The 7th Glyco@Event will take place at Cermav, Chartreuse room on Wednesday, March 14th from 2:00 to 3:40. The invited speaker is Sébastien Mongrand, from Laboratory of Membrane Biogenesis, CNRS - Université de Bordeaux, who will give a talk on “Glycosyl-Inositol Phosphoryl Ceramides, the major sphingolipids in plants”. A young glycoscientist from Glyco@Alps, Yotam Navon will kick off the event with a short talk.

Invited speaker

Glycosyl-Inositol Phosphoryl Ceramides, the major sphingolipids in plants

Sébastien Mongrand, Laboratory of Membrane Biogenesis, CNRS - Université de Bordeaux

Unlike glycerophospholipids, sphingolipids and sterols in plant plasma membrane (PM) display striking differences by comparison with their animal’s counterparts in term of chemistry and abundance. In this talk, I would like to reinvestigate the role for the major sphingolipid on earth, namely the Glycosyl Inositol Phosphor Ceramides, GIPCs. These sphingolipids display a great structural glycan diversity in the plant kingdom, and are involved in structuring membrane raft domains with phytosterols. GIPCs are most likely locate in the outer leaflet of the PM allowing a striking asymmetrical distribution between the two leaflets. GIPCs contain very long chain fatty acids with up to 26 carbon atoms (often 2-hydroxylated) which can interdigitate the outer leaflet with the inner leaflet. Finally, GIPCs contain sugar with up to 14 residues, likely making a very bulky polar head.
Broad methods are currently used to challenge the role of GIPCs in the PM structure from lipid purification (because GIPCs are not commercially available), liposomes studies, environment-sensitive probes, MS-based lipidomics and solid-state NMR on protein-free liposomes. GIPCs are involved in the binding of Necrosis and ethylene-inducing peptide 1–like (NLP) proteins which constitute a superfamily of proteins produced by plant pathogenic bacteria, fungi, and oomycetes.
The ins and outs of lipid asymmetry, raft formation, and interdigitation in plant membrane biology will be extensively discussed during this talk.

Young scientist talk

The interaction of lipid membranes with cellulose nano-crystals

Yotam Navon, Cermav

Using elementary building blocks to mimic and reconstruct biological structures is intriguing both from fundamental aspects, providing a simple model to study a complex environment, as well as from the applicative point of view, opening the possibility of utilizing such constructs for the creation of new bio-inspired materials. Understanding the key parameters governing the interaction between the building blocks of such systems is highly important.
In this frame work of bio-inspired materials, the plant cell wall provides an interesting model since its basic building blocks are abundant, eco-friendly and possess outstanding properties. In the plant kingdom, one of the first steps of cell wall constitution is the deposition of cellulose microfibrils on top of the plant plasma membrane.
In this work we have investigated the interaction between cellulose nano-crystals (CNCs) and lipid membranes using 2D and 3D architectures.  Quartz Crystal Microbalance with Dissipation (QCM-D) and Total Internal Reflection Fluorescence microscope (TIRF) were used for the investigation of the 2D system, in which CNCs were deposited on top of supported lipid membranes (SLBs). The interaction between lipid vesicles and CNCs was studied in suspension using Isothermal Titration Calorimetry (ITC), light scattering and Transmission Electron Microscopy (TEM). Key parameters governing the interaction were elucidated and the results are discussed in the context of plant cell wall inspired materials.