Summary
Mass spectrometry-based proteomics enables large-scale identification and quantification of proteins using ESI and MALDI ionization coupled with high-resolution analyzers like Orbitrap and TOF.
Key Points
- 1ESI and MALDI are primary ionization methods
- 2Bottom-up proteomics digests proteins for MS/MS analysis
- 3Orbitrap provides ultra-high resolution
- 4Quantification via label-free, SILAC, or isobaric tagging
Mass spectrometry (MS) has revolutionized proteomics. Key ionization methods include Electrospray Ionization (ESI) for LC-MS coupling and MALDI for tissue imaging. Bottom-up proteomics involves protein digestion, LC separation, and MS/MS analysis. Mass analyzers include TOF, Quadrupole, Orbitrap, and Ion Trap. Tandem MS fragmentation (CID, HCD, ETD) reveals peptide sequences. Quantification uses label-free methods, SILAC metabolic labeling, or isobaric tags (TMT/iTRAQ). Database searching tools like MaxQuant enable protein identification with FDR control.