Application of the Fragments and Structure Analysis of Matrix-assisted Laser Desorption/Ionization Time-of-flight Mass Spectrometry in Peptide Sequencing.

The peptides of angiotensin II and fragment 18-39 of adrenocorticotropic hormone were determined by MALDI-TOF-MS-FAST. Main amino acid compositions and partial sequences of the peptides have been analyzed by the mass data of fragment ion peaks in the FAST spectra. The primary structures of these two peptides were identified by searching the protein databases. The research results showed that FAST is a powerful tool for determining the primary structure of peptides because of its high sensitivity, quickness and accuracy.