... & Antonini E (1968) The binding of carbon monoxide by human hemoglobin. Proof of valid-ity of the spectrophotometric method and direct determi-nation of the equilibrium. J Biol Chem, 243, ... University of Roma ‘Tor Vergata’, Italy4 Department of Molecular, Cellular and Animal Biology, University of Camerino, Italy5 Department of Structural and Functional Biology, and Center of Neuroscience, ... 104m)1Æs)1overthe pH range explored (Table 1). The y intercept of plots of kobsversus [NO] corresponded to koff; thevalues of koffranged between 1.9 · 10)1and 4.8 ·10)1s)1(Table 1)....