title: Enhanced expression of a recombinant malaria candidate vaccine in Escherichia coli by codon optimization.
abstract: This study was conducted to compare the expression of three constructs of a multistage candidate vaccine (FALVAC-1) against Plasmodium falciparum in an Escherichia coli system: a synthetic gene with P. falciparum codons, a synthetic gene with optimized E. coli codons, and a synthetic gene with P. falciparum codons co-transformed with a RIG plasmid, which encodes three tRNAs (AG(A/G), ATA, GGA) that recognize rare E. coli codons. The expression of the protein increased at least threefold with codon optimization. The presence of the RIG plasmid in the co-transforming cells did not significantly increase the expression level of the gene with P. falciparum codons. The growth of cells transformed by the construct with P. falciparum codons was significantly slower than that of cells transformed by the construct with optimized E. coli codons after induction of protein expression with IPTG. The cells containing the non-codon optimized gene co-expressed with RIG plasmid had the slowest growth at all time points in culture. Thus, codon optimization significantly increases the yield of P. falciparum candidate vaccines in the E. coli expression system.
authors.affiliation: Division of Parasitic Diseases, Centers for Disease Control and Prevention, 4770 Buford Highway, Chamblee, GA 30341, USA. zaz6@cdc.gov
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Zhou
authors.forename: Paul
authors.initials: P
authors.lastname: Schnake
authors.forename: Lihua
authors.initials: L
authors.lastname: Xiao
authors.forename: Altaf A
authors.initials: AA
authors.lastname: Lal
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000953:Antigens, Protozoan / Q000235:genetics; D001483:Base Sequence; D015153:Blotting, Western; D002455:Cell Division / Q000235:genetics; D002847:Chromatography, Agarose; D003001:Cloning, Molecular; D003062:Codon / Q000235:genetics*; D016054:DNA, Protozoan / Q000235:genetics / Q000276:immunology; D004591:Electrophoresis, Polyacrylamide Gel; D000939:Epitopes / Q000235:genetics / Q000276:immunology; D004926:Escherichia coli / Q000235:genetics* / Q000254:growth & development; D015870:Gene Expression / Q000187:drug effects / Q000235:genetics*; D015964:Gene Expression Regulation, Bacterial; D005813:Genes, Synthetic / Q000235:genetics / Q000276:immunology; D005822:Genetic Vectors / Q000235:genetics; D007544:Isopropyl Thiogalactoside / Q000494:pharmacology; D017780:Malaria Vaccines / Q000032:analysis / Q000096:biosynthesis* / Q000235:genetics; D008969:Molecular Sequence Data; D010963:Plasmodium falciparum / Q000235:genetics / Q000276:immunology*; D015202:Protein Engineering / Q000379:methods; D012343:RNA, Transfer / Q000235:genetics; D016415:Sequence Alignment; D012689:Sequence Homology, Nucleic Acid; D014614:Vaccines, Synthetic / Q000032:analysis / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D000953:Antigens, Protozoan; D003062:Codon; D016054:DNA, Protozoan; D000939:Epitopes; D017780:Malaria Vaccines; D014614:Vaccines, Synthetic; D007544:Isopropyl Thiogalactoside; D012343:RNA, Transfer