title: 3,3',5,5'-tetramethylbenzidine/H2O2 staining is not specific for heme proteins separated by gel electrophoresis.
abstract: Staining of sodium dodecyl sulfate or lithium dodecyl sulfate gels with 3,3',5,5'-tetramethylbenzidine (TMBZ)/H2O2 after electrophoresis has frequently been used as a specific method of detecting heme proteins. That TMBZ is an electron donor for O2 reduction by the nonheme-soluble cytochrome oxidase/nitrite reductase from Nitrosomonas europaea is now shown; this protein is detected by the TMBZ/H2O2 method. A method for the determination of TMBZ oxidase activity is given; hence, the detection of artifactual staining due to proteins of this type is possible.
mesh_terms: D001560:Benzidines; D055598:Chemical Phenomena; D002621:Chemistry; D003576:Electron Transport Complex IV / Q000032:analysis*; D004591:Electrophoresis, Polyacrylamide Gel; D006420:Hemeproteins / Q000032:analysis*; D006861:Hydrogen Peroxide; D009247:NADH, NADPH Oxidoreductases / Q000032:analysis*; D009572:Nitrite Reductases / Q000032:analysis*; D009606:Nitrosomonas / Q000201:enzymology; D013194:Staining and Labeling
chemical_list: D001560:Benzidines; D006420:Hemeproteins; C021758:3,3',5,5'-tetramethylbenzidine; D006861:Hydrogen Peroxide; D009247:NADH, NADPH Oxidoreductases; D009572:Nitrite Reductases; D003576:Electron Transport Complex IV