Chemo-selective proteomics in microbial systems.

SUMMARYOver the past two decades, the field of bioorthogonal chemistry has transitioned from emerging to an established cornerstone of scientific inquiry. In parallel, advances in microbial and host-microbe research have highlighted the need for functional approaches that extend beyond genomic and transcriptomic analyses to directly interrogate protein-level activity. Despite this need, proteomic strategies capable of resolving dynamic, heterogeneous, and low-abundance protein populations remain underdeveloped in microbial systems. This review highlights the convergence of chemo-selective proteomic technologies with microbial biology, focusing on bioorthogonal non-canonical amino acid tagging (BONCAT), activity- or affinity-based protein profiling, and bioorthogonal post-translational modifications, and comments on possibilities for novel applications for the use of click chemistry-based tools in the functional interrogation of microbial systems. Together, these strategies enable spatiotemporal resolution of protein synthesis, selective profiling of microbial subpopulations, and direct characterization of protein activity and regulation in complex biological contexts, including single-species cultures, host-associated environments, and polymicrobial communities. Continued development and utilization of these technologies will enable deeper mechanistic insight into how microbial systems function and respond to environmental and host-derived cues.