title: Liver fluke β-tubulin isotype 2 binds albendazole and is thus a probable target of this drug.
abstract: Albendazole is a benzimidazole drug which can be used to treat liver fluke (Fasciola hepatica) infections. Its mode of action is believed to be the inhibition of microtubule formation through binding to β-tubulin. However, F. hepatica expresses at least six different isotypes of β-tubulin, and this has confused, rather than clarified, understanding of the molecular mechanisms of benzimidazole drugs in this organism. Recombinant F. hepatica β-tubulin proteins were expressed in, and purified from, Escherichia coli. These proteins were then used in pull-down assays in which albendazole was covalently linked to Sepharose. β-Tubulin isotype 2 was pulled down in this assay, and this interaction could be reduced by adding competing albendazole. Molecular modelling of β-tubulin isotypes suggests that changes in the side change conformations of residue 200 in the putative albendazole binding site may be important in determining whether, or not, a particular isotype will bind to the drug. These results, together with previous work demonstrating that albendazole causes disruption of microtubules in the liver fluke, strongly suggest that β-tubulin isotype 2 is one of the targets of this drug.
authors.affiliation: School of Biological Sciences, Queen's University Belfast, Medical Biology Centre, 97 Lisburn Road, Belfast BT9 7BL, UK.
authors.forename: Emma
authors.initials: E
authors.lastname: Chambers
authors.forename: Louise A
authors.initials: LA
authors.lastname: Ryan
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Hoey
authors.forename: Alan
authors.initials: A
authors.lastname: Trudgett
authors.forename: Neil V
authors.initials: NV
authors.lastname: McFerran
authors.forename: Ian
authors.initials: I
authors.lastname: Fairweather
authors.forename: David J
authors.initials: DJ
authors.lastname: Timson
mesh_terms: D015766:Albendazole / Q000378:metabolism*; D000818:Animals; D000871:Anthelmintics / Q000378:metabolism*; D001665:Binding Sites; D004926:Escherichia coli / Q000235:genetics; D005210:Fasciola hepatica / Q000187:drug effects*; D015801:Helminth Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D008958:Models, Molecular; D011485:Protein Binding; D020033:Protein Isoforms / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics / Q000302:isolation & purification; D014404:Tubulin / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D000871:Anthelmintics; D015801:Helminth Proteins; D020033:Protein Isoforms; D011994:Recombinant Proteins; D014404:Tubulin; D015766:Albendazole