De Novo Biosynthesis of Terminal Alkyne-Tagged Natural Products and Applications

Natural products are important small molecules widely used as drugs, pesticides, herbicides, and biological probes. Tagging natural products with a unique chemical handle, such as an alkyne functionality, enables the visualization, enrichment, quantification, and mode of action study of natural products through bioorthogonal chemistry. However, the labeling of natural products has not been adequately explored compared to that of macromolecules. We recently developed a new general platform to tag natural products by characterizing and engineering the novel terminal alkyne synthetic biology that living systems offer. In addition to directly producing orthogonally functional natural product analogues that can be subjected to facile chemical modification for drug screening, our work may significantly advance the field of natural product research through coupling with diverse azido analytical handles. For example, using a fluorogenic probe, in situ detection and quantification of natural products in producing cell cultures can be accomplished for the first time, enabling the facile selection of the best overproduction strain. Furthermore, since azide-alkyne click chemistry has recently emerged as one of the most powerful tools in drug discovery and chemical biology, our findings open the door to numerous biological applications in which in situ enzymatic generation of a terminal alkyne is required or preferred.