Importance of Data Acquisition Parameters in Identifying Aspartic Acid Isomerization in Degradation Products of Therapeutic Peptides

摘要

we have demonstrated that by applying targeted data acquisition strategy and recording ETD MS/MS spectra in profile mode in the ion trap, isotope pattern of multiply charged fragment ions can be observed which allows for determining correct charge state and mass shift due to deamidation and aspartate isomerization. Traditionally, centroiding has been the choice of method because it produces smaller data files on the computer. However, our experience has been that data files are only 20% larger in profile mode, and nowadays time constraint of a project is a more pressing issue than data storage.