Effect of functional groups on incorporation behavior of amino acid-type surfactant into phospholipid vesicle membrane.
Effect of functional groups on incorporation behavior of amino acid-type surfactant into phospholipid vesicle membrane.
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官能团对氨基酸型表面活性剂掺入磷脂囊泡膜行为的影响。
DOI：
10.5650/jos.58.607
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发表时间：
2009
影响因子：
1.5
通讯作者：
T. Asakawa
中科院分区：
文献类型：
--
作者：
Akio Ohta;Yuya Miyazato;Hiroyasu Sasaki;K. Yasuhara;T. Asakawa
研究了N-十二酰氨基酸型表面活性剂在水溶液中对L-α-二棕榈酰磷脂酰胆碱(DPPC)囊泡的掺入行为。从囊泡捕获荧光探针的泄漏测量中发现，当浓度小于临界胶束浓度(CMC)的十分之一时，这些表面活性剂对DPPC囊泡的影响不是很大，但即使在略低于临界胶束浓度(CMC)时，也会导致探针从囊泡中显著释放。氨基酸型表面活性剂的疏水性增强，促进了表面活性剂的渗漏。但是，在低于CMC的浓度下，除了N-十二酰基苯丙氨酸体系外，DPPC膜中DPH的极化几乎不受表面活性剂的影响。用等温滴定量热法测定了表面活性剂与DPPC囊泡的结合热和结合常数。当结合热与表面活性剂的种类无关时，结合常数随表面活性剂中氨基酸种类疏水性的增加而增大。饱和状态下结合表面活性剂与DPPC分子的摩尔比远大于十二烷基硫酸钠体系。此外，该比例不受氨基酸侧链结构的影响。
The incorporation behaviors of some N-dodecanoyl amino acid-type surfactants into L-alpha-dipalmitoylphosphatidylcholine (DPPC) vesicles in aqueous solution were investigated. From the leakage measurements of a vesicle-entrapped fluorescence probe, it was found that these surfactants did not affect the DPPC vesicle so much at a very low concentration less than a one-tenth of the critical micelle concentration (CMC), but caused a significant release of the probe form the vesicles even at just below the CMC. The leakage induced by amino acid-type surfactants was promoted by increasing hydrophobicity of the amino acid. However the polarization of DPH embedded in the DPPC membrane was almost unchanged by incorporation of the surfactants at the concentration below the CMC except for the N-dodecanoylphenylalanine system. The binding enthalpy and the binding constant of the surfactant to DPPC vesicles were estimated by isothermal titration calorimetry. While the binding enthalpy was independent of the kind of surfactant, the binding constant increases with increasing hydrophobicity of the amino acid species in the surfactants. The molar ratio of bound surfactant to DPPC molecule in the saturated state was much greater than that for sodium dodecyl sulfate system. Further the ratio was not influenced by the structure of the amino acid side chain.
N-十二酰基-L-色氨酸在脂质体膜内结构域形成的荧光研究
影响因子：
2.4
作者：
K. Yasuhara;T. Shimanouchi;H. Umakoshi;R. Kuboi
通讯作者：
R. Kuboi