Hydrogen evolution, electron-transfer, hydride-transfer reactions in a nickel-iron hydrogenase model complex: A theoretical study of the distinctive reactivities for the conformational isomers of nickel-iron hydride

2021 ◽  
Author(s):  
Miho Isegawa ◽  
Takahiro Matsumoto ◽  
Seiji Ogo

Hydrogen fuel is a promising alternative to fossil fuel. Therefore, efficient hydrogen production is crucial to elucidate the distinctive reactivities of metal hydride species, the intermediates formed during hydrogen activation/evolution...

2001 ◽  
Vol 67 (10) ◽  
pp. 4583-4587 ◽  
Author(s):  
Gilles De Luca ◽  
Pascale de Philip ◽  
Zorah Dermoun ◽  
Marc Rousset ◽  
André Verméglio

ABSTRACT Resting cells of the sulfate-reducing bacteriumDesulfovibrio fructosovorans grown in the absence of sulfate had a very high Tc(VII)-reducing activity, which led to the formation of an insoluble black precipitate. The involvement of a periplasmic hydrogenase in Tc(VII) reduction was indicated (i) by the requirement for hydrogen as an electron donor, (ii) by the tolerance of this activity to oxygen, and (iii) by the inhibition of this activity by Cu(II). Moreover, a mutant carrying a deletion in the nickel-iron hydrogenase operon showed a dramatic decrease in the rate of Tc(VII) reduction. The restoration of Tc(VII) reduction by complementation of this mutation with nickel-iron hydrogenase genes demonstrated the specific involvement of the periplasmic nickel-iron hydrogenase in the mechanism in vivo. The Tc(VII)-reducing activity was also observed with cell extracts in the presence of hydrogen. Under these conditions, Tc(VII) was reduced enzymatically to soluble Tc(V) or precipitated to an insoluble black precipitate, depending on the chemical nature of the buffer used. The purified nickel-iron hydrogenase performed Tc(VII) reduction and precipitation at high rates. These series of genetic and biochemical approaches demonstrated that the periplasmic nickel-iron hydrogenase of sulfate-reducing bacteria functions as a Tc(VII) reductase. The role of cytochromec 3 in the mechanism is also discussed.


2014 ◽  
Vol 136 (35) ◽  
pp. 12385-12395 ◽  
Author(s):  
Mioy T. Huynh ◽  
David Schilter ◽  
Sharon Hammes-Schiffer ◽  
Thomas B. Rauchfuss

Author(s):  
Richard Cammack ◽  
Victor M. Fernandez ◽  
E. Claude Hatchikian

2020 ◽  
Author(s):  
Shiny Joseph Srinivasan ◽  
Sarah Cleary ◽  
Caroline Paul ◽  
Miguel A. Ramirez ◽  
Kylie Vincent

<p>Robust [NiFe] hydrogenase 1 (Hyd1) from <i>Escherichia coli</i> is shown to have non-native, H<sub>2</sub>-dependent activity for FMN and FAD reduction, and to function as a promising recycling system for FMNH<sub>2</sub> supply to flavoenzymes for chemical synthesis, giving a total turnover number over 10 million when coupled with an Old Yellow Enzyme ene reductase. </p>


1998 ◽  
Vol 120 (3) ◽  
pp. 548-555 ◽  
Author(s):  
Maria Pavlov ◽  
Per E. M. Siegbahn ◽  
Margareta R. A. Blomberg ◽  
Robert H. Crabtree

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