Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: EC:1.12.7.2 (
hydrogenase
)
3,522
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
An indium
tin
oxide (ITO) electrode was chemically modified by one layer of viologen (VIO) derivative, which possessed a persistent and reproducible electrochemical response. A monolayer of a thermal stable
hydrogenase
from Thiocapsa roseopersicina was stabilized on a synthesized poly-L-lysine subphase surface and transferred onto the electrode for fabrication of an ITO-VIO-
hydrogenase
heterogeneous system. Electrochemical properties of both the ITO-VIO monolayer and the heterogeneous ITO-VIO-
hydrogenase
system have been investigated. Hydrogen evolution could be measured by potentiostating the VIO-
hydrogenase
-covered ITO electrode to "electroplate" [(VIO+)n]surf, and a large increase in hydrogen evolution was observed when using an electrolyte solution containing sodium dithionite. We discuss the possible electron transfer process.
...
PMID:Fabrication of an electrode-viologen-hydrogenase heterogeneous system and the electrochemical hydrogen evolution. 1084 7
Pyridylthio-modified multiwalled carbon nanotubes (pythio-MWNTs) have been prepared by a reaction of the oxidized MWNTs with S-(2-aminoethylthio)-2-thiopyridine hydrochloride. The obtained pythio-MWNTs nanocomposites formed stable floating monolayers at the air-water interface, which were transferred onto substrate surfaces by the Langmuir-Blodgett (LB) method. Compositions and morphologies of the LB films were characterized by absorption, Raman, X-ray photoelectron spectra as well as by scan electron microscopy and atomic force microscopy. These pythio-MWNTs LB films were then used as a support to immobilize
hydrogenase
(H(2)ase) to form bionanocomposite of pythio-MWNTs-H(2)ase. Cyclic voltammograms for indium
tin
oxide electrode covered with the pythio-MWNTs-H(2)ase films were investigated in both Ar and H(2) saturated 0.05 M KCl electrolyte solutions at pH from 4.0 to 9.0. A reversible redox couple of [4Fe-4S](2+/1+) clusters of H(2)ase was recorded when the pH value was 6.0 and 9.0, with reduction and oxidation potentials appearing at about -0.70 and -0.35 V vs Ag/AgCl, respectively. It was revealed that the H(2)ase was of high catalytic activity and strong stability in the LB films of pythio-MWNTs-H(2)ase. Hence, we suggested that the present bionanocomposites could be used as heterogeneous biocatalyst to catalyze reversible reaction between protons and H(2), resulting in potential applications in biohydrogen evolution and H(2) biofuel cells.
...
PMID:Langmuir-Blodgett films of pyridyldithio-modified multiwalled carbon nanotubes as a support to immobilize hydrogenase. 2035 22
In natural photosynthesis, light is used for the production of chemical energy carriers to fuel biological activity. The re-engineering of natural photosynthetic pathways can provide inspiration for sustainable fuel production and insights for understanding the process itself. Here, we employ a semiartificial approach to study photobiological water splitting via a pathway unavailable to nature: the direct coupling of the water oxidation enzyme, photosystem II, to the H2 evolving enzyme,
hydrogenase
. Essential to this approach is the integration of the isolated enzymes into the artificial circuit of a photoelectrochemical cell. We therefore developed a tailor-made hierarchically structured indium-
tin
oxide electrode that gives rise to the excellent integration of both photosystem II and
hydrogenase
for performing the anodic and cathodic half-reactions, respectively. When connected together with the aid of an applied bias, the semiartificial cell demonstrated quantitative electron flow from photosystem II to the
hydrogenase
with the production of H2 and O2 being in the expected two-to-one ratio and a light-to-hydrogen conversion efficiency of 5.4% under low-intensity red-light irradiation. We thereby demonstrate efficient light-driven water splitting using a pathway inaccessible to biology and report on a widely applicable in vitro platform for the controlled coupling of enzymatic redox processes to meaningfully study photocatalytic reactions.
...
PMID:Wiring of Photosystem II to Hydrogenase for Photoelectrochemical Water Splitting. 2604 91
The decahaem cytochrome MtrC from Shewanella oneidensis MR-1 was employed as a protein electron conduit between a porous indium
tin
oxide electrode and redox enzymes. Using a
hydrogenase
and a fumarate reductase, MtrC was shown as a suitable and efficient diode to shuttle electrons to and from the electrode with the MtrC redox activity regulating the direction of the enzymatic reactions.
...
PMID:A decahaem cytochrome as an electron conduit in protein-enzyme redox processes. 2719 68
The biological formate hydrogenlyase (FHL) complex links a formate dehydrogenase (FDH) to a
hydrogenase
(H
2
ase) and produces H
2
and CO
2
from formate via mixed-acid fermentation in
Escherichia coli
. Here, we describe an electrochemical and a colloidal semiartificial FHL system that consists of an FDH and a H
2
ase immobilized on conductive indium
tin
oxide (ITO) as an electron relay. These
in vitro
systems benefit from the efficient wiring of a highly active enzyme pair and allow for the reversible conversion of formate to H
2
and CO
2
under ambient temperature and pressure. The hybrid systems provide a template for the design of synthetic catalysts and surpass the FHL complex
in vivo
by storing and releasing H
2
on demand by interconverting CO
2
/H
2
and formate with minimal bias in either direction.
...
PMID:Reversible and Selective Interconversion of Hydrogen and Carbon Dioxide into Formate by a Semiartificial Formate Hydrogenlyase Mimic. 3163 93
