Creative Proteomics
Peptidomics Services
Top-down mass spectrometry, as an emerging approach for characterization of intact proteins, is established as a contrast to the bottom-up strategy, which is also called shotgun method, for analysis of peptides from enzymatic or chemical cleavage of intact proteins. Currently the bottom-up strategy is the most mature and most widely used approach for protein identification, characterization of post-translational modifications, and even relative and absolute quantification. But meanwhile, the application of the bottom-up strategy is limited by its inherent shortages.Most popular related searches
In top-down proteomics, intact proteins are isolated from complicated biological matrices through PAGE or immunoenrichment, for direct analysis using electrospray ionization (ESI) or matrix-assisted laser desorption/ionization (MALDI) to generate ions and then fragment ions with collision introduced dissociation (CID), higher energy collision introduced dissociation (HCD), electron-capture dissociation (ECD) or electron-transfer dissociation (ETD) and analyze with tandem mass spectrometry, making it a promising alternative strategy for protein identification, profiling, sequencing and PTM characterization.