ALPHA-KETOGLUTARATE DEPENDENT DIOXYGENASES - MECHANISM FOR PROLYL HYDROXYLASE ACTION

The enzymatic conversion of proline residues to hydroxyproline residues within collagen peptides is discussed in mechanistic terms. The chemistry of previously suggested reaction mechanisms is reviewed, and a new mechanism which is based on recently published data is proposed. The key issue in the new interpretation is the coupling of the exothermic oxidative decarboxylation of α-ketoglutaric acid to the endothermic production of an oxo-iron species, which then stereospecifically effects an aliphatic hydroxylation of the proline ring. © 1979.