Cytochrome c: A Thermodynamic Study of Relationships among Oxidation State, Ion‐Binding and Structural Parameters: 2. Ion‐Binding Linked to Oxidation State

The specific binding of anions to oxidized horse‐heart cytochrome c has been studied by two methods: measuring the effect of ion concentration on the redox potential, and directly by gel nitration. The anions investigated were: chloride, phosphate, ADP and sulfanilate. The binding constants estimated are in the range of 1–10 mM⁻¹, and the number of sites per protein molecule are 1 to 2. The specificity of anion binding to the oxidized protein is demonstrated.