ION CHANNELS FORMED BY HIV-1 VPU - A MODELING AND SIMULATION STUDY

Vpu is an oligomeric integral membrane protein encoded by HIV-1 which forms ion channels, each subunit of which contains a single transmembr ane helix. Models of Vpu channels formed by bundles of N=4, 5 or 6 tra nsmembrane helices have been developed by restrained molecular dynamic s and refined by 100 ps simulations with mater molecules within the po re. Pore radius profiles and conductance predictions suggest that the N=5 model corresponds to the predominant channel conductance level of the channel. Potential energy profiles for translation of Na+ or Cl- i ons along the Vpu N=5 pore are consistent with the weak cation selecti vity of Vpu channels. (C) 1997 Federation of European Biochemical Soci eties.