共存区域，LD + LO。磷脂酰胆碱-胆固醇系统中Id和两相区之间的相边界以及Io和两相区之间的边界在高于无胆固醇磷脂酰胆碱双层的主链熔融转变温度25-33 ℃的温度下聚结。在牛脑鞘磷脂的情况下，ld-lo相聚结发生在比纯鞘磷脂的熔融温度高约47 ° C。通过比较胆固醇诱导的磷脂酰胆碱、磷脂酸、磷脂酰乙醇胺、磷脂酰甘油和磷脂酰丝氨酸衍生物的Amax值的变化，研究了胆固醇与不同头基电荷的甘油磷脂相互作用的选择性。（250字处删节）
The influence of cholesterol on the phase behavior of glycerophospholipids and sphingomyelins was investigated by spin-label electron spin resonance (ESR) spectroscopy. 4-(4,4-Dimethyl-3-oxy-2-tridecyl-2-oxazolidinyl)butanoic acid (5-SASL) and 1-stearoyl-2-[4-(4,4-dimethyl-3-oxy-2-tridecyl-2-oxazolidinyl)butanoy l]-sn- glycero-3-phosphocholine (5-PCSL) spin-labels were employed for this purpose. The outer hyperfine splitting constants, Amax, measured from the spin-label ESR spectra as a function of temperature were taken as empirical indicators of cholesterol-induced changes in the acyl chain motions in the fluid state. The Amax values of 5-PCSL exhibit a triphasic dependence on the concentration of cholesterol for phosphatidylcholines and bovine brain sphingomyelin. We interpret this dependence as reflecting the existence of liquid-disordered, ld, liquid-ordered, lo, and coexistence regions, ld + lo. The phase boundary between the ld and the two-phase region and the boundary between the lo and the two-phase region in the phosphatidylcholine-cholesterol systems coalesce at temperatures 25-33 degrees C above the main-chain melting transition temperature of the cholesterol-free phosphatidylcholine bilayers. In the case of bovine brain sphingomyelin, the ld-lo phase coalescence occurs about 47 degrees C above the melting temperature of the pure sphingomyelin. The selectivity of interaction of cholesterol with glycerophospholipids of varying headgroup charge was studied by comparing the cholesterol-induced changes in the Amax values of derivatives of phosphatidylcholine, phosphatidic acid, phosphatidylethanolamine, phosphatidylglycerol, and phosphatidylserine spin-labeled at the fifth position of the sn-2 chain.(ABSTRACT TRUNCATED AT 250 WORDS)