title: Magnetic dye affinity beads for the adsorption of beta-casein.
abstract: Casein is well known as a good protein emulsifier and beta-casein is the major component of casein and commercial sodium caseinate. Dye affinity adsorption is increasingly used for protein separation. beta-Casein adsorption onto Reactive Red 120 attached magnetic poly(2-hydroxyethyl methacrylate) (m-PHEMA) beads was investigated in this work. m-PHEMA beads (80-120 microm in diameter) were produced by dispersion polymerization. The dichlorotriazine dye Reactive Red 120 was attached covalently as a ligand. The dye attached beads, having a swelling ratio of 55% (w/w) and carrying different amounts of Reactive Red 120 (9.2 micromol . g(-1)-39.8 micromol . g(-1)), were used in beta-casein adsorption studies. The effects of the initial concentration, pH, ionic strength and temperature on the adsorption efficiency of dye attached beads were studied in a batch reactor. The non-specific adsorption on the m-PHEMA beads was 1.4 mg . g(-1). Reactive Red 120 attachment significantly increased the beta-casein adsorption up to 37.3 mg . g(-1). More than 95.4% of the adsorbed beta-casein was desorbed in 1 h in a desorption medium containing 1.0 M KSCN at pH 8.0. We concluded that Reactive Red 120 attached m-PHEMA beads can be applied for beta-casein adsorption without significant losses in the adsorption capacities.
authors.affiliation: Department of Chemistry, Biochemistry Division, Adnan Menderes University, Aydin, Turkey. sinanakgol@yahoo.co.uk
authors.forename: Sinan
authors.initials: S
authors.lastname: Akgöl
authors.forename: Nilay
authors.initials: N
authors.lastname: Bereli
authors.forename: Adil
authors.initials: A
authors.lastname: Denizli
mesh_terms: D002364:Caseins / Q000737:chemistry / Q000302:isolation & purification*; D002846:Chromatography, Affinity / Q000379:methods; D008280:Magnetics; D008863:Microspheres; D011102:Polyhydroxyethyl Methacrylate / Q000737:chemistry*; D014227:Triazines / Q000737:chemistry*
chemical_list: D002364:Caseins; D014227:Triazines; D011102:Polyhydroxyethyl Methacrylate; C042516:reactive red 120 dye