Fig. 3
From: Towards the understanding of the enzymatic cleavage of polyisoprene by the dihaem-dioxygenase RoxA
UV–vis spectra of RoxA variants in the presence of NO. The original spectra (black) of RoxAWt (a), RoxA F317Y (b) and (ferricyanide-)reoxidised RoxA-Wt (c) are compared with the spectra in NO-saturated buffer (red); the difference spectra (RoxA + NO minus RoxA) are shown in blue. The (fully oxidised) preparation in b, c show basically identical difference maxima while RoxA-Wt as isolated results in slightly distinct difference maxima caused by the presence of the oxygenated haem. d A direct comparison of the UV–vis Q-band region of all three preparations in presence of NO visualises their identity, however, suggesting that also the ferrous–O2-haem of RoxA as isolated (red) reacts to the same ferric NO-species as in oxidised RoxA-Wt (purple) and RoxA-F317 (green)