Affinity of C60 neat fullerenes with membrane proteins: a computational study on potassium channels

Most studies of the interactions of neat and functionalized fullerenes with cells have focused so far on their ability to cross the cell membrane envelopes. Membranes are, however, also host to a large number of proteins responsible for various cellular functions. Among these, ion channels are prominent components of the nervous system. Recently, it was shown that fullerenes may act as blockers or modulators of a variety of K+ channels. Here we use computer simulations to investigate the propensity of such nanocompounds to bind to K+ channels. Our results based on extensive atomistic molecular dynamics simulations reveal a variety of specific binding sites depending on the structure and properties of the channel. The corresponding binding free energies and putative mechanisms suggest that C60 may indeed effectively hinder the function of K+ channels and hence induce toxicity.