Development of new surfactants for protein extraction using reversed micelles

反胶束溶剂萃取法为从发酵介质和极稀溶液中分离纯化蛋白质提供了一种新的方法。众所周知，在分离过程中，表面活性剂扮演着重要的角色，因为溶解的蛋白质由表面活性剂LayR稳定。然而，对于蛋白质提取的最佳表面活性剂的设计和合成却鲜有人关注。在本研究中，合成了可能用于反胶束蛋白质提取操作的新型表面活性剂，得到了以下结果：1.表面活性剂在脂肪族溶剂(如正己烷、正庚烷或异辛烷)中的优先溶解性，以及通过以强疏水的双烷基链作为疏水基团可以形成大量增溶水的反胶束。2.具有相同水溶能力的不同表面活性剂在蛋白质提取中的行为可能显著不同。其中萃取效率似乎由表面活性剂和蛋白质之间形成的界面络合物的性质决定。3.庞大的表面活性剂链为表面活性剂在蛋白质表面的吸附提供了空间位阻，从而抑制了蛋白质/表面活性剂络合物的溶剂化，从而抑制了蛋白质的提取。在这些条件下，沉淀物要么在主体水相中形成，要么在界面上形成。表面活性剂能与蛋白质形成紧密堆积的络合物，是优良的蛋白质增溶剂。二油基磷酸(Dolpa)是目前最好的蛋白质提取表面活性剂之一。目前，我们正在研究蛋白质的提取机理和新开发的反胶束体系的新应用。

Solvent extraction using reversed micelles provides an attractive to conventional procedures for the separation and purification of proteins from fermentation media and from very dilute solution. In the separation process, it is well known that a surfactant plays an important role, because solubilized proteins are stabilized by a surfactant layr. However, little attention has been paid to the design and synthesis of optimal surfactants for the protein extraction. In this study, new surfactants have been synthesized for potential use in reversed micellar protein extraction operations, and the following results were obtained :1.Preferential solubility of the surfactant in an aliphatic solvent such as hexane, heptane or iso-octane, and the formation of reversed micelles with solubilization of significant quantities of water can be achieved by using strongly hydrophobic, twin alkyl chains as the hydrophobic moiety.2.Different surfactants having identical water solubilizing capacities can have significantly different behavior in protein extractions, where extraction efficiency appears to be governed by the nature of the interfacial complex that forms between surfactants and proteins.3.Bulky surfactant chains provide a steric hindrance to the adsorption of the surfactant to the protein surface, thus inhibiting solvation of the protein/surfactant complex, and hence protein extraction. Under these conditions, a precipitate forms either in the bulk aqueous phase or at the interface. Surfactants that can from a close packed complex with the protein are excellent protein solubilizing agents. Dioleyl phosphoric acid (DOLPA) appears to be one of the best surfactants currently available for protein extraction.Now, we are studying more detail about extraction mechanism of proteins and novel application of newly developed reversed micelar sysytem.