NEW APPROACH TO THE THERMODYNAMIC STUDY OF ABO ANTIBODIES

  • 1 January 1979
    • journal article
    • research article
    • Vol. 37  (3) , 547-553
Abstract
Enthalpy change was determined for natural anti-A (B and O subjects) and anti-B (A1, A2 and O subjects). Entropy change, free energy change and association constant were calculated according to the law of mass action and the Wurmser method. The concentrations of allohemagglutinins were measured by the Wilkie and Becker method using an autoanalyzer. 2-Mercaptoethanol was used to estimate the proportions of Ig[immunoglobulin]G and IgM and their respective contribution to the thermodynamic properties. Individual enthalpy and entropy changes were different for each subject so that only the average values of these thermodynamic parameters represented a characteristic of the phenotype. There was a correlation between enthalpy and entropy changes and the relative proportion of anti-A or anti-B IgG. There was heterogeneity of the values of association constant. Free energy change was about 10 kcal mol-1 for all anti-A and anti-B. The low energy binding between antigen and antibody was confirmed. The role of environment and red-cell phenotype in the synthesis of allohemagglutinins was confirmed.