A study of some solution equilibria of biological significance

Abstract

The stability constants of some lead(II)-ligand anion complexes already measured have been recalculated and others of some lead(II) and zinc(II) complexes have been measured by glass and chloride electrode potentiometry. These constants have been used in computer models of biological systems in order to assess the suitability of current and proposed therapeuticals as lead(II) sequestering agents in vivo. Glutathione is proposed as the most promising ligand for the treatment of plumbism. Thermodynamic functions for some lead(II)-ligand anion complexes have been determined, by calorimetry and temperature variation of formation constants, and from these some complex structures in aqueous solution have been suggested. The interaction of bovine serum albumin with lead(II) and copper(II) has been studied potentiometrically. The effect of some antirheumatoid arthritis drugs on the copper(II)-bovine serum albumin interaction has been observed by visible spectroscopy and molecular filtration. It is concluded that some of these drugs have the ability to release copper(II) from this protein bound situation. A contribution has been made to an interlaboratory potentiometric study of the nickel(II)-glycinate complexing system and a comparison of results from several laboratories is presented.