Enzymatic function of hemoglobin
as a nitrite reductase that produces
NO under allosteric control
J. Clin. Invest. Zhi Huang, et al. 115:2099 doi:10.1172/JCI24650 [
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Figure 4Maximal rates for nitrite reduction to NO occurs around the Hb P
50. (
A) The negative of the change in deoxyheme concentration (obtained by spectral deconvolution) over time during the reaction of nitrite (10 mM) with partially oxygenated (0–40%) Hb (50 μM total heme). (
B) Instantaneous rate of deoxyheme consumption over the course of the experiment described in
A. (
C) Initial rate (intercept of the polynomial fitting in
B at 0 seconds) of reaction for the conditions described above plotted as a function of initial oxygen saturation. (
D) The instantaneous rate of deoxyheme consumption versus fraction ligated or oxidized ferric hemes (relative to total heme: deoxy-, met-, and iron-nitrosyl-Hb) during the course of the anaerobic reaction of nitrite (10 mM) with deoxyheme (50 μM).
