Effect of a Dispersion of Interfacial Electron Transfer Rates on Steady State Catalytic Electron Transport in [NiFe]-hydrogenase and Other Enzymes

2002 ◽  
Vol 106 (50) ◽  
pp. 13058-13063 ◽  
Author(s):  
Christophe Léger ◽  
Anne K. Jones ◽  
Simon P. J. Albracht ◽  
Fraser A. Armstrong
Keyword(s):  
Electron Transfer ◽  
Steady State ◽  
Electron Transport ◽  
Interfacial Electron Transfer ◽  
Transfer Rates

Surface complexation of colloidal semiconductors strongly enhances interfacial electron-transfer rates

Langmuir ◽  
1991 ◽  
Vol 7 (12) ◽  
pp. 3012-3018 ◽  
Author(s):  
Jacques. Moser ◽  
Swarnalatha. Punchihewa ◽  
Pierre P. Infelta ◽  
Michael. Graetzel
Keyword(s):  
Electron Transfer ◽  
Surface Complexation ◽  
Interfacial Electron Transfer ◽  
Transfer Rates ◽  
Colloidal Semiconductors

pH sensitivity of interfacial electron transfer at a supported graphene monolayer

Nanoscale ◽  
2019 ◽  
Vol 11 (31) ◽  
pp. 14742-14756
Author(s):  
Michel Wehrhold ◽  
Tilmann J. Neubert ◽  
Anur Yadav ◽  
Martin Vondráček ◽  
Rodrigo M. Iost ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Liquid Interface ◽  
Ph Sensitivity ◽  
Graphene Monolayer ◽  
Interfacial Electron Transfer ◽  
Electrostatic Effects ◽  
Transfer Rates

Electron transfer rates at graphene are found to vary with pH, attributed to electrostatic effects at the graphene-liquid interface.

scholarly journals Adaptation to Disruption of the Electron Transfer Pathway for Fe(III) Reduction in Geobacter sulfurreducens

2005 ◽  
Vol 187 (17) ◽  
pp. 5918-5926 ◽  
Author(s):  
Ching Leang ◽  
L. A. Adams ◽  
K.-J. Chin ◽  
K. P. Nevin ◽  
B. A. Methé ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Steady State ◽  
Electron Transport ◽  
Outer Membrane ◽  
Geobacter Sulfurreducens ◽  
Significant Shift ◽  
Deficient Mutant ◽  
Wild Type ◽  
Transcript Levels ◽  
Electron Transfer Pathway

ABSTRACT Previous studies demonstrated that an outer membrane c-type cytochrome, OmcB, was involved in Fe(III) reduction in Geobacter sulfurreducens. An OmcB-deficient mutant was greatly impaired in its ability to reduce both soluble and insoluble Fe(III). Reintroducing omcB restored the capacity for Fe(III) reduction at a level proportional to the level of OmcB production. Here, we report that the OmcB-deficient mutant gradually adapted to grow on soluble Fe(III) but not insoluble Fe(III). The adapted OmcB-deficient mutant reduced soluble Fe(III) at a rate comparable to that of the wild type, but the cell yield of the mutant was only ca. 60% of that of the wild type under steady-state culturing conditions. Analysis of proteins and transcript levels demonstrated that expression of several membrane-associated cytochromes was higher in the adapted mutant than in the wild type. Further comparison of transcript levels during steady-state growth on Fe(III) citrate with a whole-genome DNA microarray revealed a significant shift in gene expression in an apparent attempt to adapt metabolism to the impaired electron transport to Fe(III). These results demonstrate that, although there are many other membrane-bound c-type cytochromes in G. sulfurreducens, increased expression of these cytochromes cannot completely compensate for the loss of OmcB. The concept that outer membrane cytochromes are promiscuous reductases that are interchangeable in function appears to be incorrect. Furthermore, the results indicate that there may be different mechanisms for electron transfer to soluble Fe(III) and insoluble Fe(III) oxides in G. sulfurreducens, which emphasizes the importance of studying electron transport to the environmentally relevant Fe(III) oxides.

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