FUZZINESS - Highly unstructured protein complexes studied by NMR spectroscopy

Main area:Protein chemistry
Target group:Biochemistry, Molecular Biomedicine, Biology
Educational level:Masters
Project description:

We seek two highly ambitious and qualified students for masters’ projects, both founded at the Structural Biology and NMR Laboratory (SBiNLab) at UCPH. One project is in collaboration with the single-molecule fluorescence Laboratory of Prof. Ben Schuler at the University of Zurich and one is in collaboration with Prof Olaf Nielsen at BIO, UCPH. Your background should preferably be in chemistry, biochemistry, nanotechnology, or something similar.

Background - Many proteins contain large unstructured regions that are functionally important. They are often involved in interactions with other proteins, and upon binding, different degrees of disorder can persist. Surprisingly, evidence has accumulated that complexes between such intrinsically disordered regions can remain fully unstructured – a notion supported by simulations and established results from polymer chemistry. However, owing to a lack of suitable methods, we currently have very little understanding of how a protein complex can be stable and exert a specific function in the absence of a well-defined binding interface.

Projects - The overall goal is to reveal the mechanisms and biological relevance of this newly recognized phenomenon of highly unstructured protein complexes from the molecular to the cellular level. We are uniquely positioned for this challenge: We have identified two different protein systems of remarkable, physiologically relevance; one that includes two largely unstructured proteins, and one that includes a disordered protein and a highly folded protein. The masters’ projects are intended to elucidate the structural and dynamical properties of the complexes representing archetypes of this new paradigm of biomolecular recognition.

Methods -­ The main experimental method will be nuclear magnetic resonance (NMR) spectroscopy. The student will express and purify a selection of stable-­isotope-labeled variants for NMR studies. The structural and dynamical properties of the free proteins and their complex will be probed using various multi-­dimensional NMR experiments and advanced data analysis methods as well as other biophysical methods. An array of complementary biophysical methods is available at the SBiNLab including circular dichroism, fluorescence spectroscopy, mass spectrometry, rapid-­mixing stopped-flow kinetics, and more. In addition, one student will have the option of being introduced to using cutting-­edge single-­molecule fluorescence techniques, which are ideally suited for probing such exceedingly dynamic and structurally heterogeneous systems, during short-­term stays in the laboratory of Prof. Ben Schuler at the University of Zurich.

The projects are partially funded by grants from the Novo Nordisk Foundation and the Danish Research Council.

For further information, please contact Prof. Birthe Kragelund (bbk@bio.ku.dk) or Dr. Pétur Heidarsson (p.heidarsson@bioc.uzh.ch).

When - As soon as possible…
Methods used:nuclear magnetic resonance (NMR), isotope labelled protein expression, circular dichroism (CD), fluorescence spectroscopy, mass spectrometry (MS), stopped-flow kinetics and single-molecule fluorescence techniques.
Keywords:NMR, protein dynamics, fuzziness, protein interactions, protein structure
Supervisor(s): Birthe B. Kragelund