METHOD OF MASS-SPECTROMETRIC SEQUENCING OF PEPTIDES WITH THE PREFERENTIAL B-ION FORMATION Russian patent published in 2018 - IPC G01N33/68 

FIELD: chemistry.

SUBSTANCE: invention relates to bioorganic chemistry and can be used to determine the amino acid sequence of peptides and their fragments by mass spectrometry method. For this, sequencing of the dansylated peptide based on the direct introduction of the solution into the ion source followed by fragmentation of the molecular peptide ion in the area between the nozzle and the skimmer of the ion source by the action of an electric field at several discrete values of the electric field strength in the range 10²–10⁴ V/m and residual gas pressure in the range of 100–2,000 Pa. Presence of a dansyl residue on the N-terminal amino group of the peptide allows to avoid the cyclization of short fragments of the peptide and leads to the preferential formation of b-ions, which are registered predominantly in the form of protonated dehydrated fragments, including the smallest molecular weight ions b₁ and b₂, which allows to determine the full amino acid sequence of the parent peptide. Average values of the fragmentation parameters: voltage on the capillary 3,400 V, on the nozzle 90–140 V, on the skimmer 60–90 V, the values of these parameters vary depending on the nature and number of amino acids that form the peptide, the system records and determines the amino acid sequence of the peptides.

EFFECT: invention provides a simplification of the interpretation of mass spectra and increases the reliability of determining the complete amino acid sequence of the peptides to be studied.

1 cl, 5 dwg, 1 ex