title: Metal chelate affinity precipitation: purification of BSA using poly(N-vinylcaprolactam-co-methacrylic acid) copolymers.
abstract: This investigation involves the metal chelate affinity precipitation of bovine serum albumin (BSA) using a copper ion loaded thermo-sensitive copolymer. The copolymer of N-vinylcaprolactam with methacrylic acid PNVCL-co-MAA was synthesized by free radical polymerization in aqueous solution, and Cu(II) ions were attached to provide affinity properties for BSA. A maximum loading of 48.1mg Cu(2+) per gram of polymer was attained. The influence of pH, temperature, BSA and NaCl concentrations on BSA precipitation and of pH, ethylenediaminetetraacetic acid (EDTA) and NaCl concentrations on elution were systematically probed. The optimum conditions for BSA precipitation occurred when pH, temperature and BSA concentration were 6.0, 10°C and 1.0 mg/ml, respectively and the most favorable elution conditions were at pH 4.0, with 0.2M NaCl and 0.06 M EDTA. The maximum amounts of BSA precipitation and elution were 37.5 and 33.7 mg BSA/g polymer, respectively. It proved possible to perform multiple precipitation/elution cycles with a minimal loss of polymer efficacy. The results show that PNVCL-co-MAA is a suitable matrix for the purification of target proteins from unfractionated materials.
authors.affiliation: College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Songjiang University City, Shanghai, PR China.
authors.forename: Yuan-Qing
authors.initials: YQ
authors.lastname: Ling
authors.forename: Hua-Li
authors.initials: HL
authors.lastname: Nie
authors.forename: Christopher
authors.initials: C
authors.lastname: Brandford-White
authors.forename: Gareth R
authors.initials: GR
authors.lastname: Williams
authors.forename: Li-Min
authors.initials: LM
authors.lastname: Zhu
mesh_terms: D000818:Animals; D002417:Cattle; D002614:Chelating Agents / Q000737:chemistry; D003300:Copper / Q000737:chemistry*; D004492:Edetic Acid / Q000737:chemistry; D005590:Fractional Precipitation / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D007769:Lactams / Q000737:chemistry*; D008689:Methacrylates / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D012710:Serum Albumin, Bovine / Q000737:chemistry / Q000302:isolation & purification*; D012965:Sodium Chloride / Q000737:chemistry; D013696:Temperature
chemical_list: D002614:Chelating Agents; D007769:Lactams; D008689:Methacrylates; D011108:Polymers; C008384:methacrylic acid; D012710:Serum Albumin, Bovine; D012965:Sodium Chloride; D003300:Copper; D004492:Edetic Acid