High-density ligand attachment to brominated allyl matrices and application to mixed mode chromatography of chymosin

Allylated cellulose, agarose and methacrylate matrices, activated with allyl bromide or allyl glycidyl ether, were modified by aqueous bromination, preferably with N-bromosuccinimide. Amine, thiol and sulphite ligands were attached efficiently and in high densities (1-1.5 mmol/g dry) to the brominated matrices, using concentrated reaction mixtures. Organic solvents were not required. Bromohydroxypropyl matrices and amine or carboxylate derivatives could thus be used to produce matrices for all major forms of adsorption chromatography. This chemistry was used to prepare high-density mercaptoalkyl acid matrices, which were successfully applied to mixed mode purification of crude chymosin and compared with matrices used previously. (C) 1997 Elsevier Science B.V.