Ionic binding properties of carrier ampholytes

Radioactive ampholytes were synthesized with specific activity of 638 microCi/g. These were used in studies of ampholyte binding to target proteins under non-ionic conditions. These radioactive ampholytes bound to target proteins but were dissociable in sodium chloride solutions with dissociation occurring in a concentration dependent way. The ampholytes could be dissociated from target molecules using excess unlabelled ampholytes synthesized in the laboratory as well as commercial ampholytes. Radioactive ampholytes were bound to target proteins with different isoelectric points and the bound ampholytes were eluted and analyzed by recycling isoelectric focusing. The results showed that acidic proteins bound basic ampholytes and basic proteins bound acidic ampholytes. Acidic radioactive ampholytes were selectively bound by Sephacryl S-200 and ampholyte exchange from protein to Sephacryl S-200 was shown.