This website uses cookies so that we can provide you with the best user experience possible. Cookie information is stored in your browser and performs functions such as recognising you when you return to our website and helping our team to understand which sections of the website you find most interesting and useful.
Talk to Our Scientists
Epitope mapping identifies antigen regions recognized by antibodies. Traditional methods like x-ray crystallography and alanine scanning are costly, lack resolution and require specialized expertise. However, innovative Mass Spectrometry (MS) techniques like Chemical Cross-Linking (XL-MS) and Hydrogen Deuterium eXchange (HDX-MS) offer advantages of higher resolution, increased cost-effectiveness, and more accessible results, making them the preferred choice for conformational epitope mapping.
Linear Vs Conformational Epitopes
Epitopes are categorized as linear or conformational, with linear epitopes consisting of a sequential amino acid stretch lacking 3D structure, while conformational epitopes require tertiary folding for binding. Conformational epitopes often arise from discontinuous amino acid sequences, necessitating structural folding.
Mapping techniques can identify both epitope types, but linear methods cannot map conformational epitopes. Resolution varies, with higher resolution techniques being more complex and time-consuming, requiring more material and time.
Identifying Cross-Linked Peptides Using XL-MS
Peptide cross-links can be identified using mass spectrometry through various methods. Traditional approaches include chemical labeling combined with mass spectrometry, where cross-linked peptides are labeled with specific chemical tags before analysis.
However, this method has limitations in terms of complexity, potential artifacts, and incomplete coverage. In contrast, chemical cross-linking mass spectrometry (XL-MS) directly cross-links protein residues, allowing for the identification of cross-linked peptides without the need for labeling.
XL-MS offers benefits such as enhanced specificity, reduced sample manipulation, and increased coverage of cross-links. Due to these advantages, XL-MS is rapidly becoming the preferred method for peptide cross-link identification.
XL-MS Applications:
- Protein-Protein Interactions
- Mapping Aggregates
- Parallel Paratope Mapping Analysis
How does Hydrogen Deuterium eXchange Mass Spectrometry (HDX-MS) work and when should it be applied?
HDX-MS facilitates epitope mapping and protein structural analysis. It involves labeling proteins with deuterium atoms from a solvent, analyzing peptide deuteration rates via MS. The benefits of HDX-MS include sensitivity with minimal sample prep.
Limitations are that it requires specialized equipment and expertise, meaning that partnership with a contract research organization (CRO) is often necessary to uncover valuable insights.
HDX-MS Applications:
- Biosimilar characterization
- Higher order structure
- Conformational/Protein dynamics
- Small molecules interaction
- Protein-Protein interactions
- Protein folding characterization
Epitope Mapping Solutions for Bispecific Antibody Challenges
The challenges in making bispecific antibodies, including design complexity, manufacturability, immunogenicity, stability, pharmacokinetics, and manufacturing costs, are well-known. MS epitope mapping provides solutions by precisely characterizing antibody-antigen interactions, epitope specificity, and structural features. This enables optimization of antibody design for improved specificity and reduced immunogenicity, as well as assessment of stability and pharmacokinetics.
Additionally, MS facilitates quality control and characterization during manufacturing, ensuring consistency and quality of bispecific antibodies.
Why Choose CovalX
At CovalX, we offer innovative solutions tailored to your protein characterization challenges. With a focus on advanced MS techniques for the biophysical characterization of proteins, particularly XL-MS and HDX-MS methodologies, we can give you the support you need to advance your research efforts efficiently and effectively.
From accurately identifying antigen regions to real-time protein interaction analysis, we provide precise and reliable results, empowering you to make breakthrough discoveries with confidence.
Readout | Characterization of conformational or linear epitopes |
---|---|
Determination of both epitope and paratope | |
Affordable | Competitive cost compared to other mapping techniques |
Low Sample Consumption | Only 200μg of each antigen/antibody required |
Full Compatibility | No need for immobilization, recombinant protein work, peptide synthesis or micro-array. The interaction is analyzed directly by Mass Spectrometry in solution. Analysis of full mAbs, fAbs, tagged proteins or modified proteins. |
Fast Turnaround | Four to five weeks delivery time (less with RUSH) |
Quality Work | Expert team with more than 15+ years of epitope mapping experience using mass spectrometry. |