Influence of serum albumins on decomposition rates of para-substituted 1-phenyl-3-methyltriazenes and 5-(3-methyl-1-triazeno)imidazole-4-carboxamide in near physiological conditions.

The influence of human serum albumin on the decomposition rates of some arylmonomethyltriazenes in buffered aqueous solution was investigated. From the experimental data, a model for the triazene-albumin interaction was derived, and the thermodynamic parameters were systematically calculated by two independent methods. The results show marked dependence of the energetics of binding on the substituent in the triazene aromatic ring. For most of the triazenes studied, the binding with albumin was mainly enthalpy driven. Measurements also were performed using bovine and murine serum albumins.