Curvature Effect of a Phosphatidylethanolamine-Included Membrane on the Behavior of Cinnamycin on the Membrane

Abstract

The behavior of cinnamycin on a biomimetic membrane was studied with respect to the curvature of a phosphatidylethanolamine (PE)-included membrane with the adhesion measured using an atomic force microscope (AFM). The membrane was formed through vesicle fusion on the hydrophobic surface of silica spheres, which was used to define the curvature of the membrane. The hydrophobicity was generated by the reaction of alkyl-silane and analyzed with an X-ray photoelectron spectrometer. The cinnamycin, immobilized covalently to the AFM tip coated with 1-mercapto-1-undecanol that was observed to be inert to any adhesion to the membrane, showed that the adhesion became stronger with the increase in the curvature. The correlation between the adhesion and the curvature was linearly proportional. Since it was found that the cinnamycin was bound to a PE headgroup and the binding was enhanced by the interaction of the hydrophobic area located at one side of the cinnamycin, the linear proportionality seems to suggest that the interaction is related to the one dimensional orientation of the binding.