Effect of Protein Incorporation on the Nanostructure of the Bicontinuous Microemulsion Phase of Winsor-III Systems: A Small-Angle Neutron Scattering Study
详细信息 查看全文
- 作者：Douglas G. Hayes ; Javier A. Gomez del Rio ; Ran Ye ; Volker S. Urban ; Sai Venkatesh Pingali ; Hugh M. O鈥橬eill
- 刊名：Langmuir
- 出版年：2015
- 出版时间：February 17, 2015
- 年：2015
- 卷：31
- 期：6
- 页码：1901-1910
- 全文大小：585K
- ISSN：1520-5827
文摘
Small-angle neutron scattering (SANS) analysis using the Teubner鈥揝trey model has been employed to evaluate the effect of protein incorporation into the middle, bicontinuous microemulsion (B渭E) phase of Winsor-III (WIII) systems formed by an aerosol-OT (AOT)/alkyl ethoxylate mixed surfactant system to understand better the extraction of proteins into and out of B渭Es and to study the effect of proteins on a system that serves as a biomimetic analog of cell membranes. Under conditions of high salinity, the incorporation of positively charged proteins cytochrome c, lysozyme, and 伪-chymotrypsin, near their solubilization limit in the B渭Es promoted the release of water and oil from the B渭Es, a decrease in the quasi-periodic repeat distance (d), an increase in ordering (a decrease in the amphiphilicity factor, fa) for the surfactant monolayers, and a decrease in the surface area per surfactant headgroup, suggesting that the proteins affected the self-assembly of components in the B渭E phase and produced Debye shielding of AOT鈥檚 sulfonate headgroup. For WIII systems possessing lower salinity, cytochrome c reduced the efficiency of surfactant in the B渭E phase, noted by increases in d and fa, suggesting that the enzyme and AOT underwent ion pairing. The results of this study demonstrate the importance of ionic strength to modulate protein鈥搒urfactant interactions, which in turn will control the release of proteins encapsulated in the B渭Es, relevant to WIII-based protein extraction and controlled release from B渭E delivery systems, and demonstrate the utility of B渭Es as a model system to understand the effect of proteins on biomembranes.