Increasing Protein Charge State When Using Laser Electrospray Mass Spectrometry

• DOI: 10.1007/s13361-015-1084-3
• Publication Date: 2015-03-09T13:41:20Z
• Authors: Santosh Karki; Paul M. Flanigan; Johnny J. Perez; Jieutonne J. Archer; Robert J. Levis
• Keywords: Trifluoroacetic acid

Femtosecond (fs) laser vaporization is used to transfer cytochrome c, myoglobin, lysozyme, and ubiquitin from the condensed phase into an electrospray (ES) plume consisting of a mixture supercharging reagent, m-nitrobenzyl alcohol (m-NBA), trifluoroacetic acid (TFA), acetic (AA), or formic (FA). Interaction acid-sensitive proteins like c myoglobin with highly charged ES droplets resulted in shift higher charge states comparison acid-stable lysozyme ubiquitin. Laser mass spectrometry (LEMS) measurements showed increase both average (Zavg) state maximum intensity (Zmode) for compared conventional ionization (ESI-MS) under equivalent solvent conditions. A marked ion abundance was observed LEMS (ranging 19+ 21+ versus 13+ 16+) 26+ 18+ 21+) using solution containing m-NBA TFA. as function flow rate yielded increasing decreasing rates myoglobin.