Chiral Recognition of Dipeptides in a Biomembrane Model

Abstract

Chiral recognition of the enantiomeric couples of ditryptophan and diphenylalanine was observed by (1)H NMR spectroscopy in micelles formed by sodium N-dodecanoyl-L-prolinate. Ditryptophan showed a selective association with the Z domains of the amidic aggregates, whereas diphenylalanine did not show any selectivity in the association. Partition coefficients between water and aggregates were evaluated by diffusion NMR experiments. Intramolecular distances of ditryptophan isomers associated with chiral aggregates were obtained by ROESY experiments and were used as constraints in molecular mechanics calculations. From these calculations, information on the conformation of the peptides in the chiral aggregates was obtained.

Discrimination of enantiomers of dipeptide derivatives with two chiral centers by tetraaza macrocyclic chiral solvating agents using1H NMR spectroscopy

“…9 Therefore, it is necessary to intensively develop more effective chiral auxiliaries for their chiral discrimination by 1 H NMR spectroscopy. 10 Herein, dipeptide derivatives were selected as one of the most representative species with two stereo configurations. Generally, dipeptides or their derivatives contain two identical or different chiral amino acid residues with one or two stereocenters.…”

Lipid Bilayer Crossing—The Gate of Symmetry. Water-Soluble Phenylproline-Based Blood-Brain Barrier Shuttles

“…[23][24][25] However, 6 the chiral interactions between the BBB and BBB-shuttles have not been studied before.…”

Chiral Recognition in Biomembrane Models: What is behind a ‘Simple Model’

“…Note that in the absence of micelles, the homochiral and heterochiral dipeptides feature a similar conformation. 23 It was after these findings that we began to suggest the hypothesis that the chiral functions of self-assemblies might be expressed as chiral clefts that could be localized in various regions of the aggregates, in the hydrophilic area as well as in the hydrophobic one. For investigating the role of the hydrophobic region in the enantio-discriminating process in different models, we carried out an analogous 1 H NMR spectroscopic investigation on the stereoisomers of Trp-Trp in micelles of 1,2-diheptanoyl-sn-glycero-3-phosphatidylcholine (DHPC) (by static NMR spectroscopy) and in liposomes of POPC and DMPC (by HR-MAS NMR) (see Scheme 1).…”

“…34 In the investigation of the chiral recognition of Trp-Trp in chiral micelles and liposomes, 23,27 we had to choose between two possible approaches of calculations for simulating the solute-aggregate system: (i) the molecular dynamics approach that involves a full description at the atomic level of the dipeptides, aggregates, and solvent (water), and (ii) the simulation of merely the solute (the dipeptide) using some experimental constraints.…”