on 05-01-201210:53 AM - edited on 10-15-202112:07 PM by AnalyteGuru
Hao Z, Schwartz JC, Hühmer AF. Scientific Poster Mass spectrometry has drawn more and more attention as an alternative technology to traditional protein N-, as well as C-terminal, sequencing. Electron transfer dissociation (ETD) mass spectrometry is particularly advantageous for sequencing applications because ETD is relatively insensible to the size, the amino acid composition, and post-translational modifications of proteins, therefore randomly cleaves peptide backbone bonds. ETD of intact proteins is highly efficient, generating very informative, yet extremely complex spectra that contain highly charged product ions that are difficult, or even impossible to resolve at unit resolution. ETD technology was recently implemented in a hybrid linear ion trap - Orbitrap mass spectrometer whose high resolution and mass accuracy facilitate analysis of intact proteins using ETD. For unit resolution instruments, proton transfer reaction (PTR) following ETD was developed to reduce spectral complexity. PTR removes protons from multiply charged product ions, generating simplified spectra that contain product ions at charge states resolvable at unit resolution. In this study, the utility of an LTQ Orbitrap XL ETD and an LTQ XL ETD with PTR for intact protein sequencing was investigated.