Cobinamide production of hydrogen in a homogeneous aqueous photochemical system, and assembly and photoreduction in a (βα)8 protein.

ABSTRACT: Components of a protein-integrated, earth-abundant metal macrocycle catalyst, with the purpose of H2 production from aqueous protons under green conditions, are characterized. The cobalt-corrin complex, cobinamide, is demonstrated to produce H2 (4.4 ± 1.8 × 10(-3) turnover number per hour) in a homogeneous, photosensitizer/sacrificial electron donor system in pure water at neutral pH. Turnover is proposed to be limited by the relatively low population of the gateway cobalt(III) hydride species. A heterolytic mechanism for H2 production from the cobalt(II) hydride is proposed. Two essential requirements for assembly of a functional protein-catalyst complex are demonstrated for interaction of cobinamide with the (βα)8 TIM barrel protein, EutB, from the adenosylcobalamin-dependent ethanolamin

SUBMITTER: Robertson WD 

PROVIDER: S-EPMC3737076 | biostudies-literature | 2013 Aug

REPOSITORIES: biostudies-literature