Lipid-protein interactions. Effect of apolipoprotein A-I on phosphatidylcholine polar group conformation as studied by proton nuclear magnetic resonance.
Lipid-protein interactions. Effect of apolipoprotein A-I on phosphatidylcholine polar group conformation as studied by proton nuclear magnetic resonance.
复制标题
脂质-蛋白质相互作用。
DOI：
10.1021/bi00541a027
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发表时间：
1982
期刊：
影响因子：
2.9
通讯作者：
Phillips,MC
中科院分区：
文献类型：
--
作者：
Reijngoud,DJ;Lund-Katz,S;Hauser,H;Phillips,MC
为了确定载脂蛋白对磷脂酰胆碱（PC）极性基团构象的影响，对MLPC-人载脂蛋白AI（apo AI）复合物进行了分析。在上述MLPC系统、卵PC小单层囊泡和人HDL 3中加入顺磁位移试剂Fe（CN）63™后，极性基团质子共振的位移比已用于比较所有系统中的PC极性基团构象。在与MLPC的复合物中的大部分α-螺旋载脂蛋白AI分子的位置是从其对脂质分子的各个部分的良好分辨的 * H共振的化学位移和自旋-晶格弛豫时间（T [）的影响推导出来的。这些数据是一致的载脂蛋白AI分子躺在MLPC胶束的表面与他们的两亲性，螺旋段插入J A的详细图片的脂蛋白的表面的组成部分的结构和动力学是必需的，以了解磷脂-载脂蛋白的相互作用，因为它们发生在血清脂蛋白颗粒的表面上。将载脂蛋白插入磷脂双层以形成脂质-蛋白质复合物，导致磷脂的物理性质发生相当大的变化[综述参见Morrisett et al.（1977）]。例如，β-磷脂与载脂蛋白的结合引起烃链堆积和运动的变化以及磷脂链熔融中协同性的丧失（Andrews et al.，1976; Morrisett等人，1977;斯托费尔等人，1978; Gilman等人，1981年）。血清载脂蛋白结合对磷脂酰胆碱（PC）1极性基团构象的影响尚未得到很好的阐明，显然，在充分理解脂蛋白（例如，与细胞或酶）的表面相互作用之前，需要这些信息。
MLPC-human apolipoprotein AI (apo AI) complexes have been analyzed in order to determine the effects of apoprotein on phosphatidylcholine (PC) polar group conformation. The shift ratios of the polar group proton resonances after addition of the paramagnetic shift reagent Fe (CN) 63™ to the above MLPC systems, egg PC small unilamellar vesicles, andhuman HDL3 have been used to compare the PC polar group con-formations in all systems. The location of the largely a-helical apo AI molecules in the complex with MLPC was deduced from its effects on the chemical shifts and spin-lattice relaxation times (T [) of the well-resolved* H resonances from the various parts of the lipid molecules. The data are consistent with the apo AI molecules lying in the surface of the MLPC micelle with their amphipathic,-helical segments intercalated jA detailed picture of the structure and dynamics of the components of the surface of lipoproteins is required in order to understand phospholipid-apolipoprotein interactions as they occur on the surface of serum lipoprotein particles. Insertion of apolipoproteins into phospholipid bilayers to form lipid-protein complexes brings about considerable changes in the physical properties of the phospholipids [for a review, see Morrisett et al.(1977)]. For instance, association of phos-pholipids with apolipoproteins causes changes in hydrocarbon chain packing and motion and a loss of cooperativity in chain melting of the phospholipids (Andrews et al., 1976; Morrisett et al., 1977; Stoffel et al., 1978; Gilman et al., 1981). The effects of serum apolipoprotein binding on phosphatidylcholine (PC) 1 polar group conformation have not been elucidated well, and clearly this information is required before the surface interactions of lipoproteins (eg, with cells or enzymes) can be understood fully.