Bioconjugate Platform for Iterative Backbone N -Methylation of Peptides.
Zheng, Y., Ongpipattanakul, C., Nair, S.K.(2022) ACS Catal 12: 14006-14014
- PubMed: 36793448 
- DOI: https://doi.org/10.1021/acscatal.2c04681
- Primary Citation of Related Structures:  
7TWK, 7TWL, 7TWM - PubMed Abstract: 
N -methylation of peptide backbones has often been utilized as a strategy towards the development of peptidic drugs. However, difficulties in the chemical synthesis, high cost of enantiopure N -methyl building blocks, and subsequent coupling inefficiencies have hampered larger-scale medicinal chemical efforts. Here, we present a chemoenzymatic strategy for backbone N -methylation by bioconjugation of peptides of interest to the catalytic scaffold of a borosin-type methyltransferase. Crystal structures of a substrate tolerant enzyme from Mycena rosella guided the design of a decoupled catalytic scaffold that can be linked via a heterobifunctional crosslinker to any peptide substrate of choice. Peptides linked to the scaffold, including those with non-proteinogenic residues, show robust backbone N -methylation. Various crosslinking strategies were tested to facilitate substrate disassembly, which enabled a reversible bioconjugation approach that efficiently released modified peptide. Our results provide general framework for the backbone N -methylation on any peptide of interest and may facilitate the production of large libraries of N -methylated peptides.
Organizational Affiliation: 
Department of Biochemistry, University of Illinois at Urbana-Champaign, Roger Adams Laboratory, 600 S. Mathews Ave., Urbana, IL, 61801, USA.