An Interdisciplinary Approach To The Target Elucidation of Novel Antibiotic 31G12

Author

Larissa A. Walker, University of Montana

Year of Award

2018

Document Type

Thesis

Degree Type

Master of Science (MS)

Degree Name

Cellular, Molecular and Microbial Biology

Other Degree Name/Area of Focus

Microbiology

Department or School/College

Division of Biological Sciences

Committee Chair

Nigel Priestley

Committee Co-chair

Michael Minnick

Commitee Members

Stephen Lodmell

Keywords

S. aureus, antibiotic, photoaffinity labeling, bioinformatics, synthesis

Publisher

University of Montana

Subject Categories

Bioinformatics | Microbiology | Organic Chemistry

Abstract

Staphylococcus aureus is a Gram-positive bacterial pathogen responsible for nosocomial and community-acquired infections that can quickly acquire antibiotic resistance. We have identified a novel triazole antimicrobial 31G12 based on the natural product core of nonactin isolated from the fermentation of Streptomyces griseus, that is active against many Gram-positive bacteria as well as antibiotic resistant methicillin-resistant S. aureus and vancomycin-resistant Enterococcus. The synthesis and characterization indicate that 31G12 exists as a mixture of two rotamers at room temperature and displays bacteriostatic activity against S. aureus with moderate mammalian cell toxicity. We have currently identified potential protein targets of 31G12 in S. aureus via an interdisciplinary approach to the target elucidation. First, a chemical proteomic strategy using photoaffinity labeling revealed a potential target protein at approximately 110 kDa when visualized via western blot and in-gel scans. Second, whole-genome sequencing and a bioinformatics approach revealed two potential proteins, thioredoxin-fold protein and L11 methyltransferase to be good candidates based on dose-response curves. Although the mode of action has not been established, this work provides a rational framework to expand the efficacy of this novel class of antimicrobials through structure-based drug design to improve potency against Gram-positive bacteria and reduce mammalian cell toxicity.

Recommended Citation

Walker, Larissa A., "An Interdisciplinary Approach To The Target Elucidation of Novel Antibiotic 31G12" (2018). Graduate Student Theses, Dissertations, & Professional Papers. 11306.
https://scholarworks.umt.edu/etd/11306