Determining the Mechanism of Action of the Antibiotic Argyrin B
Research Mentor(s)
Spiegel, P. Clint
Description
Elongation factor G (EF-G) is a key bacterial translation factor and GTPase that is highly conserved in bacteria, with homologs in many other organisms. The peptide argyrin B, derived from myxobacteria and actinomycetes targets EF-G specifically. Argyrin B has shown antibiotic activity against the bacteria Pseudomonas aeruginosa and membrane compromised strains of other gram negative bacteria. In order to elucidate the mechanism of action for argyrin B we performed in vitro experiments with the E. coli 70s bacterial ribosomes and different EF-G variants. We initially observed the results of argyrin B on EF-G to 70S binding and the GTPase activity that this binding facilitates. We also examined the binding affinity for substrate analogues. This work then investigated the effects on the two key functions of EF-G, translocation and ribosome recycling. We ascertained from our experimentation that argyrin B increases binding to the ribosome, while having only a marginal effect on GTPase activity and substrate binding. Furthermore argyrin B did not present a change in ribosomal translocation but the drug does appear to inhibit ribosome dissociation, a key step in ribosome recycling. These experiments will narrow the possibilities of the mechanism of argyrin B and work to further the understanding of a unique antibiotic.
Document Type
Event
Start Date
15-5-2019 9:00 AM
End Date
15-5-2019 5:00 PM
Location
Carver Gym (Bellingham, Wash.)
Department
Chemistry
Genre/Form
student projects, posters
Subjects – Topical (LCSH)
Peptide antibiotics; Pseudomonas aeruginosa; Guanosine triphosphatase; Binding sites (Biochemistry)
Type
Image
Rights
Copying of this document in whole or in part is allowable only for scholarly purposes. It is understood, however, that any copying or publication of this document for commercial purposes, or for financial gain, shall not be allowed without the author’s written permission.
Language
English
Format
application/pdf
Determining the Mechanism of Action of the Antibiotic Argyrin B
Carver Gym (Bellingham, Wash.)
Elongation factor G (EF-G) is a key bacterial translation factor and GTPase that is highly conserved in bacteria, with homologs in many other organisms. The peptide argyrin B, derived from myxobacteria and actinomycetes targets EF-G specifically. Argyrin B has shown antibiotic activity against the bacteria Pseudomonas aeruginosa and membrane compromised strains of other gram negative bacteria. In order to elucidate the mechanism of action for argyrin B we performed in vitro experiments with the E. coli 70s bacterial ribosomes and different EF-G variants. We initially observed the results of argyrin B on EF-G to 70S binding and the GTPase activity that this binding facilitates. We also examined the binding affinity for substrate analogues. This work then investigated the effects on the two key functions of EF-G, translocation and ribosome recycling. We ascertained from our experimentation that argyrin B increases binding to the ribosome, while having only a marginal effect on GTPase activity and substrate binding. Furthermore argyrin B did not present a change in ribosomal translocation but the drug does appear to inhibit ribosome dissociation, a key step in ribosome recycling. These experiments will narrow the possibilities of the mechanism of argyrin B and work to further the understanding of a unique antibiotic.