Photosensitive nitrile hydratase intrinsically possesses nitric oxide bound to the non-heme iron center: evidence by Fourier transform infrared spectroscopy

AbstractNitrile hydratase (NHase) from Rhodococcus sp. N771 is a photosensitive enzyme that catalyzes hydration of nitriles to the corresponding amides. Light-induced Fourier transform infrared difference spectra between the inactive and active forms of NHase were measured with both the natural (14N) and 15N-labeled NHases. The results showed, for the first time, that NHase intrinsically possesses nitric oxide (NO) molecules bound to the non-heme iron center. The possible role of NO in the photoactivation process of NHase is discussed