title: [Expression of a novel human interleukin-13 in E.coli and its biological activity assay].
abstract: OBJECTIVE
  To express a novel Gln98-deleted human interleukin-13 in E.coli.
  
  
  METHODS
  Total RNA was isolated from Jurkat cells costimulated with PHA and ConA. A 358 bp-specific DNA fragment encoding hIL-13 was amplified by semi-nested RT-PCR. DNA sequencing showed that the target DNA was a Gln98-deleted novel splicing of hIL-13. This hIL-13 cDNA and plasmid pBV220 were ligated at BamH I and EcoR I sites to construct the expression vector. After transforming E.coli strain DH5alpha, the expression of the novel splicing hIL-13 gene was induced by shifting culture temperature from 30 degrees Celsius to 42 degrees Celsius. The expression product was then purified by chromatography on Sepharcryl-200 gel column, and the bioactivity was detected by MTT colorimetry on the growth of TF-1 cell line.
  
  
  RESULTS
  The novel rhIL-13 was expressed in the form of inclusion bodies. After purification and renaturation, the specific activity of the novel rhIL-13 was 1.6x10(6) IU/mg.
  
  
  CONCLUSIONS
  The novel rhIL-13 with biological activity has been obtained, which lays the foundation for treating cancer and septicemia by the cytokine in future.
authors.affiliation: Department of General Surgery, No.304 Hospital of PLA, Beijing 100037,China.
authors.forename: Da-Dong
authors.initials: DD
authors.lastname: Wang
authors.forename: Ji-Ye
authors.initials: JY
authors.lastname: Li
authors.forename: Jin-Hui
authors.initials: JH
authors.lastname: Wang
authors.forename: Dong-Gang
authors.initials: DG
authors.lastname: Xu
authors.forename: Hua-Bo
authors.initials: HB
authors.lastname: Jiao
authors.forename: Tao
authors.initials: T
authors.lastname: Li
authors.forename: Qun
authors.initials: Q
authors.lastname: Deng
authors.forename: Jia-Xi
authors.initials: JX
authors.lastname: Wang
authors.forename: Zhan-Liang
authors.initials: ZL
authors.lastname: Li
mesh_terms: D018076:DNA, Complementary / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics; D015870:Gene Expression; D006801:Humans; D002479:Inclusion Bodies; D018793:Interleukin-13 / Q000235:genetics; D010957:Plasmids
chemical_list: D018076:DNA, Complementary; D018793:Interleukin-13