Hydrogens detected by subatomic resolution protein crystallography in a [NiFe] hydrogenase

摘要: A sub-angstrom-resolution X-ray crystal structure of [NiFe] hydrogenase, with direct detection the products heterolytic splitting dihydrogen into a hydride bridging Ni and Fe proton attached to sulphur cysteine ligand. hydrogenases use nickel iron catalyse reversible oxidation molecular hydrogen. They are focus much research worldwide because their potential in biotechnology serving as natural models for biomimetic catalysts energy sector hydrogen production conversion. In protein crystallography it is notoriously difficult detect hydrogens, particularly significant problem where hydrogens involved directly reaction. Hideaki Ogata et al. have succeeded obtaining sub-angstrom resolution hydrogenase leading most even close metal ions. Using technique authors were able dihydrogen: that bridges ions, sulfur The enzyme reversibly converts protons electrons at catalyst1. location abundant key importance understanding function protein2,3,4,5,6. However, atoms one major problems, since they display only weak contributions diffraction quality single crystals often insufficient obtain resolution7. Here we report standard (∼91.3 kDa mass) 0.89 A resolution. strictly anoxically isolated has been obtained specific spectroscopic state, active reduced Ni-R (subform Ni-R1) state. high resolution, proper refinement strategy careful modelling allow positioning large part structure. This led (H−) (H+) Ni–H− Fe–H− bond lengths 1.58 A 1.78A, respectively. Furthermore, can assign Fe–CO Fe–CN− ligands site, hydrogen-bond networks preferred transfer pathway hydrogenase. Our results demonstrate precise comprehensive information available from ultra-high-resolution structures proteins an alternative neutron other methods such NMR structural analysis.