Preparation of a novel metal-chelate affinity beads for albumin isolation from human plasma

摘要

In this study, we developed a novel approach to obtain a high protein-adsorption capacity utilizing 2-methacryloylamidohistidine (MAH) as a biollgand. MAH was synthesized by reacting methacryloyl chloride and histidine. Spherical beads, with an average size of 150-200 mum, were obtained by the radical suspension polymerization of MAH, ethyleneglycol dimethacrylate (EGDMA), and 2-hydroxyethyl methacrylate (HEMA) conducted in an aqueous dispersion medium. p(EGDMA-HEMA-MAH) beads had a specific surface area of 17.6 m(2)/g. The synthesized MAH monomer was characterized by NMR. p(EGDMA-HEMA-MAH) beads were characterized by a swelling test, FTIR, and elemental analysis. Then, Cu(II) ions were incorporated into the beads and Cu(II) loading was found to be 0.96 mmol/g. These beads, with a swelling ratio of 65% and containing 1.6 mmol MAH/g, were used in the adsorption/desorption of human serum albumin (HSA) from both aqueous solutions and human serum. The adsorption of HSA onto p(EGDMA-HEMA-MAH) was low (8.8 mg/g). Cu(II) chelation onto the beads significantly increased the HSA adsorption (56.3 mg/g). The maximum HSA adsorption was observed at pH 8.0 Higher HSA adsorption was observed from human serum (94.6 mg HSA/g). Adsorptions of other serum proteins were obtained as 3.7 mg/g for fibrinogen and 8.5 mg/g for gamma-globulin. The total protein adsorption was determined as 107.1 mg/g. Desorption of HSA was obtained using a 0.1M Tris/HCI buffer containing 0.5M NaSCN. High desorption ratios (to 98% of the adsorbed HSA) were observed. It was possible to reuse Cu(II)-chelated p(EGDMA-HEMA-MAH) beads without significant decreases in the adsorption capacities. (C) 2003 Wiley Periodicals, Inc. [References: 37]