High resolution mass spectrometer

• Subject Area: Basic Research in Biology and Medicine ; Analytical Chemistry
• Term: Funded in 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 559568237

This application is for a high resolution mass spectrometer with an electrospray ionization (ESI) source for sensitive qualitative and quantitative analysis of complex biological samples, in particular for the analysis of enzymatically and non-enzymatically modified proteins. In view of the breakdown of a high-resolution mass spectrometer last year and the need to replace another high-resolution mass spectrometer in the near future (purchase in 2009), the requested instrument is intended to close the resulting gap in order to be able to work on collaborative projects and service samples in addition to our own projects. The analysis of complex samples and the heterogeneity of modified proteins and peptides require the highest possible resolution and mass accuracy of mass spectra, including fragment ion spectra. Both data dependent acquisition (DDA) and data independent acquisition (DIA) methods are required to identify as many co-eluting compounds as possible. A focus of current and future work is on post-translational enzymatic and especially non-enzymatic modifications, which require alternative fragmentation techniques, such as electron transfer dissociation (ETD) or electron capture dissociation (ECD), in addition to classical collision-induced dissociation (CID). To characterize isomeric compounds that cannot be separated chromatographically, an integrated ion mobility spectrometer is required. The usually limited sample volumes require coupling to an (existing) nanoUPLC with flow rates of 100 nL/min to 300 nL/min and for robust quantitative analysis coupling to a UPLC with flow rates of 1 µL/min to 200 µL/min. Comprehensive characterization of post-translational modifications requires analyses at the peptide level (bottom-up) to identify site-specific modifications and at the protein level (top/middle-down) to estimate the homogeneity of modifications and the heterogeneity of protein variants as well as their relative proportions.

• DFG Programme: Major Research Instrumentation
• Major Instrumentation: Hochauflösendes Massenspektrometer
• Instrumentation Group: 1700 Massenspektrometer
• Applicant Institution: Universität Leipzig
• Leader: Professor Dr. Ralf Hoffmann