PhD Offer (M/W) - Charge detection mass spectrometry coupled action spectroscopy in the mid-IR range for structural characterization of viruses

5 Jan 2024
Job Information

Organisation/Company

CNRS - Institut Lumière-Matière

Research Field

Chemistry
Physics

Researcher Profile

Recognised Researcher (R2)
Leading Researcher (R4)
First Stage Researcher (R1)
Established Researcher (R3)

Country

France

Application Deadline

29 Feb 2024 - 22:00 (UTC)

Type of Contract

Temporary

Job Status

Full-time

Offer Starting Date

3 Jun 2024

Is the job funded through the EU Research Framework Programme?

Not funded by an EU programme

Is the Job related to staff position within a Research Infrastructure?

No

Offer Description

Viruses appear to constitute the most abundant and robust biological entities on earth. All viruses contain a nucleic acid genome and a protein capsid that covers the genome. The capsid is almost always made up of repeating structural subunits that are arranged in one of two symmetrical structures, a helix or an icosahedron. The final, mature capsid is a relatively robust protein complex able to protect the viral genome from physicochemical aggressions; however, it is also a metastable, dynamic structure poised to undergo controlled conformational transitions required to perform its biological activity. Studies aiming at evaluating the fragmentation of viruses are very scarce.
New electrostatic traps (based on charge detection mass spectrometry (CDMS)) have recently been implemented to achieve fragmentation experiments on selected ions. The coupling with a CO2 laser allows to perform infrared multiphoton dissociation of and to determine the unimolecular dissociation energy of activation of macro‐polymers and whole DNAs. The trapped ions are then irradiated with CO2 laser and fragmented by vibrational heating following a multiphoton IR activation.
The project will be conducted following two key objectives:
(i) Perform native mass spectrometry on molecular self‐assemblies of single viral particles and demonstrate that the CDMS technique is a viable experimental method for the detection and identification of viral particles
(ii) Adopt a multi‐scale approach to obtain structural and energetic information on single viral particles using action spectroscopy, i.e. stability studies by photo‐dissociation using wide spectral range available by compact laboratory lasers in mid‐infrared (IR).
These studies would permit to apprehend mass distribution and dissociation pattern of viruses at the single molecule level. These measurements will be improved by the implementation of vibration selective photofragmentation using tunable mid‐IR laser (5 to 9 μm range) to access their fine structures. Indeed, in this mid‐IR range, vibrations are specific to the different components of viral particles and can be used as fingerprints. In particular one of the ultimate goal is to establish a link between the photo‐fragmentation observed in viruses and their structure and establish laws and mechanisms for energy dissipation in these objects.

Funding category: Financement de l'Union européenne
HORIZON-EIC-2022-PATHFINDEROPEN-01
PHD title: Doctorat de Physique
PHD Country: France

Requirements
Specific Requirements

The phD student will work on the upgrading of the experimental set‐up as well as on the development of the experimental setup aiming at characterizing viruses and their photo‐fragmentation. A big part of the phD work will be to perform and interpret photo‐fragmentation induced by infrared laser irradiation on intact viruses. Also, the student will take part in statistical modeling development models polymers using heating/cooling stages to reproduce the observed dissociation dynamics.
The candidate should possess a master in chemistry or physical chemsitry and basic knowledge in molecular physics and spectroscopy, biochemistry and technical knowledge in mass spectrometry.

Additional Information
Work Location(s)

Number of offers available

1

Company/Institute

CNRS - Institut Lumière-Matière

Country

France

City

Villeurbanne

Geofield

Where to apply

Website

https://www.abg.asso.fr/fr/candidatOffres/show/id_offre/119215

Contact

Website

https://ilm.univ-lyon1.fr/

STATUS: EXPIRED