Assignment of individual heme EPR signals of Desulfovibrio baculatus (strain 9974) tetraheme cytochrome c3. A redox equilibria study. 1988

I Moura, and M Teixeira, and B H Huynh, and J LeGall, and J J Moura
Centro de Quimica Estrutural Complexo I, UNL, Lisboa, Portugal.

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.

UI MeSH Term Description Entries
D010084 Oxidation-Reduction A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471). Redox,Oxidation Reduction
D003574 Cytochrome c Group A group of cytochromes with covalent thioether linkages between either or both of the vinyl side chains of protoheme and the protein. (Enzyme Nomenclature, 1992, p539) Cytochromes Type c,Group, Cytochrome c,Type c, Cytochromes
D003901 Desulfovibrio A genus of gram-negative, anaerobic, rod-shaped bacteria capable of reducing sulfur compounds to hydrogen sulfide. Organisms are isolated from anaerobic mud of fresh and salt water, animal intestines, manure, and feces.
D004578 Electron Spin Resonance Spectroscopy A technique applicable to the wide variety of substances which exhibit paramagnetism because of the magnetic moments of unpaired electrons. The spectra are useful for detection and identification, for determination of electron structure, for study of interactions between molecules, and for measurement of nuclear spins and moments. (From McGraw-Hill Encyclopedia of Science and Technology, 7th edition) Electron nuclear double resonance (ENDOR) spectroscopy is a variant of the technique which can give enhanced resolution. Electron spin resonance analysis can now be used in vivo, including imaging applications such as MAGNETIC RESONANCE IMAGING. ENDOR,Electron Nuclear Double Resonance,Electron Paramagnetic Resonance,Paramagnetic Resonance,Electron Spin Resonance,Paramagnetic Resonance, Electron,Resonance, Electron Paramagnetic,Resonance, Electron Spin,Resonance, Paramagnetic
D006418 Heme The color-furnishing portion of hemoglobin. It is found free in tissues and as the prosthetic group in many hemeproteins. Ferroprotoporphyrin,Protoheme,Haem,Heme b,Protoheme IX

Related Publications

I Moura, and M Teixeira, and B H Huynh, and J LeGall, and J J Moura
November 1990, Journal of molecular biology,
I Moura, and M Teixeira, and B H Huynh, and J LeGall, and J J Moura
June 1989, European journal of biochemistry,
I Moura, and M Teixeira, and B H Huynh, and J LeGall, and J J Moura
October 1988, European journal of biochemistry,
I Moura, and M Teixeira, and B H Huynh, and J LeGall, and J J Moura
September 1993, The Biochemical journal,
I Moura, and M Teixeira, and B H Huynh, and J LeGall, and J J Moura
July 1976, Journal of molecular biology,
I Moura, and M Teixeira, and B H Huynh, and J LeGall, and J J Moura
December 1986, FEBS letters,
I Moura, and M Teixeira, and B H Huynh, and J LeGall, and J J Moura
December 1991, European journal of biochemistry,
I Moura, and M Teixeira, and B H Huynh, and J LeGall, and J J Moura
June 1995, European journal of biochemistry,
Copied contents to your clipboard!