Comparison of the crystal structures of two pentadehydropeptides containing DeltaPhe residues, namely (Z,Z)-N-(tert-butoxycarbonyl)glycyl-alpha,beta-phenylalanylglycyl-alpha,beta-phenylalanylglycine (or Boc(0)-Gly(1)-Delta(Z)Phe(2)-Gly(3)-Delta(Z)Phe(4)-Gly(5)-OH) methanol solvate, C(29)H(33)N(5)O(8) x CH(4)O, (I), and (E,E)-N-(tert-butoxycarbonyl)glycyl-alpha,beta-phenylalanylglycyl-alpha,beta-phenylalanylglycine (or Boc(0)-Gly(1)-Delta(E)Phe(2)-Gly(3)-Delta(E)Phe(4)-Gly(5)-OH), C(29)H(33)N(5)O(8), (II), indicates that the Delta(Z)Phe residue is a more effective inducer of folded structures than the Delta(E)Phe residue. The values of the torsion angles phi and psi show the presence of two type-III' beta-turns at the Delta(Z)Phe residues and one type-II beta-turn at the Delta(E)Phe residue. All amino acids are linked trans to each other in both peptides. Beta-turns present in the peptides are stabilized by intramolecular 4-->1 hydrogen bonds. Molecules in both structures form two-dimensional hydrogen-bond networks parallel to the (100) plane.

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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2855584PMC
http://dx.doi.org/10.1107/S0108270110003094DOI Listing

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February 2025

Departament d'Enginyeria Química and Barcelona Research Center in Multiscale Science and Engineering, EEBE, Universitat Politècnica de Catalunya, C/ Eduard Maristany, 10-14, 08019 Barcelona, Spain; Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology, Baldiri Reixac 10-12, 08028 Barcelona Spain. Electronic address:

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