title: [Expression of recombinant human Flt3 ligand in Escherichia coli and its purification and characterization].
abstract: OBJECTIVE
  To establish a highly efficient expression system of recombinant human Flt3 ligand (rhFL) in E. coli and a suitable purification method of the expressed products.
  
  
  METHODS
  Human FL encoding cDNA was introduced into pProEXHT plasmid to express a 6 x His-FL fusion protein in E. coli. The fusion protein expressed in inclusion body was isolated, solubilized and refolded, and then purified by chromatography on a metal-chelating affinity column (MCAC). Its activity was detected by stimulating the proliferation of CD(34)(+) cells.
  
  
  RESULTS
  The amount of rhFL expressed was about 15% of total bacterial proteins and the purity of rhFL was 90% after MCAC. The combination of rhFL, granulocyte colony-stimulating factor and erythropoietin could stimulate CD(34)(+) cells to a 400 fold expansion.
  
  
  CONCLUSIONS
  The purified rhFL had a potent activity to stimulate hematopoietic stem cells to expanse in vitro.
authors.affiliation: Beijing Red Cross Chaoyang Hospital, Beijing 100020, China.
authors.forename: W
authors.initials: W
authors.lastname: Zheng
authors.forename: J
authors.initials: J
authors.lastname: Liu
authors.forename: X
authors.initials: X
authors.lastname: Lü
authors.forename: X
authors.initials: X
authors.lastname: Pei
authors.forename: Z
authors.initials: Z
authors.lastname: Sun
mesh_terms: D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D015870:Gene Expression; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000187:drug effects; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics* / Q000302:isolation & purification* / Q000378:metabolism / Q000494:pharmacology; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology
chemical_list: D008565:Membrane Proteins; D011993:Recombinant Fusion Proteins; C084881:flt3 ligand protein