Copper-substituted forms of the wild type and C42A variant of rubredoxin
2013 (English)In: Journal of Inorganic Biochemistry, ISSN 0162-0134, E-ISSN 1873-3344, Vol. 127, 232-237 p.Article in journal (Refereed) Published
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) 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 Cull(S-Cys)n species. These Cu(II) intermediates are susceptible to auto-reduction by ligand S-Cys to produce stable Cu(l) 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.
Place, publisher, year, edition, pages
2013. Vol. 127, 232-237 p.
Rubredoxin, Mutant coordination site, Copper-substituted iron-sulfur center, UV-visible, EPR
IdentifiersURN: urn:nbn:se:uu:diva-210210DOI: 10.1016/j.jinorgbio.2013.06.003ISI: 000324661500028OAI: oai:DiVA.org:uu-210210DiVA: diva2:661453