DC Biosciences proposes a combination of de novo sequencing of monoclonal antibodies or other recombinant proteins combined with tandem mass tag (TMT) labelling and quantitative mass spectrometry to monitor and assess temporal stability during product storage.
Assessing the storage stability of a protein product by tandem mass tag (TMT) labelling and quantitative mass spectrometry begins with an initial understanding of the amino acid sequence of the antibody or protein. If you do not have access to the cell line or the sequence, you can use mass spectrometry-based proteomics to determine the sequence prior to production or further characterization. We use the world-leading REmAb de novo protein sequencing technology as part of our solution.
Samples of an antibody or protein that have been stored for different lengths of time, or under different conditions, can be assessed by combining the tandem mass tag (TMT) reagent with quantitative mass spectrometry. This will provide information on the stability of a product and/or the rate of degradation. Such information will be invaluable in determining accurate storage shelf-life of, e.g., protein therapeutics.
The TMT isobaric labels are amine-reactive and modify the N-terminus of peptides and the side chain of lysine residues. Currently, TMT reagents are available as 6-, 10-, 11-, 16- and 18-plex kits. Briefly, peptides generated by digestion of the antibodies/proteins are modified with these small, stable, isotopically-labelled molecular tags. After the individual samples have been labelled with the different tags, the samples are combined and analysed by mass spectrometry.
At this point, the mass of the same (labelled) peptide across the different samples is indistinguishable. Only after selection and fragmentation of the peptide (and release of the isobaric label) can the origin of the peptide be determined. In addition, the release of the label enables the relative quantitation of the peptide between conditions.
Entire antibodies and proteins can be thus labelled, and the analysis can be focused on, e.g., the epitope-recognising areas of the antibodies or active sites in catalytic proteins.
In short, if your project requires information on the long-term storage stability of your monoclonal antibodies or proteins, this solution is crucial. Our innovative blend of TMT labelling, quantitative mass spectrometry and de novo sequencing will produce the accurate data you need to move your project forward.