Kinetic studies of protein-carbohydrate interactions at the bilayer interface of catanionic vesicles

Abstract

In this paper, we describe our work on surface functionalization and modification of catanionic vesicles with an aim toward increasing their range of applications. Conventional vesicles are formed from double-tailed phospholipids and have important roles in biology. Unlike conventional phospholipids vesicles, aqueous mixtures of cationic and anionic single-tailed surfactants can spontaneously form unilamellar vesicles without sonication or extrusion. These vesicles dubbed “catanionic vesicles” in the literature are extremely stable with respect to salt and pH and are composed of inexpensive components. They are promising candidates for a variety of biotechnological applications including drug delivery and vaccine development. Our studies report that the ability to control the distribution of glycoconjugates in the vesicle bilayer surface provides a method to study protein-carbohydrate multivalent binding kinetics in a biomimetic environment. In this work, the exterior of catanionic vesicles was controllably functionalized by insertion of the hydrocarbon chain of the glycoconjugate n-dodecyl- β -D-glucopyranoside (C₁₂-glucose) at varying concentrations. We demonstrate how this platform consisting of a carbohydrate functionalized bilayer can be use to evaluate binding inhibitors for the lectin ConA.