title: Expression of human interleukin-11 cDNA in E. coli.
abstract: A 551-bp hIL-11 gene fragment that includes no nucleotide sequences encoding signal polypeptide and the initial 8 amino acids of the mature protein was cloned into a high-level expression vector pEx31B of E. coli. The authors identified the recombinant plasmid, designated pEx31-IL11, by restriction endonucleases digestion and DNA sequencing. The resulting recombinant plasmids were then used to transform E. coli strain HB101, and expression in the PL promoter system, which is temperature-regulated, was achieved. The expressed fusion protein amounts to 50% of total bacterial proteins. The hIL-11 protein expressed in E. coli was fused to the N-terminal 99 amino acids of the MS2 polymerase to form the inclusion body. These recombinant proteins can be purified to about 80% by extracting inclusion body with urea. One IL-6-dependent cell line 7 TD1 was used for bioassay. The recombinant hIL-11 protein was preliminarily purified and renatured to a specific activity of 10(5)U/mg, even in the presence of an excess of a neutralizing anti-IL-6 antibody.
authors.affiliation: Institute of Basic Medical Sciences, Beijing, China.
authors.forename: J
authors.initials: J
authors.lastname: Miao
authors.forename: J
authors.initials: J
authors.lastname: Wang
authors.forename: S
authors.initials: S
authors.lastname: Peng
authors.forename: P
authors.initials: P
authors.lastname: Tang
authors.forename: M
authors.initials: M
authors.lastname: Zou
authors.forename: J
authors.initials: J
authors.lastname: Duan
authors.forename: C
authors.initials: C
authors.lastname: Zhao
authors.forename: X
authors.initials: X
authors.lastname: Ma
mesh_terms: D018076:DNA, Complementary / Q000096:biosynthesis* / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D015870:Gene Expression; D006801:Humans; D017370:Interleukin-11 / Q000235:genetics*; D010957:Plasmids; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis*
chemical_list: D018076:DNA, Complementary; D017370:Interleukin-11; D011993:Recombinant Fusion Proteins