Investigation of crudes of synthesis of [Leu31, Pro34]-neuropeptide Y by capillary zone electrophoresis/mass spectrometry.
[Leu31, Pro34]-Neuropeptide Y is a thirty-six amino-acid peptide which has a measured relative molecular mass of 4222. Solid-phase synthesis of this peptide resulted in complex crudes of synthesis which were examined by capillary zone electrophoresis (CZE)/electrospray ionization mass spectrometry (ES-MS). The separation efficiency of CZE combined with the mass specificity of mass spectrometry yielded rapid and reliable information on the target peptide and a number of associated side products, which were mainly acetylated peptide sequences having relative molecular masses in the range 2240-4101. Such incomplete or, as they are commonly called, difficult sequences are provoked by problems of swelling and aggregation of the growing peptide chains in the course of synthesis. The use of mass spectrometry is indispensable for obtaining reliable information on the inevitable side products. Initial tuning of the ion source and optimization of the coupling between the CZE system and the mass spectrometer were achieved by performing a number of measurements pertaining to artificially made mixtures of commercial neuropeptides.
Glaxo Research Laboratories, Verona, Italy.
A
A
Zaramella
O
O
Curcuruto
M
M
Hamdan
C
C
Cabrele
E
E
Peggion
D000595:Amino Acid Sequence; D004586:Electrophoresis; D005449:Fluorenes / Q000737:chemistry; D007202:Indicators and Reagents; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D009478:Neuropeptide Y / Q000031:analogs & derivatives* / Q000032:analysis / Q000138:chemical synthesis
D005449:Fluorenes; D007202:Indicators and Reagents; D009478:Neuropeptide Y; C062259:neuropeptide Y, Leu(31)-Pro(34)-; C054007:1-(9-fluorenyl)methyl chloroformate