Postdoc position in in-cell MAS-DNP at CEA/Univ. Grenoble Alpes, France

Post-doctoral position at CEA / Univ. Grenoble Alpes (France)

Methodological developments towards in-cell MAS-DNP

A post-doctoral position is available immediately for a period of 18 months to work with Sabine Hediger and Gaël De Paëpe on developing MAS-DNP for the study of proteins in cells. More information about our group at CEA Grenoble / Univ. Grenoble Alpes and a list of recent publications can be found here: https://nmr-dnp-grenoble.net.

Context of the project:

Cellular applications of solid-state NMR are associated with major challenges: low sensitivity and resolution, need for isotopic labelling strategies able to suppress the large cellular background, and integrity of the cells possibly compromised by the large G-force induced by fast pneumatic sample spinning (Magic Angle Spinning, MAS). Dynamic Nuclear Polarization (DNP) has emerged as a viable route to significantly improve the sensitivity of solid-state NMR, including for biomolecular and in-cell applications. In addition, DNP experiments are performed at low temperature (about 100 K), which offers the additional advantage to protect the cell integrity. However, the spectral resolution of DNP spectra is often impaired due to conformational heterogeneity induced by the loss of molecular dynamics at such temperatures. In particular, in the biomolecular context, DNP has therefore been mainly applied to systems with previously known assignment or with highly specific isotopic labeling.

Project :
In this context, our lab recently introduced a selective approach dubbed SelDNP, able to produce high-resolution DNP spectra specific for interaction sites, and enabling the identification of binding site residues without pre-knowledge of the protein structure or NMR assignment. Whereas SelDNP was originally demonstrated on a lectin using a biradical-derived carbohydrate ligand, recent results have shown that the approach can be combined with site-directed spin labeling and is also able to reveal metal-binding sites. This selective approach is very promising for targeting a biomolecule in the crowded environment of the cell, but as well for removing the cell background signal, which may become significant at low protein concentrations. The selective DNP approach will be further developed for in-cell investigations, and applied to follow the complex formation of an artificial enzyme in the cell.

Requirements and application:
Applicants are expected to have a doctoral degree in liquid-state and/or solid-state biomolecular NMR spectroscopy. Knowledge about MAS-DNP will be considered as a plus. The successful candidate will be recruited for 18 months and will benefit from an ANR postdoctoral fellowship. Deadline for application is mid of January. Interested candidates are welcomed to send an email to: sabine.hediger@cea.fr

Grenoble is one of the major cities in Europe for research with a large international scientific community. In addition, Grenoble has a large international student population, is a very pleasant city to live in, and is known as the “Capital of the Alps” with easy access to great skiing and hiking. It is also only 2 hours’ drive to the Mediterranean Sea, Italy, or Switzerland. Grenoble, Lyon, and Geneva airports are nearby and permit straightforward international travel.

Project-related references:

1. I. Marin-Montesinos, D. Goyard, E. Gillon, O. Renaudet, A. Imberty, S. Hediger, G. De Paëpe, Selective high-resolution DNP-enhanced NMR of Biomolecular binding sites, Chem. Sci. 10 (2019) 3366-3374. DOI: 10.1039/C8SC05696J
2. D. Gauto, O. Dakhlaoui, I. Marin-Montesinos, S. Hediger, G. De Paëpe, Targeted DNP for biomolecular Solid-State NMR, Chem. Sci. 12 (2021) 6223-6237. DOI: 10.1039/D0SC06959K.
3. O. Dakhlaoui, T. Halbritter, D. Gauto, E. Gillon, V. Chazalet, A. Varrot, A. Imberty, S. Th. Sigurdsson, S. Hediger, G. De Paëpe, Site-directed spin labeling combined with selective DNP-enhanced NMR for probing biomolecular structural information, Manuscript in preparation.
4. O. Dakhlaoui, D. Gauto, E. Gillon, A. Varrot, A. Imberty, S. Th. Sigurdsson, S. Hediger, G. De Paëpe, Highlighting the vicinity of biomolecular diamagnetic metal binding sites with selective DNP-enhanced NMR, Manuscript in preparation.
-- _____________________________________________________________   Sabine Hediger Interdisciplinary Research Institute of Grenoble CEA Grenoble 17 rue des Martyrs 38054 Grenoble Cedex 9 France Tel.: +33 4 38 78 65 79 Fax : +33 4 38 78 50 90 Email : sabine.hediger@cea.fr