“…Protonated peptides have also been extensively studied by mass spectrometry coupled to laser fragmentation spectroscopy, either in the IR or in the UV range. [9][10][11][12][13][14][15][16][17] In addition to optical spectroscopy measurements, important structural information on the amino-acid sequence and the secondary structure is gained from the analysis of the collision-induced dissociation (CID) or electron-capture dissociation (ECD) fragments, [18][19][20][21][22][23][24][25][26][27][28] in particular for assessing the influence of stereochemical aspects on the structures. [29] Among the factors structuring the supramolecular shape of peptides in a well-defined and orderly manner, the absolute configuration of the sub-units plays an important role.…”