Identification of Effectors: Precipitation of Supernatant Material

Part of the Methods in Molecular Biology book series (MIMB, volume 1615)


Bacterial secretion systems allow the transport of proteins, called effectors, as well as external machine components in the extracellular medium or directly into target cells. Comparison of the secretome, i.e. the proteins released in the culture medium, of wild-type and mutant cells provides information on the secretion profile. In addition, mass spectrometry analyses of the culture supernatant of bacteria grown in liquid culture under secreting conditions allows the identification of secretion system substrates. Upon identification of the substrates, the secretion profile serves as a tool to test the functionality of secretion systems. Here we present a classical method used to concentrate the culture supernatant, based on trichloroacetic acid precipitation.

Key words

Supernatant TCA precipitation Secretome 



This work was supported by the Centre National de la Recherche Scientifique, the Aix-Marseille Université and grants from the Agence Nationale de la Recherche (ANR-14-CE14-0006-02 and ANR-15-CE11-0019-01). The doctoral studies of N.F. are supported by the ANR-14-CE14-0006-02 grant.


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Copyright information

© Springer Science+Business Media LLC 2017

Authors and Affiliations

  1. 1.Laboratoire d’Ingénierie des Systèmes Macromoléculaires (LISM, UMR7255), Institut de Microbiologie de la MéditerranéeAix-Marseille Univ – CNRSMarseille Cedex 20France

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