The role of post-translational modification in the photoregulation of Fe-type nitrile hydratase†
Abstract
The inactive, nitrosyl bound form of Fe-type nitrile hydratase (NHase) contains two active site cysteine residues that are post-translationally modified to sulfenate (SO−) and sulfinate (SO2−) ligands. DFT and INDO/S calculations support the hypothesis that these unusual modifications play a key role in modulating the electronic absorption spectra and photoreactivity of the Fe(III) centre in the enzyme.