TY - JOUR
T1 - Redox couples of inducible nitric oxide synthase
AU - Udit, Andrew K.
AU - Belliston-Bittner, Wendy
AU - Glazer, Edith C.
AU - Le Nguyen, Yen Hoang
AU - Gillan, James M.
AU - Hill, Michael G.
AU - Marletta, Michael A.
AU - Goodin, David B.
AU - Gray, Harry B.
PY - 2005/8/17
Y1 - 2005/8/17
N2 - We report direct electrochemistry of the iNOS heme domain in a DDAB film on the surface of a basal plane graphite electrode. Cyclic voltammetry reveals FeIII/II and FeII/I couples at -191 and -1049 mV (vs Ag/AgCl). Imidazole and carbon monoxide in solution shift the FeIII/II potential by +20 and +62 mV, while the addition of dioxygen results in large catalytic waves at the onset of FeIII reduction. Voltammetry at higher scan rates (with pH variations) reveals that the FeIII/II cathodic peak can be resolved into two components, which are attributable to FeIII/II couples of five- and six-coordinate hemes. Digital simulation of our experimental data implicates water dissociation from the heme as a gating mechanism for ET in iNOS.
AB - We report direct electrochemistry of the iNOS heme domain in a DDAB film on the surface of a basal plane graphite electrode. Cyclic voltammetry reveals FeIII/II and FeII/I couples at -191 and -1049 mV (vs Ag/AgCl). Imidazole and carbon monoxide in solution shift the FeIII/II potential by +20 and +62 mV, while the addition of dioxygen results in large catalytic waves at the onset of FeIII reduction. Voltammetry at higher scan rates (with pH variations) reveals that the FeIII/II cathodic peak can be resolved into two components, which are attributable to FeIII/II couples of five- and six-coordinate hemes. Digital simulation of our experimental data implicates water dissociation from the heme as a gating mechanism for ET in iNOS.
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U2 - 10.1021/ja0520114
DO - 10.1021/ja0520114
M3 - Article
C2 - 16089428
AN - SCOPUS:23844434855
SN - 0002-7863
VL - 127
SP - 11212
EP - 11213
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 32
ER -