Bioscience for an integrated understanding of health

Category: Standard Studentships

Put a ring on it: threaded molecular probes as tools for cancer cell biology

Project No. 2103

Primary Supervisor

Dr Matthias Baud – University of Southampton


Prof Steve Goldup – University of Southampton

Professor Michelle Garrett – University of Kent


Background and significance

Recent years have seen the emergence of new classes of hetero-bifunctional chemical probes where two fragments are “linked” together by a chemical linker, to enforce a new interaction between two Proteins Of Interest (POIs) and redirect the system towards a particular cellular fate (e.g. relocalisation, proteasomal degradation, post-translational modification) [Chem. Rev. 2017, 11269]. These “molecular glues” (MolGlues) have generated huge interest and excitement and significant current research is directed towards applying them i) to target “undruggable” protein systems and signalling pathways [Cell Research 2016, 484]; and ii) to optimise their properties for use in vivo to address unmet therapeutic needs in areas such as cancer and neurodegenerative conditions. However, modulation of key properties such as membrane permeability, aqueous solubility, metabolic stability and biodistribution have proven challenging [Explor. Target Antitumor. Ther. 2020, in press].


In this proof-of-concept study, we will address this challenge by threading the MolGlue linker through a molecular ring to generate a structure called a “rotaxane”. We have developed methods to prepare such rotaxanes using “click” chemistry [J. Am. Chem. Soc. 2016, 16329], and demonstrated that threading DNA through a molecular ring effectively modulates its properties [J. Am. Chem. Soc. 2020, 5985]. Our hypothesis is that threading the linker of MolGlue probes through a molecular ring will changes its biological properties in a modular and straightforward manner, allowing MoGlues to be tuned quickly and effectively.


  1. Design and synthesise rotaxane-MolGlues, varying the structure of the threaded macrocycle and characterise their physico-chemical properties in biophysical assays.
  2. Evaluate rotaxane-MolGlues in vitro versus the parent non-rotaxane probes using a palette of molecular/cell biology techniques.
  3. Use optimised rotaxane-MolGlues to interrogate the CHK1 kinase pathway -a critical regulator of the DNA damage response which plays multiple pivotal functions in human physiology and cancer, in order to demonstrate the power of the rotaxane-MolGlue approach.