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Institut de Biologie StructuraleGrenoble / France

Contact person(s) related to this article / BOERI-ERBA Elisabetta

Presentation

NATIVE MASS SPECTROMETRY OF PROTEIN COMPLEXES

Team leader: Elisabetta Boeri Erba

Our team is interested in studying protein complexes by native mass spectrometry (native MS). This specific MS technique allows the preservation within the gas phase of non-covalent interactions between subunits of a protein assembly. After different steps of analysis (Figure 1) one can build 2D interaction maps of protein complexes. Native MS represents a powerful and appropriate tool to study the architecture of protein complexes of different sizes (from some tens of kDa up to MDa) when high-resolution structural data are not available. It complements the existing methods in structural biology since it requires very little amounts of sample (5 to 10 μM of a protein complex are sufficient for a successful analysis), tolerates heterogeneity of subunit composition, does not require crystals, and symmetry in the structure does not represent an advantage


Fig 1. A 2D interaction network of subunits within protein complexes can be generated through a multi-step process using native mass spectrometry (native MS).
Step 1. Under denaturing conditions, the subunits of a complex are chromatographically separated and their masses are determined.
Step 2. Using MS conditions optimized for preserving non-covalent interactions, the measured mass of the intact complex reveals the stoichiometry of the subunits.
Step 3. A series of tandem MS spectra indicates which are subunits located within the core and which are peripheral proteins.
Step 4. By adding organic solvent, overlapping sub-complexes (e.g. dimers, trimers) are generated. The composition of the different sub-complexes reveals the interactions between the subunits.
Step 5. Individual subunits can be mixed in solution and a mass shift can be detected if a subcomplex is generated.
Step 6. The combination of all these data allows one to draw an accurate 2D interaction network of a protein complex.

Key Words:


Native mass spectrometry, protein complexes, non-covalent interactions, 2D interaction maps.

Techniques:

- Expression and purification of protein complexes
- Native mass spectrometry
- Protein biophysical characterization

Team members:

- Luca Signor, CEA Research Engineer

Available services:

- Mass spectrometry platform http://www.isbg.fr/samples-preparat...

Selected Publications:

Boeri Erba E, Petosa C (2015) The emerging role of native mass spectrometry in characterizing the structure and dynamics of macromolecular complexes. Protein Sci. 24(8):1176-92. doi: 10.1002/pro.2661

Boeri Erba E, Klein PA, Signor L. (2015) Combining a NHS ester and glutaraldehyde improves crosslinking prior to MALDI MS analysis of intact protein complexes. J Mass Spectrom. 50(10):1114-9. doi: 10.1002/jms.3626

Boeri Erba E (2014) Investigating macromolecular complexes using top-down mass spectrometry. Proteomics. 14(10):1259-70. doi: 10.1002.

Signor L, Boeri Erba E. (2013) Matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometric analysis of intact proteins larger than 100 kDa. J Vis Exp, (79). doi: 10.3791/50635.

Levy ED, Boeri Erba E, Robinson CV, Teichmann SA. (2008) Assembly reflects evolution of protein complexes. Nature. 453: 1262-5.