Efficient protein folding is essential for cell viability and this process is aided by a complex interplay between various specialized proteins (chaperons) and protein complexes. The accumulation of misfolded proteins is an important feature of many neurodegenerative diseases (such as Alzheimer, Parkinson, and Huntington) and plays also a central role in aging mechanisms. Importantly, the protein folding machinery is not static but needs to adapt to various cellular and environmental conditions. Using mass spectrometry based strategies, our work aims at the characterization of complexes involved in protein folding and the unraveling of their regulation on the transcriptional and post-translational level. To this end, we collaborate very closely with the other groups of the Department of Cellular Biochemistry.
Mass spectrometry based proteomics analyzes the protein complements in complexes, cells, tissues and organisms. The goal of proteomics is not only to determine the identity of proteins but also their quantities, localization, dynamics, post-translational modifications, and interaction partners. Proteomics can be carried out at the whole cell or tissue level but, often more interestingly, may be focused on specific and functionally relevant cellular substructures or complexes. In our group we mainly use an Orbitrap electrospray-ionization mass spectrometer coupled to a nanoHPLC system, which allows the efficient separation of complex peptide mixtures at very low flow rates (200 nL/min.). The Orbitrap mass spectrometer combines the advantageous features of high sensitivity, resolution, mass accuracy and sampling speed, and is therefore very well suited for all types of proteomics analyses. To enable accurate relative quantitation of proteins and their post-translational modifications we mainly employ a metabolic labeling technique termed Stable isotope labeling with amino acids in cell culture (SILAC). The development, adaption, and refinement of proteomics techniques for protein folding research are important goals of this group.
People involved in the work
Liang Zhao, PhD
Albert Ries, Technician