MasterNanosciences, nanotechnologies

The project aims at elucidating the 3D organization of neutral and charged oligo-and polysaccharides which are well-known for their ability to form physical gels (e.g. agarose carrageenan, alginate). The modalities of chain-chain interactions are still debated and only very few and ancient data dealing with the conform and intermolecular interactions of these macromolecules are reported in the literature. Taking advantage of the facilities available at CERMAV: Chromatography, electron microscopy and NMR platform, we propose to investigate the structure of the gelling polysaccharides and enzymatically prepared oligosaccharides.
 
- We propose to purify series of oligosaccharides of DP2 to DP6 obtained by enzymatic degradation of agarose, carrageenan and alginate. All the required enzymes and purification system are available in the laboratory.
- The oligosaccharides will be precipitated /crystallized and analyzed by solid-state NMR in order to compare the conformational properties of the oligosaccharides with the corresponding polysaccharides. This step is determinant to select the oligosaccharides that could be used as representative model of the polysaccharides.
- In the cases of anionic oligosaccharides, the precipitation/crystallization experiments will be conducted monitoring ions composition and concentration of the solutions.
- The crystallization will be controlled by electron microscopy and when possible, electron diffraction will be recorded.
 
At the end, we should have selected the best oligosaccharides for further investigations which should lead to the 3D structures of the gelling polysaccharides.