Tau protein is a microtubule-associated protein localized and expressed in human brain cells, predominantly in axons of neurons. The function of this protein is imperative for correct axonal microtubule formation and function. Tau protein has been found to form aggregates and filamentous structures in the brains of patients suffering from Alzheimer’s disease or other neurodegenerative diseases. However, the exact molecular mechanism of neurodegeneration remains unknown. Tau protein belongs to the group of intrinsically disordered proteins. These proteins do not occupy a given 3D structure but rather exist as a highly dynamic ensemble of conformations. The disordered nature and inherent flexibility of Tau in monomeric state prevent its structural characterization by Cryo-EM or X-ray crystallography. On the other hand, it makes Nuclear Magnetic Resonance (NMR) a method of choice for studying its structural and interaction properties.

In the proposed diploma thesis project, several advanced NMR techniques will be utilized to study the properties of Tau protein. Firstly, temperature effects on secondary structure propensities of full-length tau protein (tau isoform 2N4R) will be studied. The student will also investigate the effect of phosphorylation by GSK-3 beta kinase on the interaction of Tau protein with microtubules. Additionally, the student will perform the expression of Tau protein in E. coli cells while optimizing the expression protocol for effective isotopic labeling. The desired protein construct labeled by 19F and 15N will be further utilized for in-cell NMR experiments.