Pore formation by the mitochondrial porin of rat brain in lipid bilayer membranes.
The porin of the outer membrane of rat-brain mitochondria was isolated and purified. The protein showed a single band of apparent Mr 35,500 on dodecyl sulfate-containing polyacrylamide gels. The incorporation of rat-brain porin into artificial lipid bilayer membranes showed that it is able to form pores with an average single-channel conductance of 400 pS in 0.1 M KCI. The pores were found to be voltage-dependent and switched to substrates at higher transmembrane potentials. The voltage-dependence of the rat brain pore was considerably smaller than that of the other known eukaryotic porins. The possible role of the rat-brain porin in the regulation of transport process across the outer mitochondrial membrane is discussed.
D000818:Animals; D001921:Brain / Q000648:ultrastructure*; D002712:Chlorides / Q000378:metabolism; D004553:Electric Conductivity; D007473:Ion Channels / Q000502:physiology*; D007700:Kinetics; D008051:Lipid Bilayers / Q000378:metabolism*; D008564:Membrane Potentials; D008565:Membrane Proteins / Q000302:isolation & purification / Q000502:physiology*; D008928:Mitochondria / Q000032:analysis* / Q000648:ultrastructure; D008930:Mitochondria, Liver / Q000032:analysis; D009492:Neurospora crassa / Q000032:analysis; D018272:Porins; D011188:Potassium / Q000378:metabolism; D051381:Rats; D050994:Voltage-Dependent Anion Channels
D002712:Chlorides; D007473:Ion Channels; D008051:Lipid Bilayers; D008565:Membrane Proteins; D018272:Porins; D050994:Voltage-Dependent Anion Channels; D011188:Potassium