APPLICATION OF ISOTHERMAL TITRATION CALORIMETRY FOR DETECTING LIPID-MEMBRANE SOLUBILIZATION
APPLICATION OF ISOTHERMAL TITRATION CALORIMETRY FOR DETECTING LIPID-MEMBRANE SOLUBILIZATION
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DOI：
10.1016/0009-2614(95)00139-u
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发表时间：
1995-03-31
影响因子：
2.8
通讯作者：
BLUME, A
中科院分区：
文献类型：
--
作者：
HEERKLOTZ, H;LANTZSCH, G;BLUME, A
等温滴定量热法是检测添加洗涤剂后脂膜增溶的一种很好的方法。作为例子，研究了非离子洗涤剂C(12)EO(6)对脂质POPC的滴定。测定的滴定热的主要贡献是洗涤剂在胶束和膜之间转移时的热差。以胶束形式加入的洗涤剂被转移到膜中，直到饱和洗涤剂的脂摩尔/摩尔比，R(Sat)=1.45+/-0.07。在R(Sat)以上，膜被增溶为胶束。随后，滴定热的符号由吸热变为放热。当R(Sol)=5.0+/-0.4时，膜完全溶解后，滴定热几乎完全消失。
Isothermal titration calorimetry is presented to be an excellent method of detecting lipid membrane solubilization upon the addition of detergents. As an example, the titration of the non-ionic detergent C(12)EO(6) to the lipid POPC is studied. The main contribution to the measured titration heat is the detergent's enthalpy difference upon transfer between micelles and membranes. The detergent added as micelles is transferred into membranes up to the saturating detergent per lipid mol/mol ratio, R(sat) = 1.45 +/- 0.07. Beyond R(sat) the membranes are solubilized to micelles. Subsequently, the titration heat changes its sign from endothermic to exothermic. After complete membrane dissolution at R(sol) = 5.0 +/- 0.4 the titration heat vanishes nearly completely.