School of Chemistry and Biochemistry Special Seminar
“Understanding and Manipulating Protein-Protein Interactions Using Chemical Biology Approaches”
Andrew J. Wilson, Ph.D.
Professor of Organic Chemistry
Deputy Director Ashbury Centre for Structural Molecular Biology
University of Leeds, Leeds, UK
Protein-protein interactions (PPIs) mediate all cellular signalling processes and play a central role in disease. Therefore, a key problem in life-sciences research is to understand PPIs with molecular and temporal resolution – this would allow the identification of the transient intermediates that play key roles in the function of biomacromolecular machines, signalling, translocation and folding to illuminate our understanding of disease development e.g. aberrant intracellular cell signalling in cancer and aggregation in amyloid disease. In this presentation I will discuss the development of a suite of diazirine-based cross-linking reagents. Diazirines are ideal cross-linking groups because upon excitation with UV light, they generate highly reactive carbenes capable of indiscriminate insertion into proximal bonds. We are interested in applying these reagents to study β-sheet mediated PPIs specifically assembly of peptides into amyloid fibrils and will illustrate how, in combination with state-of the art mass-spectrometry, cross-linking encodes non-covalent structure in cross-linked peptides. Focusing on the helix mediated NOXA-B/MCL-1 PPI I will then describe efforts to develop peptides conjugated to ruthenium (II) (tris)chelates as reagents that can perform photo-activated “traceless” protein-labelling reactions – a necessary first step in being able to label proteins in live cells without abrogating their normal function. The final part of this presentation will highlight our efforts to develop coiled-coils and proteomimetics as inhibitors of α-helix-mediated PPIs. The proteomimetic approach, utilises a generic scaffold to mimic the spatial and angular projection of “hot-spot” side chains found on the key helix mediating the PPI of interest. I will outline the development of oligoamide proteomimetic foldamers as inhibitors of PPIs involved in oncology (e.g. p53/hDM2, NOXA-B/Mcl-1, HIF-1α/p300). Finally, I will outline how we have used proteomimetics to reactivate a protein, where a segment of helical secondary structure has been removed.