CO binding and ligand discrimination in human myeloperoxidase

UV/visible spectroscopy are applied to confirm the small spectral shifts induced by CO in ferrous myeloperoxidase (MPO) and the formation of a heme ferrous-CO compound. Two different conformations of the bound CO and identical recombination rate constants observed by Fourier transform infrared spectroscopy are in rapid thermal equilibrium rather than two distinct protein populations with different binding sites.