How change in chirality prevents β-amyloid type interaction in a protonated cyclic dipeptide dimer

Abstract

The protonated dimers of the diketopiperazine dipeptide cyclo (LPhe-LHis) and cyclo (LPhe-DHis) are studied by laser spectroscopy combined with mass spectrometry to shed light on the influence of stereochemistry on...

Does Chiral Sensitivity of a Structure Depend on the Metal Core? Alkali Ion Complexes of Cyclo(Tyr‐Tyr)

“…We have undertaken a study of DKP dipeptides containing at least one aromatic amino acid under jet-cooled or ion trap conditions. [7][8][9][10][11][12][13][14][15][16] Among the studied systems, those containing two aromatic amino-acids are of special interest as they raise the question of the localisation of the electronic transition and the coupling between the two aromatic chromophores (see Figure 1). The most stable structures of neutral bi-chromophore DKP dipeptides, like cyclo(phenylalanyl-phenylalanyl) (c-Phe-Phe) or cyclo(phenylalanyl-tyrosyl) (c-Phe-Tyr), [10,14,15] are very similar, although spectroscopically discernible, whether the two residues have identical or opposite absolute configurations.…”

“…From the fundamental point of view, they provide model systems for studying the influence of the chirality of the residues on the structure of sterically constrained systems. We have undertaken a study of DKP dipeptides containing at least one aromatic amino acid under jet‐cooled or ion trap conditions [7–16] . Among the studied systems, those containing two aromatic amino‐acids are of special interest as they raise the question of the localisation of the electronic transition and the coupling between the two aromatic chromophores (see Figure 1).…”