Ono T, Goto M, Nakashio F, Hatton T A
Department of Chemical Science & Technology, Faculty of Engineering, Kyushu University, Fukuoka, Japan.
Biotechnol Prog. 1996 Nov-Dec;12(6):793-800. doi: 10.1021/bp960055y.
A new surfactant, dioleyl phosphoric acid (DOLPA), has been applied to the extraction of hemoglobin using reversed micelles. The reversed micelles formed by DOLPA can easily extract hemoglobin from aqueous to reversed micellar solutions. DOLPA is the first surfactant to extract hemoglobin completely without using any cosurfactants. On the basis of the difference between DOLPA and AOT reversed micelles in the forward extraction behavior of hemoglobin, the nature of the interfacial complex that would be formed between surfactants and hemoglobin at the oil--water interface was found to be the dominant factor in determining the extraction efficiency of hemoglobin be reversed micelles. In addition, back-transfer studies of hemoglobin from the DOLPA reversed micelles were also carried out by the phase transfer method. It was found that hemoglobin, once dissolved into the DOLPA reversed micelles, is not transferred to a fresh aqueous solution even when the conditions are adjusted to not allow the forward transfer of hemoglobin. However, the addition of several kinds of alcohol drastically improved the yield in the back-transfer of hemoglobin. The efficiency in the back-transfer of hemoglobin strongly depends on the aqueous conditions that are in contact with the reversed micelles, such as pH, ionic strength, and alcohol concentration. A pH higher than the pI of hemoglobin, a salt concentration lower than that of the water pool, and the proper concentration of alcohol are required for the recovery aqueous phase to ensure the back-transfer of hemoglobin from the DOLPA reversed micelles.
一种新型表面活性剂二油酰磷酸（DOLPA）已被应用于利用反胶束提取血红蛋白。由DOLPA形成的反胶束能够轻易地将血红蛋白从水相提取到反胶束溶液中。DOLPA是第一种在不使用任何助表面活性剂的情况下就能完全提取血红蛋白的表面活性剂。基于DOLPA和AOT反胶束在血红蛋白正向提取行为上的差异，发现表面活性剂与血红蛋白在油水界面处形成的界面复合物的性质是决定反胶束提取血红蛋白效率的主要因素。此外，还通过相转移法对血红蛋白从DOLPA反胶束中的反向转移进行了研究。结果发现，血红蛋白一旦溶解到DOLPA反胶束中，即使将条件调整为不允许血红蛋白正向转移，它也不会转移到新鲜的水相中。然而，添加几种醇类物质能显著提高血红蛋白反向转移的产率。血红蛋白反向转移的效率强烈依赖于与反胶束接触的水相条件，如pH值、离子强度和醇浓度。为了使水相回收以确保血红蛋白从DOLPA反胶束中反向转移，需要一个高于血红蛋白pI值的pH值、一个低于水池盐浓度的值以及适当浓度的醇。
