Effect of protein incorporation on the nanostructure of the bicontinuous microemulsion phase of winsor-III systems: A small-angle neutron scattering study

Douglas G. Hayes, Javier A. Gomez Del Rio, Ran Ye, Volker S. Urban, Sai Venkatesh Pingali, Hugh M. O'Neill

Research output: Contribution to journalArticlepeer-review

16 Scopus citations

Abstract

Small-angle neutron scattering (SANS) analysis using the Teubner-Strey model has been employed to evaluate the effect of protein incorporation into the middle, bicontinuous microemulsion (BE) 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 BEs 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 α-chymotrypsin, near their solubilization limit in the BEs promoted the release of water and oil from the BEs, 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 BE phase and produced Debye shielding of AOT's sulfonate headgroup. For WIII systems possessing lower salinity, cytochrome c reduced the efficiency of surfactant in the BE 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-surfactant interactions, which in turn will control the release of proteins encapsulated in the BEs, relevant to WIII-based protein extraction and controlled release from BE delivery systems, and demonstrate the utility of BEs as a model system to understand the effect of proteins on biomembranes.

Original languageEnglish
Pages (from-to)1901-1910
Number of pages10
JournalLangmuir
Volume31
Issue number6
DOIs
StatePublished - Feb 17 2015

Fingerprint

Dive into the research topics of 'Effect of protein incorporation on the nanostructure of the bicontinuous microemulsion phase of winsor-III systems: A small-angle neutron scattering study'. Together they form a unique fingerprint.

Cite this