TY - JOUR
T1 - Electron spin resonance spin-trapping detection of superoxide generated by neuronal nitric oxide synthase
AU - Vásquez-Vivar, Jeannette
AU - Martásek, Pavel
AU - Hogg, Neil
AU - Karoui, Hakim
AU - Masters, Bettie Sue Siler
AU - Pritchard, Kirkwood A.
AU - Kalyanaraman, B.
N1 - Copyright:
Copyright 2021 Elsevier B.V., All rights reserved.
PY - 1999
Y1 - 1999
N2 - NOS is a ubiquitous enzyme that has an oxygenase and reductase activity. NOS reduces electron acceptors, at the reductase domain, by a one-electron mechanism that is not inhibited by SOD. One example of this activity is the direct reduction of ferricytochrome c by nNOS. Redox cycling electron acceptors (EA in Scheme 1), such as lucigenin and NBT, are reduced by NOS to generate an intermediate radical (EA(red)). This radical can then be reoxidized to the parent compound by oxygen, and in the process generate superoxide. Consequently, both NBT and lucigenin will enhance NADPH-dependent superoxide generation in the presence of flavoprotein reductases such as NOS. The artificial generation of superoxide from lucigenin and NBT is a major pitfall in the use of these compounds as superoxide probes. We conclude that the use of ESR spin-trapping techniques, although not free of problems, is a viable technique for the detection and quantification of superoxide in systems containing nNOS.
AB - NOS is a ubiquitous enzyme that has an oxygenase and reductase activity. NOS reduces electron acceptors, at the reductase domain, by a one-electron mechanism that is not inhibited by SOD. One example of this activity is the direct reduction of ferricytochrome c by nNOS. Redox cycling electron acceptors (EA in Scheme 1), such as lucigenin and NBT, are reduced by NOS to generate an intermediate radical (EA(red)). This radical can then be reoxidized to the parent compound by oxygen, and in the process generate superoxide. Consequently, both NBT and lucigenin will enhance NADPH-dependent superoxide generation in the presence of flavoprotein reductases such as NOS. The artificial generation of superoxide from lucigenin and NBT is a major pitfall in the use of these compounds as superoxide probes. We conclude that the use of ESR spin-trapping techniques, although not free of problems, is a viable technique for the detection and quantification of superoxide in systems containing nNOS.
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U2 - 10.1016/S0076-6879(99)01080-0
DO - 10.1016/S0076-6879(99)01080-0
M3 - Article
C2 - 9919565
AN - SCOPUS:0031795460
VL - 301
SP - 169
EP - 177
JO - ImmunoMethods
JF - ImmunoMethods
SN - 0076-6879
ER -