Polymerix 2019 – Résumé de la conférence de David Ropartz
Analyse Structurale de la Paroi de Chondrus crispus : Exploration de Nouvelles Méthodologies en Spectrométrie de Masse
Auteurs : D. Ropartz 1, C. Le Moine 1, M. Jam2, M. Czjzek2, C. Hervé2, H. Rogniaux 3
1 INRA, UR1268 Biopolymers Interactions Assemblies F-44316 NANTES, France
2 Sorbonne Université, CNRS, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, F-29688, Roscoff, France
david.ropartz[@]inra.fr
Résumé
The cells of marine macroalgae are surrounded by polysaccharide rich cell walls and these polysaccharides are frequently sulfated. This is of no equivalence in land plants, whereas sulfated glycans are also found in animals [1]. These cell walls often display complex architectures that change with time, throughout the life cycle of the algae and as a function of environmental changes. The widely distributed red macroalga Chondrus crispus, a genomic red algal research model [2] and a species most important for coastal ecology and economy, is an important producer of carrageenans used in industry. In C. crispus two main life-stages are found and although they are isomorphic and almost mechanically equivalent, their cell walls contained structural variants of sulfated carrageenans that differ sharply in their rheological properties. In addition to the main carrageenan motifs, other components and/or carbohydrate structures may be present in those walls to explain such differences. However, identifying these polysaccharide structures today still represent a true analytical challenge, in view of their complexity and their entanglement within the context of a complex cell wall. In this study the red alga C. crispus was used as a model system to develop innovative technologies based on mass spectrometry [3]. The results obtained were complemented by more conventional approaches based on monosaccharide composition analyses, and oligosaccharides profiling using specific recombinant enzymes [4]. We will discuss how the results obtained allowed gaining an understanding on the relationships between the glycan structures and the physico-mechanical properties of the walls. Our approach further allowed the validation of new analytical methods for structural analyses of complex and highly sulfated carbohydrates. This new technology can now be applied to other systems.
Biographie de David Ropartz
David Ropartz exerce ses activités sur la plate-forme BIBS de l’INRA de Nantes depuis 2007.
Après avoir obtenu son doctorat en chimie analytique en 2015, David Ropartz a pris la responsabilité du laboratoire de spectrométrie de masse ou il exerce ses activités de recherche sur la caractérisation des oligo/polysaccharides en développant des technologies innovantes autour des techniques séparatives (UHPLC et mobilité ionique) et des méthodes d’activation des ions pour la spectrométrie de masse en tandem (dissociation par transfert de charge et photo-dissociation).