THE EFFECT OF THE SIMULTANEOUS OPERATION OF 2 METAL-IONS ON SOLUBLE AND IMMOBILIZED PEROXIDASE

Changes in the activity of peroxidase (EC 1.11.1.7) were compared unde r the influence of two simultaneously present metal ions, one of which deactivates most enzymes (mercury or cadmium) while the other possess es stimulating properties (magnesium, manganese or calcium). A possibi lity of a considerable increase in peroxidase activity (50-200%) was f ound in the presence of the ions of manganese, magnesium or calcium, i n spite of the presence of ions known to possess toxic properties (mer cury or cadmium). An enzyme immobilization method was employed in orde r to determine the kind of protein functional groups (COOH or NH2) inv olved in the processes of peroxidase activity changes due to the prese nce of metal ions. It was found that by immobilizing peroxidase by fre e amino groups of the enzyme, one achieves a considerable decrease in the toxic effect of mercury or cadmium, and a higher increase in perox idase activity in the presence of manganese, magnesium or calcium.