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

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

Company:

Location: Lyon

Job Description: 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)[1]) 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.[2]

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

Requirements

Research Field Chemistry » Physical chemistry Education Level Master Degree or equivalent

Skills/Qualifications

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

Languages ENGLISH Level Excellent

Research Field Chemistry » Physical chemistry Years of Research Experience None

Additional Information

Eligibility criteria

having a master (M2 level equivalent in France)

Selection process

send CV and motivation letter along with 2 external referees.

Additional comments

Fluency in English: the candidate should be conversant and articulate in English and must have strong writing skills. Knowledge of French is not required but

would be appreciated. Website for additional job details

Work Location(s)

Number of offers available 1 Company/Institute Institut Lumière Matière (UMR5306 CNRS and Claude Bernard University – Lyon1 Country France Geofield

Where to apply E-mail

rodolphe.antoine@univ-lyon1.fr

Contact City

Lyon Website

Street

5 rue de la Doua, 69100 Villeurbanne, France Postal Code

69600

STATUS: EXPIRED

Salary:

Application:apply for this job.

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