NONPOROUS MAGNETIC CHELATOR SUPPORTS FOR PROTEIN RECOVERY BY IMMOBILIZED METAL AFFINITY ADSORPTION

Micron-sized non-porous magnetic adsorbents derivatized with the metal chelating agent, iminodiacetic acid (IDA), have been prepared for the selective recovery of proteins. Four preparative routes employing epo xide activation chemistry were investigated to introduce IDA onto the surface of polyglutaraldehyde-coated particles. The presence of surfac e bound IDA was demonstrated by the selective binding of Cu2+ and by t he behaviour of Cu2+-charged and uncharged supports towards native hae m proteins known to bind porous polymer-based Cu2+-IDA adsorbents. The simplest and most direct procedure was developed further. Supports pr epared by this method were optimised with respect to ligand density an d specific binding capacity. These coating and derivatization methods resulted in supports with a high level of substitution and low non-spe cific binding while retaining a high effective surface area for bindin g of the target protein (>200 mg g(-1)). The resulting magnetic chelat or supports possess excellent long term storage stability.