Effects of changes in glycan composition on glycoprotein dynamics: example of N-glycans on insulin receptor.
Fiche publication
Date publication
juillet 2021
Journal
Glycobiology
Auteurs
Membres identifiés du Cancéropôle Est :
Pr DAUCHEZ Manuel, Pr BAUD Stéphanie
Tous les auteurs :
Rao RM, Wong H, Dauchez M, Baud S
Lien Pubmed
Résumé
Glycosylation is among the most common post-translational modifications in proteins, although it is observed in only about 10% of all the protein structures in protein data bank (PDB). Modifications of sugar composition in glycoproteins profoundly impact the overall physiology of the organism. One such example is the development of insulin resistance, which has been attributed to the removal of sialic acid residues from N-glycans of insulin receptor (IR) from various experimental studies. How such modifications affect the glycan-glycoprotein dynamics, and ultimately their function is not clearly understood to date. In this study, we performed molecular dynamics simulations of glycans in different environments. We studied the effects of removal of sialic acid on the glycan, as well as on the dynamics of leucine-rich repeat L1 domain of the IR ectodomain. We observed perturbations in L1 domain dynamics as a result of the removal of sialic acid. The perturbations include an increase in the flexibility of insulin-binding residues, which may affect insulin binding with IR. These changes are accompanied by perturbations in glycan-protein interactions and perturbation of long-range allosteric dynamics. Our observations will further aid in understanding the role of sugars in maintaining homeostasis and how changes in glycan composition may lead to perturbations in homeostasis, ultimately leading to conditions such as insulin resistance.
Mots clés
N-glycan, insulin receptor, insulin resistance, protein dynamics, sugars
Référence
Glycobiology. 2021 Jul 30;: