Contact us
If you have a question or need a quotation for your project using one of our services, please just fill out the Inquiry Form on the "Contacts" page, and we will do our best to respond to your inquiry within 24 hours.
A free online tool for protein cleavage sites prediction with a chosen enzyme.
Calculate monoisotopic and average mass of a custom peptide or peptides predicted from a protein.
The cleavage specificities of selected enzymes.
A comprehensive and freely accessible resource of protein sequence and functional information.
Mass spectrum simulation tool for peptide/protein sequences. The number of charge can be custom defined.
An online tool predicts m/z values for SMS ions generated from selected fragmentation methods such as CID, ECD, or ETD. The ion type and maximum number of charge can be pre-defined.
PDB provides the most complete collection of information about the 3D structures of proteins, protein complexes and other biomolecules.
Useful links
HDX-MS Epitope Mapping Service
Epitope mapping is the process of identifying the binding site of an antibody on its target antigen protein. Epitope mapping is a crucial step during the development of new antibody drugs, vaccines, and diagnostics. It can help better understand the mechanism of how they function and develop more potent molecular candidates, and also provide required structural information for regulatory filling and patent protection. Epitopes can be classified into two main groups: linear and conformational. Linear epitopes are composed of a sequence of continuous amino acids on just one segment of the antigen protein. In contrast, conformational epitopes are formed by amino acids from a number of discontinuous segments which are brought together upon three-dimensional protein folding. This character makes conformational epitopes more difficult to map because they are only formed in the native structure of the antigen, which cannot be reliably mimicked by using peptides. The vast majority of antibodies act through specific binding to the conformational epitopes on their antigen targets.
HDX-MS epitope mapping determines the antibody binding site by using Hydrogen/Deterium eXchange coulpled with Mass Spectrometry. This technique measures the solvent accessibility of amino acid residues in the protein thus can determine the interaction site of the antigen-antibody complex in its native solution, and does not introduce any modifications (e.g. mutation) to either the antigen or the antibody. During analysis, both the antigen by itself and the antigen-antibody complex are incubated in deuterated solvent to allow the hydrogens to exchange with deuterium. Because the antibody provides extra protection for those residues in the binding site, the epitope can thus be determined by comparing the exchange behavior of the unbound antigen with that of the antigen-antibody complex.
The widely used pepsin digestion based “bottom-up” HDX-MS approach normally can only provide peptide level resolution with a limited sequence coverage. At NovoAb we have developed an innovative FineMapping technology based on “top-down” and “middle-down” HDX-MS strategies, which enhanced the epitope mapping spatial resolution up to single amino acid, with a more complete sequence coverage up to 100%. Unlike epitope mapping using a peptide library, which only works best for linear epitopes, our HDX-MS fine mapping service platform works well for both linear and conformational epitopes, thanks to its direct use of the intact antigen protein at its native conditions. Read more about epitope mapping here.
Key features:
- 100% success rate
- Amino acid resolution
- Linear and conformational epitopes
- High-throughput screening of >50 candidates against one antigen
- Accurate mapping for glycosylated antigens by FineMapping technology
- Epitope mapping for unpurified/difficult targets
- Epitope mapping for bispecific antibodies
- Tailored service by top-down, bottom-up, or middle-down HDX-MS
- Unparalleled sensitivity using subzero HPLC technology
- Comprehensive and easy-to-understand report
