Protein complexes in bacterial and yeast mitochondrial membranes differ in their sensitivity towards dissociation by SDS.
Previously, a 2D gel electrophoresis approach was developed for the Escherichia coli inner membrane, which detects membrane protein complexes that are stable in sodium dodecyl sulfate (SDS) at room temperature, and dissociate under the influence of trifluoroethanol [R. E. Spelbrink et al., J. Biol. Chem. 280 (2005), 28742-8]. Here, the method was applied to the evolutionarily related mitochondrial inner membrane that was isolated from the yeast Saccharomyces cerevisiae. Surprisingly, only very few proteins were found to be dissociated by trifluoroethanol of which Lpd1p, a component of multiple protein complexes localized in the mitochondrial matrix, is the most prominent. Usage of either milder or more stringent conditions did not yield any additional proteins that were released by fluorinated alcohols. This strongly suggests that membrane protein complexes in yeast are less stable in SDS solution than their E. coli counterparts, which might be due to the overall reduced hydrophobicity of mitochondrial transmembrane proteins.
Gubbens
Jacob
J
Chemical Biology and Organic Chemistry, Bijvoet Center for Biomolecular Research and Institute of Biomembranes, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands. j.gubbens@uu.nl
Slijper
Monique
M
de Kruijff
Ben
B
de Kroon
Anton I P M
AI
D004926:Escherichia coli / Q000737:chemistry*; D029968:Escherichia coli Proteins / Q000737:chemistry*; D008565:Membrane Proteins / Q000737:chemistry*; D024101:Mitochondrial Proteins / Q000737:chemistry*; D046912:Multiprotein Complexes / Q000737:chemistry*; D012441:Saccharomyces cerevisiae / Q000737:chemistry*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry*; D012967:Sodium Dodecyl Sulfate / Q000737:chemistry*
D029968:Escherichia coli Proteins; D008565:Membrane Proteins; D024101:Mitochondrial Proteins; D046912:Multiprotein Complexes; D029701:Saccharomyces cerevisiae Proteins; D012967:Sodium Dodecyl Sulfate