S. Yamashoji, CHARACTERIZATION OF EXTRACELLULAR MENADION-CATALYZED H2O2 PRODUCTION BY NIH 3T3 CELLS/, Biochemistry and molecular biology international, 44(3), 1998, pp. 555-563
The extracellular menadione-catalyzed H2O2 production by NIH/3T3 cells
was expected to depend on plasma membrane-bound NAD(P)H:quinone oxido
reductase. This enzyme was estimated to be a flavoprotein with the mol
ecular mass of 70 KDa. Km values of plasma membrane-bound NAD(P)H:quin
one oxidoreductase producing H2O2 were 60 mu M for NADH and 150 mu M f
or NADPH. Ca2+ ionophore A23187 controlled menadione-catalyzed H2O2 pr
oduction by the cells in time-and concentration-dependent manner.