Structural Mass Spectrometry and Proteomics

The overarching objective of our Unit is to develop new methodologies for the analysis of proteins and protein complexes by high resolution mass spectrometry. We focus particularly on “top-down” approaches, performed on the entire protein. The development of these approaches requires an understanding of the fragmentation mechanisms of peptides or proteins, another theme developed in the group. The proteomics facility, which is also part of the Unit, proposes high quality service in proteomics including large scale protein identification, quantification and analysis of posttranslational modifications.

• LTQ Orbitrap Velos with a module ETD (Thermo Fisher),
• 4800 MALDI TOF/TOF  (AB-MDS-SCIEX),
• Qstar XL (AB-MDS-SCIEX).

• two nano-HPLC Ultimate 3000 (LC-Packings) Dionex,
• one HPLC (Agilent).
  

• two Protean IEF cell (BioRad),
• one HPE FlapTop Tower (Serva Electrophoresis).

Top down strategies, based on the study of entire proteins, hold great promise for structural protein analysis. Whilst the classical, bottom up approach can be useful for locating proteins already deposited in the databases, only a top down methodology can yield complete and unambiguous structural characterization in a time efficient manner.

In this regard a particularly important application is the analysis and localisation of post translational modifications. This often relies on efficient, selective and comprehensive fragmentation such as that provided by electron capture dissociation (ECD).

Most recently these techniques have been used in the analysis of PilE, an 18 kDa protein that is strongly involved in the virulence of Neisseria Meningitidis.

Our unit is part of the recent consortium for Top Down Proteomics.

References:
Posttranslational Modification of Pili upon Cell Contact Triggers N. meningitidis Dissemination
Chamot-Rooke J, Mikaty G, Malosse C, Soyer M, Dumont A, Gault J, Imhaus A-F, Martin P, Trellet M, Clary G, Chafey P, Camoin L, Nilges M, Nassif X, Duménil G, - Science, 331, 778-782 (2011) DOI

Alternative Neisseria spp. type IV pilin glycosylation with a glyceramido acetamido 2,4,5-trideoxyhexose residue
Chamot-Rooke J, Rousseau B, Lanternier F, Mikaty G, Mairey E, Malosse C, Bouchoux G, Pelicic V, Camoin L, Nassif X,  Dumenil G - Proc. Nat. Acad. Sci. USA. 104, 14783-14788 (2007). DOI

Contact:
Julia CHAMOT-ROOKE
Structural Mass Spectrometry and Proteomics
Batiment Biologie Integrative des Maladies Emergentes.
Institut Pasteur
28 Rue du Docteur Roux
75724 PARIS Cedex 15
Email : julia.chamot-rooke@pasteur.fr