Liver fluke β-tubulin isotype 2 binds albendazole and is thus a probable target of this drug

• Published in: Parasitology research (1987) 2010-10, Vol.107 (5), p.1257-1264
• Main Authors: Chambers, Emma, Ryan, Louise A, Hoey, Elizabeth M, Trudgett, Alan, McFerran, Neil V, Fairweather, Ian, Timson, David J
• Format: Article
• Language: English
• Subjects: agarose; albendazole; Albendazole - metabolism; Animals; Anthelmintics - metabolism; benzimidazole; Binding Sites; Biological and medical sciences; Biomedical and Life Sciences; Biomedicine; Escherichia coli; Escherichia coli - genetics; Fasciola hepatica; Fasciola hepatica - drug effects; Fundamental and applied biological sciences. Psychology; General aspects; General aspects and techniques. Study of several systematic groups. Models; Helminth Proteins - genetics; Helminth Proteins - isolation & purification; Helminth Proteins - metabolism; Immunology; Invertebrates; liver flukes; mechanism of action; Medical Microbiology; Microbiology; microtubules; Models, Molecular; Original Paper; Protein Binding; Protein Isoforms - genetics; Protein Isoforms - isolation & purification; Protein Isoforms - metabolism; Protein Structure, Tertiary; protein synthesis; Recombinant Proteins - biosynthesis; Recombinant Proteins - genetics; Recombinant Proteins - isolation & purification; tubulin; Tubulin - genetics; Tubulin - isolation & purification; Tubulin - metabolism
• ISSN: 0932-0113; 1432-1955
• DOI: 10.1007/s00436-010-1997-5

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.