Top Down-based Sequencing

In top-down proteomics, intact protein molecular ions generated by ESI or MALDI are introduced into mass analyzer and are subjected to gas-phase fragmentation. Top-down analysis facilitates direct observation of C- and N-termini for identification of truncations and distinguish one isoform from the other by different sequences.

Compared with conventional Edman degradation, Creative Proteomics can provide both N- and C-terminal sequencing services, using MALDI ISD mass spectrometry under Top-Down strategy. even when the termini are blocked by modification, including N-terminal acetylation, N-terminal pyroglutamic acid, sequence truncations and signal sequences. This analysis can be also used for characterization of protein degradation, and enzymatic cleavage.

The top-down sequence analysis confirms 20-80 residues from both the N-terminal and the C-terminal of the intact protein.

http://www.creative-proteomics.com/services/top-down-based-sequencing.htm