Abstract
Critical micelle concentrations, micellar sizes and ellipticities at 220 nm were determined for sucrose monoesters of caprylic, capric and lauric acids. The interaction of these esters with proteins were also studied. The sucrose esters of caprylic and capric acids were found to bind only at discrete binding sites of native bovine serum albumin and this binding did not induce any detectable change in the protein conformation, while virtually no binding of the ligands to ovalbumin was observed, which lacks strong affinity sites in its native state. Together with the results of thermal denaturation experiments of the proteins in the presence of detergents, the present results indicate that the mode of interaction of sucrose esters with the proteins is quite similar to that of Triton X-100, a widely used nonionic detergent. Furthermore, it is suggested that the sucrose esters of caprylic and capric acids might be promising detergents for use in membrane protein research.
