the iron chelator desferrioxamine at a concentration of 10 microm or higher brought about an irreversible loss of enzyme activity of a partially purified preparation containing an excess of catalase , whereas this same chelator at a lower concentration afforded considerable protection of the enzyme 's activity during the final purification stage despite the quasi-total absence of catalase and the presence of an excess of ferrous iron .
C0011145
desferrioxamine
C0282193
excess