[Computer analysis of the spatial structure of the amphotericin channel]

Energy of Amphotericin B cholesterol complex in a membrane was calculated by the method of atom--atomic potentials. The complex is shown to have two stable states. One of them is stabilized by electrostatic interactions between charged groups of neighbouring antibiotic molecules due to a decline of the molecules to the pore radius. Another state with radial orientation of antibiotic molecules and smaller pore diameter is stabilized mainly by van-der-Waals forces. A conclusion is made that transitions between open and closed states may result from small shifts and turn of all the antibiotic molecules in the complex.