Open AccessTwo pentadehydropeptides with different configurations of the ΔPhe residues
Author(s) -
Makowski Maciej,
Lisowski Marek,
Maciąg Anna,
Wiktor Maciej,
Szlachcic Anna,
Lis Tadeusz
Publication year - 2010
Publication title -
acta crystallographica section c
Language(s) - English
Resource type - Journals
eISSN - 1600-5759
pISSN - 0108-2701
DOI - 10.1107/s0108270110003094
Subject(s) - hydrogen bond , residue (chemistry) , chemistry , amino acid residue , stereochemistry , crystal structure , peptide , glycine , amino acid , methanol , crystallography , molecule , peptide sequence , organic chemistry , biochemistry , gene
Comparison of the crystal structures of two pentadehydropeptides containing ΔPhe residues, namely ( Z , Z )‐ N ‐( tert ‐butoxycarbonyl)glycyl‐α,β‐phenylalanylglycyl‐α,β‐phenylalanylglycine (or Boc 0 –Gly 1 –Δ Z Phe 2 –Gly 3 –Δ Z Phe 4 –Gly 5 –OH) methanol solvate, C 29 H 33 N 5 O 8 ·CH 4 O, (I), and ( E , E )‐ N ‐( tert ‐butoxycarbonyl)glycyl‐α,β‐phenylalanylglycyl‐α,β‐phenylalanylglycine (or Boc 0 –Gly 1 –Δ E Phe 2 –Gly 3 –Δ E Phe 4 –Gly 5 –OH), C 29 H 33 N 5 O 8 , (II), indicates that the Δ Z Phe residue is a more effective inducer of folded structures than the Δ E Phe residue. The values of the torsion angles ϕ and ψ show the presence of two type‐III′β‐turns at the Δ Z Phe residues and one type‐II β‐turn at the Δ E Phe residue. All amino acids are linked trans to each other in both peptides. β‐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.