Deep Proteoform Sequencing with Top-Down Direct Mass Technology (opens in new tab)

Individual Ion Mass Spectrometry (I2MS) using Direct Mass Technology mode on an Orbitrap mass spectrometer (DMTm) increases sensitivity, resolution, and mass range for protein analysis. Here, we present an end-to-end workflow for deep proteoform sequencing using top-down mass spectrometry with DMTm. By assigning the charge of individual fragment ions and converting spectra from the m/z to the mass domain, DMTm resolves overlapping isotopic distributions that have limited conventional top-down...