| Autor: |
McLaughlin MP; Department of Chemistry, University of Rochester, Rochester, New York 14618, United States., Retegan M, Bill E, Payne TM, Shafaat HS, Peña S, Sudhamsu J, Ensign AA, Crane BR, Neese F, Holland PL |
| Jazyk: |
angličtina |
| Zdroj: |
Journal of the American Chemical Society [J Am Chem Soc] 2012 Dec 05; Vol. 134 (48), pp. 19746-57. Date of Electronic Publication: 2012 Nov 20. |
| DOI: |
10.1021/ja308346b |
| Abstrakt: |
The apoprotein of Pseudomonas aeruginosa azurin binds iron(II) to give a 1:1 complex, which has been characterized by electronic absorption, Mössbauer, and NMR spectroscopies, as well as X-ray crystallography and quantum-chemical computations. Despite potential competition by water and other coordinating residues, iron(II) binds tightly to the low-coordinate site. The iron(II) complex does not react with chemical redox agents to undergo oxidation or reduction. Spectroscopically calibrated quantum-chemical computations show that the complex has high-spin iron(II) in a pseudotetrahedral coordination environment, which features interactions with side chains of two histidines and a cysteine as well as the C═O of Gly45. In the (5)A(1) ground state, the d(z(2)) orbital is doubly occupied. Mutation of Met121 to Ala leaves the metal site in a similar environment but creates a pocket for reversible binding of small anions to the iron(II) center. Specifically, azide forms a high-spin iron(II) complex and cyanide forms a low-spin iron(II) complex. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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