PH-REGULATED ELECTRORETENTION CHROMATOGRAPHY - TOWARDS A NEW METHOD FOR THE SEPARATION OF PROTEINS ACCORDING TO THEIR ISOELECTRIC POINTS

The pH-dependent electroretention behavior of model proteins cytochrom e c and ribonuclease A was studied in a hollow fiber arrangement, simi lar to that used in electrical field-flow fractionation. Field-induced immobilization of the proteins at the inner wall of the fiber was a f unction of the pH adjusted in the solution surrounding it, indicating that the pH inside the fiber lumen, relevant for protein migration, qu ickly equilibrates to the regulated value outside. A complete separati on of the model proteins was achieved. Advantages of the principle as well as prospects for the development of a technique separating more t han two protein species according to their isoelectric points are disc ussed.