title: Gene fusion and expression of heat-labile and heat-stable enterotoxins of enterotoxigenic Escherichia coli.
abstract: The vaccine candidate comprising the genes that code the B subunit of the heat-labile enterotoxin (LT-B) and the heat-stable enterotoxin (ST) of enterotoxigenic E. coli (ETEC) had been constructed by recombinant genetic techniques. The 5'terminus of the gene encoding pro-ST was genetically fused to the 3'terminus of the LT-B gene. The pro-ST gene containing mature ST sequence and pro sequence which codes for the pro region of ST precursors was amplified by PCR from pSLN004 plasmid. To reduce toxicity of the ST in vitro was substituted Leu for Ala residue at position 14 of ST by oligonucleotide-directed site mutagenesis. For this construction, the expression of ST antigenicity and LT antigenicity were obtained when a five amino-acid or a nine-amino-acid linker were included between the LT-B and pro-ST moieties. The LT-B/pro-ST fusion peptides possessed no enterotoxic activity of heat-stable and heat-labile enterotoxins, and retained the ability to bind GM1 ganglioside. More importantly, these LT-B/pro-ST fusion peptides were immunogenic. The preparations containing the hybrid molecule elicited special antibodies that were to recognize native toxin in vitro.
authors.affiliation: Beijing Institute of Biotechnology, China.
authors.forename: X
authors.initials: X
authors.lastname: Bing
authors.forename: Z
authors.initials: Z
authors.lastname: Zhaoshan
authors.forename: L
authors.initials: L
authors.lastname: Shuqin
authors.forename: S
authors.initials: S
authors.lastname: Dong
authors.forename: H
authors.initials: H
authors.lastname: Cuifen
mesh_terms: D000818:Animals; D001427:Bacterial Toxins / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D004768:Enterotoxins / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D004927:Escherichia coli Infections / Q000517:prevention & control; D029968:Escherichia coli Proteins; D022361:Escherichia coli Vaccines / Q000276:immunology* / Q000633:toxicity; D051379:Mice; D008807:Mice, Inbred BALB C; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000276:immunology; D014611:Vaccination
chemical_list: D001427:Bacterial Toxins; D004768:Enterotoxins; D029968:Escherichia coli Proteins; D022361:Escherichia coli Vaccines; D011993:Recombinant Fusion Proteins; C034151:heat stable toxin (E coli); C027538:heat-labile enterotoxin, E coli