Recent advances in therapeutic research have led to an increasing number of small peptides being used as drug like molecules that are highly specific and which offer greater efficacy while being safe for human consumption(Fosgerau and Hoffmann 2015). Metabolic diseases and oncology form a major fraction of therapeutic targets for peptides, with peptides being studied as an alternative to chemotherapy(Kaspar and Reichert 2013). Here we discuss a high throughput assay established to screen a peptide library (Phylomers) for target – peptide interactions and to test their efficacy as protein – protein interaction disruptors.
For our study, library of 10000 Phylomers was generated based on a limited repertoire of protein interaction motifs found in nature that exhibit high affinity interactions and bioactivity, from which 384 were selected (encompassing variety of structural folds with differential degree of net charge and hydrophobicity - hydrophilicity) for our initial study. The phylomers were cloned in gateway vectors with a C- terminal cherry-myc tag for expression in the Leishmania tarentolae cell-free system. Our assay identified six phylomers that have high specificity and efficacy towards cMyc and SOX18, important genes which are associated with cancer metastasis. These phylomers bind tightly to the targets and 3/10 phylomers disrupt cMyc and SOX18 interaction with their respective partners with low-micromolar affinity. These phylomers are currently been tested in an in-vivo assay to study their efficacy in cells. If successful these phylomers can form the newest breed of small peptide drug-like molecules
Our phylomer screen is currently being expanded to assess the capacity of phylomers to specifically detect mutated / oligomeric state of proteins associated with diseases and disorders. The specific phylomers can form the basis of novel biomarkers that can selectively detect genomic mutations associated with diseases and can be developed as early detection kits for certain genetic illnesses.