title: Optimized gene synthesis and high expression of human interleukin-18.
abstract: Human interleukin-18 (hIL-18), originally known as an IFN-gamma-inducing factor, is a recently cloned cytokine that is secreted by Kupffer cells of the liver and by stimulated macrophages. We have previously established a method of expression and purification of IL-18. The yield however remains low and the insufficient expression of a heterologous protein could be due to skewed codon usage between the expression host and the cDNA donor. The sequence of mature hIL-18 has 37 a.a. rare codons for Escherichia coli in a total of 157 a.a. To overcome this problem, gene synthesis was performed with optimized codons for the expression host E. coli. The final yield of the hIL-18 protein with optimized codons was about five times higher than the yield with the native sequence. Using a minimal medium, this system produces large quantities of labeled proteins that can be used in NMR analysis. Our simple and efficient production system can be applied to the production of other cytokines for new structural and therapeutic use.
authors.affiliation: Department of Pediatrics, Gifu University School of Medicine, Tsukasa 40, Gifu 500-8705, Japan.
authors.forename: Ailian
authors.initials: A
authors.lastname: Li
authors.forename: Zenichiro
authors.initials: Z
authors.lastname: Kato
authors.forename: Hidenori
authors.initials: H
authors.lastname: Ohnishi
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Hashimoto
authors.forename: Eiji
authors.initials: E
authors.lastname: Matsukuma
authors.forename: Kentaro
authors.initials: K
authors.lastname: Omoya
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Yamamoto
authors.forename: Naomi
authors.initials: N
authors.lastname: Kondo
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D002850:Chromatography, Gel; D003062:Codon / Q000235:genetics; D005822:Genetic Vectors / Q000235:genetics; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism; D020382:Interleukin-18 / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics* / Q000494:pharmacology; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012343:RNA, Transfer / Q000235:genetics; D016415:Sequence Alignment
chemical_list: D003062:Codon; D020382:Interleukin-18; D007371:Interferon-gamma; D012343:RNA, Transfer