On-target ultrasonic digestion of proteins

Authors

  • Hugo M. Santos,

    Corresponding author
    • Departamento de Química, Centro de Química Fina e Biotecnologia, (CQFB), REQUIMTE, Faculdade de Ciências e Tecnologia, (FCT), Universidade Nova de Lisboa, (UNL), Caparica, Portugal
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    • These authors contributed equally to this work.

  • Petri Kouvonen,

    1. Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, Turku, Finland
    2. Department of Biology, Institute of Molecular Systems Biology, ETH, Zurich, Switzerland
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    • These authors contributed equally to this work.

  • Jose-Luis Capelo,

    1. Departamento de Química, Centro de Química Fina e Biotecnologia, (CQFB), REQUIMTE, Faculdade de Ciências e Tecnologia, (FCT), Universidade Nova de Lisboa, (UNL), Caparica, Portugal
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  • Garry L. Corthals

    Corresponding author
    • Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, Turku, Finland
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  • Colour Online: See the article online to view Figs. 1–3 in colour.

Correspondence: Dr. Garry L. Corthals, Turku Centre for Biotechnology, University of Turku, 50210 Turku, Finland

E-mail: garry.corthals@btk.fi

Fax: +358 2 2518808

Additional corresponding author: Dr. Hugo M. Santos,

E-mail: hms14862@fct.unl.pt

Abstract

In the present work, we report a novel on-target protein cleavage method. The method utilizes ultrasonic energy and allows up to 20 samples to be cleaved in 5 min for protein identification and one sample in 30 s for on-tissue digestion. The standard proteins were spotted on a conductive glass slide in a volume of 0.5 μL followed by 5 min of ultrasonication after trypsin addition. Controls (5 min, 37°C no ultrasonication) were also assayed. After trypsin addition, digestion of the tissues was enhanced by 30 s of ultrasonication. The samples were analyzed and compared to those obtained by using conventional 3 h heating proteolysis. The low sample volume needed for the digestion and reduction in sample-handling steps and time are the features that make this method appealing to the many laboratories working with high-throughput sample treatment.

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