Detection and interpretation of redox potential optima in the catalytic activity of enzymes.
It is no surprise that the catalytic activity of electron-transport enzymes may be optimised at certain electrochemical potentials in ways that are analogous to observations of pH-rate optima. This property is observed clearly in experiments in which an enzyme is adsorbed on an electrode surface which can supply or receive electrons rapidly and in a highly controlled manner. In such a way, the rate of catalysis can be measured accurately as a function of the potential (driving force) that is applied. In this paper, we draw attention to a few examples in which this property has been observed in enzymes that are associated with membrane-bound respiratory chains, and we discuss its possible origins and implications for in vivo regulation.
Inorganic Chemistry Laboratory, Oxford University, England, UK.
Sean J
SJ
Elliott
Christophe
C
Léger
Harsh R
HR
Pershad
Judy
J
Hirst
Kerensa
K
Heffron
Nicolas
N
Ginet
Francis
F
Blasco
Richard A
RA
Rothery
Joel H
JH
Weiner
Fraser A
FA
Armstrong
D000818:Animals; D002384:Catalysis; D002417:Cattle; D004563:Electrochemistry; D004579:Electron Transport; D004926:Escherichia coli; D006863:Hydrogen-Ion Concentration; D007506:Iron-Sulfur Proteins; D008928:Mitochondria / Q000201:enzymology; D050901:Nitrate Reductase; D009565:Nitrate Reductases; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000737:chemistry*; D013385:Succinate Dehydrogenase / Q000737:chemistry
D007506:Iron-Sulfur Proteins; D010088:Oxidoreductases; D013385:Succinate Dehydrogenase; D009565:Nitrate Reductases; D050901:Nitrate Reductase; C045664:dimethyl sulfoxide reductase