Assignment of individual heme EPR signals of Desulfovibrio baculatus (strain 9974) tetraheme cytochrome c3. A redox equilibria study
- Citation:
- Assignment of individual heme EPR signals of Desulfovibrio baculatus (strain 9974) tetraheme cytochrome c3. A redox equilibria study, Moura, I., Teixeira M., Huynh B. H., Legall J., and Moura J. J. , Eur J Biochem, Sep 15, Volume 176, Number 2, p.365-9, (1988)
Abstract:
An EPR redox titration was performed on the tetraheme cytochrome c3 isolated from Desulfovibrio baculatus (strain 9974), a sulfate-reducer. Using spectral differences at different poised redox states of the protein, it was possible to individualize the EPR g-values of each of the four hemes and also to determine the mid-point redox potentials of each individual heme: heme 4 (-70 mV) at gmax = 2.93, gmed = 2.26 and gmin = 1.51; heme 3 (-280 mV) at gmax = 3.41; heme 2 (-300 mV) at gmax = 3.05, gmed = 2.24 and gmin = 1.34; and heme 1 (-355 mV) at gmx = 3.18. A previously described multi-redox equilibria model used for the interpretation of NMR data of D. gigas cytochrome c3 [Santos, H., Moura, J.J.G., Moura, I., LeGall, J. & Xavier, A. V. (1984) Eur. J. Biochem. 141, 283-296] is discussed in terms of the EPR results.
Notes:
0014-2956 (Print)0014-2956 (Linking)Journal ArticleResearch Support, Non-U.S. Gov'tResearch Support, U.S. Gov't, Non-P.H.S.Research Support, U.S. Gov't, P.H.S.
