A mechanistic study of the copper(II)-peptide-catalyzed superoxide dismutation. A pulse radiolysis study

Journal Article · Wed Aug 29 00:00:00 EDT 1990 · Journal of the American Chemical Society; (United States)

DOI:https://doi.org/10.1021/ja00174a006· OSTI ID:5452106

Goldstein, S; Czapski, G ^[1]; Meyerstein, D ^[2]

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1. Hebrew Univ. of Jerusalem (Israel)
2. Ben-Gurion Univ. of the Negev, Beer-Sheva (Israel)

The reactivity of O{sub 2}{sup {minus}} toward Cu(II)-peptides containing glycine and histidine for which E{degree}{sub Cu(III)/Cu(II)} {<=} 1.08 V was investigated by the pulse radiolysis technique. It has been found that the ability of the various complexes to catalyze O{sub 2}{sup {minus}} dismutation depends inversely on the redox potential of the couple Cu(III)/Cu(II). The Cu(II)-peptides containing histidine, which have higher redox potentials than that of the couple O{sub 2}{sup {minus}}/H{sub 2}O{sub 2}, do not catalyze the reaction at all. Although no direct evidence was found for the formation of Cu(III)-peptide, the results suggest that the mechanism of the catalysis of O{sub 2}{sup {minus}} dismutation proceeds via alternate oxidation and reduction of the metal by O{sub 2}{sup {minus}}. Furthermore, this mechanism is supported by indirect observations, which are discussed in detail.

• OSTI ID: 5452106
• Journal Information: Journal of the American Chemical Society; (United States), Vol. 112:18; ISSN 0002-7863
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
SUPEROXIDE RADICALS
CHEMICAL REACTIONS
COPPER COMPLEXES
METALLOPROTEINS
PEPTIDES
RADIOLYSIS
SENSITIVITY
SUPEROXIDE DISMUTASE
CHEMICAL RADIATION EFFECTS
COMPLEXES
DECOMPOSITION
ENZYMES
ORGANIC COMPOUNDS
OXIDOREDUCTASES
PROTEINS
RADIATION EFFECTS
RADICALS
TRANSITION ELEMENT COMPLEXES
550200* - Biochemistry
560120 - Radiation Effects on Biochemicals
Cells
&amp; Tissue Culture