Peptide mapping plays an essential role in characterizing therapeutic
proteins and antibodies, as required by FDA “well characterized biological
product concept” and ICH Q6B guidelines. ProtTech’s Peptide Mapping service
can provide important information about the structure and comparability of a
therapeutic protein product: i) it can confirm the amino acid sequence of a
protein, including its N- and C-terminus, which can’t be predicted based on
its gene sequence. ii) It can provide qualitative and quantitative information
about site and ratio of post-translation modifications (PTM), such as
glycosylation, acetylation, sulfation and phosphorylation. iii) It can provide
qualitative and quantitative information about degradation of a protein product,
including oxidation and deamidation.
ProtTech’s Peptide Mapping service offers several
unique features in characterizing therapeutic proteins: i) it is based on
LC-MS/MS (Tandem MS) technology, which, in contrast to LC-MS or MALDI-TOF based
peptide mapping, performs “sequencing” instead of “matching” peptides,
so the primary sequence of a protein can be conclusively confirmed by our
peptide mapping service; ii) Our proprietary ProtTechPepMap software tool is
capable of identifying protein N- and C-terminus, many types of common and
customer specified post-translational modifications, as well as degradation
products such as oxidation and deamidation; iii) In addition to using UV-Visible
chromatograph to detect and measure changes between a test protein product and a
reference standard, we also compare MS intensities of peptides between a test
sample and a reference, which can complement the limitations of the UV-Visible
chromatography in detecting small changes and separating co-eluted peptide
peaks.
