Intramolecular Electron Transfer in Azurin: Difference between revisions
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The most extreme modification of the Cu binding site of azurin, again by Yi Lu and coworkers, was to create the di-copper Cu<sub>A</sub> <scene name='70/703985/Azurin_purple/1'>site</scene> of ''Pseudomonas denitrificans'' cytochrome oxidase in azurin. In this transformation the Cu binding loop CSELCGINHAL replaced CTF_P_GHSAL of ''Pseudomonas aeruginosa'' azurin. The Cu<sub>A</sub> site is also the site of reduction of cytochrome oxidase. The reactivity of this site, for single electron reduction, was established by the same method as used for the other azurin mutants <ref>Enhanced rate of intramolecular electron transfer in an engineered purple CuA azurin. Farver, O., Lu, Y., Ang, M. C., & Pecht, I. (1999). Proceedings of the National Academy of Sciences of the United States of America, 96(3), 899-902. ['''http://dx.doi.org/DOI: 10.1073/pnas.96.3.899''' DOI: 10.1073/pnas.96.3.899]</ref>. Depending on pH, the site can have its single unpaired electron delocalized (mixed valence, pH 4) or localized on a single Cu (trapped valence, pH 8). The site is about a factor of 3 more reactive than the type 1 azurin site, when compared at pH 5, even though the driving force for the reaction is somewhat less. The estimate for the reorganization energy of the Cu<sub>A</sub> site is slightly lower than that of a type 1 center. | The most extreme modification of the Cu binding site of azurin, again by Yi Lu and coworkers, was to create the di-copper Cu<sub>A</sub> <scene name='70/703985/Azurin_purple/1'>site</scene> of ''Pseudomonas denitrificans'' cytochrome oxidase in azurin. In this transformation the Cu binding loop CSELCGINHAL replaced CTF_P_GHSAL of ''Pseudomonas aeruginosa'' azurin. The Cu<sub>A</sub> site is also the site of reduction of cytochrome oxidase. The reactivity of this site, for single electron reduction, was established by the same method as used for the other azurin mutants <ref>Enhanced rate of intramolecular electron transfer in an engineered purple CuA azurin. Farver, O., Lu, Y., Ang, M. C., & Pecht, I. (1999). Proceedings of the National Academy of Sciences of the United States of America, 96(3), 899-902. ['''http://dx.doi.org/DOI: 10.1073/pnas.96.3.899''' DOI: 10.1073/pnas.96.3.899]</ref>. Depending on pH, the site can have its single unpaired electron delocalized (mixed valence, pH 4) or localized on a single Cu (trapped valence, pH 8). The site is about a factor of 3 more reactive than the type 1 azurin site, when compared at pH 5, even though the driving force for the reaction is somewhat less. The estimate for the reorganization energy of the Cu<sub>A</sub> site is slightly lower than that of a type 1 center. | ||
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== References == | == References == | ||
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