CovalX

CovalX developed a method for a fast, sensitive and accurate analysis of protein complexes by High-Mass MALDI mass spectrometry. Unfragmented and undigested, the protein complexes are detected intact using specially developed cross-linking reagents and high-mass detection system.

Using cross-linking chemistry and High-Mass MALDI ToF mass spectrometry, it becomes possible to easily analyze non-covalent protein complexes in the 1-1000 kDa range.

The use of High-Mass MALDI allows a much faster, cheaper and more accurate method for studying protein interactions:

• Stoechiometry of the complex: unique information for understanding the shape of your protein complex.
  
• Clear identification of the partners involved in the complex.
  
• No need for immobilization, the complex is detected without labeling.
  
• Fast: 30 minutes per assay.
  
• Specific: only the specific complexes are detected.
  
• Sensitive: Only a few hundred femtomol of protein sample is a few ul are require to achieve the analysis.

Antibody-Antigen interactions are largely used in drug discovery, molecular biology, pharmacology and clinical diagnostics. The characterization of the monoclonal antibodies of interest is a pre-requisite for drug discovery, quality control, to improve detection assays, making sure that the best antibody is developed for a specific project.

CovalX technology for antibody characterization allows:

• Interaction Analysis: characterization of the immuno-complex, stoechiometry of the binding
  
• Multi-binding experiments: sandwich assays
  

The characterization of the interaction between a monoclonal antibody and its antigen is crucial for understanding the structural properties of an immuno-complex. Using chemical cross-linking and High-Mass MALDI mass spectrometry, it is possible to detemine with high-accuracy the mass of the antigen targeted by a monoclonal antibody. The stoechiometry of the interaction between the antigen and the antibody is also determined. This analysis is crucial when developing therapeutic antibodies.

CovalX provides various techniques for mapping of conformational epitopes using the most advanced mass spectrometry equipment.

Crosslinking Coupled Mass Spectrometry (XL-MS)

Based on our unique MALDI mass spectrometry technology and decades of crosslinking experiences, CovalX offers characterization of epitopes with high resolution. Using mass spectrometry and covalent tagging it is possible to characterize conformational and linear epitopes in weeks, with a resolutions of 1-3 amino acids. No need for peptide synthesis or micro-array chips, mass spectrometry allows identity of the interacting peptides with unmatched accuracy.
This technique provides the lowest cost, lowest sample consumption and shortest analysis time possible when compared with other conformational epitope mapping technique available. Additionally because the complexes are first covalently stabilized, multiple enzymes can be utilized providing highly optimized digestion conditions with the highest sequence coverage possible.

This technique can provide both epitope and paratope data in one experiment. Over the years this technique has been established as a reliable source of data for both research and patent filing purposes.

Hydrogen Deuterium Exchange (HDX)

HDX has been utilized on a research scale for many years at the academic level and within larger pharmaceutical companies. More recently with the advancement of automated robotics, sample handling and data analysis software, HDX can now be offered on a timescale and with sample consumptions reasonable for more mainstream analysis.
CovalX is using the latest mass spectrometry equipment, HDX automation robotics and software to rapidly characterize the binding sites using HDXMS. Additionally, CovalX has technicians with combined decades of experience optimizing and understanding HDXMS workflows.

CovalX Advantages

• Speed: 3-4 weeks for one epitope; 5-6 weeks for projects with up to 5 epitopes against the same antigen. Possibility to screen simultaneously up to 100 monoclonal antibody against the same target.
  
• Sample Consumption: 150 ug of antigen and 150 ug of mAb/epitope.
  
• Resolution down to 1-3 amino-acids.
  
• Applicable for conformational, discontinuous and linear epitopes.
  
• Applicable for any therapeutic proteins or antigen. No limit in size. No limit in complexity (multimers, hydrophobicity)
  
• No need for crystallography, recombinant protein work, peptide synthesis, micro-array. The interaction is analyzed directly, by mass spectrometry.
  
• Cost: The CovalX techniques save money in 3 ways
  
  • Lowest cost for analysis of any true conformational technique
    
  • Sample consumption: Lowest sample used saves on production costs/time
    
  • Time: Our techniques are fast and reliable.
    

The analysis of the aggregation phenomenon of therapeutic proteins is of crucial importance as more and more pharmaceutical products are proteins or peptides. CovalX introduces a unique tool for the direct characterization of therapeutic protein samples based on High-Mass MALDI mass spectrometry.

The ability of an antigen to simultaneously bind two different monoclonal antibodies needs to be addressed for the structural characterization of both antigens and monoclonal antibodies. In practice, this is important for the development of immunochemical sandwich assays. By combining chemical cross-linking and High-Mass MALDI mass spectrometry, it becomes possible to perform multibinding experiments with high accuary and sensitivity.