1,3-Diyne Constrained alpha-Helix Peptides: New tools for Interrogating Protein-Protein Interactions

Lead Research Organisation: University of Leicester
Department Name: Chemistry

Abstract

In this research project, we will develop an innovative new experimental method to conformationally constrain peptides to fold into an alpha-helix secondary structure. The resulting molecules will be useful chemical tools for the regulation of protein-protein interactions.
Protein-protein interactions are involved in the regulation of cellular functions and represent attractive targets to medicinal chemists. While these molecular recognition events involve interactions over large surface areas, the majority of the binding affinity and specificity has been found to originate from constellations of a few amino acid residues that are described as interaction 'hotspots'. At a molecular level, these constellations of residues are frequently found to be specific protein secondary structures such as the alpha-helix, beta-strand/sheet and turn conformations. These structural motifs present molecular functionality with the correct orientation and spacing to interact with complementing functionality on the partner protein. Although the helical motif is usually thermodynamically favoured in folded proteins, isolated peptides typically lack the ability to spontaneously adopt the helical conformation. Efforts to excise specific helical motifs from an active protein sequence have thus necessitated synthetic modifications to link distant residues to induce an alpha-helix conformation. These conformational constraints have been used to produce alpha-helical peptide mimics for probing protein-protein interaction binding surfaces and have in some instances furnished lead compounds for drug discovery. However, in many examples the functionality linking the distant amino acid residues is too flexible to induce helical structure and so does not act as a conformational constraint or improve the physicochemical properties of the peptide. In this project we will address this challenge by developing a highly rigid conformational constraint based on a 1,3-diyne side-chain to side-chain bridge and produce functional tool compounds to investigate protein-protein interactions.

Planned Impact

This research project has the potential to have significant and wide-ranging impact. Our aim is to develop the chemistry required to produce new peptide tools that will be used to regulate protein-protein interactions.
The new chemical biology tools we propose could impact a diverse range of beneficiaries including academics, the pharmaceutical industry and the general public. We plan to engage with beneficiaries in academia and the pharmaceutical industry through dissemination of our research results in high impact journals, at conferences (both home and abroad) and through professional networks (e.g. Protein-Protein Interaction Network). The general public will also be engaged with our research using news articles appearing on our website and through social networking sites.
Conformationally constrained peptides are a potential new class of therapeutic agent that possess the high affinity and specificity of biologics (i.e. protein therapeutics) and also the pharmacokinetic properties of small molecules. Our second objective in this project is to produce conformationally constrained peptide mimics of the SMRT corepressor and assess its ability to regulate the HDAC3/corepressor protein-protein interaction. At this stage we will seek to protect the intellectual property associated with potential lead compounds and use this as leverage to obtain funding to establish a spinout company. This company will have a positive impact on the UK economy by providing employment and training for skilled workers. If successful, the company would also have a positive impact on peoples health and well being by providing improved therapeutics.
The postdoctoral researcher will present the proposed research at the Houses of Parliament as part of the SET for Britain competition. We will use this as a platform to engage with politicians in order to influence UK scientific policy.

Publications

10 25 50
 
Description We have developed a novel method with which to prepare non-native amino acids. These amino acids are proving to be extremely useful as building blocks to produce biotheraputic drug molecules called "girder peptides" and also for producing synthetic proteins with unatural functions. We have now used these girder peptides to target Bcl-2 in cancer.
Exploitation Route Our hope is that this technology will be used by other research groups to target protein-protein interactions mediated by an alpha-helix at the binding interface.
Within our own group we are applying the technology to produce girder peptides that target a number of different biochemical pathways involved in cancer (c-Myc/Max, BIM/Bcl2, HDAC/corepressor and Aurora-A/TPX2) and severe pain (VGSC/conotoxins).
Sectors Aerospace, Defence and Marine,Agriculture, Food and Drink,Chemicals,Education,Healthcare,Pharmaceuticals and Medical Biotechnology

 
Description The work resulting from this grant funding has lead to a new funded research project in collaboration with the MoD Dstl that focuses on the development of stapled analogues of conotoxin peptides.
First Year Of Impact 2016
Sector Chemicals,Government, Democracy and Justice,Pharmaceuticals and Medical Biotechnology
Impact Types Policy & public services

 
Description Defence Science and Technology Laboratory (DSTL) project grant
Amount £240,000 (GBP)
Funding ID DSTLX1000100329 
Organisation Defence Science & Technology Laboratory (DSTL) 
Sector Public
Country United Kingdom
Start 03/2016 
End 03/2018
 
Description Leverhulme Trust Project Grant
Amount £129,566 (GBP)
Funding ID RPG-2014-372 
Organisation The Leverhulme Trust 
Sector Academic/University
Country United Kingdom
Start 03/2015 
End 03/2017
 
Description MRC Confidence in Concept award
Amount £20,000 (GBP)
Organisation Medical Research Council (MRC) 
Sector Academic/University
Country United Kingdom
Start 12/2015 
End 12/2016
 
Description University Central Infrastructure Fund
Amount £195,000 (GBP)
Organisation University of Leicester 
Sector Academic/University
Country United Kingdom
Start 02/2016 
End 07/2016
 
Title Asymmetric Synthesis of alpha,alpha-disubstituted amino acids 
Description Efficient asymmetric synthesis of unnatural alkenyl amino acids required for peptide 'stapling' has been achieved using alkylation of a fluorine-modified NiII Schiff base complex as the key step 
Type Of Material Technology assay or reagent 
Provided To Others? No  
Impact N/A 
 
Description DSTL - VGSC/conotoxins 
Organisation Defence Science & Technology Laboratory (DSTL)
Country United Kingdom 
Sector Public 
PI Contribution Synthesis of conotoxin mimetics
Collaborator Contribution Biological evaluation of conotoxin mimetics
Impact No outputs as yet.
Start Year 2015
 
Description HDAC project 
Organisation University of Leicester
Country United Kingdom 
Sector Academic/University 
PI Contribution Peptidomimetic regulators of HDAC activity
Collaborator Contribution HDAC activity assay for biological evaluation of peptidomimetics
Impact G. M. Hudson, P. Watson, L. Fairall, A. G. Jamieson, J. W. R. Schwabe, Insights into the recruitment of class IIa HDACs to the SMRT/NCoR transcriptional repression complex. J. Bio. Chem., 2015, 290, 18237-18244. P. J. Watson, C. J. Millard, A. M. Riley, N. S. Robertson, L. C. Wright, H. Y. Godage, S. M. Cowley, A. G. Jamieson, B. V. L. Potter, John W. R. Schwabe, The mechanism of activation of class I HDAC complexes by inositol phosphates. Nat. Commun., accepted
Start Year 2011
 
Description Martin Dyer and Meike Vogler - BIM/Bcl2 
Organisation University of Leicester
Country United Kingdom 
Sector Academic/University 
PI Contribution Synthesis of conformationally constrained BIM peptides.
Collaborator Contribution Biological evaluation of conformationally constrained BIM peptides in B-cells.
Impact Jamieson group - synthetic chemistry Dyer Group - cancer Vogler Group - cancer cell biology
Start Year 2015
 
Description Proteomimetic Probes to Determine the Structural requirements of TPX2 for Activation of Protein Kinase Aurora-A 
Organisation University of Leeds
Department School of Biochemistry and Microbiology Leeds
Country United Kingdom 
Sector Academic/University 
PI Contribution Solid phase synthesis of TPX2 proteomimetics
Collaborator Contribution Evaluation of TPX2 proteomimetic binding to Aurora-A using ITC and activity based assays.
Impact Yana Rennie, Patrick J. McIntyre, Richard Bayliss, Andrew G Jamieson, Proteomimetic Probes to Determine the Structural requirements of TPX2 for Activation of Protein Kinase Aurora-A. Manuscript in preparation.
Start Year 2013
 
Description Invited Research Seminars 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact Invited research seminars at Universities of Dundee, Durham, Nottingham Trent, Lincoln & Strathclyde. Invoked discussion and debate regarding the use of stapled peptides in chemical biology and drug discovery.
Year(s) Of Engagement Activity 2013,2014,2015,2016