Sequencing
- Sequencing
- Peptide sequence via MSn
- Cyclic peptides
For peptide sequencing we use the MS/MS method. Whether complete elucidation of the sequence is possible or not depends on the nature of the sequence. For peptides containing 20-30 amino acid residues, complete sequence elucidation is usually possible.
Difference between Edman and MSn sequencing:
Whereas Edman degradation starts at the N-terminus and proceeds sequentially to the C-terminus, MSn fragments the complete molecule. As a consequence:
Under certain circumstances Edman can fail after a couple of amino acids whereas
MS/MS can fail for longer peptides primarily at the N- and/or C-terminus.
In contrast to Edman degradation, MS/MS can fail only for a short part of the sequence but verifying the sequence on both sides of the unverified part.
- For information about limitations of the methods download PDF.
