X-ray absorption spectroscopy of iron-tyrosinate proteins

Roe, A. L.; Schneider, David J.; Mayer, Ruth; Pyrz, J. W.; Widom, Joanne; Que, Larry

doi:10.1021/ja00318a021

Cited by 286 publications

(293 citation statements)

References 3 publications

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“…Because 2 and 3 μm beads sediment in water within a few minutes, the solution density must be increased by addition of 0.05 g/mL glucose leading to a final density of 1.02 g/mL, which efficiently hinders sedimentation (PS density ρ = 1.05 g/mL; glucose ρ = 1.6 g/cm 3 ). This addition of glucose does not significantly affect the refractive index of the solution, which changes from 1.33 to 1.34.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Multiscattering-Enhanced Absorption Spectroscopy

2015

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An original scheme for sensitive absorption measurements, particularly well-suited for low analyte concentrations, is presented. The technique is based on multiscattering-enhanced absorption spectroscopy (MEAS) and benefits from the advantages of conventional absorption spectroscopy: simplicity, rapidity, and low costs. The technique relies on extending the optical path through the sensing volume by suspending dielectric beads in the solution containing the analytes of interest, resulting in multiple scattering of light, which increases the optical path length through the sample. This way, a higher sensitivity and lower limit of detection, compared to those of conventional absorption spectroscopy, can be achieved. The approach is versatile and can be used for a broad variety of analytes. Here, it is applied to the detection of phenol red, 10 nm gold nanoparticles, and envy green fluorescence dye; the limit of detection is decreased by a factor of 7.2 for phenol red and a factor of 3.3 for nanoparticles and dye. The versatility of this approach is illustrated by its application in increasing the sensitivity of colorimetric detection with gold nanoparticle probes and a commercially available hydrogen peroxide bioassay. The influence of different parameters describing the scattering medium is investigated in detail experimentally and numerically, with very good agreement between the two. Those parameters can be effectively used to tailor the enhancement for specific applications and analytes.

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Section: ■ Results and Discussionmentioning

confidence: 99%

Multiscattering-Enhanced Absorption Spectroscopy

2015

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“…The relatively weaker and broader edge peak of H64C also suggests more sulfur and less nitrogen ligands on average around the iron atoms (65). However, the integrated peak areas (0.203 eV for the wild-type ARF and 0.286 eV for H64C) for the 1s 3 3d transition at ϳ7113 eV fall in the range expected for tetrahedral compounds (66,67).…”

Section: Probing the Novel [2fe-2s] Cluster Surroundings In The Oxidimentioning

confidence: 91%

Engineering a Three-cysteine, One-histidine Ligand Environment into a New Hyperthermophilic Archaeal Rieske-type [2Fe-2S] Ferredoxin from Sulfolobus solfataricus

Kounosu

Cosper

et al. 2004

Journal of Biological Chemistry

128

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We heterologously overproduced a hyperthermostable archaeal low potential (E m ‫؍‬ ؊62 mV) Rieske-type ferredoxin (ARF) from Sulfolobus solfataricus strain P-1 and its variants in Escherichia coli to examine the influence of ligand substitutions on the properties of the [2Fe-2S] cluster. While two cysteine ligand residues (Cys 42 and Cys 61 ) are essential for the cluster assembly and/or stability, the contributions of the two histidine ligands to the cluster assembly in the archaeal Riesketype ferredoxin appear to be inequivalent as indicated by much higher stability of the His 64 Proteins containing Rieske-type [2Fe-2S] clusters are widespread in nature from hyperthermophilic Archaea and Bacteria to Eukarya and play critical electron transfer roles in various pathways such as aerobic respiration, photosynthesis, and biodegradation of various alkene and aromatic compounds (1-4). In contrast to regular plant-and vertebrate-type ferredoxins having complete cysteinyl ligations, the Rieske-type cluster has an asymmetric iron-sulfur core with the S ␥ atom of each of the two cysteine residues coordinated to one iron site and the N ␦ atom of each of the two histidine residues coordinated to the other iron site. This asymmetric ligation results in some unique redox and spectroscopic properties (for reviews, see Refs. 1 and 3-5). This cluster coordination was firmly established by recent x-ray crystal structures of several different Rieske-type protein domains (6 -11).Two different types of Rieske clusters are observed in proteins. One type displays higher reduction potentials (E m ) 1 of approximately ϩ150 to ϩ490 mV and occurs in proton-translocating respiratory complexes (cytochrome bc 1 /b 6 f complexes and their archaeal homologs without c-type cytochromes), being involved in not only electron transfer but also substrate binding and oxidation at the quinol-oxidizing Q o site (2-5, 12-15). The other type displays lower E m values of approximately Ϫ150 to Ϫ50 mV and has been found in a diverse group of bacterial multicomponent terminal oxygenases and soluble Rieske-type ferredoxins (1, 3, 8, 9, 16 -27). However, none of the latter class has been characterized in detail from any archaeal species.We recently found that the genomic DNA sequence of the thermoacidophilic archaeon Sulfolobus solfataricus strain P-1 (DSM 1616T) encodes an archaeal homolog of bacterial small Rieske-type ferredoxins with no consensus disulfide signature (DDBJ accession number AB047031 (27)). This arf gene was found by homology search against the deduced amino acid sequence of Sulfolobus tokodaii sulredoxin, a water-soluble homolog of a high potential Rieske protein (E m,low pH ϳ ϩ190 mV) with a consensus disulfide linkage (DDBJ accession number AB023295) 2 (28 -30) (Fig. 1). Subsequent cloning and heterologous overexpression in Escherichia coli of this S. solfataricus arf gene encoding the archaeal Rieske-type ferredoxin (ARF) (27) have provided an opportunity to define the influence of surrounding amino acid residues on the electronic and s...

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“…[2] Distortions that change the pre-edge intensity are changes from six-to five-or four-coordinate tetrahedral sites. [1,3] Another alternative is the presence of a strongly binding ligand, e.g., the metal-oxo groups proposed to be the reactive species in many enzymatic and synthetic systems. [4][5][6][7] Oxo groups also appear as bridging ligands in many bi-and multinuclear transition metal complexes.…”

Section: Introductionmentioning

confidence: 99%

Applications to metal K pre-edges of transition metal dimers illustrate the approximate origin independence for the intensities in the length representation

et al. 2016

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PostprintThis is the accepted version of a paper published in Molecular Physics. This paper has been peer-reviewed but does not include the final publisher proof-corrections or journal pagination. Citation for the original published paper (version of record):Sørensen, L K., Guo, M., Lindh, R., Lundberg, M. (2017) Applications to metal K pre-edges of transitionmetal dimers illustrate the approximate origin independence for the intensities in the length representation Molecular Physics, 115(1-2): 174-189

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X-ray absorption spectroscopy of iron-tyrosinate proteins

Cited by 286 publications

References 3 publications

Multiscattering-Enhanced Absorption Spectroscopy

Multiscattering-Enhanced Absorption Spectroscopy

Engineering a Three-cysteine, One-histidine Ligand Environment into a New Hyperthermophilic Archaeal Rieske-type [2Fe-2S] Ferredoxin from Sulfolobus solfataricus

Applications to metal K pre-edges of transition metal dimers illustrate the approximate origin independence for the intensities in the length representation

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