Synthesis, Efficacy, and Molecular Targeting of Hydrazide Class trans-translation Inhibitors
Open Access
- Author:
- Babunovic, Gregory Hunter
- Area of Honors:
- Microbiology
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Kenneth Charles Keiler, Thesis Supervisor
Dr. Sarah Ellen Ades, Thesis Honors Advisor
Scott Brian Selleck, Faculty Reader - Keywords:
- antibiotics
bacteria
trans-translation
inhibitor
protein
click chemistry
synthesis
hydrazide
target
pathogen - Abstract:
- Antibiotic resistance is a serious and growing problem in the modern world, and the discovery and characterization of novel antimicrobials is a top priority. Trans-translation, a conserved and oftentimes essential ribosome-rescue process in bacteria, is a promising target for novel antibacterial drugs. A high-throughput screening assay for the in vivo inhibition of trans-translation identified several molecular classes of compounds that potently inhibit this pathway; members of these classes have shown antibiotic activity against pathogenic and nonpathogenic bacteria. Here, various members of a novel class of trans-translation inhibitors with an acyl hydrazide-thiol-amide substructure were synthesized and tested for antibiotic activity against both pathogenic and nonpathogenic bacteria. An inhibitor with confirmed antibiotic efficacy was used in combination with other known inhibitors of trans-translation and was found to have additive effects with members of the oxadiazole class, implying a related molecular target. A molecular probe for the novel class of inhibitors was synthesized and used in a click chemistry based assay to identify protein binding partners of this class of compounds within bacterial lysates. The click chemistry-based assay identified a protein of approximately 25 kDa that appears to be selectively bound by this probe; this protein is only bound in lysates containing accumulated stalled non-stop ribosomal complexes that are substrates for the trans-translation reaction. Future studies will seek to validate this result and investigate whether this protein is a target of the novel inhibitor class.