title: Large cation-selective pores from rat liver peroxisomal membranes incorporated to planar lipid bilayers.
abstract: Fusion of a highly purified fraction of rat liver peroxisomal membranes to planar lipid bilayers incorporates large, cation-selective voltage-dependent pores. The PK/PCl ratio of these pores, estimated in KCl gradients, is close to 4. The pores display several conductance states and spend most of the time open at voltages near 0 mV, closing at more positive and negative voltages. At voltages near 0 mV the most frequent open state has a conductance of 2.4 nS in 0.3 M KCl. At voltages more positive and more negative than 10 mV the most frequent open state displays a conductance of 1.2 nS in 0.3 M KCl. With these results pore diameters of 3 and 1.5 nm, respectively, can be estimated. We suggest that these pores might account for the unusually high permeability of peroxisomes to low molecular weight solutes. Fusion also incorporates a perfectly anion-selective, two-open states channel with conductances of 50 and 100 pS in 0.1 M KCl.
mesh_terms: D000818:Animals; D000838:Anions; D002412:Cations; D004553:Electric Conductivity; D007425:Intracellular Membranes / Q000502:physiology*; D007473:Ion Channels / Q000502:physiology; D008051:Lipid Bilayers; D008099:Liver / Q000378:metabolism*; D008297:Male; D008830:Microbodies / Q000378:metabolism*; D051381:Rats
chemical_list: D000838:Anions; D002412:Cations; D007473:Ion Channels; D008051:Lipid Bilayers