Ether phosphatidylcholines: comparison of miscibility with ester phosphatidylcholines and sphingomyelin, vesicle fusion, and association with apolipoprotein A-I.
Ether phosphatidylcholines: comparison of miscibility with ester phosphatidylcholines and sphingomyelin, vesicle fusion, and association with apolipoprotein A-I.
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醚磷脂酰胆碱：与酯磷脂酰胆碱和鞘磷脂的混溶性、囊泡融合以及与载脂蛋白 A-I 的关联的比较。
DOI：
10.1021/bi00371a064
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发表时间：
1986
期刊：
影响因子：
2.9
通讯作者：
Massey,JB
中科院分区：
文献类型：
--
作者：
McKeone,BJ;Pownall,HJ;Massey,JB
Baylor医学院和卫理公会医院内科，休斯敦，得克萨斯州77030接收于1986年6月19日;修订的Mandarin pt接收于1986年8月14日摘要：醚连接的磷脂酰胆碱（PC）和鞘磷脂的不可水解基质已被用于研究脂解酶的作用机制。由于醚PC，鞘磷脂，和酯PC的氢键供体和受体的双分子层的羰基区域的数量不同，我们已经检查了几个物理性质的醚PC和鞘磷脂在模型系统中，以验证其适用性作为nonhydrolyzable脂质基质。用差示扫描量热法研究了醚PC与酯PC、鞘磷脂和胆固醇的分子间相互作用。从1，2-O-双十六烷基-J/J-甘油-3-磷酸胆碱的凝胶到液晶相变的温度依赖性构建的相图（DPPC-醚）和1，2-0-双十四烷基-m-甘油-3-磷酸胆碱（DMPC-醚）与1，2-二肉豆蔻酰-N，N-甘油-3-磷酸胆碱（DMPC）和1，2-二棕榈酰-n-甘油基-3-磷酸胆碱（DPPC）在凝胶和液晶相中表现出完全的脂质溶解性。此外，蛋黄鞘磷脂（EYSM）与DMPC或DMPC-醚和1，2-二硬脂酰基-sn-甘油基-3-磷酸胆碱（DSPC）或1，2-O-双十八烷基-sn-甘油基-3-磷酸胆碱（DSPC-醚）的相图证明EYSM在酯和醚PC中的溶解性没有重大差异。10摩尔%的胆固醇的酯和醚PC的混合物的热转变的效果也表明胆固醇的任何一种脂质的小偏好。通过凝胶过滤测定，DMPC、DMPC-醚、DPPC和DPPC-醚的小的单双层囊泡与较大的聚集体的融合表明酯PC囊泡稍微更稳定。比较载脂蛋白AI与DMPC及DMPC-乙醚多层脂质体的结合率。该速率在任一脂质的凝胶-液晶转变温度（7 ℃）下最快，并且与蛋白质插入脂质基质中的晶格缺陷一致。醚PC与酯PC、鞘磷脂、胆固醇和载脂蛋白以类似于酯PC的方式相互作用。这些脂质之间的相互作用似乎是占主导地位的烃链相互作用，而不是在羰基区域的氢键基团。因此，醚PC似乎是合适的酯PC的类似物，用于阐明脂解的结构-功能机制。
Department of Internal Medicine, Baylor College of Medicine and The Methodist Hospital, Houston, Texas 77030 Received June 19, 1986; Revised Manuscript Received August 14, 1986 abstract: Nonhydrolyzable matrices of ether-linked phosphatidylcholines (PCs) and sphingomyelin have been used tostudy the mechanism of action of lipolytic enzymes. Since ether PCs, sphingomyelin, and ester PCs vary in the number of hydrogen bond donors and acceptors in the carbonyl region of the bilayer, we have examined severalphysical properties of ether PCs and sphingomyelin in model systems to validate their suitability as nonhydrolyzable lipid matrices. The intermolecular interactions of ether PCs with ester PCs, sphingomyelin, and cholesterol were investigated by differential scanning calorimetry. Phase diagrams constructed from the temperature dependence of the gel to liquid-crystalline phase transition of 1, 2-0-dihexadecyl-j/j-glycero-3-phosphocholine (DPPC-ether) and 1, 2-0-ditetradecyl-m-glycero-3-phosphocholine (DMPC-ether) with both l, 2-dimyristoyl-j/i-glycero-3-phosphocholine (DMPC) and 1, 2-dipalmitoyl-i «-glycero-3-phosphocholine (DPPC) demonstrated complete lipid miscibility in the gel and liquid-crystalline phases. Additionally, phase diagrams of egg yolk sphingomyelin (EYSM) with DMPC or DMPC-ether and l, 2-distearoyl-sn-glycero-3-phosphocholine (DSPC) or l, 2-0-dioctadecyl-j «-glycero-3-phosphocholine (DSPC-ether) demonstrated no major differences in miscibility ofEYSM in ester and ether PCs. The effect of 10 mol% cholesterol on the thermal transitions of mixtures of ester and ether PCs also indicates little preference of cholesterol for either lipid. Thefusion of small single bilayer vesicles of DMPC, DMPC-ether, DPPC, and DPPC-ether to larger aggregates as determined by gel filtration indicated that the ester PC vesicles were somewhat more stable. The rate of association of apolipoprotein AI with DMPC or DMPC-ether multilamellar liposomes was compared. The rate was fastest at the gel—* liquid-crystalline transition temperature (7C) of either lipid and was consistent with the insertion of the proteininto lattice defects in the lipid matrix. Ether PCs interact with ester PCs, sphingomyelin, cholesterol, and apolipoproteins in a manner similar to ester PCs. The interaction betweenthese lipids appears to be dominated by hydrocarbon chain interactions instead of the hydrogen bonding groups in the carbonyl region. Thus, ether PCs appear to be suitable analogues of the ester PCs for the elucidation of structural-functional mechanisms of lipolysis.