公开(公告)号：US20180356426A1

公开(公告)日：2018-12-13

申请号：US16002749

申请日：2018-06-07

Applicant: Purdue Research Foundation ,  AMGEN

Inventor： Stephen T. Ayrton ,  Robert Graham Cooks ,  Tawnya Flick ,  Da Ren

IPC: G01N33/68 ,  H01J49/00 ,  H01J49/10

CPC classification number: G01N33/6848 ,  H01J49/0031 ,  H01J49/10

Abstract: The invention generally relates to methods for determining whether a peptide includes aspartate or isoaspartate. In certain aspects, methods of the invention involve binding an aspartate/isoaspartate residue in a peptide with a label to produce a labeled peptide. The labeled peptide is then ionized. The ionizing process causes the label to undergo rearrangement in a gas phase at a higher rate if the label is bound to the aspartate residue as compared to if the label is bound to the isoaspartate residue. The methods of the invention then involve performing a mass spectrometry analysis to detect the rearrangement of the label, thereby determining whether the peptide includes aspartate or isoaspartate.