This paper describes using an endogenous enzyme of S. aureus to incorporate small molecules into the cell wall. They were able to get fluorescein, biotin, and azide incorporated into the cell wall by engineering small molecule substrates with modified functionality. Additionally, a bioorthogonal click [3+2] cycloaddition reaction was performed with the modified cell wall containing an azide, showing that the small molecule incorporation into the cell wall can be used as reactive handles in vivo.
Sortase is an established tool for all sorts of bioconjugation reactions. We will discuss it in Topic 18: Bioconjugation Reactions and Applications
ReplyDeleteThe sortase reaction definitely seems useful, especially considering the selectivity of the peptide substrate and ability to modify the N-terminus with many small molecules.
ReplyDeleteTargeting S. Aureus is particularly relevant due to the prevalence of deaths recently associated with the bacteria.
I wonder if this method could be a way to study protein turn-over or the life-span of cell-wall integrated proteins or other proteins. You could watch the intensity of the fluorescence fade, and infer that proteins are being degraded and replaced with non-tagged versions. Although bacteria reproduce so fast that I guess this would be another way it could fade.
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