Browsing by Subject "Raman spectrometry"
Now showing items 1-20 of 26
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Coupling of helix E-F motion with the O-nitrito and 2-nitrovinyl coordination in myoglobin
(2017)Myoglobin (Mb) is known to react slowly with nitirite to form the green pigment by NO2 − cordination to the heme Fe in the O-binding nitrito (O1[sbnd]N[dbnd]O2) mode and to the heme 2-vinyl position. Nitrite is a powerful ...
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Article
Decay of the transient CuB-CO complex is accompanied by formation of the heme Fe-CO complex of cytochrome cbb3-CO at ambient temperature: Evidence from time-resolved fourier transform infrared spectroscopy
(2002)Time-resolved step-scan Fourier infrared spectroscopy has been used to study the CO-bound cbb3-type cytochrome c oxidase from Pseudomonas stutzeri at room temperature. We observe a single band in the FTIR spectrum at 1956 ...
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Detection of the His-heme Fe2+-NO species in the reduction of NO to N2O by ba3-oxidase from thermus thermophilus
(2005)Reaction pathways in the enzymatic formation and cleavage of the N-N and N-O bonds, respectively, are difficult to verify without the structure of the intermediates, but we now have such information on the heme a3 2+-NO ...
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Direct detection of Fe(IV)=O intermediates in the cytochrome aa3 oxidase from Paracoccus denitrificans[H2O2 reaction
(2003)We report the first evidence for the formation of the "607- and 580-nm forms" in the cytochrome oxidase aa3/H2O2 reaction without the involvement of tyrosine 280. The pKa of the 607-580-nm transition is 7.5. The 607-nm ...
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Direct observation of ultrafast long-range charge separation at polymer-fullerene heterojunctions
(2014)In polymeric semiconductors, charge carriers are polarons, which means that the excess charge deforms the molecular structure of the polymer chain that hosts it. This results in distinctive signatures in the vibrational ...
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Effects of the CePO 4 on the oxygen storage and release properties of CeO 2 and Ce 0.8Zr 0.2O 2 solid solution
(2004)In an attempt to gain fundamental information about the role of P on the chemical deactivation of a three-way catalyst (TWC), P was deliberatively incorporated in CeO 2 and Ce 0.8Zr 0.2O 2 solid solution. XRD, Raman, XPS, ...
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Intermolecular hydrogen bonding in chlorine dioxide photochemistry: A time-resolved resonance Raman study
(2001)The geminate-recombination and vibrational-relaxation dynamics of chlorine dioxide (OClO) dissolved in ethanol and 2,2,2-trifluoroethanol (TFE) are investigated using time-resolved resonance Raman spectroscopy. Stokes ...
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Investigating the phase-dependent photochemical reaction dynamics of chlorine dioxide using resonance Raman spectroscopy
(2002)Recent progress in understanding the phase-dependent reactivity demonstrated by halooxides is outlined. Specifically, resonance Raman intensity analysis (RRIA) and time-resolved resonance Raman (TRRR) studies of chlorine ...
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New antimony(III) halide complexes with dithiocarbamate ligands derived from thiuram degradation: The effect of the molecule's close contacts on in vitro cytotoxic activity
(2016)Antimony(III) halide complexes of the formulae {[SbBr(Me2DTC)2]n} (1), {[SbI(Me2DTC)2]n} (2) and {[(Me2DTC)2Sb(μ2-I)Sb(Me2DTC)2]+.I3-} (3) (Me2DTC = dimethyldithiocarbomate) were synthesized from SbX3, (X = Br or I) and ...
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Article
Nitric oxide activation and reduction by heme-copper oxidoreductases and nitric oxide reductase
(2008)The understanding of the dynamics and conformational control involved in the interplay between structure and function of nitric oxide reductase (Nor) and heme-copper oxidoreductases in their function to convert nitric oxide ...
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Nitric-oxide reductase: Structure and properties of the catalytic site from resonance Raman scattering
(2002)We have applied resonance Raman spectroscopy to investigate the properties of the dinuclear center of oxidized, reduced, and NO-bound nitric-oxide reductase from Paracoccus denitrificans. The spectra of the oxidized enzyme ...
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Nitrite coordination in myoglobin
(2017)The coordination of nitrite in myoglobin (Mb) has been characterized by resonance Raman spectroscopy and the frequencies of the nitrite bound to the heme Fe as well to the 2-vinyl have been computed by density functional ...
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The origin of the Fe IV = O intermediates in cytochrome aa 3 oxidase
(2012)The dioxygen reduction mechanism in cytochrome oxidases relies on proton control of the electron transfer events that drive the process. Proton delivery and proton channels in the protein that are relevant to substrate ...
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Probing nitrite coordination in horseradish peroxidase by resonance Raman spectroscopy: Detection of two binding sites
(2017)Nitrite is a powerful oxidant that affects the activity of peroxidases towards various substrates and leads to heme macrocycle modifications in members of the peroxidase family, such as the horseradish peroxidase (HRP). ...
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Probing the nitrite and nitric oxide reductase activity of cbb3 oxidase: Resonance Raman detection of a six-coordinate ferrous heme-nitrosyl species in the binuclear b3/CuB center
(2015)In this work we report the first spectroscopic evidence demonstrating that cbb3 oxidase catalyzes the reduction of nitrite to nitrous oxide under reducing anaerobic conditions. The reaction proceeds through the formation ...
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The protein effect in the structure of two ferryl-oxo intermediates at the same oxidation level in the heme copper binuclear center of cytochrome c oxidase
(2013)Identification of the intermediates and determination of their structures in the reduction of dioxygen to water by cytochrome c oxidase (CcO) are particularly important to understanding both O2 activation and proton pumping ...
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Resonance Raman detection of a ferrous five-coordinate nitrosylheme b3 complex in cytochrome cbb3 oxidase from Pseudomonas stutzeri
(2002)Understanding the chemical nature of the nitric oxide (NO) moiety of nitrosylheme copper oxidases is crucial for elucidation of the NO activation process. In the present work, direct resonance Raman spectroscopic observation ...
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Resonance Raman detection of the Fe2+-C-N modes in heme-copper oxidases: A probe of the active site
(2004)Resonance Raman spectroscopy has been employed to investigate the reduced cyano complexes of cytochrome aa3 from bovine heart and Rhodobacter sphaeroides and of cytochrome bo3 from E. coli. In the aa 3-type oxidases, the ...
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Resonance Raman detection of the myoglobin nitrito heme Fe-O-N=O/2-nitrovinyl species: Implications for helix E-helix F interactions
(2015)The description of biological activity in heme proteins responsible for activating small molecules requires identification of ligand movement into the metal and non-metal binding sites. Mechanisms of nitrite reductase ...
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The role of the cross-link His-Tyr in the functional properties of the binuclear center in cytochrome c oxidase
(2002)Resonance Raman and Fourier transform infrared spectroscopies have been used to study the aa3-type cytochrome c oxidase and the Y280H mutant from Paracoccus denitrificans. The stability of the binuclear center in the absence ...