Complete Post-Translational Modification Mapping of Pathogenic N. meningitidis Pilins Requires Top-Down Mass Spectrometry

摘要

In pathogenic bacteria post-translationally modified proteins have been found to promote bacterial survival and evasion from the host immune system. In the human pathogen Neisseria meningitidis the protein PilE is the major building block of type IV pili, extracellular filamentous organelles that play a major role in pathogenesis. Previous reports have shown that PilE can be expressed as different proteoforms, each harbouring its own set of post-translational modifications (PTMs) and that specific proteoforms are key in promoting virulence [1]. Efficient tools that allow complete PTM mapping of proteins involved in bacterial infection are therefore strongly needed. We show here, using clinical strains, that top-down mass spectrometry is required to achieve this goal when more than two proteoforms are present simultaneously.