On the nature of the iron sulfur cluster in a deuterated algal ferredoxin

Anderson, R. E.; Dunham, William; Sands, Richard H.; Bearden, Alan J.; Crespi, Henry L.

doi:10.1016/0005-2728(75)90132-2

Cited by 69 publications

(44 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Given this equation, assuming that the intrinsic hyperfine coupling constants for cysteine H and H R protons are 1.0 and 0.1 MHz, respectively; assuming that these nuclei are coupled only to the closer of the two Fe centers; and allowing the value of J eff to float, then one can obtain good agreement with the experimental hyperfine data on plant-type Fd's. However, the value of J eff obtained from this procedure is only about one-half the experimentally determined value of -100 cm -1 for plant-type Fd's 112,120,[134][135][136][137] Nonetheless, the conclusion from the application of this model for the hyperfine shifts of reduced plant-type Fd's is that this system is indeed valence-trapped, even at room temperature on the NMR time scale, and that the extra electron resides entirely on the Fe ligated to Cys 41 and 46 (M 1 ). 35,130 The same conclusion is reached for the vertebrate Fd's, namely, that the system is valence-trapped and that M 1 (ligated by Cys46 and 53) is the Fe(II) center.…”

Section: Implementation Of a Strategy For Paramagnetic Resonance Assimentioning

confidence: 91%

Paramagnetic NMR Spectroscopy and Density Functional Calculations in the Analysis of the Geometric and Electronic Structures of Iron−Sulfur Proteins

2005

View full text Add to dashboard Cite

Paramagnetic NMR spectroscopy has been underutilized in the study of metalloproteins. One difficulty of the technique is that paramagnetic relaxation broadens signals from nuclei near paramagnetic centers. In systems with low electronic relaxation rates, this makes such signals difficult to observe or impossible to assign by traditional methods. We show how the challenges of detecting and assigning signals from nuclei near the metal center can be overcome through the combination of uniform and selective 2H, 13C, and 15N isotopic labeling with NMR experiments that utilize direct one-dimensional (2H, 13C, and 15N) and two-dimensional (13C-X) detection. We have developed methods for calculating NMR chemical shifts and relaxation rates by density functional theory (DFT) approaches. We use the correspondence between experimental NMR parameters and those calculated from structural models of iron-sulfur clusters derived from X-ray crystallography to validate the computational approach and to investigate how structural differences are manifested in these values. We have applied this strategy to three iron-sulfur proteins: Clostridium pasteurianum rubredoxin, Anabaena [2Fe-2S] ferredoxin, and human [2Fe-2S] ferredoxin. Provided that an accurate structural model of the iron-sulfur cluster and surrounding residues is available from diffraction data, our results show that DFT calculations can return NMR observables with excellent accuracy. This suggests that it might be possible to use calculations to refine structures or to generate structural models of active sites when crystal structures are unavailable. The approach has yielded insights into the electronic structures of these iron-sulfur proteins. In rubredoxin, the results show that substantial unpaired electron spin is delocalized across NH...S hydrogen bonds and that the reduction potential can be changed by 77 mV simply by altering the strength of one of these hydrogen bonds. In reduced [2Fe-2S] ferredoxins, hyperfine shift data have provided quantitative information on the degree of valence trapping. The approach described here for iron-sulfur proteins offers new avenues for detailed studies of these and other metalloprotein systems.

show abstract

Section: Implementation Of a Strategy For Paramagnetic Resonance Assimentioning

confidence: 91%

Paramagnetic NMR Spectroscopy and Density Functional Calculations in the Analysis of the Geometric and Electronic Structures of Iron−Sulfur Proteins

2005

View full text Add to dashboard Cite

show abstract

“…The origin of the distribution is believed to be variations of the metal-ligand bond lengths due to random solvent interactions. We characterize the spread in the electronic spin energies with Gaussian distributions in the parameters g, D, and E=D, which is referred to as g- [51] and D-strain [46]. The metal-ligand variations will also cause a variation in the Mn-Mn distance in the molecules of a sample.…”

Section: Broadening Mechanisms Of the Epr Spectramentioning

confidence: 99%

Quantitative analysis of dinuclear manganese(II) EPR spectra

Golombek

Hendrich

2003

Journal of Magnetic Resonance

103

View full text Add to dashboard Cite

“…These include clusters with complete cysteine coordination as in ferredoxins, [7, 8, 20, 140–143] or with some degree of noncysteine coordination. This section focuses on advanced EPR studies of the protein-derived, non-cysteinyl ligands of the FeS cluster.…”

Section: Cluster Ligationmentioning

confidence: 99%

“…These spectroscopic techniques were invented roughly concurrently with the discovery of FeS proteins (i.e., late 1950’s – early 1960’s), [3–6] and ENDOR was applied to two-iron ferredoxins (2Fe-Fds) not long thereafter. [7, 8]…”

Section: Introductionmentioning

confidence: 99%

Advanced paramagnetic resonance spectroscopies of iron–sulfur proteins: Electron nuclear double resonance (ENDOR) and electron spin echo envelope modulation (ESEEM)

Cutsail

Telser

Hoffman

2015

Biochimica et Biophysica Acta (BBA) - Molecular Cell Research

View full text Add to dashboard Cite

The advanced electron paramagnetic resonance (EPR) techniques, electron nuclear double resonance (ENDOR) and electron spin echo envelope modulation (ESEEM) spectroscopies, provide unique insights into the structure, coordination chemistry, and biochemical mechanism of Nature’s widely distributed iron-sulfur cluster (FeS) proteins. This review describes the ENDOR and ESEEM techniques and then provides a series of case studies on their application to a wide variety of FeS proteins including ferredoxins, nitrogenase, and radical SAM enzymes.

show abstract

On the nature of the iron sulfur cluster in a deuterated algal ferredoxin

Cited by 69 publications

References 12 publications

Paramagnetic NMR Spectroscopy and Density Functional Calculations in the Analysis of the Geometric and Electronic Structures of Iron−Sulfur Proteins

Paramagnetic NMR Spectroscopy and Density Functional Calculations in the Analysis of the Geometric and Electronic Structures of Iron−Sulfur Proteins

Quantitative analysis of dinuclear manganese(II) EPR spectra

Advanced paramagnetic resonance spectroscopies of iron–sulfur proteins: Electron nuclear double resonance (ENDOR) and electron spin echo envelope modulation (ESEEM)

Contact Info

Product

Resources

About