Fig. 4. (A) UV-vis spectra of the ferrous Adgb–CaM complex (5 μM in 100 mM phosphate buffer, pH 7.0) in reaction with sodium nitrite (10 mM). The absorbance difference between 386 nm and 423 nm versus time is shown as an inset, which was fitted to the double-exponential equation, with that of ferrous Adgb shown for comparison. (B) The plots of the rate constant (k1) versus the nitrite concentrations for Adgb in the absence and the presence of CaM, which were fitted to the Michaelis–Menten equation.
