These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Electronic properties of the dissimilatory sulphite reductase from Desulfovibrio vulgaris (Hildenborough): comparative studies of optical spectra and relative reduction potentials for the [Fe4S4]-sirohaem prosthetic centres.
    Author: Lui SM, Soriano A, Cowan JA.
    Journal: Biochem J; 1994 Dec 01; 304 ( Pt 2)(Pt 2):441-7. PubMed ID: 7998978.
    Abstract:
    The dissimilatory sulphite reductase (desulfoviridin) from the sulphate-reducing bacterium Desulfovibrio vulgaris (Hildenborough) displays distinct optical and redox characteristics relative to the haem subunit of Escherichia coli assimilatory sulphite reductase. For high-spin pentaco-ordinate desulfoviridin there is minimal change in the absorbance of the oxidized chromophores both after reduction or after addition of exogenous ligands. A ligand-metal charge-transfer band approximately 702 nm is observed in both the oxidized and one-electron-reduced enzyme. E.p.r. spectroscopy has been used to define the relative reduction potentials for sirohaem and [Fe4S4] centres (delta E0 = Es0-Ec0) as a function of sirohaem axial co-ordination. Typically delta E0 lies in a range from -10 to -50 mV. These results show a correlation with the sigma-donor or pi-acceptor properties of the ligand and stand in sharp contrast with estimates for the E. coli enzyme. The electronic properties of the coupled [Fe4S4]-sirohaem redox centre common to both nitrite- and sulphite-reducing enzymes are apparently strongly dependent on the environment generated by protein side chains.
    [Abstract] [Full Text] [Related] [New Search]