Analysis of the oxidase activity induced by CCl(4) and H(2)O(2) in different recombinant myoglobins.

Hemoproteins may present several functions due to their prosthetic groups. After a long time, well-studied proteins such as myoglobin have surprised us with new functions. Myoglobin is a hemoprotein which has some well described and unexpected functions within the organism. Oxidase activity in standard myoglobins has been described and this activity was attributed to a covalent linkage between heme and some amino acid residues such as histidine, when myoglobins are treated with alkyl halides, and tyrosine, and when myoglobins are treated with H(2)O(2). We have found that the oxidase activity, due to H(2)O(2) treatment, can appear in different myoglobins, which presents no key residue, such as Tyr 103, for the oxidase activity previously described in the literature.