THE POLYISOPRENOID CHAIN-LENGTH INFLUENCES THE INTERACTION OF UBIQUINONES WITH PHOSPHOLIPID-BILAYERS
THE POLYISOPRENOID CHAIN-LENGTH INFLUENCES THE INTERACTION OF UBIQUINONES WITH PHOSPHOLIPID-BILAYERS
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DOI：
10.1016/0005-2736(82)90270-x
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发表时间：
1982-01-01
期刊：
影响因子：
--
通讯作者：
QUINN, PJ
中科院分区：
文献类型：
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作者：
KATSIKAS, H;QUINN, PJ
用差示扫描量热法和广角X-射线衍射分析研究了泛醌同系物与聚类异戊二烯链长从3到10个单位和二棕榈酰磷脂酰胆碱双层之间的相互作用。降低泛醌与磷脂的摩尔比为约10摩尔%的混合分散体中的聚类异戊二烯链长引起磷脂的凝胶-液晶相转变温度的降低和转变的加宽。焓测量结果表明，大部分磷脂（>92%）参与了转变吸热，凝胶相的形成也通过在0.42 nm处存在尖锐的X射线反射来证实。这些结果与模型一致，其中所有的泛醌同源物在冷却至相变温度以下时最终经历与进入凝胶相的磷脂分子的相分离。减少聚类异戊二烯链的长度改变了泛醌分子的两亲性平衡，并且反映在较短链泛醌在通过主相变再加热时插入磷脂分子之间的趋势中。
The interaction between ubiquinone homologues with polyisoprenoid chain lengths varying from 3 to 10 units and dipalmitoylphosphatidylcholine bilayers has been examined by differential scanning calorimetry and wide angle X-ray diffraction analysis. Decreasing the polyisoprenoid chain lengths of ubiquinone in mixed dispersions with phospholipid in mol ratios of about 10 mol% caused a decrease in the gel-liquid crystalline phase transition temperature of the phospholipid and a broadening of the transition. Enthalpy measurements showed that most of the phospholipid (>92%) was involved in the transition endotherm and the formation of a gel phase was also confirmed by the presence of a sharp X-ray reflection at 0.42 nm. These results are consistent with a model in which all of the ubiquinone homologous ultimately undergo a phase separation from phospholipid molecules entering a gel phase on cooling below the phase transition temperature. Reducing the length of the polyisoprenoid chain alters the amphipathic balance of the ubiquinone molecules and is reflected in the tendency of shorter chain ubiquinones to intercalate between the phospholipid molecules upon reheating through the main phase transition.