Poster Presentation International Peptide Symposium 2023

Natural product cyclic peptides (NPcPs) are a vital source of therapeutics. Unfortunately, the structural complexity of NPcPs has hindered chemical and biochemical efforts to synthesize analogues for drug discovery. While the synthesis of linear peptide is often straightforward, regio- and chemo-selective peptide macrocyclization is still challenging. Non-ribosomal peptides are a major class of NPcPs, they are assembled by modular mega enzymes known as non-ribosomal peptide synthetases (NRPS).¹ Each module is responsible for sequentially adding a new amino acid to the covalently bound linear peptide. This sequential order is pre-defined by evolution. Then, the mature cyclic precursor is typically released via macrocyclization by thioesterase (TE domain).² Herein, while we studying the biosynthesis of an antimycobacterial NRcP we developed a chemical macrocyclization strategy which is fast (mins), operationally simple and high yielding. We combined this  with late stage functionalization enzymes to complete rapid chemoenzymatic synthesis of several natural product analogues. More notably, we successfully applied this fast cyclization to other NPcPs comprising various cyclization styles. This method will aid future efforts to engineer NRPS biosynthetic pathways and facilitate the synthesis of derivative libraries of bioactive NPcPs.