Peptide mapping by mass spectrometry (peptide mass fingerprinting) is used in protein characterization to produce a unique ‘fingerprint’ of an individual protein and to compare this with the theoretical gene-derived amino acid sequence. This analysis is used for identification purposes at all stages of drug discovery or to demonstrate comparability and consistency between batches for release during manufacturing. It may also be used for the characterisation of reference batches.
Peptide mapping is a very powerful tool in protein characterisation. Peptide mapping can also be used for:
Dilsulphide bridge assignment
Guiding the choice of signals for subsequent MS/MS or gas phase sequence analysis
MS Peptide Mapping was originally developed at SGS M-Scan in the early 1980’s using Fast Atom Bombardment MS (FAB-MS). The protein molecule is fragmented using specific enzymatic or chemical methods and the resulting peptide mixture analysed using MS, now the modern techniques of Electrospray (ES-MS) or MALDI TOF-MS. For complex mixtures, on-line LC-MS can be used.
Peptide mapping is a key part of the ICH Q6B guidelines for characterization and confirmation of biopharmaceuticals in support of new marketing applications.