CYTOCHROME-P450 AND AROMATIC BASES - A H-1-NMR STUDY

Camphor-free cytochrome P450 (Cyt P450) from Pseudomonas putida has been investigated in the presence of aromatic bases like pyridine, imidazole, and N-methylimidazole. H-1 NMR signals of the heme protons indicate that the bases bind both in the hydrophobic cavity and at the metal. Even a ternary Cyt P450-pyridine-imidazole system has been detected. The electronic spectra are capable of monitoring the binding at the metal. The derivatives with these bases are low spin and their H-1 NMR spectra have been investigated through DNOE and 2D NOESY spectroscopy. An assignment of some heme protons is proposed. This represents the first high-resolution NMR study on Cyt P450. Through saturation-transfer spectroscopy a partial assignment has been made on the high-spin Cyt P450(cam).