Signatope Cross-Species TXP Assays

Mass spectrometry (MS) is a highly specific mean for the detection and quantification of proteins. The incorporation of a targeted enrichment step using antibodies led to further improvements in sensitivity and the development of mass spectrometry-based immunoassays. Here, the analyte - the protein itself or a tryptic peptide thereof - is enriched by an antibody prior to the mass spectrometric read-out.

MS-based immunoassays provide advantages over classical sandwich immunoassays, since the mass spectrometric readout confirms the identity of the analyte unambiguously and only one capture molecule is required. Additionally, the mass spectrometric data allow discrimination between different protein isoforms associated with related or alternatively processed or spliced genes, which is difficult when antibodies are used exclusively.

The lack of appropriate antibodies has so far limited the application of MS-based immunoassays approaches for protein quantification. Our novel concept of using group-specific anti-peptide antibodies, so-called Triple X Proteomics (TXP) antibodies for the enrichment of groups of signature peptides, enables us to develop multi-specific antibodies, which can be used for the enrichment step of multiple analytes harboring a common motif. Since the motifs comprise only 4 amino acids, TXP antibodies can be used for enrichment of protein families and for development of cross-species assays.

We have established MS-based immunoassays employing TXP antibodies for several applications, including a number of cross-species ADME/Tox assays that represent truly translational marker assays.

We offer

  • Membrane protein (GPCR) assays

  • Coagulation factor assays

  • Assays for Cytochrome P450 (CYP) enyzmes and drug transporters

  • DILI and DIKI marker assays

  • Assay development for any protein in any specimen and any species

Please email us to receive more information.

References

Steinhilber A, et al. (2018). “Mass Spectrometry-Based Immunoassay for the Quantification of Banned Ruminant Processed Animal Proteins in Vegetal Feeds.” Anal Chem.

Weiss F, et al. (2018). “Direct Quantification of Cytochromes P450 and Drug Transporters-A Rapid, Targeted Mass Spectrometry-Based Immunoassay Panel for Tissues and Cell Culture Lysates.” Drug Metab Dispos 46(4): 387-396.

MacLean C, et al. (2017). “Concept: The Use of Targeted Immunoaffinity Proteomics for Routine Assessment of In Vitro Enzyme Induction.” J Pharm Sci 106(12): 3453-3457.

Wegler C, et al. (2017). “Variability in Mass Spectrometry-based Quantification of Clinically Relevant Drug Transporters and Drug Metabolizing Enzymes.” Mol Pharm 14(9): 3142-3151.

Weiss F, et al. (2015). “Indirect protein quantification of drug-transforming enzymes using peptide group-specific immunoaffinity enrichment and mass spectrometry.” Sci Rep 5: 8759.

Weiss F, et al. (2014). “Catch and measure-mass spectrometry-based immunoassays in biomarker research.” Biochim Biophys Acta 1844(5): 927-932.

Eisen D, et al. (2013). “G protein-coupled receptor quantification using peptide group-specific enrichment combined with internal peptide standard reporter calibration.” J Proteomics 90: 85-95.

Volk S, et al. (2012). “Combining ultracentrifugation and peptide termini group-specific immunoprecipitation for multiplex plasma protein analysis.” Mol Cell Proteomics 11(7): O111 015438.

Hoeppe S, et al. (2011). “Targeting peptide termini, a novel immunoaffinity approach to reduce complexity in mass spectrometric protein identification.” Mol Cell Proteomics 10(2): M110 002857.

Planatscher H, et al. (2010). “Optimal selection of epitopes for TXP-immunoaffinity mass spectrometry.” Algorithms Mol Biol 5: 28.

Poetz O, et al. (2009). “Proteome wide screening using peptide affinity capture.” Proteomics 9(6): 1518-1523.