Distribution of electrostatic potential around amphotericin B and its membrane targets

Amphotericin B is a well-known anti-fungal polyene macrolide antibiotic used widely in the treatment of systemic fungal infections. The molecular mechanism of the anti-fungal action of amphotericin B is still not elucidated and is under study. In the present article molecular electrostatic properties of amphotericin B and its membrane targets (cholesterol and ergosterol) were studied. The electrostatic potential around all three molecules was calculated using Poisson-Boltzmann methods. The physiological environment (water and membrane) was taken into account in these calculations. The distribution of electrostatic potential was presented on molecular surfaces. It was found that both targets have quite different electrostatic patterns that may be important for interaction with the antibiotic. The calculations of electrostatic potential for Amphotericin B also revealed some new features about the hydrophobic/hydrophilic pattern of this drug. The knowledge of how the electrostatic potential distributes around the studied molecules will be useful to build a model of amphotericin B-sterol channel.