The Carrier Ampholytes, Ionic Strength and Influence on Solubility of Proteins

THE CARRIER AMPHOLYTES, IONIC STRENGTH AND INFLUENCE ON SOLUBILITY OF PROTEINS 

The concept of ionic strength was devised by Debye and Hiickel (47) in order to describe the electric double layer and the general structure of the ionic cloud surrounding a dissolved particle. It is given by 

The ions under consideration are assumed to be freely moving and charges of opposite sign are assumed not to be separated. The concept is much used in connection with the electrophoresis of proteins. The solubility of proteins depends partly on the ionic conditions of the environment. In salt solutions these ionic conditions can be discussed satisfactorily with the ionic strength concept, but not in ampholyte solutions. In spite of the fact that the ionic strength is low, the carrier ampholytes at their isoelectric points contribute to the ionic cloud surrounding the dissolved protein molecules. Thus they also contribute to the solubility and stability conditions of the protein molecule. 

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