Sequencing of cyclosporins by fast atom bombardment and linked-scan mass spectrometry |
| |
Authors: | Vladimír Havlí
ek Alexandr Jegorov Petr Sedmera Miroslav Ryska |
| |
Institution: | Vladimír Havlíček,Alexandr Jegorov,Petr Sedmera,Miroslav Ryska |
| |
Abstract: | The mass spectrometric sequence determination of amino acid residues in cyclosporins using fast atom bombardment, collisionally activated dissociations in the first field-free region and linked B/E scan is described. The general fragmentation scheme was derived from the spectra of cyclosporins A, B, C, D, F, G, L and DH-MeBmt1]CS. The main fragmentation pathways start by primary splitting between amino acids 2–3, 1–11 and 5–6. The corresponding N-terminal b-type ions are common fragment types in the mass spectra. The 1–11 splitting can be enhanced by the introduction of a lactone group into the peptide ring by conversion of cyclosporins into isocyclosporins. The fragmentation scheme was used for amino acid sequence determination in four new natural cyclosporins, MeLeu1]CS, Leu4]CS, Ile4]CS and Leu5]CS. |
| |
Keywords: | |
|
|