MALDI-TOF/TOF mass spectrometry system

• Subject Area: Plant Sciences
• Term: Funded in 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 469113358

The applicant's working group has specialised in the identification and functional-structural characterisation of mobile proteins from plants for many years. Recently, the research has focused on RNA-binding proteins that can be involved in signal transmission regulating developmental processes or stress responses. The requested MALDI-TOF / TOF is an essential component for the analyses, and not only the success of the own projects, but also of joint projects (DFG, ERC) depends on the instrument. The device applied for is a replacement for a defective MALDI-TOF / TOF mass spectrometer system that cannot be put back into operation due to the discontinuation of series production. Matrix Assisted Laser Desorption Ionization -Time of Flight Mass Spectrometry (MALDI-TOF MS) is a highly sensitive measuring method for determining the mass of biomolecules and is one of the elementary methods in protein analysis. It allows gentle ionisation of the analytes (from peptides to whole proteins) and can therefore be used in a wide range of applications with many options for sample preparation. Compared to other mass spectrometric methods for protein analysis, MALDI-MS is insensitive to other sample components, while at the same time having high sensitivity in the femto- to even attomolar concentration range and short measuring times. The separation of sample preparation from the actual analysis by loading an external steel plate instead of coupling a sensitive HPLC in LC-MS systems allows the device to be used in a variety of ways in research and teaching. Samples can be prepared even by inexperienced students, doctoral candidates or cooperation partners and stored, and measured at a different timepoint by an experienced user. The resulting spectra are easy to evaluate due to limited ionisation levels what enables a quick interpretation of results. In addition, tandem MS allows the determination of partial amino acid sequences and the precise detection of specific amino acid modifications. In addition, MALDI-TOF MS enables the fundamental structural characterisation of proteins. Structural MS can also be used to localise areas of interaction with other proteins or with RNAs. In the applying working group, the mass spectrometric methods are complemented and supplemented using modern methods for high-resolution structure determination (SAXS, X-ray structure analysis) and functional characterisation (e.g., quantitative determination of protein-RNA affinities). By this combination, RNA-binding proteins relevant for systemic signal transmission cannot only be identified, but structure-function relationships can be deciphered at the same time.

• DFG Programme: Major Research Instrumentation
• Major Instrumentation: MALDI-TOF/TOF Massenspektrometer System
• Instrumentation Group: 1700 Massenspektrometer
• Applicant Institution: Universität Hamburg
• Leader: Professorin Dr. Julia Kehr