The Canonical Helix of Urea Oligomers at Atomic Resolution: Insights Into Folding‐Induced Axial Organization

Abstract

Helical by nature: Urea-based peptidomimetics with proteinogenic side chains are fully helical in the crystalline state (see picture). Four acyclic residues are sufficient to drive complete helix formation with all complementary H-bonding sites being satisfied (up to 14 for a 8-mer). Helices pack head-to-tail to create infinite H-bonded networks with different topologies.