Immobilization of conalbumin onto polystyrene/divinylbenzene co-polymers: towards finding the best support for MAMC

Immediately after the successful immobilization of conalbumin onto CNBr-activated Sepharose, efforts were begun to find a less expensive support and a more benign chemistry of activation. The potential of the Sepharose-conalbumin conjugate for decontamination of several metal-containing waste-waters has been established, and a new method of chromatography has emerged, named metalloprotein affinity metal chromatography (MAMC). Efforts to immobilize conalbumin onto polystyrene/divinylbenzene co-polymers, using the well known and commercially available Merrifield, aminomethyl and plain polystyrene resins are presented here. Immobilizations of conalbumin were carried out on the Merrifield and Aminomethyl resins, but the procedures were time consuming and complicated by polymer aggregation. Because of high cost of these materials, research was directed towards the activation and functionalization of plain polystyrene/divinylbenzene co-polymers. Chlorosulfonation followed by sulfonamide formation was attempted on three commercially available polymers. Successful polysulfonamide formation was achieved with bislysine copper(II) acting as a diamine. Removal of the copper allows the unblocking of the alpha amino group of the immobilized lysine which in turn is treated with glutaraldehyde, affording an activated support for immobilization of proteins. To date, approximately 46 mg transferrin/g dry matrix have been successfully immobilized. The chemical and biological inertness of this support makes it a good candidate to scale up the procedure and continue the optimization of MAMC.