Investigations into ivermectin resistance mechanisms in parasitic nematodes and the development of PROTAC technology towards the selective degradation of HIV Capsid protein

Ruddell, Stuart (2019) Investigations into ivermectin resistance mechanisms in parasitic nematodes and the development of PROTAC technology towards the selective degradation of HIV Capsid protein. PhD thesis, University of Glasgow.

Abstract

This thesis comprises two projects detailing the synthesis and testing of bifunctional molecules. The projects were aimed at addressing the key biological problems of combating drug resistance and the requirement for novel therapeutic strategies.

Chapter one details the first of these projects, which was concerned with elucidating the mechanism(s) of drug resistance in parasitic nematodes by using bifunctional fluorescent chemical probes based on the anthelmintic drug ivermectin. The first section presents the relevant background information for the project including information regarding the mechanism of action of ivermectin and the basic anatomy of nematodes, which were used to guide the design of the probes, BLI and FBI. The second section discusses the synthesis of each of the probes as well as their biological assaying used to assess the utility of the probes for the purposes of studying ivermectin resistance. The FBI probe was then administered to both free-living and parasitic nematode strains, which when assessed with fluorescence microscopy, successfully identified the route of ivermectin uptake. Furthermore, the data generated was consistent with impaired drug uptake as an operative mechanism of ivermectin resistance. The final section comprises experimental data regarding the preparation and characterisation of the discussed compounds as well as biological assay data.

Chapter two details a project aimed at developing heterobifunctional PROTAC molecules towards the selective degradation of HIV capsid protein in human cells. The first section presents the relevant background information for the project including information on the chosen protein targets, which was used to guide the design of the PROTAC molecules. These molecules are based on the HIV capsid inhibitor PF74. The second section discusses the synthesis of each of the PROTAC molecules. Additionally, the synthesis of (S)- and (R)-PF74 and an epimerisation study of PF74 are discussed. The third section discusses the biological assaying of the enantiomers of PF74, which successfully identified (S)-PF74 as significantly more active than (R)-PF74. In addition, the testing of each of the synthesised PROTACs is presented, which successfully demonstrated inhibition of HIV replication and answered fundamental questions regarding PROTAC target engagement. The final section comprises experimental data regarding the preparation and characterisation of the discussed compounds as well as biological assay data.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Keywords: Anthelmintic, bifunctional molecule, chemical biology, fluorescent probe, HIV, ivermectin, nematode, PF74, PROTAC.
• Subjects: Q Science > QD Chemistry; Q Science > QR Microbiology; Q Science > QR Microbiology > QR355 Virology
• Colleges/Schools: College of Science and Engineering > School of Chemistry
• Supervisor's Name: France, Dr. David
• Date of Award: 2019
• Embargo Date: 11 October 2022
• Depositing User: Mr Stuart Ruddell
• Unique ID: glathesis:2019-75081
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 29 Oct 2019 08:57
• Last Modified: 06 Dec 2019 14:13
• Thesis DOI: 10.5525/gla.thesis.75081
• URI: http://theses.gla.ac.uk/id/eprint/75081