title: Micromolar colorimetric detection of 2-hydroxy ketones with the water-soluble tetrazolium WST-1.
abstract: The archetypal triphenyl tetrazolium chloride (tetrazolium red) has been used in spectrophotometric microplate assays for 2-hydroxy ketones and, by extension, for the activity of enzymes including aminotransferase, transketolase, and pyruvate decarboxylase. Better sensitivity, dynamic range, and reproducibility of this method may be achieved by (i) in situ solubilization of the colored formazan with Cremophor EL and (ii) use of the newer-generation tetrazolium salts tetrazolium violet, iodonitrotetrazolium, or WST-1 (water-soluble tetrazolium). Two to 125 μM hydroxy pyruvate, dihydroxy acetone, and indole pyruvate produced by serine:pyruvate, β-alanine (ω-amino acid):pyruvate, and aromatic amino acid aminotransferase, respectively, could be detected with WST-1.
authors.affiliation: The Advanced Centre for Biochemical Engineering, Department of Biochemical Engineering, University College London, London WC1H 0AH, UK. Electronic address: martin.bommer@gmx.net.
authors.forename: Martin
authors.initials: M
authors.lastname: Bommer
authors.affiliation: The Advanced Centre for Biochemical Engineering, Department of Biochemical Engineering, University College London, London WC1H 0AH, UK.
authors.forename: John M
authors.initials: JM
authors.lastname: Ward
mesh_terms: D001419:Bacteria / Q000201:enzymology; D003124:Colorimetry / Q000379:methods*; D057075:Enzyme Assays / Q000379:methods; D007659:Ketones / Q000032:analysis*; D011767:Pyruvate Decarboxylase / Q000378:metabolism; D012995:Solubility; D013053:Spectrophotometry / Q000379:methods; D013778:Tetrazolium Salts / Q000737:chemistry*; D000637:Transaminases / Q000378:metabolism; D014867:Water / Q000737:chemistry
chemical_list: D007659:Ketones; D013778:Tetrazolium Salts; D014867:Water; C009591:triphenyltetrazolium; D000637:Transaminases; D011767:Pyruvate Decarboxylase
keywords: 2-Hydroxy ketone; Activity assay; Aminotransferase; Transaminase; Triphenyl tetrazolium chloride; Water-soluble tetrazolium