Improving Sample Treatment for In-Solution Protein Identification by Peptide Mass Fingerprint Using Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry

Three ultrasonic energy sources were studied to speed up the sample treatment for in-solution protein identification by peptide mass fingerprint using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Protein reduction, alkylation, and enzymatic digestion steps were done in 15 min. Nine proteins, including zinc resistance-associated protein precursor from Desulfovibrio desulfuricans strain G20 and split-soret cytochrome c from D. desulfuricans ATCC27774 were successfully identified with the new protocol. Keywords: in-solution protein digestion • protein identification • ultrasonic probe • sonoreactor • ultrasonic bath • MALDI-TOF−MS