COMPARISON OF THREE SOFTWARE PACKAGES FOR IDENTIFICATION OF MCF 7 MEMBRANE PROTEINS EXTRACTED WITH TRIFLUOROETHANOL.

The discovery of new markers or therapeutic targets for cancer implies the exploration of sub-proteomes to have access to proteins which couldn't be visible by total proteome exploration. The membrane compartment is currently one of the mos

Thiophilic adsorption revisited☆

International audienceSpecific and efficient selection of serum immunoglobulins, but not other proteins, on T-gel remains difficult. T-gel capacity was determined for different activation conditions and serum loadings. Mass spectrometry analysis was used to identify the proteins found in the flow-through and in the eluted fractions. Alpha-2-macroglobulin and albumin were the major contaminants of the eluates. The influence of the competition between immunoglobulins and the other serum proteins on the adsorption was also studied. Using a serum depleted in immunoglobulins (flow-through of a first chromatography on T-gel), many serum proteins were retained on the T-gel, including albumin. We conclude that T-gel selectivity is less than absolute and may reflect for a large part the experimental conditions of the adsorption

Usefulness of autoantigens depletion to detect autoantibody signatures by multiple affinity protein profiling

International audiencePatients with cancer produce specific autoantibodies against protein antigens present in limited amount among a large background of immunoglobulins (Igs), nonrelevant as biomarkers, including natural antibodies. Multiple affinity protein profiling (MAPPing) that combines 2-D immunoaffinity chromatography, enzymatic digestion of the isolated proteins, and identification by MS/MS, may facilitate the identification of these so far unknown patient antibodies. The first immunoaffinity chromatography is crucial, as it is used for selectively removing proteins (autoantigens) recognized by natural antibodies. Application of this depletion step to colon cancer cell proteins is specifically described along with the identification of the natural autoantigens, as well as the coupling of this depletion step with the next steps. By enabling to separate antibody-binding proteins recognized by either natural autoantibodies or patient-specific antibodies this approach may contribute significantly towards the definition of autoantibody signatures

Mitochondrial proteomic approach reveals galectin-7 as a novel BCL-2 binding protein in human cells

Our results reveal a network of new potential Bcl-2 partners identified through the Bcl-2 immunocapture and mass spectrometry approach and analyzed by gene ontology mining. Importantly, we report for the first time the identification of galectin-7, a member of a family of β-galactoside-binding lectins, as a new mitochondrial Bcl-2 interacting partner