Liver glycogen fragility in the presence of hydrogen-bond breakers

作者：Xinle Tan, Ziyi Wang, Ut Cheung, Zhenxia Hu, Qinghua Liu, Liang Wang, Mitchell A. Sullivan, Daniel Cozzolino, Robert G. Gilbert · 发表于：International Journal of Biological Macromolecules · 年份：2024 · DOI：10.1016/j.ijbiomac.2024.131741 · 被引用次数：5 · 研究领域：Pancreatic function and diabetes、Diet, Metabolism, and Disease、Metabolism, Diabetes, and Cancer

Glycogen, a complex branched glucose polymer, is responsible for sugar storage in blood glucose homeostasis. It comprises small β particles bound together into composite α particles. In diabetic livers, α particles are fragile, breaking apart into smaller particles in dimethyl sulfoxide, DMSO; they are however stable in glycogen from healthy animals. We postulate that the bond between β particles in α particles involves hydrogen bonding. Liver-glycogen fragility in normal and db/db mice (an animal model for diabetes) is compared using various hydrogen-bond breakers (DMSO, guanidine and urea) at different temperatures. The results showed different degrees of α-particle disruption. Disrupted glycogen showed changes in the mid-infra-red spectrum that are related to hydrogen bonds. While glycogen α-particles are only fragile under harsh, non-physiological conditions, these results nevertheless imply that the bonding between β particles in α particles is different in diabetic livers compared to healthy, and is probably associated with hydrogen bonding.