title: Simplified purification of equine chorionic gonadotropin (eCG)--an example of the use of magnetic microsorbents for the isolation of glycoproteins from serum.
abstract: Classical purification of the glycoprotein equine chorionic gonadotropin (eCG) from serum includes pH fractionation with metaphosphoric acid, two ethanol precipitation steps as well as dialysis followed by fixed-bed chromatography. A simplified process requiring only 1/3 of the solvent and improving the yield from 53 to 65% has been developed. The process comprises an ultra-/diafiltration step after the first ethanol precipitation, directly followed by an adsorption/desorption procedure based on magnetic microadsorbents with N,N-diethyl-ammonium functionalization. The process reaches an overall purification factor of eCG of more than 1800 and an average product activity of 1300 IU(ELISA)/mg. After adapting the parameters of the fractionation and the type of magnetic microadsorbents, the new concept is likely to be transferable to other serum proteins.
authors.affiliation: Institute of Functional Interfaces, Karlsruhe Institute of Technology, Hermann von Helmholtz Platz 1, 76344 Eggenstein Leopoldshafen, Germany.
authors.forename: Christine
authors.initials: C
authors.lastname: Müller
authors.forename: Kerstin
authors.initials: K
authors.lastname: Wagner
authors.forename: Katrin
authors.initials: K
authors.lastname: Frankenfeld
authors.forename: Matthias
authors.initials: M
authors.lastname: Franzreb
mesh_terms: D000327:Adsorption; D000818:Animals; D005591:Chemical Fractionation; D006063:Chorionic Gonadotropin / Q000302:isolation & purification*; D006023:Glycoproteins / Q000302:isolation & purification*; D006736:Horses; D008280:Magnetics; D008863:Microspheres; D044967:Serum / Q000737:chemistry*; D014462:Ultrafiltration / Q000379:methods
chemical_list: D006063:Chorionic Gonadotropin; D006023:Glycoproteins