Oxygen Stability in the New [FeFe]-Hydrogenase from <i>Clostridium beijerinckii</i> SM10 (CbA5H)

Abstract

The newly isolated Clostridium beijerinckii [FeFe]-hydrogenase CbA5H was characterized by Fourier transform infrared spectroscopy coupled to enzymatic activity assays. This showed for the first time that in this enzyme the oxygen-sensitive active state H_ox can be simply and reversibly converted to the oxygen-stable inactive H_inact state. This suggests that oxygen sensitivity is not an intrinsic feature of the catalytic center of [FeFe]-hydrogenases (H-cluster), opening new challenging perspectives on the oxygen sensitivity mechanism as well as new possibilities for exploitation in industrial applications.