title: [Comparison of two techniques for expression and purification of glycogen synthase kinase 3β].
abstract: OBJECTIVE
  To establish a method for the expression of glycogen synthase kinase 3β with high purity and biological activity.
  
  
  METHODS
  E.coli expression system and baculovirus-insect cell expression system were used to produce the kinase, followed by purification using His-tag and GST-tag and determination of its purity and activity by SDS-PAGE and kinase reaction, respectively.
  
  
  RESULTS
  Glycogen synthase kinase 3β produced from E.coli represented 54% of the total bacterial protein, as compared with 96% of the total protein from the insect cell system .Glycogen synthase kinase 3β produced from insect cell exhibited an one-fold higher biological activity than the protein obtained from E.coli.
  
  
  CONCLUSIONS
  Compared with the protein from E.coli system, glycogen synthase kinase 3β from the insect cell expression system is endowed with a higher purity and bioactivity.
authors.affiliation: Proteomics Center, Zhongshan School of Medicine, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China. sfeixu@126.com
authors.forename: Shao-fei
authors.initials: SF
authors.lastname: XU
authors.forename: Jie
authors.initials: J
authors.lastname: XU
authors.forename: Ming-tao
authors.initials: MT
authors.lastname: LI
mesh_terms: D000818:Animals; D016367:Baculoviridae / Q000378:metabolism*; D004926:Escherichia coli / Q000378:metabolism*; D005822:Genetic Vectors; D038362:Glycogen Synthase Kinase 3 / Q000096:biosynthesis* / Q000302:isolation & purification; D007313:Insecta / Q000166:cytology
chemical_list: D038362:Glycogen Synthase Kinase 3