Methacryloylamidoglutamic acid having porous magnetic beads as a stationary phase in metal chelate affinity chromatography.

We have prepared a novel magnetic metal-chelate adsorbent utilizing methacryloylamidoglutamic acid (MAGA) as a metal-chelating ligand. MAGA was synthesized by using methacryloyl chloride and L-glutamic acid dihydrochloride. Magnetic beads with an average diameter of 50–100 μm were produced by suspension polymerization of 2-hydroxyethyl methacrylate (HEMA) and MAGA in the presence of Fe₃O₄ particles carried out in an aqueous dispersion medium. Magnetic beads were charged with the Cu²⁺ ions directly via MAGA for the adsorption of cytochrome c (cyt c) from aqueous solutions. The maximum cyt c adsorption capacity of the Cu²⁺-chelated beads (0.86 mmol/g Cu²⁺ loading) was found to be 37 mg/g at pH 8.0 in phosphate buffer. Cyt c adsorption on the poly(HEMA-MAGA) beads was 15.4 mg/g. Cu²⁺ charging increased the cyt c adsorption significantly (37 mg/g). Cyt c adsorption decreased with increasing temperature. Cyt c molecules could be adsorbed and desorbed five times with these adsorbents without noticeable loss in their cyt c adsorption capacity. The resulting magnetic chelator beads posses excellent long term storage stability. [ABSTRACT FROM AUTHOR]