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Rusticyanin is a soluble blue copper protein found in abundance in the periplasmic space of Thiobacillus ferrooxidans, an acidophilic bacterium capable of growing chemolithotrophically on soluble ferrous sulfate. The one-electron-transfer reactions between soluble iron and purified rusticyanin were studied by stopped-flow spectrophotometry in acidic solutions containing each of 14 different anions. The second-order rate constants for both the Fe(II)-dependent reduction and the Fe(III)-dependent oxidation of the rusticyanin varied as a function of the identity of the principal anion in solution. Analogous electron-transfer reactions between soluble iron and bis(dipicolinato)cobaltate(III) or bis(dipicolinato)ferrate(II) were studied by stopped-flow spectrophotometry under solution conditions identical with those of the rusticyanin experiments. Similar anion-dependent reactivity patterns were obtained with soluble iron whether the other reaction partner was rusticyanin or either of the two organometallic complexes. The Marcus theory of outer-sphere electron transfer reactions was applied to this set of kinetic data to demonstrate that the rusticyanin may possess at least two electron-transfer pathways for liganded iron, one where the pattern of electron-transfer reactivity is controlled largely by protein-independent activation parameters and one where the protein exhibits an anion-dependent kinetic specificity. The exact role of rusticyanin in the iron-dependent respiratory electron transport chain of T. ferrooxidans remains unclear.
R C Blake, and
K J White, and
E A Shute
November 1987,
The Journal of biological chemistry,
R C Blake, and
K J White, and
E A Shute
February 1992,
Indian journal of biochemistry & biophysics,
R C Blake, and
K J White, and
E A Shute
January 1967,
Biokhimiia (Moscow, Russia),
R C Blake, and
K J White, and
E A Shute
August 1991,
FEBS letters,
R C Blake, and
K J White, and
E A Shute
March 1996,
FEMS microbiology letters,
R C Blake, and
K J White, and
E A Shute
October 1991,
Biochemistry,
R C Blake, and
K J White, and
E A Shute
September 1992,
Journal of molecular biology,
R C Blake, and
K J White, and
E A Shute
November 1998,
Biochimica et biophysica acta,
R C Blake, and
K J White, and
E A Shute
May 1986,
Archives of biochemistry and biophysics,
R C Blake, and
K J White, and
E A Shute
September 1994,
Biochemical and biophysical research communications,
