NSF Award
2401556
With the support of the Chemistry of Life Processes (CLP) program in the Division of Chemistry, Dr. Christopher Reid and his students at Bryant University are studying the development of small molecule probes to study bacterial cell wall metabolism. Most bacteria are surrounded by a carbohydrate-based polymer called peptidoglycan. This polymer defines cell shape and withstands the outward facing osmotic pressure. The metabolism of peptidoglycan is a highly complex and coordinated process between synthetic and degradative processes. While understanding of peptidoglycan biosynthesis is relatively robust, there are significant knowledge gaps regarding the degradative steps and how they are coordinated with biosynthesis. To address the lack of chemical biology methods to study peptidoglycan degradation, this proposal looks to expand on the success of the N-acetylglucosaminidase inhibitor masarimycin in the Gram-positive organism Bacillus subtilis to develop an array of masarimycin-based chemical biology reagents for the microbial glycoscience community. This work could provide new insights into the role degradative enzymes such as N-acetylglucosaminidases play in cell growth and division. This research will be conducted with a significant number of undergraduate researchers. As such, the Reid laboratory will continuesto contribute to the training and development of the next generation of scientists. This support will allow for the Reid laboratory to contribute to the growth and development of the chemical life science ecosystem in Rhode Island. <br/><br/>Most bacteria are surrounded by a peptidoglycan cell wall that defines their shape and withstands the outward facing osmotic pressure. Peptidoglycan metabolism is a highly complex and coordinated process between synthetic and degradative enzymes. While understanding of the biosynthetic steps is relatively robust, significant knowledge gaps exist regarding the degradative steps and how they are coordinated with biosynthesis. To address the lack of tools to study peptidoglycan metabolism and degradative enzymes in particular, the Reid Lab at Bryant University has developed the small molecule probe, masarimycin (Mas), to inhibit the major active N-acetylglucosaminidase LytG from Bacillus subtilis. Through this proposal, the Reid lab seeks to expand this work by developing new glycosyl triazole and diamide inhibitors of N-acetylglucosaminidases against representative Gram-negative, positive, and Mycolicibacteria. Masarimycin provides a vehicle through which to study the differences in peptidoglycan metabolism and regulation in rod- and coccoid-shaped bacteria. To achieve these goals, the Reid Lab will pursue three objectives in parallel. For the first objective, studies will build on their preliminary identification of GlcNAcase diamide inhibitors in B. subtilis and S. pneumoniae to create a second-generation masarimycin inhibitor with potentially improved potency and physical-chemical properties. For the second objective, preliminary glycosyl-triazole and diamide leads against Escherichia coli and Mycolicibacterium smegmatis will be evaluated to determine if these new inhibitors disrupt cell wall metabolism in Gram-negative and acid-fast bacteria in the same manner as in Gram-positive organisms. Finally, a comparative study between B. subtilis and S. pneumoniae will be performed, using masarimycin as a probe, to investigate the differences in PG metabolism between rod- and coccoid-shaped bacteria. The proposed work could open the door for masarimycin, and diamide inhibitors in general, to serve as valuable chemical biology reagents for studying PG metabolism across key bacterial genera.<br/><br/>This project is jointly funded by the Chemistry of Life Processes (CLP) program and the Established Program to Stimulate Competitive Research (EPSCoR).<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
