Purification of human interleukin-4 produced in Escherichia coli.
An interleukin-4 (IL4)-encoding cDNA isolated from human splenocytes was used to construct an expression plasmid that directs a high-level synthesis of mature IL4 protein in Escherichia coli. The expression was under the control of the major leftward promoter, pL, of phage lambda and the phage Mu ribosome-binding site. The IL4 protein was present as insoluble inclusion bodies in the bacterial extract. The IL4 could be solubilized in 5 M MgCl2 and was purified to homogeneity by several chromatographic steps. The yield of protein from bacteria ranged between 3 and 5 mg of IL4 protein per gram of wet cells. The specific activity of the recombinant human IL4 was about the same as that of the natural product.
Jayaram
B
B
Laboratory of Molecular Biology, State University, Gent, Belgium.
Devos
R
R
Guisez
Y
Y
Fiers
W
W
D000818:Animals; D002478:Cells, Cultured; D002850:Chromatography, Gel; D003001:Cloning, Molecular; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000235:genetics*; D005822:Genetic Vectors; D006801:Humans; D015847:Interleukin-4 / Q000235:genetics / Q000302:isolation & purification*; D010957:Plasmids; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics; D012995:Solubility
D011994:Recombinant Proteins; D015847:Interleukin-4