Suicide inactivation of peroxidase from Chamaerops excelsa palm tree leaves.

The concentration and time-dependences and the mechanism of the inactivation of Chamaerops excelsa peroxidase (CEP) by hydrogen peroxide were studied kinetically with four co-substrates (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), guaiacol, o-dianisidine and o-phenylenediamine). The turnover number (r) of H(2)O(2) required to complete the inactivation of the enzyme varied for the different substrates, the enzyme most resistant to inactivation (r=4844) with ABTS being the most useful substrate for biotechnological applications, opening a new avenue of enquiry with this peroxidase.