E.p.r.-spectroscopic studies on the molybdenum–iron site of nitrogenase from Clostridium pasteurianum

The e.p.r. spectroscopy of the nitrogenase molybdenum-iron protein from Clostridium pasteurianum was re-investigated. The sharpness of the delta Ms = +/- 3 g′z peak from the +/- 3/2 Kramer's doublet enables the observation and quantification of incompletely resolved hyperfine splittings from the stable magnetic nuclei 95Mo and 57Fe in samples enriched in these isotopes. No couplings to 1H or 17O could be discerned by examination of spectra from samples exchanged into 2H2O and H2(17)O respectively. Simulation of the spectrum from 95Mo-enriched samples yields a hyperfine coupling of 2.9 MHz, and indicates that the earlier electron-nuclear-double-resonance-derived estimate of 8.1 +/- 0.2 MHz is substantially in error.

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Electron nuclear double-resonance (ENDOR) spectroscopy of amine oxidase from pig plasma

Biochemical Journal ◽

10.1042/bj2370609 ◽

1986 ◽

Vol 237 (2) ◽

pp. 609-612 ◽

Cited By ~ 18

Author(s):

G J Baker ◽

P F Knowles ◽

K B Pandeya ◽

J B Rayner

Keyword(s):

Hyperfine Coupling ◽

Amine Oxidase ◽

Double Resonance ◽

Spectroscopic Studies ◽

Water Molecules ◽

Electron Nuclear Double Resonance ◽

Endor Spectroscopy ◽

Amino Acid Histidine ◽

Plasma Amine Oxidase ◽

Hyperfine Couplings

Electron nuclear double-resonance (‘ENDOR’) spectroscopic studies on pig plasma amine oxidase have been carried out at 15 K. Deuterium-exchange studies show the presence of two sets of exchangeable protons, probably from two water molecules; from the magnitude of their hyperfine couplings, one is assigned to be equatorially, and the other axially, co-ordinated. Only one 14N hyperfine coupling is observed, suggesting that the bonding of all amino acid (histidine) or organic cofactor ligands is similar. Upon addition of azide, a further hyperfine coupling to nitrogen is observed which is smaller than that observed for the native enzyme; the hyperfine couplings to the remaining nitrogens are slightly altered.

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Distinct structural features of the .alpha. and .beta. subunits of nitrogenase molybdenum-iron protein of Clostridium pasteurianum: an analysis of amino acid sequences

Biochemistry ◽

10.1021/bi00408a021 ◽

1988 ◽

Vol 27 (8) ◽

pp. 2800-2810 ◽

Cited By ~ 16

Author(s):

Shu Zhen Wang ◽

Jiann Shin Chen ◽

John L. Johnson

Keyword(s):

Amino Acid ◽

Structural Features ◽

Amino Acid Sequences ◽

Clostridium Pasteurianum ◽

Beta Subunits ◽

Molybdenum Iron Protein ◽

Iron Protein

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Electron Spin Resonance, Electron Nuclear Double Resonance, and Electron Spin-Echo Spectroscopic Studies of Argonne Premium Coals

Advances in Chemistry - Magnetic Resonance of Carbonaceous Solids ◽

10.1021/ba-1993-0229.ch024 ◽

1992 ◽

pp. 451-466 ◽

Cited By ~ 1

Author(s):

Xinhua Chen ◽

Hugh McManus ◽

Larry Kevan

Keyword(s):

Electron Spin Resonance ◽

Electron Spin ◽

Spin Echo ◽

Double Resonance ◽

Electron Spin Echo ◽

Spectroscopic Studies ◽

Electron Nuclear Double Resonance ◽

Spin Resonance ◽

Resonance Electron

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Oxidative inactivation of the molybdenum-iron-protein component of nitrogenase from clostridium pasteurianum

Molecular and Cellular Biochemistry ◽

10.1007/bf00232888 ◽

1979 ◽

Vol 26 (2) ◽

Cited By ~ 3

Author(s):

Carlos Gomez-Moreno ◽

KE Bacon

Keyword(s):

Protein Component ◽

Clostridium Pasteurianum ◽

Molybdenum Iron Protein ◽

Iron Protein ◽

Oxidative Inactivation

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Electron nuclear double resonance study of a nitrogen centre in diamond

Proceedings of the Royal Society of London Series A - Mathematical and Physical Sciences ◽

10.1098/rspa.1966.0228 ◽

1966 ◽

Vol 295 (1441) ◽

pp. 99-106 ◽

Cited By ~ 56

Keyword(s):

Hyperfine Coupling ◽

Double Resonance ◽

Axially Symmetric ◽

Electron Nuclear Double Resonance ◽

Quadrupole Coupling ◽

Coupling Parameters ◽

Small Change

Endor measurements on a type 1b diamond with paramagnetic nitrogen centres were made at 4.2, 77 and 300 °K by means of a 35000 Mc/s spectrometer. The axially symmetric nitrogen hyperfine coupling and quadrupole coupling parameters at 4.2 °K are A iso. , = 92.228 ± 0.001, A aniso. = 10.903 ± 0.002, P = – 3.974 ± 0.001 Mc/s. A small change of hyperfine coupling with temperature was observed.

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Electron-Nuclear Double Resonance and Hyperfine Sublevel Correlation Spectroscopic Studies of Flavodoxin Mutants from Anabaena sp. PCC 7119

Biophysical Journal ◽

10.1016/s0006-3495(99)77017-7 ◽

1999 ◽

Vol 77 (3) ◽

pp. 1712-1720 ◽

Cited By ~ 19

Author(s):

Milagros Medina ◽

Anabel Lostao ◽

Javier Sancho ◽

Carlos Gómez-Moreno ◽

Richard Cammack ◽

...

Keyword(s):

Double Resonance ◽

Spectroscopic Studies ◽

Electron Nuclear Double Resonance ◽

Anabaena Sp ◽

Hyperfine Sublevel Correlation

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Visible, EPR and electron nuclear double-resonance spectroscopic studies on the two metal-binding sites of oxovanadium (IV)-substituted D-xylose isomerase

European Journal of Biochemistry ◽

10.1111/j.1432-1033.1991.tb15818.x ◽

1991 ◽

Vol 196 (2) ◽

pp. 305-312 ◽

Cited By ~ 19

Author(s):

Ralf BOGUMIL ◽

Jurgen HUTTERMANN ◽

Reinhard KAPPL ◽

Rainer STABLER ◽

Christoph SUDFELDT ◽

...

Keyword(s):

Metal Binding ◽

Binding Sites ◽

Double Resonance ◽

Xylose Isomerase ◽

Spectroscopic Studies ◽

Electron Nuclear Double Resonance ◽

Metal Binding Sites

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The first 1H and 14N ENDOR spectra of an oxygen-centered radical adduct of DMPO-type nitrones

Canadian Journal of Chemistry ◽

10.1139/v88-377 ◽

1988 ◽

Vol 66 (9) ◽

pp. 2395-2402 ◽

Cited By ~ 11

Author(s):

D. Larry Haire ◽

Uwe M. Oehler ◽

H. Duane Goldman ◽

Robert L. Dudley ◽

Edward G. Janzen

Keyword(s):

Electron Paramagnetic Resonance ◽

Long Range ◽

Double Resonance ◽

Electron Nuclear Double Resonance ◽

Paramagnetic Resonance ◽

Spectral Signatures ◽

Radical Adduct ◽

Sequence Patterns ◽

Hyperfine Splittings ◽

Electron Paramagnetic

We report the first 1H and 14N electron nuclear double resonance (ENDOR) spectra of oxygen-centered radical adducts (i.e., derived from the addition of tert-butoxyl radicals) of 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) as well as the related cyclic nitrones: 4-phenyl-5,5-dimethyl-1-pyrroline-N-oxide (4-Ph-DMPO) and 3,3,5,5-tetramethyl-1-pyrroline-N-oxide (M4PO). Features of the electron paramagnetic resonance (EPR) and ENDOR spectra of these cyclic (pyrrolidine) aminoxyl (nitroxide) species along with some deuterated analogues in liquid toluene solutions are highlighted. For instance, we found several long-range γ-H hyperfine splittings (HFS's) detectable by ENDOR that provide unique spectral signatures for these radical adducts. Conformational assignments of the pyrrolidine aminoxyl structures based upon the EPR and ENDOR findings are also discussed. Signs of the various hyperfine splittings (i.e., aN, [Formula: see text]) investigated by cross-relaxation intensity sequence patterns (CRISP) in the ENDOR spectra are also presented.

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