Porin from Thiobacillus versutus

Abstract

The porin of Thiobacillus versutus IFO 14567 was isolated by extraction of cell-envelopes with sodium dodecyl sulfate. It exhibited strong porin-activity after reconstitution into artificial lipid bilayer membranes. The diameter of the pore was determined as 1.6 nm, with a weak selectivity for cations being observed. The porin migrated as a single band (Mr 35 kDa) on SDS-polyacrylamide gel-electrophoresis after heating (100 degrees C, 5 min). The porin oligomer was not sensitive towards EDTA. Analytical ultracentrifugation studies demonstrated the native oligomer to be a trimer.