Direct Ionization of Large Proteins and Protein Complexes by Liquid Sample Desorption Electrospray Ionization-Mass Spectrometry (DESI-MS)

摘要

Advances in mass spectrometry ionization techniques, namely electrospray ionization (ESI), have opened the door to an array of applications in studying protein structure and function. One limitation is the strict requirements for ESI-compatible sample solvents, often causing protein denaturation. This limitation can be overcome by implementing a new ambient desorption ESI (DESI) technique, liquid DESI. Liquid DESI enables proteins to be ionized under native conditions while using a spray solvent that is most conducive to ESI measurements. The application of liquid DESI to large proteins and protein complexes is possible due to the coupling of this source to an instrument with broader m/z range, and has additional uses in real time conformational change studies as well as mechanistic experiments.