The fourth Glyco Morning event will take place at Nanobio building on Friday 20 October from 10 to 12. The invited speaker is David Rose, from the University of Waterloo, who will give a talk on “The human starch digestion system: the intestinal alpha-glucosdases”. Two young glycoscientists from Glyco@Alps, Marie Couturier (Cermav) and Anais Vieira Da Cruz (DCM) will kick off the event with short talks.

Invited speaker

The human starch digestion system: the intestinal alpha-glucosdase

David Rose, Department of biology, University of Waterloo, Canada

Post-amylase digestion of starch to glucose in humans is carried out by two intestinal alpha-glucosidase enzymes, each of which contains two GH31 family glycoside hydrolases. The talk will report on our progress in understanding the structures, mechanisms and specificities of these enzymes. Clinical conditions of maldigestion of starch and sucrose related to enzyme variants will also be discussed.

Young scientists talks

Wood deconstruction by Pycnoporus coccineus : from omics to enzyme discovery

Marie Couturier, Cermav

White rot fungi are considered key primary degraders of lignocellulosic biomass in nature, as they are able to mineralize cellulose, hemicellulose and lignin. Recent comparative genomics studies showed that these fungi use a wide diversity of enzymes for wood degradation. Pycnoporus coccineus, a Polyporale fungus that was able to grow well on both coniferous and deciduous wood, was selected for transcriptomic and proteomic studies. The early response of the fungus to softwood (pine) and hardwood (aspen) feedstocks was analyzed, and the secreted enzyme cocktails were tested for lignocellulose deconstruction. The results led to the identification of a new family of carbohydrate-active enzymes.

Synthesis of novel iminosugars and their interaction with alpha-glucosidases of the GH31 family

Anais Vieira Da Cruz, Département de Chimie Moléculaire, Université Grenoble Alpes

Glycosidases (glycoside hydrolases) are a large family of enzymes that catalyze the hydrolytic degradation of polysaccharides and the maturation of glycoconjugates. Their inhibition constitute an attractive therapeutic approach for the treatment of various diseases. Due to the ubiquity of glycosidases, one of the main research challenges for the development of new drugs acting as glycosidase inhibitors is to design molecules which are selective inhibitors of a specific type of glycosidases.
Recently,  our  team  has  synthesized  novel  indolizidine  and  quinolizidine  iminosugars  bearing  a  quaternary center  at  the  ring  junction,  which  exhibit  potency  at  nanomolar  concentrations  and  outstanding  selectivity against GH31 ?-­?-glucosidases. A crystallographic study of these inhibitors co-­--cristallyzed with an ?-­?-glucosidase from Cellvibrio japonicus (CjAgd31B) has allowed the visualization of their interactions with specific amino acids
in the active site of the enzyme and the formulation of a plausible hypothesis explaining their selectivity.