Direct Mass Spectrometry Analysis of Protein Complexes and Intact Proteins up to >70 kDa from Tissue.
Rian L GriffithsAlbert KonijnenbergRosa VinerHelen J CooperPublished in: Analytical chemistry (2019)
Native liquid extraction surface analysis (LESA) mass spectrometry allows direct analysis of folded proteins and protein complexes from biological substrates, such as dried blood spots and thin tissue sections, by use of native-like extraction/ionization solvents. Previously, we have demonstrated native LESA mass spectrometry of folded proteins up to 16 kDa as well as the 64 kDa hemoglobin tetramer, from mouse tissues. With denaturing LESA solvents, the highest mass protein detected in tissue to date is ∼37 kDa. Here, we demonstrate native LESA mass spectrometry by use of a Q Exactive UHMR Hybrid Quadrupole-Orbitrap (QE-UHMR) mass spectrometer, pushing the upper mass limit of proteins detected in tissue to >70 kDa. Moreover, a protein trimer of 42 kDa was detected and its stoichiometry confirmed by higher energy collision dissociation (HCD). The benefits of inclusion of detergents in the LESA sampling solvent are also demonstrated.
Keyphrases
- mass spectrometry
- liquid chromatography
- gas chromatography
- heat shock protein
- high resolution
- high performance liquid chromatography
- ionic liquid
- tandem mass spectrometry
- capillary electrophoresis
- protein protein
- high resolution mass spectrometry
- ultra high performance liquid chromatography
- binding protein
- small molecule
- gene expression