High-performance affinity chromatography of basic fibroblast growth factor on polystyrene sulphonate resins modified...

Basic fibroblast growth factor (bFGF) is a heparin-binding growth factor, so it was usually purified by affinity chromatography on a heparin-grafted support. It was previously observed that, among several modified polystyrene that exhibit anticoagulant heparin-like properties, insoluble polystyrenes modified by chlorosulphonation substituted with serine (PSSer) develop specific interactions with bFGF in solution. These PSSer resins were used as stationary phases in high-performance affinity chromatography in order to separate the radiolabelled growth factor from a bovine brain crude extract. The growth factor is strongly bound to the solid phase, as demonstrated by the adsorption isotherms. It can be adsorbed on the resin at low ionic strength and be desorbed by raising the salt concentration in the eluent. The effects of flow-rate, of the initial buffer and of the slope of the salt gradient on the adsorption and on the desorption of bFGF were investigated in order to study the thermodynamic and the kinetic parameters of the interactions and to define the optimum conditions for a fast and efficient separation of the growth factor.