Thermodynamics of Metalloprotein Combinations: Buffer Effects in Copper-Albumin Complexes.

摘要

Quantitative studies have been made recently of the extent of binding of cupric ions by crystallized bovine albumin (3) at pH's below 5 as well as of the optical properties of copper-albumin complexes (4). These investigations have indicated that in the pH region near 5, copper is bound primarily by the free carboxyl residues of this protein. Corresponding studies with amino acids and peptides have demonstrated that the nature of their complexes with cupric ion may change with pH and that the contribution of amine group interaction to the stabilization of the metal complex becomes increasingly important with increasing pH. For a fuller understanding of the nature of copper proteins at pH's of physiological importance, it has seemed appropriate to extend earlier studies to higher pH's. Detailed results on the effect of buffer and of temperature at a pH of 6.5 are described in this report.