► MASS SPECTROMETRY

• Protein identification by mass spectrometry (LC-MS/MS) : peptides are obtained from a SDS-PAGE gel or solution following enzymatic treatment and are analyzed by nanoLC-MSMS. MS/MS spectra are compared with protein data from public or specific databases.

• Characterization of post-translational modifications (phosphorylation, acetylation, ...): post-translational modifications are identified in the MS/MS spectra and modification sites are validated by visual inspection of the MS/MS spectra.
• Relative quantification of proteins (to compare experimental conditions) : identification and relative quantification of proteins in a complex mixture by Label Free (LFQ), SILAC or TMT/iTRAQ labeling.
• Accurate mass measurement of small molecules, peptides, proteins,oligonucleotides and synthetic polymers : by MALDI/TOF or ESI/Orbitrap after deconvolution of multiply charged ions.

Three types of services are available:

• Equipment: BLITZ and Biacore T200 and consumables (subject to access approval   and training)
• Customized services
• Project Management

The BLItz system provides two types of analyses that are simple, quick and inexpensive:

• Detection and quantification of tagged proteins (His, GST, Strep…) or antibodies in a culture supernatant before checking the level of expression of the protein of interest,
• Detection and characterization of interactions (protein-protein or protein-small molecule, protein-carbohydrate, protein-DNA, protein-RNA) before advanced characterization on the Biacore T200.

The Biacore T200 provides several types of high-sensitive analyses:

• Characterization of interactions (protein-protein, protein-small molecule, protein-carbohydrate, protein-DNA and protein-RNA, protein-cell, protein-virus particle by determination of kinetic constants: association (ka) and dissociation (kd) constants, affinity (KD and KA) and thermodynamic properties of interactions (ΔG and ΔH; analyses at different temperatures)
• Characterization of antibodies: screening and selection of the best antibodies, determination of kinetic and affinity constants, identification of epitopes, immunization follow-up…
• Analysis of competitive process or multi-molecular assemblies: screening of drugs inhibiting interactions, characterization of sites of interaction by competition, analysis of complexes involving several partners…
• Determination of concentration of a biomolecule based on specific interactions with a high affinity binding partner
• And finally, capture, isolation and recovery of unknown binding partners and their identification by Mass Spectrometry.