TY - JOUR
T1 - Effect of protein incorporation on the nanostructure of the bicontinuous microemulsion phase of winsor-III systems
T2 - A small-angle neutron scattering study
AU - Hayes, Douglas G.
AU - Gomez Del Rio, Javier A.
AU - Ye, Ran
AU - Urban, Volker S.
AU - Pingali, Sai Venkatesh
AU - O'Neill, Hugh M.
N1 - Publisher Copyright:
© 2015 American Chemical Society.
PY - 2015/2/17
Y1 - 2015/2/17
N2 - 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.
AB - 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.
UR - http://www.scopus.com/inward/record.url?scp=84923197018&partnerID=8YFLogxK
U2 - 10.1021/la504606x
DO - 10.1021/la504606x
M3 - Article
C2 - 25603188
AN - SCOPUS:84923197018
SN - 0743-7463
VL - 31
SP - 1901
EP - 1910
JO - Langmuir
JF - Langmuir
IS - 6
ER -