Neutrophil elastase as a versatile cleavage enzyme for activation of αvβ3 integrin-targeted small molecule drug conjugates with different payload classes in the tumor microenvironment.

The development of bioconjugates for the targeted delivery of anticancer agents is gaining momentum after recent success of antibody drug conjugates (ADCs) in the clinic. Smaller format conjugates may have several advantages including better tumor penetration; however, cellular uptake and trafficking may be substantially different from ADCs. To fully leverage the potential of small molecule drug conjugates (SMDCs) with potent binding molecules mediating tumor homing, novel linker chemistries susceptible for efficient extracellular activation and payload release in the tumor microenvironment (TME) need to be explored.

Structure-activity relationship of ipglycermide binding to phosphoglycerate mutases.

Catalysis of human phosphoglycerate mutase is dependent on a 2,3-bisphosphoglycerate cofactor (dPGM), whereas the nonhomologous isozyme in many parasitic species is cofactor independent (iPGM). This mechanistic and phylogenetic diversity offers an opportunity for selective pharmacologic targeting of glycolysis in disease-causing organisms. We previously discovered ipglycermide, a potent inhibitor of iPGM, from a large combinatorial cyclic peptide library.

Discovery of quorum quenchers targeting the membrane-embedded sensor domain of the receptor histidine kinase, AgrC.

We combined mRNA display technology with lipid-nanodisc based selections and identified high-affinity ligands targeting the integral membrane sensor domain of the histidine kinase AgrC as potent inhibitors of Staphylococcus aureus quorum sensing-modulated virulence. Our study highlights the potential of this integrated approach for identifying functional modulators of integral membrane proteins.

Toolbox of Diverse Linkers for Navigating the Cellular Efficacy Landscape of Stapled Peptides.

Stapled peptides have great potential as modulators of protein-protein interactions (PPIs). However, there is a vast landscape of chemical features that can be varied for any given peptide, and identifying a set of features that maximizes cellular uptake and subsequent target engagement remains a key challenge. Herein, we present a systematic analysis of staple functionality on the peptide bioactivity landscape in cellular assays.

RNA Display Methods for the Discovery of Bioactive Macrocycles.

The past two decades have witnessed the emergence of macrocycles, including macrocyclic peptides, as a promising yet underexploited class of de novo drug candidates. Both rational/computational design and in vitro display systems have contributed tremendously to the development of cyclic peptide binders of either traditional targets such as cell-surface receptors and enzymes or challenging targets such as protein-protein interaction surfaces. mRNA display, a key platform technology for the discovery of cyclic peptide ligands, has become one of the leading strategies that can generate natural-product-like macrocyclic peptide binders with antibody-like affinities.

Development of Cell-Permeable, Non-Helical Constrained Peptides to Target a Key Protein-Protein Interaction in Ovarian Cancer.

There is a lack of current treatment options for ovarian clear cell carcinoma (CCC) and the cancer is often resistant to platinum-based chemotherapy. Hence there is an urgent need for novel therapeutics. The transcription factor hepatocyte nuclear factor 1β (HNF1β) is ubiquitously overexpressed in CCC and is seen as an attractive therapeutic target.

Structural and calorimetric studies demonstrate that the hepatocyte nuclear factor 1β (HNF1β) transcription factor is imported into the nucleus via a monopartite NLS sequence.

The transcription factor hepatocyte nuclear factor 1β (HNF1β) is ubiquitously overexpressed in ovarian clear cell carcinoma (CCC) and is a potential therapeutic target. To explore potential approaches that block HNF1β transcription we have identified and characterised extensively the nuclear localisation signal (NLS) for HNF1β and its interactions with the nuclear protein import receptor, Importin-α. Pull-down assays demonstrated that the DNA binding domain of HNF1β interacted with a spectrum of Importin-α isoforms and deletion constructs tagged with eGFP confirmed that the HNF1β (229)KKMRRNR(235) sequence was essential for nuclear localisation.