Analysis of the ion transfer through the channel of 9,11,13,15-phenylalanylgramicidin A.
The behavior of an analogue of gramicidin A in which all four tryptophanyl residues are substituted by phenylalanyl and which shows a strong voltage effect on the single channel conductance is analyzed on the basis of a 'three-barrier--two-site' model. It is shown that in the gramicidin family the side chains of some amino acids, in spite of their location, which point outside the channel can play a major role in the binding of ions in the channel and thus can significantly modify the energy profile of the channel.
D001692:Biological Transport; D004553:Electric Conductivity; D006096:Gramicidin / Q000031:analogs & derivatives; D007473:Ion Channels / Q000502:physiology*; D007477:Ions; D007700:Kinetics; D008954:Models, Biological
D007473:Ion Channels; D007477:Ions; D006096:Gramicidin; C036306:gramicidin A, 15-des-Trp-Phe-