You might have seen a lot of publications and webinars discussing ZipChip’s MS compatible charge variant analysis of biotherapeutic mAbs, but did you know you can use ZipChip for peptide mapping too? Some of our earliest customers have been using their systems for peptide mapping and love it because it’s easy, fast, and provides an orthogonal approach to LC for separating tricky analytes like conjugated peptides, complex glycopeptides, isomerized residues, and degradants. You can find applications of peptide maps and peptide analysis with ZipChip in cancer research (1), anti-viral therapy research (2), glycoproteomics (3), and biopharma (4).
One application of peptide mapping that is getting impossible to ignore is the multi-attribute method (MAM). While still relatively new, MAM is gaining popularity in the biopharmaceutical industry. In its simplest form, MAM is a quantitative peptide map used to directly monitor multiple CQAs of biopharmaceutical drug substances, such as post-translational modifications, sequence variants, and impurities. It is appealing with regards to a quality by design (QbD) approach because it can streamline the characterization workflow and be utilized at many different stages of development from early in discovery to process development and potentially even QC. However, the long LC gradients (sometimes more than 2 hours) often needed to accurately measure vital CQAs presents a potential bottleneck for MAM as it is increasingly used for analysis. ZipChip’s peptide mapping run times are typically about 15 minutes which would result in major time savings for these experiments.
A recent publication from Amgen explored ZipChip as an alternative separation technique for MAM analysis. Initially attracted by the speed of ZipChip peptide maps, the authors explored how ZipChip performs for key peptides that are often troublesome to separate with LC, specifically isoAsp from Asn- and Asp-containing peptides. For many peptides ZipChip was able to resolve all variants of the degraded peptides and provide site specific characterization of the degradants, and for the others provide information about degradation hot spots and inform decisions about stability. In a head-to-head comparison with UHPLC-MS, the ZipChip analysis was about 20 times faster, returned higher sequence coverage, and provided comparable quantitation results for a panel of 15 CQAs including deamidation, aspartic acid isomerization, methionine oxidation, and tryptophan oxidation. These results are extremely promising, and the authors conclude with noting that for a lead molecule selection MAM campaign of 60 candidates the speed of ZipChip could reduce the data collection time from 8 days to an overnight experiment. Time savings like that are hard to ignore.
In many ways both ZipChip and MAM are still newcomers to the world of biopharma. As MAM continues to be utilized in biopharma and accepted by regulatory agencies we are interested and excited to see how ZipChip may become an asset within this workflow.
Read the full details of the work done by Amgen here.