title: Renaturation and purification of rhGM-CSF with ion-exchange chromatography.
abstract: The renaturation and purification of recombinant human granulocyte macrophage colony stimulation factor (rhGM-CSF) expressed in Escherichia coli with strong anion-exchange chromatography (SAX) were studied. The effects of pH values, ratios of concentrations of GSH/GSSG, and urea concentrations in the mobile phase on the renaturation and purification of rhGM-CSF with SAX were investigated, respectively. The results show that the above three factors have remarkable influences on the efficiency of renaturation and mass recovery of rhGM-CSF. The addition of GSH/GSSG in the mobile phase can improve the formation of correct disulfide bonds in rhGM-CSF so that its renaturation yield increases. In addition, to enhance the mass recovery of rhGM-CSF with SAX, the low concentration of urea was added in the mobile phase to prevent denatured protein aggregation. Under the optimal conditions, rhGM-CSF was renatured with simultaneous purification on SAX column within 30 min only by one step. After that its specific bioactivity, mass recovery, and purity reached 1.66 x 10(7) IU x mg, 58.8%, and 96.2%, respectively.
authors.affiliation: Institute of Modern Separation Science, Key Laboratory of Modern Separation Science in Shaanxi Province, Northwest University, Xi'an 710069, China. baiquan@nwu.edu.cn
authors.forename: Quan
authors.initials: Q
authors.lastname: Bai
authors.forename: Gang
authors.initials: G
authors.lastname: Chen
authors.forename: Jianbo
authors.initials: J
authors.lastname: Liu
authors.forename: Xindu
authors.initials: X
authors.lastname: Geng
mesh_terms: D002852:Chromatography, Ion Exchange / Q000379:methods*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D016179:Granulocyte Colony-Stimulating Factor / Q000737:chemistry* / Q000302:isolation & purification* / Q000378:metabolism; D006801:Humans; D011489:Protein Denaturation; D017510:Protein Folding; D011994:Recombinant Proteins / Q000737:chemistry* / Q000302:isolation & purification* / Q000378:metabolism
chemical_list: D011994:Recombinant Proteins; D016179:Granulocyte Colony-Stimulating Factor