A5012942751- Electron Spin Resonance Studies
- Photosynthetic Processes and Mechanisms
- Hemoglobin structure and function
- Spectroscopy and Quantum Chemical Studies
- Porphyrin and Phthalocyanine Chemistry
- Metal-Catalyzed Oxygenation Mechanisms
- Advanced NMR Techniques and Applications
- DNA and Nucleic Acid Chemistry
- Electrochemical Analysis and Applications
- Photoreceptor and optogenetics research
- Metalloenzymes and iron-sulfur proteins
- Molecular Junctions and Nanostructures
- Photochemistry and Electron Transfer Studies
- Metal complexes synthesis and properties
- Lanthanide and Transition Metal Complexes
- Protein Structure and Dynamics
- DNA Repair Mechanisms
- Magnetism in coordination complexes
- Neonatal Health and Biochemistry
- Mitochondrial Function and Pathology
- Various Chemistry Research Topics
- Microbial Fuel Cells and Bioremediation
- Free Radicals and Antioxidants
- Advanced biosensing and bioanalysis techniques
- Mass Spectrometry Techniques and Applications
University at Albany, State University of New York
2005-2017
Albany Research Institute
2017
Albany State University
1996-2015
Institut de Biologie et Technologies
2009
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2009
CEA Paris-Saclay
2009
Centre National de la Recherche Scientifique
2009
University of New Mexico
2009
Kyushu University
2009
University of Cyprus
2009
Abstract The delivery of therapeutic compounds to target tissues is a central challenge in treating disease. Externally controlled drug release systems hold potential selectively enhance localized delivery. Here we describe liposomes doped with porphyrin–phospholipid that are permeabilized directly by near-infrared light. Molecular dynamics simulations identified novel light-absorbing monomer esterified from clinically approved components predicted and experimentally demonstrated give rise...
Elemental analyses, Mössbauer, and EPR data are reported to show that endonuclease III of Escherichia coli is an iron-sulfur protein. Mössbauer spectra protein freshly prepared from E. grown on 57Fe-enriched medium demonstrate the native enzyme contains a single 4Fe-4S cluster in 2+ oxidation state, with net spin zero. Upon treatment ferricyanide, fraction (less than 25%) clusters oxidized into state which yields spectrum near g = 2.01 typical 3Fe-4S cluster. The magnetic field dependence...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCoordination compounds of polyoxovanadates with a hexametalate core. Chemical and structural characterization [VV6O13[(OCH2)3CR]2]2-, [VV6O11(OH)2[(OCH2)3CR]2], [VIV4VV2O9(OH)4[(OCH2)3CR]2]2-, [VIV6O7(OH)6](OCH2)3CR]2]2-Qin Chen, David P. Goshorn, Charles Scholes, Xiao Ling Tan, Jon ZubietaCite this: J. Am. Chem. Soc. 1992, 114, 12, 4667–4681Publication Date (Print):June 1, 1992Publication History Published online1 May 2002Published inissue 1 June...
The isolation and purification of yeast cytochrome c oxidase is described. Characterization the purified protein indicates that it spectroscopically identical with isolated from beef heart. Preparations isotopically substituted are obtained incorporating [1,3-15N2]histidine or [beta,beta-2H2]cysteine. Electron paramagnetic resonance electron nuclear double spectra proteins identify unambiguously at least 1 cysteine histidine as ligands to CuA suggest substantial spin density delocalized onto...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTElectron nuclear double resonance (ENDOR) from heme and histidine nitrogens in single crystals of aquometmyoglobinCharles P. Scholes, Aviva Lapidot, Rita Mascarenhas, Toshiro Inubushi, Roger A. Isaacson, George FeherCite this: J. Am. Chem. Soc. 1982, 104, 10, 2724–2735Publication Date (Print):May 1, 1982Publication History Published online1 May 2002Published inissue 1 1982https://doi.org/10.1021/ja00374a007RIGHTS & PERMISSIONSArticle...
A combination of spectroscopy and DFT calculations has been used to define the geometric electronic structure nitrite bound type 2 (T2) copper site at high low pH in reductase from Rhodobacter sphaeroides. At there is no electron transfer reduced 1 (T1) T2 copper, while protonation triggers T1 → generation NO. The calculated reaction coordinate for N−O bond cleavage reduction by suggests that process best described as proton triggering transfer. Bidentate binding play a major role activating...
The reaction of ferric cytochrome c peroxidase (CcP) from Saccharomyces cerevisiae with peroxide produces compound I, characterized by both an oxyferryl iron center and a protein-based free radical. electron paramagnetic resonance (EPR) signal the CcP I radical can be resolved into broad majority component which accounts for approximately 90% spin intensity narrow minority 10% integrated [Hori, H., & Yonetani, T. (1985) J. Biol. Chem. 260, 3549-3555]. It was shown previously that is...
The synthesis of efficient water-oxidation catalysts demands insight into the only known, naturally occurring catalyst, oxygen-evolving complex (OEC) photosystem II (PSII). Understanding water oxidation mechanism requires knowledge where and when substrate binds to OEC. Mn catalase in its Mn(III)–Mn(IV) state is a protein model OEC's S2 state. From 17O-labeled exchanged di-μ-oxo di-Mn(III,IV) coordination sphere catalase, CW Q-band ENDOR spectroscopy revealed two distinctly different 17O...
Using low frequency 2 to 4 GHz EPR at 10 K, we have resolved previously unseen hyperfine structure associated with the EPR-detectable copper signal of cytochrome c oxidase. The observed appears consistent coupling copper; although account for all structure, an additional magnetic interaction is required as well. This work points out utility technique resolving electronic structural information from and possibly other paramagnetic sites in biomolecules when random variation g values a cause...
We report the development of a high-yield heterologous expression system for copper-containing nitrite reductase from denitrifying variant Rhodobacter sphaeroides. Typical yields wild-type protein are 20 mg L-1, which can be fully loaded with copper. Nitrite contains an unusual blue-green Type 1 copper center redox/electron transfer function and nearby 2 where binds is reduced to nitric oxide. The enzyme was characterized by: (1) its optical spectrum; (2) EPR spectrum showing rhombic...
A combination of spectroscopies and density functional theory calculations indicate that there are large temperature-dependent absorption spectral changes present in green nitrite reductases (NiRs) due to a thermodynamic equilibrium between blue type 1 (T1) copper site. The axial methionine (Met) ligand is unconstrained the oxidized NiRs, which results an enthalpically favored (Δ H ≈4.6 kcal/mol) Met-bound site at low temperatures, entropically ( T Δ S ≈4.5 kcal/mol, room temperature)...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTElectron nuclear double resonance from high- and low-spin ferric hemoglobins myoglobinsC. F. Mulks, C. P. Scholes, L. Dickinson, A. LapidotCite this: J. Am. Chem. Soc. 1979, 101, 7, 1645–1654Publication Date (Print):March 1, 1979Publication History Published online1 May 2002Published inissue 1 March 1979https://pubs.acs.org/doi/10.1021/ja00501a001https://doi.org/10.1021/ja00501a001research-articleACS PublicationsRequest reuse permissionsArticle...
Na+-NQR is the entry point for electrons into respiratory chain of Vibrio cholerae. It oxidizes NADH, reduces ubiquinone, and uses free energy this redox reaction to translocate sodium across cell membrane. The enzyme a membrane complex six subunits that accommodates 2Fe−2S center several flavins. Both oxidized reduced forms exhibit radical EPR signal. Here, we present ENDOR data demonstrate that, in both enzyme, flavin semiquinone. In neutral flavin, but an anionic where N(5) deprotonated....
Abstract EPR, ENDOR and pulsed EPR were applied to the radical signals of yeast cytochrome c peroxidase‐compound I from this protein expressed in E. coli two variants prepared after site‐directed mutagenesis. The compound complexes studied first, that parent peroxidase , next, those following amino acid mutants as specific probes for I: 1. Tryptophan‐51 → Phenylalanine; 2. Tryptophan‐191 Phenylalanine. lies near heme on distal (H 2 O ‐binding) side peroxidase, while contact with proximal...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTElectron nuclear double resonance (ENDOR) of bis(imidazole) ligated low-spin ferric heme systemsCharles P. Scholes, Krzystof M. Falkowski, Shirley. Chen, and Janet. BankCite this: J. Am. Chem. Soc. 1986, 108, 7, 1660–1671Publication Date (Print):April 1, 1986Publication History Published online1 May 2002Published inissue 1 April 1986https://pubs.acs.org/doi/10.1021/ja00267a041https://doi.org/10.1021/ja00267a041research-articleACS...
Electron nuclear double resonance (ENDOR) of protons at Type 2 and 1 cupric active sites correlates with the enzymatic pH dependence, mutation nearby conserved, nonligating residues, electron transfer in heterologously expressed Rhodobacter sphaeroides nitrite reductase. Wild-type enzyme showed a 6 activity maximum but no kinetic deuterium isotope effect, suggesting are not transferred rate-limiting step reduction. However, protonatable Asp129 His287, both located near center, modulated...
The resolution of new features in the 1H electron nuclear double resonance (ENDOR) spectrum oxidized CuA site beef heart cytochrome c oxidase is presented. In a previous study, we assigned resonances ENDOR to hyperfine interactions methylene protons on one or two cysteine ligands (Stevens, T.H., Martin, C.T., Wang, H., Brudvig, G.W., Scholes, C.P., and Chan, S.I. (1982) J. Biol. Chem. 257, 12106-12113). this work, reported can be either anisotropy previously resolved proton interaction (Aiso...
The techniques of EPR and electron nuclear double resonance (ENDOR) were used to probe structure electronic distribution at the nitric oxide (NO)-ligated heme alpha 3 in nitrosylferrocytochrome moiety fully reduced cytochrome c oxidase. Hyperfine quadrupole couplings NO (in both 15NO 14NO forms), histidine nitrogens, protons near site obtained. Parallel studies also performed on NO-ligated myoglobin model NO-heme-imidazole systems. major findings interpretations were: 1) compared other...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTElectron nuclear double resonance of ferric cytochrome P450CAMRussell LoBrutto, Charles P. Scholes, Gerald C. Wagner, I. Gunsalus, and Peter G. DebrunnerCite this: J. Am. Chem. Soc. 1980, 102, 3, 1167–1170Publication Date (Print):January 1, 1980Publication History Published online1 May 2002Published inissue 1 January 1980https://pubs.acs.org/doi/10.1021/ja00523a046https://doi.org/10.1021/ja00523a046research-articleACS PublicationsRequest reuse...