In the reaction of aquacobalamin (aquaCbl) with chlorite, a stable species is detected and assigned as a Co(III)–chlorite complex, Co(III)–OClO − . Its UV–Vis spectrum is almost identical to that of aquaCbl, except for some minor differences at ~ 430 nm; cyanide can eliminate and prevent these changes. The 1 H-NMR spectra reveal strong influences of chlorite on the B2 and B4 protons of the cobalt-bound dimethyl benzimidazole l...

The ferryl state in globins has previously been reported to undergo a protonation event below pH 5, as assessed using pH jump experiments with stopped-flow UV–Vis spectroscopy. This protonation entails hypsochromic shifts in the α and β bands (~ 20 to 40 nm) and an ~ 10 nm reduction in the energy difference between these two bands. We now report that in Mb this event is also characterized by a hypsochromic shift in the Soret b...