In the growing field of chemical proteomics, there is a need for general methods to map the reactivity profiles of covalent probes in complex proteomes. Now, a completely unbiased proteomic workflow h...

Lakemeyer and colleagues analyze the secretome of gut bacteria to identify factors that target host PAR2. They find that the Bacteroides fragilis protease Bfp1 cleaves and activates PAR2, disrupting i...

Advancements in Osteoarthritis: From Discovery to Treatment

Genetically-encoded libraries of peptide-derived macrocycles containing electrophile "warheads" (cGELs) can be used to identify potent and selective covalent ligands for protein targets. Such cGELs ar...

Traditional methods for identifying selective protease substrates have primarily relied on synthetic libraries of linear peptides, which offer limited sequence and structural diversity. Here, we present an approach that leverages phage display technology to screen large libraries of chemically modified cyclic peptides, enabling the identification of highly selective substrates for a protease of interest. Our method uses a reactive chemical linker to cyclize peptides on the phage surface, while simultaneously incorporating an affinity tag and a fluorescent reporter. The affinity tag enables capture of the phage library and subsequent release of phages expressing optimal substrates upon incubation with a protease of interest. The addition of a turn-on fluorescent reporter allows direct quantification of cleavage efficiency throughout each selection round. The resulting identified substrates can then be chemically synthesized, optimized and validated using recombinant enzymes and cells. We demonstrate the utility of this approach using Fibroblast Activation Protein α (FAPα) and the related proline-specific protease, dipeptidyl peptidase-4 (DPP4), as targets. Phage selection and subsequent optimization identified substrates with selectivity for each target that have the potential to serve as valuable tools for applications in basic biology and fluorescence image-guided surgery (FIGS). Overall, our strategy provides a rapid and unbiased platform for effectively discovering highly selective, non-natural protease substrates, overcoming key limitations of existing methods.

Caspase-1 is a key mediator of the inflammasome pathway, which is associated with several inflammatory disorders including obesity, diabetes mellitus (DM), cardiovascular diseases (CVDs), cancers and ...

Staphylococcus aureus is a leading cause of bacteria-associated mortality worldwide. New tools are needed to both image and treat this pathogen. We previously identified a group of S. aureus serine hy...

Nature Chemical Biology - Electrophilic phage display has emerged as a powerful platform for discovering high-affinity or covalent peptide ligands. A new study reveals that this platform enables...

Microbial pathogens continue to plague human health and develop resistance to our current frontline treatments. Over the last few decades, there has b…

Horbach et al. developed chemical tools to study calpain-1 activation during pyroptosis. Using mass cytometry and IQF substrates, the authors show that calpain-1 correlates with GSDMD and caspase-1 in immune cells. They also demonstrate that calpain-1 cleaves GSDMD at a putative QRTF/Q, potentially supporting pyroptosis process.

Shen et al. investigate the use of Lactobacillus plantarum, a commensal bacterial strain, as a chassis for targeting the olfactory mucosa to facilitate precise nose-to-brain delivery of therapeutic mo...

National Institutes of Health grants generated almost $95 billion in economic activity nationwide in FY 2024 according to a new report by United for Medical Research.

Computational drug discovery is used to identify a 12-mer peptide derived from BRINP2 with potent anti-obesity effects that are independent of leptin, glucagon-like peptide 1 receptor and melanocortin...

Infections with Mycobacterium tuberculosis (Mtb) cause tuberculosis (TB), which requires at least six months of treatment with multiple antibiotics. There is emergent interest in using β-lactam antibi...

In search of new putative antimicrobial drug targets in methicillin-resistant Staphylococcus aureus, we aimed to identify and characterize retaining glycosidase activities in this bacterial pathogen. ...