González Yamaira I, Nakanishi Hisanori, Stjerndahl Maria, Kaler Eric W
Center for Molecular Engineering and Thermodynamics, University of Delaware, Newark, Delaware 19716, USA.
J Phys Chem B. 2005 Jun 16;109(23):11675-82. doi: 10.1021/jp050111q.
Small unilamellar vesicles (approximately 100 nm in diameter) form spontaneously in aqueous mixtures of histidine and sodium dodecyl benzenesulfonate. By manipulating pH, a gradual transition from micelles to vesicles to bilayers to precipitate is observed. The self-assembly of vesicles occurs over a wide range of compositions when the solution pH is lower than 6.0, the pKa of the imidazole moiety on the histidine molecule. This phenomenon is likely the result of attractive interactions between the negatively charged benzenesulfonate headgroups and the positively charged imidazole group in the amino acid. Similar results are obtained when imidazole salt itself is used.
小单层囊泡（直径约100纳米）在组氨酸和十二烷基苯磺酸钠的水性混合物中自发形成。通过调节pH值，可以观察到从胶束到囊泡再到双层膜最后到沉淀的逐渐转变。当溶液pH低于组氨酸分子上咪唑部分的pKa（6.0）时，囊泡在很宽的组成范围内发生自组装。这种现象可能是由于带负电荷的苯磺酸根基团与氨基酸中带正电荷的咪唑基团之间的吸引相互作用所致。当使用咪唑盐本身时，也会得到类似的结果。
