Enzymatic activity of plasmin in strong magnetic fields

We investigated the effects of magnetic fields on the enzymatic activity of plasmin concerning the dissolution of thrombosis. Plasmin activity in magnetic fields up to 8 T was assessed using a synthetic substrate for plasmin, D-Val-Leu-Lys-pNA. We observed that the initial rate of the reaction accelerated 5% in an 8 T magnetic field. We also measured time courses of the reaction. When the absorbance changed non-linearly and reached 60-90% of the maximum absorbance, absorbance of the mixture exposed to an 8 T magnetic field at 37°C was 7-11% lower than control samples. The results show that the enzymatic activity of plasmin was affected by a magnetic field at 8 T. This suggests that magnetic fields have an effect on the active center of the reaction of plasmin with a substrate, especially on the hydrogen bonds of the charge-relay system