Allochromatium vinosum

Figure 17.14 Cyclic voltammograms recorded at 1 V s at a PGE RDE rotating at 2500 rev min ) modified by adsorption of a submonolayer film of [NiEe]-hydrogenase from the purple photosynthetic sulfur bacterium Allochromatium vinosum in buffered aqueous solution at pH 7.0 under an atmosphere of H2 (1 bar). Reprinted with permission from Leger et al., 2002. Copyright (2002) American Chemical Society.

FIGURE 11.8 EPR spectrum of [4Fe-4S]3+ valence isomers. The experimental spectrum (solid trace) of Allochromatium vinosum HiPIP is simulated as a sum of four slightly different spectra presumably presenting four of the possible six valence isomers. Arrows indicate the g s of the four components with relative concentration (from left to right) 8%, 68%, 12%, and 12%. 

The hydrogen-consumption activity of the [NiFe] hydrogenase of Allochromatium vinosum in different redox states... 

As explained in Section 7.4 the [NiFe] hydrogenase of Allochromatium vinosum can exist in varions states, three of which are enzymically active. Activity is usually measured by following hydrogen consnmption at 30°C with benzyl viologen (E o = —359 mV) as electron acceptor. If performed with enzyme in the ready state (see Fig. 5.6 for an overview of all states), it only takes several minutes until full activity is... 

Allochromatium vinosum A. vinosum formerly Chromatium vinosum... 

Allochromatium vinosum [NiFe]-hydrogenase graphite supported adsorption Ni-Fe layer [5]... 

Bleijlevens B, Faber BW, Albracht SP (1997) The [NiFe] hydrogenase from Allochromatium vinosum studied in EPR-detectable states H/D exchange experiments that yield new information about die structure of the active site. J. Bio. Inorg. Chem. 6 763—769... 

Ogata H, Kellers P, Lubitz W. The crystal structure of the [NiFe] hydrogenase from the photosynthetic bacterium Allochromatium vinosum characterization of the oxidized enzyme (Ni-A state). J Mol Biol. 2010 402(2) 428-44. 

George SJ, Kurkin S, Thorneley RNF, Albracht SPJ. Reactions of H2, CO, and 02 with active [NiFe]-hydrogenase from Allochromatium vinosum. A stopped-flow infrared study. Biochemistry. 2004 43(21) 6808-19. 

Kurkin, S., George, S. J., Thorneley, R. N. F., and Albracht, S. P. J. 2004. Hydrogen-induced activation of the [NiFe]-hydrogenase from Allochromatium vinosum as studied by stopped-flow infrared spectroscopy. Biochem. 43, 6820-6831. 

Armstrong, F.A. (2004) Electrochemical potential-step investigations of the aerobic interconversions of [NiFeJ-hydrogenase from Allochromatium vinosum insights into the puzzling difference between unready and ready oxidized inactive states. Journal cf the American Chemical Society, 126, 14899-14909. 

It follows that if an enzyme has a very high turnover frequency, it may be difficult to determine its inherent catalytic properties. The [NiFe]-hydrogenase from Allochromatium vinosum is a good example. A film of this enzyme formed on a PGE electrode displays very high activity for Hz oxidation and, for an atmosphere of 10% Hz, the catalytic current varies with... 

Figure 4-11. Studies of the inactivation and reactivation of Allochromatium vinosum Ni-Fe hydrogenase induced by varying the electrode potential. (A) Voltammogram measured at slow scan rate (0.3 mV s ) for a sparse film of hydrogenase at a PGE electrode, pH 8.8, 45 °C, 1 bar Hl. (B) Activation kinetics observed following different reductive potential steps to potentials indicated on the voltammogram shown in inset. (C) Semi-log plots for these kinetics, indicating nearly first-order kinetics and marked dependence on step potential. Reproduced from ref. 60 with permission.

Allochromatium vinosum was formerly known as Chromatium vinosum [13]... 

Acidithiobacillus ferrooxidans 167, 177 Acidoid sol 161, 163 Agriculture 184-185 Allochromatium vinosum 172, 174-176 Allotropes 1, 3-4, 12, 17, 19, 47, 54-57 -, high-pressure 59 Aqueous sulfur sol 154 Assimilatory reduction 169 Aten s sulfur 17... 

Class-III PhaCs have been detected in unoxygenic phototrophic bacteria like Allochromatium vinosum or Thiocapsa pfennigii and occur also in cyanobacteria... 

Class in PHA synthases (prototype organism Allochromatium vinosum), are heteromeric, requiring two subunits of app. 40 kDa each, encoded by phaC and phaE. The polymerization of 5c/-hydroxyacyl-CoAs is catalysed [87]. 

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