title: A comparative 1H-n.m.r. study of MurNAc-L-Ala-D-iGln (MDP) and its analogue murabutide: evidence for a structure involving two successive beta-turns in MDP.
abstract: The active principle, MurNAc-L-Ala-D-iGln (MDP), of complete Freund's adjuvant and its analogue, MurNAc-L-Ala-D-Gln-OnBu (murabutide), which express immunomodulatory as well as other biological properties, have been studied by 2D-1H-n.m.r. spectroscopy at 500 MHz. The results suggest the presence in MDP of two successive turns involving the MurNAc-L-Ala and L-Ala-D-iGln moieties, respectively, whereas only the former turn persists in murabutide. This turn mimics the type II beta-turn found in L-D depsipeptides, whereas the other is a typical type II beta-turn for L-D peptides.
mesh_terms: D000119:Acetylmuramyl-Alanyl-Isoglutamine / Q000031:analogs & derivatives*; D002236:Carbohydrate Conformation; D006020:Glycopeptides; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D011487:Protein Conformation; D013329:Structure-Activity Relationship; D013816:Thermodynamics
chemical_list: D006020:Glycopeptides; D000119:Acetylmuramyl-Alanyl-Isoglutamine; C033575:murabutide