The characterizing of the interaction of amphotericin B with cholesteryl esters

Amphotericin B has been widely applied as a probe for sterol location in biological membrane since an alteration of its adsorption spectrum is induced by formation of sterol-polyene antibiotic complex. The binding of amphotericin B to cholesterol, cholesteryl oleate and cholesteryl linoleate has been investigated using absorbance measurements and the results have been rationalized assuming a system 1:1 drug - steroid. The binding constant of amphotericin B to cholesterol, cholesteryl oleate and cholesteryl linoleate has been determined using different methods: Benesi-Hildebrand, Scott and Scatchard. The differences in values of binding parameters are due to the small structural differences between cholesterol, cholesteryl oleate and cholesteryl linoleate molecules. (C) 2008 Elsevier B.V. All rights reserved.