Copper-substituted forms of the wild type and C42A variant of rubredoxin

Citation:
Thapper, A., A. C. Rizzi, CD Brondino, A. G. Wedd, R. J. Pais, B. K. Maiti, I. Moura, S. R. Pauleta, and J. J. Moura. "Copper-substituted forms of the wild type and C42A variant of rubredoxin." J Inorg Biochem. 127 (2013): 232-7.

Abstract:

In order to gain insights into the interplay between Cu(I) and Cu(II) in sulfur-rich protein environments, the first preparation and characterization of copper-substituted forms of the wild-type rubredoxin (Rd) from Desulfovibrio vulgaris Hildenborough are reported, as well as those of its variant C42A-Rd. The initial products appear to be tetrahedral Cu(I)(S-Cys)n species for the wild type (n=4) and the variant C42A (n=3, with an additional unidentified ligand). These species are unstable to aerial oxidation to products, whose properties are consistent with square planar Cu(II)(S-Cys)n species. These Cu(II) intermediates are susceptible to auto-reduction by ligand S-Cys to produce stable Cu(I) final products. The original Cu(I) center in the wild-type system can be regenerated by reduction, suggesting that the active site can accommodate Cu(I)(S-Cys)2 and Cys-S-S-Cys fragments in the final product. The absence of one S-Cys ligand prevents similar regeneration in the C42A-Rd system. These results emphasize the redox instability of Cu(II)-(S-Cys)n centers.

Notes:

Thapper, AndersRizzi, Alberto CBrondino, Carlos DWedd, Anthony GPais, Ricardo JMaiti, Biplab KMoura, IsabelPauleta, Sofia RMoura, Jose J GResearch Support, Non-U.S. Gov'tUnited StatesJournal of inorganic biochemistryJ Inorg Biochem. 2013 Oct;127:232-7. doi: 10.1016/j.jinorgbio.2013.06.003. Epub 2013 Jun 13.

Related External Link