Pulse radiolysis studies. IX. Reactions of the ozonide ion in aqueous solution

Felix, W.D.; Gall, B.L.; Dorfman, Leon M.

doi:10.1021/j100861a027

Cited by 64 publications

(24 citation statements)

References 5 publications

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“…Pulse radiolysis experiments were performed in the linear accelerator facility of The Ohio State University (Felix et al, 1967). The primary radicals were produced with a short pulse (0.1-0.5 p s ) of 3.5-MeV electrons impinging on an aqueous protein solution.…”

Section: Methodsmentioning

confidence: 99%

Intramolecular electron and proton transfer in proteins: formate (CO2-) reduction of riboflavin binding protein and ribonuclease A

Faraggi¹,

Steiner²,

Klapper³

1985

Biochemistry

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The formate radical (CO2-) reacts with ribonuclease A to form the cystine disulfide radical as one of the products. CO2- reacts with the riboflavin binding protein of chicken egg white with the ultimate product being the neutral flavin semiquinone. Formation of the disulfide radical in ribonuclease is slower than the reaction between protein and CO2-; formation of the flavin semiquinone in the riboflavin binding protein is slower than the protein-CO2- reaction. We conclude for both proteins that CO2- must reduce an as yet unidentified group or groups, which in turn reduce(s) the disulfide of RNase or the flavin of riboflavin binding protein. This conclusion is supported in the case of ribonuclease by the observation of a transient, broad absorption band centered between 350 and 370 nm. The CO2--initiated reductions of the disulfide in ribonuclease and the flavin in the riboflavin binding protein are mixed first- and second-order processes. We propose that the transfer of an electron from the unknown intermediate(s) to the final product involves both inter- and intramolecular paths between groups that may not be in van der Waals contact. With the hydrated electron, in contrast to CO2-, as reductant of the riboflavin binding protein, the anionic semiquinone is observed as an intermediate. The anionic semiquinone is then rapidly protonated, yielding the stable neutral semiquinone. From the reaction kinetics and protein concentration dependence, we conclude that a group or groups on the protein donate(s) a proton to the anionic semiquinone by both inter- and intramolecular paths.

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Section: Methodsmentioning

confidence: 99%

Intramolecular electron and proton transfer in proteins: formate (CO2-) reduction of riboflavin binding protein and ribonuclease A

Faraggi¹,

Steiner²,

Klapper³

1985

Biochemistry

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“…The details of the apparati~s have been described earlier (14). Pulse widths ranged from 10 to 1200 ns with a dose rate of about 10" rad s -' .…”

Section: Methodsmentioning

confidence: 99%

Spectrum, Kinetics, and Radiation Chemical Yield of Solvated Electrons in Hexamethylphosphoric Triamide

Shaede¹,

Dorfman²,

Flynn³

et al. 1973

Can. J. Chem.

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The spectrum, yield, and kinetics of solvated electrons in hexamethylphosphoric triamide were investigated by the pulse radiolysis method. The optical absorption band is in the infrared with a maximum at 2200 + 100 nm. The molar absorptivity at this maximum is (3.2 + 0.5) x 10"M-' cm-', and the oscillator strength for the transition is estimated to be f = 0.7 t 0.2. A free ion yield of G(e,-) = 2.3 + 0.4 solvated electrons/100 eV was determined from the observed yields of anthracene and pyrene radical anions formed by electron attachment.Kinetic studies provided values of the rate constants for the reaction of solvated electrons with anthracene and NZO. The decay mechanism of the solvated electrons in the absence of added solutes was found to be complex, and the half-life (in the range of 2 to 50 ps) was dependent on experimental conditions. A second transient species, absorbing at wavelengths below 500 nrn, was observed but not identified. In solutions containing bromide ion the species Br,-was observed. The pulse radiolysis of stable solutions of es-, formed by dissolving sodium metal in HMPA, is also reported. 500 nm, a Cte observee mais n'a pu ttre identifiee. Dans des solutions contenant I'ion bromure, on a observe la presence de I'espece Br,-. On discute aussi de la radiolyse par pulsations des solutions stables de e,-, formees par dissolution de sodium mktallique dans du HMPA.[Traduit par le journal]Can. J. Chem., 51,3905 (1973)

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“…The list, nonstandard, is principally based on the critical review of Elliot [14], completed by twenty or so contributions [16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35]. Within this comprehensive list, some crossed reactions or feed-back reactions hold the attention in consideration of their regulating role towards radiolysis.…”

Section: Reactionsmentioning

confidence: 99%