Chiral recognition of dipeptides in phosphatidylcholine aggregates

Abstract Enantiodiscrimination of ditryptophan enantiomers ( l -Trp- l -Trp and d -Trp- d -Trp, l -Trp- d -Trp and d -Trp- l -Trp) was observed in bio-membrane models, such as micellar aggregates of 1,2-diheptanoyl- sn -glycero-3-phospatidylcholine (DHPC) and multilamellar vesicles of either 1-palmitoyl-2-oleoyl- sn -glycero-3-phosphocholine (POPC) or 1,2-dimyristoyl- sn -glycero-3-phospatidylcholine (DMPC) by solution 1 H NMR and HR-MAS 1 H NMR, respectively. The attainment of resolved signals, allowed the first detection of enantiodiscrimination at a molecular level, and the identification of the site of chiral recognition and of the interactions and conformations of homo- and heterochiral dipeptides in large-sized aggregates formed by a common component of bio-membranes.