Magnetic Polymeric Beads Functionalized with Different Mixed-Mode Ligands for Reversible Immobilization of Trypsin

BAYRAMOĞLU G. , Ozalp V. C. , Arica M. Y.

INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH, vol.53, no.1, pp.132-140, 2014 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 53 Issue: 1
  • Publication Date: 2014
  • Doi Number: 10.1021/ie402656p
  • Page Numbers: pp.132-140


In this study, we describe a preparation of magnetic affinity support carrying different ligands for immobilization of trypsin via adsorption. The magnetic support was synthesized in the bead form using glycidylmethacrylate (GMA) and methylmethacrylate (MMA) monomers. Three different ligands (i.e., p-aminobenzoic acid, L-phenylalanine and p-aminobenzamidine,) were attached on the aminated magnetic beads surface via glutaraldhyde coupling. Specific surface area of the mp(GMA/MMA) beads was found to be 21.4 m(2)/g. The maximum trypsin adsorption was observed at pH 7.0 for p-aminobenzoic acid and L-phenylalanine and at pH 8.0 for p-aminobenzamidine carrying ligand. The maximum amounts of the enzyme adsorbed on the p-aminobenzoic acid-, L-phenylalanine-, and p-aminobenzamidine-attached magnetic beads reached 99.6, 84.2, and 75.9 mg/g with an enzyme activity recovery of 69.4, 73.2, and 22.9%, respectively. The L-phenylalanine ligand-attached support displayed a higher activity recovery than those of the p-aminobenzoic acid- and the p-aminobenzamidine-attached magnetic beads. This carrier showed also very good storage and operational stability. Trypsin immobilized on p-aminobenzoic acid showed significant activity toward casein. Trypsin could be repeatedly adsorbed and desorbed with all of the ligand-attached beads without a noticeable loss in the adsorption capacity.