Reversible reaction of 5,5'-dithiobis(2-nitrobenzoate) with the CysF9[93]beta sulfhydryl groups of the hemoglobins of the domestic cat: variation of the equilibrium and reverse rate constants with pH.

We have determined for the first time the equilibrium constant, Keq, for the reaction of Ellman's reagent, 5,5'-dithiobis(2-nitrobenzoate), with the CysF9[93]beta sulfhydryl groups of the hemoglobins of the domestic cat. In the pH range 5.6 to 9.