Ferric microperoxidase-11 catalyzes peroxynitrite isomerization

Microperoxidase-11 (MP11) is an undecapeptide derived from cytochrome c offering the possibility to investigate the reactivity of the heme group unshielded by the protein. In fact, ferric penta-coordinated MP11 catalyzes peroxynitrite isomerization to NO3− whereas hexa-coordinated cytochrome c is unreactive. MP11 may represent the active site of chimeric proteins and play a relevant role(s) in biotechnological applications.