Neighbor-directed histidine N ( tau )-alkylation: A route to imidazolium-containing phosphopeptide macrocycles.
Qian, W.J., Park, J.E., Grant, R., Lai, C.C., Kelley, J.A., Yaffe, M.B., Lee, K.S., Burke, T.R.(2015) Biopolymers 104: 663-673
- PubMed: 26152807 
- DOI: https://doi.org/10.1002/bip.22698
- Primary Citation of Related Structures:  
4X9R, 4X9V, 4X9W - PubMed Abstract: 
Our recently discovered, selective, on-resin route to N(τ)-alkylated imidazolium-containing histidine residues affords new strategies for peptide mimetic design. In this, we demonstrate the use of this chemistry to prepare a series of macrocyclic phosphopeptides, in which imidazolium groups serve as ring-forming junctions. Interestingly, these cationic moieties subsequently serve to charge-mask the phosphoamino acid group that directed their formation. Neighbor-directed histidine N(τ)-alkylation opens the door to new families of phosphopeptidomimetics for use in a range of chemical biology contexts.
Organizational Affiliation: 
Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute-Frederick, Frederick, MD, 21702.