A New Motif in the Formation of Peptide Nanotubes: The Crystallographic Signature

Terminally protected acyclic tripeptides Boc-Tyr(1)-Val(2)-Tyr(3)-OMe 1 and Boc-Tyr(1)-Ile(2)-Tyr(3)-OMe 2 self-assemble into nanotubes in
crystals through various noncovalent interactions with an average internal diameter of 5 Å (0.5 nm), and the tubular ensemble is developed
through the hydrogen-bonded side chains of tyrosine residues. The inside of the hollow nanotubular structures is hydrophilic; however, no
solvent molecules have been crystallographically detected.