TY - JOUR
T1 - Inhibition of cyclooxygenase mediated by electrochemical oxidation of gentisic acid
AU - Holmes, T. J.
AU - Vennerstrom, J. L.
AU - John, V.
N1 - Copyright:
Copyright 2004 Elsevier B.V., All rights reserved.
PY - 1985
Y1 - 1985
N2 - Prostaglandin synthase (EC 1.14.99.1, 8,11,14-eicosatrienoate, hydrogen-donor:oxygen oxidoreductase), commonly referred to as cyclooxygenase, was inhibited irreversibly upon application of a fixed oxidative potential (+0.4 V versus saturated calomel electrode) in the presence of the aspirin metabolite gentisic acid (2,5-dihydroxybenzoic acid). Electrolyses were carried out at 0°C in a phosphate buffer solution (pH 7.2, 0.1 M) using a carbon felt electrode. This electroin activation process was time-dependent and pseudeo first-order with respect to gentisic acid at concentrations up to 300 μM. These concentrations of gentisic acid are below those normally reported to be inhibitory. The enzyme was stable to this applied potential in the absence of gentisic acid. Similar treatment of apoenzyme (heme-removed) revealed no loss in catalytic activity after reconstitution to the holoenzyme. Oxyphenbutazone, a nonoxidizable competitive inhibitor of cyclooxygenase, was observed to protect the enzyme from electrolytic inactivation mediated by gentisc acid. Radiolabeling studies indicated the covalent attachment of approximately 1 eq of gentisic acid/subunit of enzyme. These studies support the possible role of quinonoid intermediates in the observed anti-inflammatory action of salicylate derivatives.
AB - Prostaglandin synthase (EC 1.14.99.1, 8,11,14-eicosatrienoate, hydrogen-donor:oxygen oxidoreductase), commonly referred to as cyclooxygenase, was inhibited irreversibly upon application of a fixed oxidative potential (+0.4 V versus saturated calomel electrode) in the presence of the aspirin metabolite gentisic acid (2,5-dihydroxybenzoic acid). Electrolyses were carried out at 0°C in a phosphate buffer solution (pH 7.2, 0.1 M) using a carbon felt electrode. This electroin activation process was time-dependent and pseudeo first-order with respect to gentisic acid at concentrations up to 300 μM. These concentrations of gentisic acid are below those normally reported to be inhibitory. The enzyme was stable to this applied potential in the absence of gentisic acid. Similar treatment of apoenzyme (heme-removed) revealed no loss in catalytic activity after reconstitution to the holoenzyme. Oxyphenbutazone, a nonoxidizable competitive inhibitor of cyclooxygenase, was observed to protect the enzyme from electrolytic inactivation mediated by gentisc acid. Radiolabeling studies indicated the covalent attachment of approximately 1 eq of gentisic acid/subunit of enzyme. These studies support the possible role of quinonoid intermediates in the observed anti-inflammatory action of salicylate derivatives.
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M3 - Article
C2 - 3932349
AN - SCOPUS:0022382881
SN - 0021-9258
VL - 260
SP - 14092
EP - 14095
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 26
ER -