Nature Communications: 29 New Peptide Asparaginyl Ligases Discovered from Viola Plants — Major Cyclic Peptide Synthesis Toolkit Expansion
A Nature Communications paper published April 27 mined natural diversity in Viola plants to discover 29 new peptide asparaginyl ligases (PALs) — enzymes that catalyze cyclization of synthetic peptide chains. The work characterizes a pH-dependent cyclization mechanism and defines transferable expression-increasing principles, substantially expanding the enzymatic toolkit available for cyclic peptide drug development. The discovery is timely given the surge of macrocyclic peptide programs at Circle Pharma, Bicycle Therapeutics, and Unnatural Products.