Kinetics and energetics of one-electron-transfer reactions involving tryptophan neutral and cation radicals

Journal Article · Wed Jan 23 23:00:00 EST 1991 · Journal of Physical Chemistry; (USA)

DOI:https://doi.org/10.1021/j100155a035· OSTI ID:5923296

Simic, M G ^[1]

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1. National Institute of Standards and Technology, Gaithersburg, MD (USA)

Reversible one-electron-transfer reactions involving the tryptophan cation and neutral radicals were investigated by pulse radiolysis. The one-electron-reduction potential of the neutral tryptophan radical at pH 7 was determined to be E{sub 7} = 1.01 {plus minus} 0.03 V by using the bis(1,4,7-triazacyclononane)nickel(III/II) redox couple with E = 0.95 V as a standard. The value obtained with promethazine (E = 0.89 V) as a standard at pH 6 was E{sub 6} = 1.11 V. From these measurements, a mean value E{sub 7} = 1.03 V results, in agreement with some earlier determinations (1.05 and 1.08 V) obtained in experiments with inorganic redox standards. The kinetics and energetics of the reactions of the tryptophan neutral and cation radicals with selected electron donors were also investigated.

• OSTI ID: 5923296
• Journal Information: Journal of Physical Chemistry; (USA), Journal Name: Journal of Physical Chemistry; (USA) Vol. 95:2; ISSN 0022-3654; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
400600 -- Radiation Chemistry
550200* -- Biochemistry
59 BASIC BIOLOGICAL SCIENCES
ACTIVATION ENERGY
AMINO ACIDS
AROMATICS
AZAARENES
AZOLES
CARBOXYLIC ACIDS
CHEMICAL RADIATION EFFECTS
CHEMICAL REACTIONS
CHEMISTRY
DATA
DECOMPOSITION
ELECTRON TRANSFER
ENERGY
ENERGY RANGE
EXPERIMENTAL DATA
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
INDOLES
INFORMATION
MEV RANGE
MEV RANGE 01-10
NUMERICAL DATA
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXIDATION
PH VALUE
PYRROLES
RADIATION CHEMISTRY
RADIATION EFFECTS
RADICALS
RADIOLYSIS
TRYPTOPHAN