Image_1_Surfactant Monolayer Bending Elasticity in Lipase Containing Bicontinuous Microemulsions.JPEG

• Main Authors: Sandra Engelskirchen, Stefan Wellert, Olaf Holderer, Henrich Frielinghaus, Michaela Laupheimer, Sven Richter, Bettina Nestl, Bernd Nebel, Bernhard Hauer
• Format: Still Image
• Language: unknown
• Published: 2021
• Subjects: Biochemistry; Environmental Chemistry; Geochemistry; Organic Chemistry; Inorganic Chemistry; Nuclear Chemistry; Medical Biochemistry: Proteins and Peptides (incl. Medical Proteomics); Medical Biochemistry and Metabolomics not elsewhere classified; Food Chemistry and Molecular Gastronomy (excl. Wine); Analytical Biochemistry; Cell Neurochemistry; Enzymes; Electroanalytical Chemistry; Analytical Chemistry not elsewhere classified; Organic Green Chemistry; Physical Organic Chemistry; Catalysis and Mechanisms of Reactions; Environmental Chemistry (incl. Atmospheric Chemistry); microemulsion; lipase; bending elasticity; neutron scattering; neutron spin echo; Antarc*; Antarctica
• Online Access: https://doi.org/10.3389/fchem.2020.613388.s001; https://figshare.com/articles/figure/Image_1_Surfactant_Monolayer_Bending_Elasticity_in_Lipase_Containing_Bicontinuous_Microemulsions_JPEG/13521725

Lipase-catalyzed reactions offer many advantages among which a high degree of selectivity combined with the possibility to convert even non-natural substrates are of particular interest. A major drawback in the applicability of lipases in the conversion of synthetically interesting, non-natural substrates is the substantial insolubility of such substrates in water. The conversion of substrates, natural or non-natural, by lipases generally involves the presence of a water–oil interface. In the present paper, we exploit the fact that the presence of lipases, in particular the lipase from Candida antarctica B (CalB), changes the bending elastic properties of a surfactant monolayer in a bicontinuous microemulsion consisting of D 2 O/NaCl -n-(d)-octane-pentaethylene glycol monodecyl ether (C 10 E 5 ) in a similar manner as previously observed for amphiphilic block-copolymers. To determine the bending elastic constant, we have used two approaches, small angle neutron scattering (SANS) and neutron spin echo (NSE) spectroscopy. The time-averaged structure from SANS showed a slight decrease in bending elasticity, while on nanosecond time scales as probed with NSE, a stiffening has been observed, which was attributed to adsorption/desorption mechanisms of CalB at the surfactant monolayer. The results allow to derive further information on the influence of CalB on the composition and bending elasticity of the surfactant monolayer itself as well as the underlying adsorption/desorption mechanism.