X-ray structure of the 18-amino acid peptide (red) bound to the swelling marker calprotectin (light blue). A lateral circulation cassette is shown. Credit: Christian Heinis (EPFL)/ Joëlle Jourdan (BÜHLMANN AG).
Researchers from BÜHLMANN and EPFL have actually developed peptides as an alternative to antibodies for discovering the protein calprotectin, crucial for diagnosing and keeping track of inflammatory disorders. These peptides use a more accurate, stable, and cost-effective ways for biomarker detection, boosting the diagnostic power of calprotectin. Additional tests are underway to equate this advancement into an useful diagnostic item.
Typical inflammatory conditions such as ulcerative colitis and Crohns disease can be diagnosed or kept track of by measuring the protein calprotectin in stool samples, while serum levels of calprotectin could be used to keep an eye on the inflammation status in rheumatoid arthritis. Calprotectin concentrations in patient samples are usually figured out using antibodies that detect the protein and bind, e.g. in lateral flow assays like the now all-too-familiar home COVID-19 test packages.
There is an issue with antibody-based calprotectin assays: the outcomes can differ depending on the type of antibody and assay utilized. This happens since antibodies may bind to various websites on the protein, or might not have a consistent structure. The antibodies can likewise become suspended over time due to unfolding or precipitation.
A lateral circulation assay for calprotectin. Credit: Christian Heinis (EPFL)/ Joëlle Jourdan (BÜHLMANN AG).
One possible option is to utilize peptides instead of antibodies to measure and identify illness markers like calprotectin. Peptides are sequences of approximately 50 amino acids that can bind to proteins with high affinity and selectivity, but, unlike antibodies, they can be chemically produced with high pureness and homogeneity. In addition, peptides are steady in time, are cheaper to produce than antibodies and with lower inter-batch irregularity, and they can be connected to a particular area on a surface area, substantially simplifying diagnostic assay advancement since it permits a more regulated and accurate way of identifying biomarkers.
With this concept, Christian Gerhold, CTO of the diagnostics company BÜHLMANN, worked with the group of Professor Christian Heinis at EPFL to establish human calprotectin ligands based on peptides. From a library of more than 500 billion various peptides, Cristina Diaz-Perlas, a postdoc in Heiniss group, isolated a number of binders of calprotectin, and showed that the peptides are matched for calprotectin metrology in simplified lateral flow assays. The finest peptide had a dissociation constant of 26 nM– a measure of how tightly it binds calprotectin, making it a great candidate for diagnostic tests.
The peptide not only binds to a big surface region of calprotectin however likewise to a specific kind of calprotectin that is the appropriate types in client samples. Under the assistance of Benjamin Ricken at BÜHLMANN, the peptide was lastly tested in professionally put together lateral circulation cassettes and discovered that it was matched for precise detection and metrology of calprotectin. In a proof-of-concept research study, this setup was utilized to quantify the concentration of calprotectin in serum gotten from patient blood samples.
The peptide established is the first synthetic affinity reagent that could be generated against the biomarker calprotectin. “The EPFL and BÜHLMANN groups are presently performing more tests with the calprotectin-specific peptide to translate the assay into a product that can bring the diagnostic power of this significantly essential biomarker to a new level to help patients struggling with inflammatory illness,” states Christian Heinis.
Christian Gerhold includes: “This partnership significantly benefited from BÜHLMANNs knowledge to manage the biomarker and produce, and proficiency of the EPFL team to create and evaluate large combinatorial libraries of peptides by phage screen.”.
Referral: “High-affinity peptides established versus calprotectin and their application as synthetic ligands in diagnostic assays” by Cristina Díaz-Perlas, Benjamin Ricken, Lluc Farrera-Soler, Dmitrii Guschin, Florence Pojer, Kelvin Lau, Christian-Benedikt Gerhold, Christian Heinis, 17 May 2023, Nature Communications.DOI: 10.1038/ s41467-023-38075-7.
Financing: Innosuisse– Schweizerische Agentur für Innovationsförderung.
Researchers from BÜHLMANN and EPFL have actually established peptides as an alternative to antibodies for detecting the protein calprotectin, crucial for detecting and keeping an eye on inflammatory disorders. With this idea, Christian Gerhold, CTO of the diagnostics business BÜHLMANN, worked with the group of Professor Christian Heinis at EPFL to develop human calprotectin ligands based on peptides. From a library of more than 500 billion different peptides, Cristina Diaz-Perlas, a postdoc in Heiniss group, isolated several binders of calprotectin, and showed that the peptides are fit for calprotectin metrology in streamlined lateral circulation assays. The peptide not only binds to a large surface area of calprotectin but also to a particular type of calprotectin that is the relevant types in client samples. Under the assistance of Benjamin Ricken at BÜHLMANN, the peptide was lastly evaluated in expertly put together lateral circulation cassettes and discovered that it was fit for precise detection and metrology of calprotectin.
