Sëmin B K, Bautina A L, Ivanov I I
Nauchnye Doki Vyss Shkoly Biol Nauki. 1989(5):32-6.
The effect of substances of different nature on the thermodynamic characteristics of dimyristoylphosphatidylcholine (DMPC) phase transition by the differential scanning microcalorimetry has been studied. The substances disposed in hydrophobic part of membrane--alpha-tocopherol, ubiquinone Q10, ionol and vitamin K3 cause the decrease of enthalpy and cooperativity of phase transition. The substances which have the side hydrocarbon chain (tocopherol and ubiquinone Q10) compared with ones without it (ionol and vitamin K3) and reduced quinones (Q10 and vitamin K3) compared with the oxidized ones have stronger influence on the enthalpy and cooperativity of transition. The inclusion of the local anesthetic dicaine disposed mainly in the zone of polar heads of phospholipids into DMPC membranes decreases the temperature of phase transition considerably and practically does not change the cooperativity. A possibility to use the method of differential scanning microcalorimetry to estimate the localization of membrane tropic substances within lipid bilayer is under discussion.
通过差示扫描量热法研究了不同性质的物质对二肉豆蔻酰磷脂酰胆碱（DMPC）相变热力学特性的影响。分布在膜疏水部分的物质——α-生育酚、泛醌Q10、紫罗兰醇和维生素K3会导致相变焓和协同性降低。与没有侧烃链的物质（紫罗兰醇和维生素K3）相比，具有侧烃链的物质（生育酚和泛醌Q10），以及与氧化型相比的还原型醌（Q10和维生素K3）对转变焓和协同性的影响更强。将主要分布在磷脂极性头部区域的局部麻醉药丁卡因加入DMPC膜中，会使相变温度大幅降低，而协同性几乎不变。文中还讨论了使用差示扫描量热法评估膜亲和性物质在脂质双层中定位的可能性。
