title: Crystal structure analyses of azasulfuryltripeptides reveal potential for γ-turn mimicry.
abstract: Azasulfurylpeptides feature an amino acid residue in which the CαH and the carbonyl are replaced respectively by a nitrogen atom and a sulfonyl group. Insight into the conformational preferences of azasulfurylpeptides containing an azasulfurylglycine (AsG) residue has been pursued using X-ray analysis in the solid state. Crystals of N-(Boc)-Pro-AsG-Val-OMe (10) and N-(Cbz)-Ala-AsG-D-Phe-Ot-Bu (11) showed tetrahedral geometries about the sulfur atom with the ω torsion angle preferring a staggered conformation. Furthermore, the ϕ and ψ torsion angles of the central azasulfuryl residue were respectively within close proximity to those of ideal inverse and classical γ-turns. In the crystal lattice, azasulfurylpeptide 11 engaged in intermolecular hydrogen bonds between the sulfonyl oxygen and hydrazide hydrogen in an antiparallel orientation.
authors: Department of Chemistry, Université de Montréal, P.O. Box 6128, Downtown Station, Montréal, QC, H3C 3J7, Canada.
authors: Stéphane
authors: S
authors: Turcotte
authors: Department of Chemistry, Université de Montréal, P.O. Box 6128, Downtown Station, Montréal, QC, H3C 3J7, Canada.
authors: William D
authors: WD
authors: Lubell
mesh_terms: D001372:Aza Compounds / Q000737:chemistry*; D018360:Crystallography, X-Ray; D018716:Molecular Mimicry; D010455:Peptides / Q000737:chemistry*; D013441:Sulfinic Acids / Q000737:chemistry*
chemical_list: D001372:Aza Compounds; D010455:Peptides; D013441:Sulfinic Acids; C048899:sulfuryl fluoride
keywords: azasulfurylpeptide; gamma turn; peptide mimicry