Multiple time scales in pulse radiolysis. Application to bromide solutions and dipeptides

Hug, Gordon L.; Wang, Yicheng; Schöneich, Christian; Jiang, Peiyun; Fessenden, Richard W.

doi:10.1016/s0969-806x(98)00303-x

Cited by 126 publications

(114 citation statements)

References 21 publications

Supporting

Mentioning

112

Contrasting

Unclassified

Order By: Relevance

“…The analysis and detection systems have been described previously. [14] Radiolytic yields are given in SI units as mmol J…”

Section: Methodsmentioning

confidence: 99%

Conformational Influence on the Type of Stabilization of Sulfur Radical Cations in Cyclic Peptides

Hug¹,

Bobrowski²,

Pogocki³

et al. 2007

ChemPhysChem

Self Cite

View full text Add to dashboard Cite

The free-radical chemistry of two oxidized cyclic dipeptides is investigated using time-resolved optical and conductivity detection. Two cyclic dipeptides, cyclo-Gly-L-Met and cyclo-D-Met-L-Met, are synthesized and irradiated with nanosecond pulses of electrons, which initiate the oxidation of the methionine side chains with hydroxyl radicals from the radiolysis of water. The cyclic peptides are taken to be models for the interior of proteins where there are no terminal groups. This opens up the possibility that neighboring-group effects can be studied directly between the initially formed sulfur radical cations and the heteroatoms associated with the peptide bonds. Such complexation of the sulfur radical cations is observed with the amide nitrogen atoms. In addition, intermolecular stabilization with the unoxidized sulfur atoms on separate cyclic dipeptide molecules is observed. Little or no intramolecular stabilization by the unoxidized sulfur in the neighboring methionine occurs in cyclo-D-Met-L-Met, in contrast to the previously observed intramolecular sulfur stabilization of the sulfur radical cation in the isomer cyclo-L-Met-L-Met. This contrasting behavior is rationalized by conformational differences in the two isomers as seen through molecular-modeling simulations. The implications for the oxidation of the protein calmodulin, which contains multiple residues of methionine, are discussed as having analogous determining factors.

show abstract

“…The analysis and detection systems have been described previously. [14] Radiolytic yields are given in SI units as mmol J…”

Section: Methodsmentioning

confidence: 99%

Conformational Influence on the Type of Stabilization of Sulfur Radical Cations in Cyclic Peptides

Hug¹,

Bobrowski²,

Pogocki³

et al. 2007

ChemPhysChem

Self Cite

View full text Add to dashboard Cite

show abstract

“…Details of the linac, the spectrophotometric detection setup, and the computercontrolled data acquisition and detection systems are described elsewhere. 18 All measurements were performed at 20°C in a high-purity silica cell of 1 cm optical path length. The concentration of radicals generated was approximately 4.0 µM per pulse with a dose of about 7 Gy (700 rad) per pulse, as determined by the thiocyanate dosimeter.…”

Section: Methodsmentioning

confidence: 99%

Pulse Radiolysis of Aqueous Thiocyanate Solution

Milosavljevic

LaVerne

2004

J. Phys. Chem. A

View full text Add to dashboard Cite

The pulse radiolysis of N 2 O saturated aqueous solutions of KSCN was studied under neutral pH conditions. The observed optical absorption spectrum of the SCN • radical in solution is more complex than previously reported, but it is in good agreement with that measured in the gas phase. Kinetic traces at 330 and 472 nm corresponding to SCN • and (SCN) 2•-, respectively, were fit using a Monte Carlo simulation kinetic model. The rate coefficient for the oxidation of SCN -ions by OH radicals, an important reaction used in competition kinetics measurements, was found to be (1.4 ( 0.1) × 10 10 M -1 s -1 , about 30% higher than the normally accepted value. A detailed discussion of the reaction mechanism is presented.

show abstract

“…The instrument and computerized data collection for time-resolved UV-Vis spectroscopy and reaction kinetics have been described elsewhere [17,18]. Thiocyanate dosimetry was carried out at the beginning of each experimental session.…”

Section: Pulse Radiolysismentioning

confidence: 99%

“…Thiocyanate dosimetry was carried out at the beginning of each experimental session. Details of the dosimetry have been reported elsewhere [18,19]. The procedure is based on the concentration of ðSCNÞ ÅÀ 2 radicals generated by the electron pulse in a N 2 O-saturated 10 À2 M SCN À solution.…”

Section: Pulse Radiolysismentioning

confidence: 99%

On the mechanism of formation and spectral properties of radical anions generated by the reduction of –[ReI(CO)3(5-nitro-1,10-phenanthroline)]+ and –[ReI(CO)3(3,4,7,8-tetramethyl-1,10-phenanthroline)]+ pendants in poly-4-vinylpyridine polymers

Bracco¹,

Lezna²,

Zúñiga³

et al. 2011

Inorganica Chimica Acta

View full text Add to dashboard Cite

Multiple time scales in pulse radiolysis. Application to bromide solutions and dipeptides

Cited by 126 publications

References 21 publications

Conformational Influence on the Type of Stabilization of Sulfur Radical Cations in Cyclic Peptides

Conformational Influence on the Type of Stabilization of Sulfur Radical Cations in Cyclic Peptides

Pulse Radiolysis of Aqueous Thiocyanate Solution

On the mechanism of formation and spectral properties of radical anions generated by the reduction of –[ReI(CO)3(5-nitro-1,10-phenanthroline)]+ and –[ReI(CO)3(3,4,7,8-tetramethyl-1,10-phenanthroline)]+ pendants in poly-4-vinylpyridine polymers

Contact Info

Product

Resources

About