Impact of Solvents on the Protein Charge States Detected by Mass Spectrometry
Disciplines
Analytical Chemistry
Abstract (300 words maximum)
Electrospray ionization (ESI) combining with mass spectrometry is a powerful soft ionization technique to identify, quantify and elucidate the structure of the small and large protein complexes. In this technique, the protein samples are required to dissolve with organic solvents which significantly influence the charge state distribution of the protein in the gas phase that occurs during the ESI process. In this study, we explore the charge state distribution of Ubiquitin in various organic solvents including hexane, methanol, DMF and DMSO by ESI-MS. The control experiment was performed by dissolving Ubiquitin in water. All mass spectrometry experiments were conducted on an Electrospray Ionization (ESI) coupled a with LTQ mass spectrometer. Mass spectra was acquired using a mass range of 200–2000 m/z. In the presence of 10% solvents, the most intense peak was observed at 6+ charge state with DMSO. The other dominant peaks are noticed for 5+ charge state when Ubiquitin was mixed with Methanol, DMSO and DMF. The large percentage of organic solvents has significantly influenced the charge state distribution of Ubiquitin. In the presence of 50% methanol, Ubiquitin showed a wide range of charge state distribution from 5+ to 11+ with the most dominant peak being noticed at 7+ charge states. This shows that alcohol causes more unfolding of Ubiquitin than hexane, DMF and DMSO. The highest ion current was also noticed for methanol compared to other solvents. The relative abundance of Ubiquitin was significantly suppressed when high percentage of DMSO, DMF, and Hexane were utilized. This study shows that methanol induced more unfolding of Ubiquitin while other solvents helped the protein to retain its folded conformation.
Academic department under which the project should be listed
CSM - Chemistry and Biochemistry
Primary Investigator (PI) Name
Mohammad A. Halim
Impact of Solvents on the Protein Charge States Detected by Mass Spectrometry
Electrospray ionization (ESI) combining with mass spectrometry is a powerful soft ionization technique to identify, quantify and elucidate the structure of the small and large protein complexes. In this technique, the protein samples are required to dissolve with organic solvents which significantly influence the charge state distribution of the protein in the gas phase that occurs during the ESI process. In this study, we explore the charge state distribution of Ubiquitin in various organic solvents including hexane, methanol, DMF and DMSO by ESI-MS. The control experiment was performed by dissolving Ubiquitin in water. All mass spectrometry experiments were conducted on an Electrospray Ionization (ESI) coupled a with LTQ mass spectrometer. Mass spectra was acquired using a mass range of 200–2000 m/z. In the presence of 10% solvents, the most intense peak was observed at 6+ charge state with DMSO. The other dominant peaks are noticed for 5+ charge state when Ubiquitin was mixed with Methanol, DMSO and DMF. The large percentage of organic solvents has significantly influenced the charge state distribution of Ubiquitin. In the presence of 50% methanol, Ubiquitin showed a wide range of charge state distribution from 5+ to 11+ with the most dominant peak being noticed at 7+ charge states. This shows that alcohol causes more unfolding of Ubiquitin than hexane, DMF and DMSO. The highest ion current was also noticed for methanol compared to other solvents. The relative abundance of Ubiquitin was significantly suppressed when high percentage of DMSO, DMF, and Hexane were utilized. This study shows that methanol induced more unfolding of Ubiquitin while other solvents helped the protein to retain its folded conformation.