I am a 4th year PhD student at the Department of Chemistry at the Royal College of Surgeons in Ireland (RCSI) University of Medicine and Health Sciences under the supervision of Prof Marc Devocelle. My research is focused on hybridising antimicrobial peptides (AMPs) with fluoroquinolone antibiotics, to produce novel drug candidates with emergent properties. Recently we disclosed the results of a proof of concept project for this in a cover article in the New Journal of Chemistry and as such we wished to investigate further into the mechanistic understanding of how these novel peptides kill or interact with bacteria.1
Dr Jerome Le Prince, of the University of Rouen, and my supervisor have been discussing a collaboration for some time and as such with the help of Prof Pascal Cosette, a proteomic analysis of bacteria exposed to sub-lethal concentrations of my peptide was proposed. By quantifying proteins being produced by the bacteria with and without exposure to antimicrobials we can infer the mechanism of action and also how bacterial stress responses adapt to such exposure. As well as proteomic analysis, there was also the opportunity to view how the peptides interacted with bacteria via confocal and fluorescent microscopy, which again allowed further insight into mechanistic characteristics of these novel AMPs.
During my stay in Rouen, I benefitted from learning many different techniques both in microbiology and analytical chemistry. All the methods associated with proteomic analysis were completely new to me and as such I found the experience challenging, but extremely rewarding. I learnt procedures including electrophoresis, protein and peptide quantification, bacterial growth analysis, peptide MS/MS data interpretation, peptide/protein quantification and identification and, some biostatistical methods and softwares for data analysis.
The opportunity to go to a new lab in another country has helped both my personal and career development. This work wouldn’t have been possible without the Mobility Fellowship provided by the EPS and the insight gained from the results is particularly important both to my PhD and the following manuscript we are preparing.
I would like to thank everyone in the CURIB building within the University of Rouen for being extremely warm and friendly during my stay, particularly Dr Sébastien Massier and Dr Hung Le who I worked with closely. Also, I would like to thank Dr Jerome Le Prince, Prof Pascal Cosette and my supervisor Prof Marc Devocelle for helping to organise and host myself during my stay. Finally, I would like to thank the EPS for funding such a project. By allowing such research mobility and experience to exist more science is possible with even more exciting results waiting to be found!
(1) Connolly, J. R. F. B.; Fitzgerald-Hughes, D.; Maresca, M.; Muldoon, J.; Devocelle, M. Ciprofloxacin as a Tryptophan Mimic within an Antimicrobial Peptide. New J. Chem. 2024, 48 (36), 15722–15725. https://doi.org/10.1039/D4NJ01445F.