title: Purification of (His)6EcoRV [recombinant restriction endonuclease EcoRV fused to a (His)6 affinity domain] by metal-chelate affinity chromatography.
abstract: The chromatographic purification of (His)6EcoRV, a fusion protein consisting of a hexahistidine affinity domain and restriction endonuclease EcoRV produced from recombinant Escherichia coli, led to high product concentrations (> or = 1 mg/ml) in the preparative mode. Increasing the amount of applied crude cell homogenate caused competition with host-specific proteins was achieved by pre-adsorption on to a DEAE anion-exchange sorbent. This, in combination with 0.5-1 M NaCl in the adsorption buffer, assured a purity > 95% and a total protein recovery of approximately 34% in the preparative mode. Contamination of the product with about 2 mol of Ni(11)/mol of (His)6EcoRV was found due to metal-ion transfer to the N-terminal high-affinity binding site at (His)6. Tris(carboxymethyl)ethylenediamine (TED)-Sepharose was employed as an Ni(11) adsorber. One passage of Ni(11)-contaminated protein solutions through the TED-Sepharose column resulted in a decrease in the Ni(11) content in the (His)6EcoRV fractions below the detection limit (approximately 0.02 mg/l) of the atomic-adsorption spectrophotometer.
authors.affiliation: Gesellschaft für Biotechnologische Forschung m.b.H., Biochemical Engineering Division, Braunschweig, Federal Republic of Germany.
authors.forename: T
authors.initials: T
authors.lastname: Oswald
authors.forename: G
authors.initials: G
authors.lastname: Hornbostel
authors.forename: U
authors.initials: U
authors.lastname: Rinas
authors.forename: F B
authors.initials: FB
authors.lastname: Anspach
mesh_terms: D000595:Amino Acid Sequence; D002846:Chromatography, Affinity / Q000379:methods*; D002852:Chromatography, Ion Exchange; D015252:Deoxyribonucleases, Type II Site-Specific / Q000737:chemistry*; D004591:Electrophoresis, Polyacrylamide Gel; D006639:Histidine / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D011993:Recombinant Fusion Proteins / Q000302:isolation & purification*
chemical_list: D011993:Recombinant Fusion Proteins; D006639:Histidine; D015252:Deoxyribonucleases, Type II Site-Specific; C027440:GATATC-specific type II deoxyribonucleases