Do you want to verify the sequence of your protein or antibody?
Peptide mapping services using mass spec is one of the most valuable methods for verifying the amino acid sequence of proteins. Therefore, the analysis is an important part of the protein characterization needed for biologics.
Sequence coverage of proteins can be optimized by careful selecti...
Do you want to verify the sequence of your protein or antibody?
Peptide mapping services using mass spec is one of the most valuable methods for verifying the amino acid sequence of proteins. Therefore, the analysis is an important part of the protein characterization needed for biologics.
Sequence coverage of proteins can be optimized by careful selection of proteases for the digest. Our peptide mapping services can also provide detailed information about post-translational modifications – including deamidation and oxidation.
The standard service includes
Digestion with trypsin cleaving after Arg and Lys residues.
Analysis of the resulting peptide mixture by nano LC-MS/MS.
Peptide map of observed peptides – to confirm the expected amino acid sequence.
NB: Only in-gel samples can be submitted for online order.
Please send a request if your samples are not in-gel. You can also inquire about the optional services below:
Optional services
Multiple protease digestions e.g. Lys-C, Glu-C, chymotrypsin, Asp-N, Arg-C.
We would like to help you as much as possible with your project and therefore provide several kinds of customer support:
Technical details
Introduction to peptide mapping analysis
In our Mass Spectrometric Peptide Mapping services, we cleave the protein/antibody into smaller peptides using a specific protease. The peptides are analyzed by mass spec and then the observed peptides correlated to the protein/antibody amino acid sequence for peptide identification.
The identified peptides in the peptide map thus confirms the specific amino acid sequences covered by the peptide map, as well as the identity of the protein/antibody. Peptide mapping using a single protease typically gives a protein sequence coverage of 30-90%. By using two or more proteases this protein coverage increases to approx. 95-100%.
Detailed characterization of a protein/antibody requires careful investigation of the protein/antibody sequence to select the best proteases, and choice of nano-flow LC-MS/MS or standard flow UV LC MS/MS to observe the peptides.
The difference between the two techniques relates to the amount of material needed for the analysis. Nano-flow can thus be conducted on low microgram protein/antibody whereas the high-flow analysis requires at least 20 microgram per analysis. The high-flow analysis also include a UV-trace of the chromatogram.
Peptide mapping analysis of mAb
Nano-flow LC-MS/MS
We perform the peptide mapping using nanoLC-MS/MS on a Dionex 3000 mass spec system running at 300 nl/min equipped with C18 capillary column connected to a high-resolution Q-TOF instrument (Bruker Impact HD). The instrument runs either with a short or long gradient, and the Q-TOF set to data dependent analysis mode (DDA), switching between MS and MS/MS mode.
The analysis provides a Base Peak Chromatogram, and collects all MS/MS data for peptides with mass/charge from 200 to 1600 Da.
High-flow LC-MS/MS with UV
The peptide mapping using high-flow LC-MS/MS is performed on a Agilent 1200 system running at 0.2 ml/min equipped with C18 column connected to a high-resolution Q-TOF instrument (Bruker Impact HD). The instrument runs either with a short or long gradient, and the Q-TOF set to data dependent analysis mode (DDA), switching between MS and MS/MS mode.
The analysis provides both a UV- and a Base peak chromatogram, and all MS/MS data is collected for peptides with m/z from 200 to 1600 Da.
Protein/Antibody peptide mapping analysis by mass spectrometry requires a pure protein/antibody in sufficient amounts to obtain good data. It is thus important to prepare samples in a clean laboratory to avoid contamination with human keratin.
NB: Only in-gel samples can be submitted for online order. Please send us a request if you would like to submit in-solution samples instead.
Minimum sample amount: ~ 20-50 microgram protein or ~ 0.5 milligram antibody.
Use Eppendorf Safe Lock tubes, or similar high-quality tubes from your lab.
Related services
You can combine this analysis with other analyses such as:
