Design and Synthesis of Diyne Girder a-Helix Peptides: Novel tools for the Regulation of Protein-Protein interactions

Lead Research Organisation: University of Glasgow
Department Name: School of Chemistry

Abstract

Protein-protein interactions (PPIs) are essential in almost every biological process. The ability to regulate PPIs using chemical probes is therefore extremely important for studying the nature of these molecular recognition events and the development of novel therapeutics. However, the development of cell-permeable chemical probes that regulate PPIs remains one of the major challenges in chemical biology due to the relatively large, dynamic nature of the PPI interface.
Recent research in the Jamieson Group has focused on developing synthetic strategies to conformationally constrain peptides to adopt their bioactive a-helix conformation and also overcome many of the poor physicochemical and pharmacological issues associated with peptides.

Hypothesis: The central hypothesis of this project is that a highly rigid side-chain to side-chain 1,3-diyne bridge will act as an extremely effective conformational constraint and thus provide peptides with high degrees of alpha-helical structure and improved binding affinity and physicochemical properties.

Specific objectives
1. Develop the synthesis of 1,3-diyne-bridged alpha-helix peptides using the Glasser-Hay reaction as a key step.
2. Application of 1,3-diyne girder peptides to the regulation of important PPIs including Gpx3/Mia40 (in collaboration with Prof Kostas Tokatlidis(MVLS)), conotoxin/VGSC (in collaboration with Dstl) and Ubiquitin protein complexes (in collaboration with Prof Helen Walden (MVLS))

This studentship will focus on the development and application of a novel technology, namely 1,3-diyne-bridged alpha-helix peptides.
We plan to apply these new chemical tools to the regulation of conotoxin/VGSC (Dstl: DSTL/AGR/R/CBRN/01), Gpx3/Mia40 (BBSRC: BB/R009031/1) protein-protein interactions. I also recently initiated a new collaboration with Prof Helen Walden (joined UoG MVLS in August 2017) to focus on the regulation of Ubiquitin protein complexes, targets that are complimentary to current research in my group on Deubiquitinase enzymes (EPSRC: EP/N034260/1). As well as investigating new avenues in existing projects, the work done by this student will provide data to underpin a future EPSRC grant application (summer 2018) on these new ubiquitin protein complex targets.
The specific work package associated with this studentship compliments those described in these grants through developing new chemistries to prepare non-native alkyne amino acids and their subsequent incorporation into specific peptide sequences using advanced microwave assisted solid phase synthesis methods. If appropriate, the student will have the opportunity to spend time at Dstl Porton Down in determine the 3D structures of the peptides using advanced NMR and molecular dynamics.

One of the unique selling points of this peptide design is the potential to use confocal Raman imaging to visualise the peptides in cells without the need to couple a fluorophore. This property will facilitate investigations into the physicochemical requirements of helix peptides to penetrate the cell membrane, one of the last major frontiers in peptide drug discovery.
The biological actively of these molecules will be assessed using fluorescence based inhibition assays (with Tokatlidis and Walden) and a microfluidic patch clamp system (with Dstl Proton Down).
Chemical Biology, a key interdisciplinary area of considerable and growing importance both nationally and internationally as highlighted in the research strategies of EPSRC, BBSRC and MRC. This particular project fits extremely well with the Chemical Biology theme of the RCUK Technology Touching Life initiative as it seeks to develop novel tool compounds with application in Biochemistry and medicine.
Importantly, this work will also provide data that has the potential to enhance my REF2021 Impact Case Study currently in development with Dstl 'Influencing Government knowledge and legislation on Biological Weapons'.

Publications

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Studentship Projects

Project Reference Relationship Related To Start End Student Name
EP/N509668/1 01/10/2016 30/09/2021
2158717 Studentship EP/N509668/1 01/10/2018 01/04/2022 Danielle Charlotte Morgan