Osmium and Cerium Porphyrins: Metalloporphyrins with Unnatural Metals as Models for Active Sites of Electron-Transfer Enzymes

Structure-function relationships can provide valuable insight into the function of enzymes. These relationships can be obtained by chemical variation or modification of the original enzyme. Many enzymes contain metal ions which either stabilize the tertiary structure or serve as active sites for the biochemical process catalyzed by the enzyme under consideration. This Comment is devoted to the use of “unnatural” metals in metalloporphyrins that may be regarded as enzyme models.