Macrocyclic peptides are promising candidates for pharmaceuticals, but their screening is difficult. Scientists have now developed an easy-to-use, high-throughput screening assay for cyclic peptides with affinity to ubiquitin, a protein that helps to degrade proteins and induce cell death. The results could lead to novel drug candidates against cancer, according to the study published in the journal Angewandte Chemie.
Drugs based on peptides (small proteins) are often too large to pass through cell membranes. To make such peptides more compact and stable — and thus more efficient — researchers are investigating their closed versions, called macrocyclic peptides. Pharmaceuticals based on macrocyclic peptides are interesting candidates for the modulation of regulatory proteins, which is an important goal in cancer research.
However, screening for such peptides is difficult. “Well-established screening approaches often require highly expensive instrumentation and appropriate training,” says Ashram Brik from the Technion-Israel Institute of Technology, Israel, who is set up to develop alternative strategies.
The researchers designed a simple screening assay based on competitive binding. Competitive binding means that unknown peptides are tested for their capabilities to displace a known peptide with known binding affinity to a target…