title: Ni(II)-based immobilized metal ion affinity chromatography of recombinant human prolactin from periplasmic Escherichia coli extracts.
abstract: A novel, two-step preparative technique is described for the purification of authentic recombinant human prolactin (rhPRL) secreted into the periplasm of transformed Escherichia coli cells. The first step is based on immobilized metal ion affinity chromatography of periplasmic extract, using Ni(II) as a relatively specific ligand for hPRL in this system. It gives superior resolution and yield than established ion-exchange chromatography. Size-exclusion chromatography is used for further purification to >99.5% purity. The methodology is reproducible, leading to 77% recovery. Identity and purity of the rhPRL were demonstrated using sodium dodecylsulphate-polyacrylamide electrophoresis, isoelectric focusing, mass spectrometry (matrix-assisted laser desorption ionization time-of-flight), radioimmunoassay, RP-HPLC and high-performance size-exclusion chromatography. In the Nb2 bioassay, the hormone showed a bioactivity of 40.9 IU/mg.
authors.affiliation: Department of Biotechnology, Institute of Nuclear and Energy Research (IPEN-CNEN), Cidade Universitária, Sao Paulo, Brazil.
authors.forename: E K
authors.initials: EK
authors.lastname: Ueda
authors.forename: P W
authors.initials: PW
authors.lastname: Gout
authors.forename: L
authors.initials: L
authors.lastname: Morganti
mesh_terms: D002846:Chromatography, Affinity / Q000379:methods*; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000235:genetics*; D006801:Humans; D007525:Isoelectric Focusing; D009532:Nickel / Q000737:chemistry*; D011388:Prolactin / Q000235:genetics / Q000302:isolation & purification*; D011994:Recombinant Proteins / Q000235:genetics / Q000302:isolation & purification
chemical_list: D011994:Recombinant Proteins; D009532:Nickel; D011388:Prolactin