Proteomic analysis of the larval stage of the parasite Echinococcus granulosus: Causative agent of cystic hydatid disease

Authors

  • Gustavo Chemale,

    1. Centro de Biotecnologia and Departamento de Biologia Molecular e Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
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  • Arjan J. van Rossum,

    1. Institute of Biological Sciences, University of Wales, Aberystwyth, Wales
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  • James R. Jefferies,

  • John Barrett,

    1. Institute of Biological Sciences, University of Wales, Aberystwyth, Wales
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  • Peter M. Brophy,

    1. Institute of Biological Sciences, University of Wales, Aberystwyth, Wales
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  • Henrique B. Ferreira,

    1. Centro de Biotecnologia and Departamento de Biologia Molecular e Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
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  • Arnaldo Zaha

    Corresponding author
    1. Centro de Biotecnologia and Departamento de Biologia Molecular e Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
    • Centro de Biotecnologia and Departamento de Biologia Molecular e Biotecnologia, Universidade Federal do Rio Grande do Sul, Caixa Postal 15005, Porto Alegre, 91501-970, RS, Brazil Fax: +55-51-33167309
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Abstract

We describe the preparation of Echinococcus granulosus metacestode protein extracts for two-dimensional electrophoresis (2-DE). Protoscoleces and hydatid fluid were prepared by precipitation using trichloroacetic acid (TCA) to remove nonprotein contaminants. Compared to the untreated control, TCA precipitation improved the 2-DE gel profile of the protoscoleces proteins. Comparison of 2-DE gels from insoluble and soluble fractions of the protoscoleces protein extract showed that most proteins are insoluble after lysis by sonication. Host serum proteins, especially albumin and globulins, caused horizontal streaking problems on the hydatid fluid 2-DE gels due to their high content in this sample. Even after the preparation of a hydatid fluid parasite enriched fraction, the high amount of bovine serum albumin and globulins made parasite-specific proteins difficult to detect by 2-DE. Despite the absence of an E. granulosus genome sequencing or expressed sequence tag (EST) projects, it was possible to identify 15 prominent protein spots from a whole protein protoscoleces 2-DE gel by peptide mass fingerprinting. These include actins, tropomyosin, paramyosin, thioredoxin reductase, antigen P-29, cyclophilin, and the heat shock proteins hsp70 and hsp20. This work demonstrates that 2-DE and PMF are important tools to identify proteins from the hydatid fluid and protoscoleces and for the comparative analysis of cysts from different hosts or between active and resting cysts.

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