Chemical and Biological Properties of α-Dicarbonyls Calorimetric Determination of the Micro Ioniztion Constants of Glutathione

摘要

The enthalpy changes for Ionization of the four acidic protons of glutathione were measured calorimetrically, from both directions, using NaOH and KC104 as titrates. For the 3rd and 4th proton ionizations, ΔH - 7.56 and 8.33 Kcal/mole, respectively. These are composite values for the overlapping Ionizations of the SH and NH3 groups of glutathione. The micro-constants for ionization of the SH and NH3+ groups were determined by resolving the composite enthalpy changes into the fractions proceeding by the sulfhydryl and amino routes.