Activity increase of horseradish peroxidase in the presence of magnetic particles

We report evidence for the effect of very low magnetic fields on a biological reaction. The presence of magnetite particles (with permanent magnetic moment of 1 emu/g) in the assay had a 30-fold increase on the rate of reaction of horseradish peroxidase. The activity of this enzyme was evaluated with two chromogen systems, and the apparent Michaelis-Menten kinetic parameters were extracted.