Characterization of post-translationally modified recombinant protein using liquid chromatography/mass spectrometry

Post-translational modification plays an important role in the biological functions of many proteins. Characterization of such modifications is crucial in the development of recombinant protein-based vaccines. Liquid Chromatography coupled with Mass Spectrometry (LC/MS) provides a powerful tool with high resolution and accuracy to characterize proteins and their post-translational modifications. The technique was applied to characterization of a Lyme vaccine protein rOspA (recombinant Outer surface protein A). The results demonstrate that LC/MS could be used to resolve and characterize various forms of post-translational lipidation of the protein. It was this detailed structural information that made it possible to validate a method for quantitative determination of the lipidation forms of rOspA.