title: Two-dimensional gel electrophoresis of rat liver microsomal membrane proteins.
abstract: Total rat liver microsomal proteins are not suitable for isoelectric focusing in polyacrylamide gels, even in the presence of sodium dodecyl sulphate and excess non-ionic detergent; considerable quantities of protein form an aggregate in the isoelectric focusing gel. This prevents resolution of microsomal proteins by the increasingly popular two-dimensional electrophoresis technique employing isoelectric focusing followed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis. The problem is caused by the extreme insolubility of some microsomal proteins, especially cytochrome P-450 species, which precipitate during isoelectric focusing. A selective extraction of microsomes with sodium deoxycholate excludes these poorly soluble proteins. The extracted proteins can then be resolved without difficulty by isoelectric focusing, and give excellent two-dimensional gel patterns showing more than 100 proteins, mainly in the pI range 5--7. The technique should be useful in studies on microsome protein topology and on changes in microsome composition.
mesh_terms: D000818:Animals; D003577:Cytochrome P-450 Enzyme System / Q000032:analysis; D004591:Electrophoresis, Polyacrylamide Gel; D007425:Intracellular Membranes / Q000032:analysis*; D008297:Male; D008565:Membrane Proteins / Q000032:analysis*; D008862:Microsomes, Liver / Q000032:analysis*; D008970:Molecular Weight; D051381:Rats; D012967:Sodium Dodecyl Sulfate
chemical_list: D008565:Membrane Proteins; D012967:Sodium Dodecyl Sulfate; D003577:Cytochrome P-450 Enzyme System