Abstract
The effect on the fragmentations of N-benzyloxycarbonyl-protected tri and tetrapeptide ethyl esters due to the existence of L-proline was examined in field desorption, fast atom bombardment and tandem mass spectrometry. A significant difference was found among the abundances of the molecular-related ion and the fragment ions formed by the cleavage of the benzyloxycarbonyl group, depending on the numbers and positions of prolyl residues in the derivatives. The results showed that the conformational difference in peptide molecules due to the existence of Pro and the existence of the amide protons near the benzyloxycarbonyl group in the peptides have an effect on the fragmentations of molecules in field desorption and fast atom bombardment mass spectrometry.
