Nonenzymatic NADPH-dependent reduction of 2,6-dichlorophenol-indophenol.
The reduction of 2,6-dichloroindophenol (DCIP) by direct interaction with NADPH was studied. The results indicate that reduction proceeds via a direct electron transfer from NADPH to DCIP, with no oxygen consumption, and a rate constant of k = 4.69 M-1.s-1. The reduced DCIP can rapidly transfer its electrons to potassium ferricyanide (K3Fe(CN)6) or ferricytochrome c, but not to nitro blue tetrazolium. Superoxide dismutase inhibits DCIP reduction in an oxygen-dependent manner by favoring the reoxidation of the reduced DCIP. We therefore conclude DCIP is not suitable for detecting O2- when the nucleotides NADH or NADPH are present.
Dupuy
C
C
U.96 INSERM, Unité de Recherche sur la Glande Thyroïde et la Régulation Hormonale, Le Kremlin-Bicêtre, France.
Kaniewski
J
J
Ohayon
R
R
Dème
D
D
Virion
A
A
Pommier
J
J
D015086:2,6-Dichloroindophenol / Q000737:chemistry / Q000378:metabolism*; D000818:Animals; D002417:Cattle; D003574:Cytochrome c Group / Q000737:chemistry / Q000378:metabolism; D004579:Electron Transport; D005292:Ferricyanides / Q000737:chemistry / Q000378:metabolism; D007700:Kinetics; D009249:NADP / Q000737:chemistry / Q000378:metabolism*; D009580:Nitroblue Tetrazolium / Q000737:chemistry / Q000378:metabolism; D010084:Oxidation-Reduction; D010101:Oxygen Consumption; D013482:Superoxide Dismutase / Q000378:metabolism
D003574:Cytochrome c Group; D005292:Ferricyanides; D009580:Nitroblue Tetrazolium; D009249:NADP; D015086:2,6-Dichloroindophenol; D013482:Superoxide Dismutase; C028033:potassium ferricyanide