Pétur Orri Heiðarsson

2019-Current- Associate Professor of Biochemistry, University of Iceland

2015-2019- Postdoctoral research fellow, University of Zurich

2013-2015- Postdoctoral research fellow, University of Cambridge/ University of Copenhagen

2013- Ph.D Biophysics, Structural Biology and NMR Laboratory, University of Copenhagen

2008- M.Sc. Biochemistry, University of Iceland

2005- B.Sc. Biochemistry, University of Iceland

Pétur Orri received his B.Sc. and M.Sc. degrees in biochemistry at the University of Iceland, where he studied the link between enzyme kinetics and flexibility. In 2008 he joined the Structural Biology and NMR Laboratory for Ph.D studies where he used nuclear magnetic resonance spectroscopy and single-molecule optical tweezers to study the protein folding problem. Pétur Orri then studied misfolding and chaperone action in a collaborative project between the University of Cambridge and the University of Copenhagen. Subsequently, he worked on understanding intrinsically disordered protein complexes with single-molecule spectroscopy, at the lab of Professor Ben Schuler, University of Zurich. In 2019, Pétur Orri joined the Department of Biochemistry, University of Iceland, as Associate Professor. Pétur Orri is also affiliated with the REPIN Centre at the University of Copenhagen, which is dedicated to rethinking protein interactions in the framework of molecular disorder.

As an organism becomes increasingly complex, so too must they evolve a more sophisticated molecular alphabet. The recent discovery of proteins that can adopt multiple structural states is one way of addressing this complexity and they have dramatically changed our view of the protein structure-function paradigm.

As much as 40% of the human proteome is predicted to consist of proteins that contain long disordered regions and therefore lack a stable, well-defined three-dimensional structure. These so-called intrinsically disordered proteins (IDPs) have sometimes been referred to as belonging to the dark proteome since they are outside the scope of traditional structural proteomics techniques. IDPs are prevalent in cellular regulation and signaling processes, and are implicated in a vast array of diseases and pathologies. To study such structurally complex molecules we employ advanced single-molecule spectroscopy techniques, usually in combination with Förster resonance energy transfer (FRET). Single-molecule FRET is a sensitive molecular ruler that allows us to measure molecular distance distributions and dynamics on a broad timescale from picoseconds to hours. A unifying theme of our research is the application of single-molecule techniques to study structurally heterogeneous proteins, especially those found in the nucleus of human cells where they play central roles in chromatin organisation and molecular chaperoning. We are particularly interested in nucleic acid binding proteins, such as transcription factors, and the complex interplay between proteins and DNA.

We have many possible research projects for interested students and postdocs, please be in touch for more information. pheidarsson@hi.is

PubMed

Selected publications

1. Schuler B, Borgia A, Borgia M, Heidarsson PO, Holmstrom ED, Nettels D, Sottini A (2020) Binding without folding- the biomolecular function of disordered polyelectrolyte complexes, Curr Opin Struct Biol 60, 66-76.
    
2. Borgia A, Borgia MB, Bugge K, Kissling VM, Heidarsson PO, Fernandes CB, Sottini A, Soranno A, Buholzer KJ, Nettels D, Kragelund BB, Best RB, Schuler B (2018) Extreme disorder in an ultrahigh-affinity protein complex, Nature 555, 61-66.
    
3. Heidarsson PO, Naqvi MM, Otazo MR, Mossa A, Kragelund BB, Cecconi C (2014) Direct single-molecule observation of calcium-dependent misfolding in human neuronal calcium sensor-1, Proc Natl Acad Sci USA 111(36), 13069-13074.
    
4. Heidarsson PO, Valpapuram I, Camilloni C, Imparato A, Tiana G, Poulsen FM, Kragelund BB, Cecconi C (2012) A highly compliant protein native state with a spontaneous-like mechanical unfolding pathway, J Am Chem Soc 134(41), 17068-17075.

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