N and C terminal Sequencing

MALDI Top-down Characterization

Identify your protein  through intact mass measurement and confirm N- and C-terminal modifications including truncations and mutations without proteolytic digestion in less than 1 minute with MALDI intact protein sequencing.

Intact mass measurement of your therapeutic (including antibodies) is possible using Bruker MALDI-TOF instruments due to the high mass range afforded by the proprietary Flash detector.
Top-Down sequencing (TDS) extends the analytic possibilities of Bruker mass spectrometers significantly. TDS permits the direct access to sequence information even from large, undigested proteins. It powerfully detects and localizes chemical modifications, PTMs, mutations and protein isoforms that are more difficult to detect using classical trypsin digests. TDS also provides the ability to characterize protein termini in a targeted fashion and extends capabilities significantly that were previously expected from Edman sequencing.
Common to all TDS methods is the utilization of fragmentation techniques that produce peptide bond fission directly at the site of excitation in the peptide sequence. This provides regular sequence ladders that are relatively simple to interpret.


Sequencing of protein N- and C-termini

MALDI-TDS efficiently reads out N- and C-terminal sequences even from large proteins (> 40 kDa) using the in-source decay fragmentation (ISD) in the MALDI source. MALDI ISD produces singly charged species making sequence read-out extremely easy. These can be used to identify an unknown protein, to assign detailed structures of fusion proteins or mutation sites. Even complex, PEGylated therapeutic proteins and antibodies (intact and subunit) can be analyzed using MALDI-TDS. Adding value to and complementary to traditional Edman sequencing capabilities, MALDI-TDS works as well on N-terminally blocked proteins and provides information about the C-terminal too. Furthermore, the whole method takes only a few minutes from sample preparation, spectrum acquisition, spectral processing using dedicated fast and reliable TDS software, to the result in the form of an annotated ISD spectrum. A PDF report can be automatically generated to provide a documented result of the analysis.

In summary, the benefits of MALDI TDS include:

  • Generate sequence information, even from large undigested proteins
  • Fast N + C termini characterization
  • Offers added-value over Edman Sequencing



Watch our video
"Top-Down Protein Sequencing in a Minute"