Polarographische Untersuchungen zur Bestimmung der Stabilität von Metall-Protein-Bindungen / Polarographic Investigations for the Determination of the Stability of Metal-Protein Bonds

Abstract

Bonds between metals (especially copper) and a protein fraction (18,100 g/mol) of a soya bean flour extract have been investigated. The binding capacity (304 nmol Cu/mg protein) and the binding stability (K = 1,046·103 in an ammonia buffer system) were determined by polarographic investigations. Changes in the polarogram caused by spiking the protein with metal ions were compared with effects in model substances. Cysteine, ethylenediamine, oxalic acid and derivatives of benzoic acid were used as chelating agents. The effects of functional groups on the metalprotein bonds were estimated by the determination of their different binding stabilities.