Zhang, F.; Liu, Y.; Da, X.-D.; Zhang, W.-B.* Toward Selective Synthesis of Protein Olympiadanes via Orthogonal Active Templates in One Step. CCS Chem. 2023, DOI: 10.31635/ccschem.023.202303071. https://doi.org/10.31635/ccschem.023.202303071

Unlike small molecules, the topological complexity of macromolecules remains largely unexplored due to the huge synthetic challenge. Herein, we report the development of orthogonal active templates for concise and selective synthesis of protein [n]heterocatenanes toward protein olympiadanes. An active template (AT-Snoop) was first developed based on the isopeptide-bond-forming RrgA domain with comparable efficiency and excellent orthogonality to the previously reported active template (AT-Spy) based on the CnaB2 domain. Their combination facilitates selective synthesis of protein [n]catenanes from multiple components in one step and the resulting structures have been verified by SDS-PAGE, SEC, LC-MS, and proteolytic digestion experiments. The results offer a promising solution to tackling the daunting challenge for the precision synthesis of protein olympiadane with five distinct ring components. Not only does the success provide new tools for protein topology engineering, but also it shall spur and fuel the future exploitation of topology-related functional benefits in protein science.