Investigation of static magnetic field effect on horseradish peroxidase enzyme activity and stability in enzymatic oxidation process

The activity of Horseradish Peroxidase (HRP) Enzyme exposed to a static magnetic field (SMF) during the oxidation reaction of pyrogallol (PGL) and the epigallocatechin gallate (EPCG) flavonoid was recorded at different times. As the data showed, the enzyme activity increased by 77.17% with increasing incubation time up to 30 min. The kinetic parameters KM and Vmax for PGL sample incubated in SMF for 30 min were 5.641 × 10−3 mM, 4.424 × 10−2 mmol/min, respectively, and for EPCG sample with the same condition were 8.65 × 10−4 mM, 2.37 × 10−3 mmol/min, respectively. Exposure of HRP enzyme to SMF changed the optimum pH from 7.0 to 6.0 in 10 min, but did not create any change in the optimum temperature of the enzyme. After 120 h, the residual activity of normal enzyme was 17% higher than that of the incubated enzyme. The structural changes of the control and HRP enzyme incubated in SMF were investigated by relative viscosity, fluorescence and CD, UV–Vis spectrophotometry. The structural changes in the presence of SMF were found to cause changes in the enzyme activity. In fact, changes in the amount of hydrogen bonds between enzymes and solvents can be a reason for this behavior from a molecular point of view. Using a static magnetic field can provide a new approach to control and direct enzyme-based biological processes. [Display omitted] •HRP incubation in a SMF increased the kcat/KM of the enzyme.•The change in HRP enzyme activity in SMF was dependent on the incubation time.•Applying a SMF could change the structure of the HRP enzyme.•The SMF changed the HRP enzyme optimum pH, but not the optimum temperature.