Changes in activity of soluble and immobilized peroxidases after treatment by various proteases and some metal ions

The proteases used were cabbage serine proteinase, trypsin, proteinase K, papain, pepsin, pronase and carboxypeptidase Y. The metal ions used were Mg, Mn, Cu, Hg, Pb and Ag. The incubation of cabbage peroxidase, soluble or immobilized, with seven different proteases and six different metal ions during 1 to 2 hours caused an increase in enzyme activity up to 250%. Longer incubation times of the peroxidase with the proteases caused a decrease of the enzyme activity but the immobilization stabilized its activity, despite the action of proteases. Especially evident was activation (from 50% to 200%) by serine proteinases, including the cabbage serine proteinase, in the presence of Pb, Hg, Cu and Mg ions after one to two hours of incubation. The observed changes in the peroxidase activities after protease and metal ion treatment may resemble those in nature or in enzymatic bioreactors.