Inhibition of peroxidase, trypsin, and alpha-chymotrypsin by platinum (II)and platinum (IV) complexes

Effects of various complexes of platinum (II) and platinum (IV) on activiti es of trypsin, a-chymotrypsin, and peroxidase were compared. The platinum ( II) complexes were found to inhibit these enzymes, though with variable eff iciency. The platinum (IV) complexes at concentrations less than or equal t o 0.2 mM efficiently inhibited peroxidase but had no effect on the protease s. An enzymatic assay was developed to measure the most effective peroxidas e inhibitor (cisplatin) at concentrations of 5-50 mu M in the presence of f ivefold excess of its isomer (transplatin).