Study and analytical application of bromopyrogallol red as a hydrogen donor substrate for peroxidase

Bromopyrogallol red is used as a hydrogen donor substrate for peroxidase. The steady-state catalytic rate depends upon enzyme and substrate concentrations, and the Michaelis-Menten parameters K-m and V-max are measured at pH 6.2 to be 2.07 x 10(-5) mol l(-1) and 1.62 x 10(-7) mol l(-1) s(-1) respectively. The quantitative assay for horseradish peroxidase is sensitive to 9.2 x 10(-12) mol l(-1), and trace hydrogen peroxide (2.1 x 10(-7)-1.5 x 10(-5) mol l(-1)) is determined spectrophotometrically. By coupling with a glucose oxidase-catalyzed reaction, glucose in human serum has been quantified with the same results as by the phenol-4-aminoantipyrine method. The method is simple, rapid and practical with high sensitivity and enzymatic activity. (C) 1999 Elsevier Science B.V. All rights reserved.