Compendium of the most significant studies with reference to properties, intake, effects.

Brewer MK, Gentry MS. Brain Glycogen Structure and Its Associated Proteins: Past, Present and Future. Adv Neurobiol. 2019;23:17-81. doi: 10.1007/978-3-030-27480-1_2. 

Abstract. This chapter reviews the history of glycogen-related research and discusses in detail the structure, regulation, chemical properties and subcellular distribution of glycogen and its associated proteins, with particular focus on these aspects in brain tissue.

Brust H, Orzechowski S, Fettke J. Starch and Glycogen Analyses: Methods and Techniques. Biomolecules. 2020 Jul 9;10(7):1020. doi: 10.3390/biom10071020. 

Abstract.  In this article, we give a brief overview of the most frequently used methods, techniques, and results. Furthermore, we give insights in the isolation, purification, and fragmentation of both starch and glycogen. An overview of the different structural levels of the glucans is given and the corresponding analytical techniques are discussed. Moreover, future perspectives of the analytical needs and the challenges of the currently developing scientific questions are included.

Besford QA, Cavalieri F, Caruso F. Glycogen as a Building Block for Advanced Biological Materials. Adv Mater. 2020 May;32(18):e1904625. doi: 10.1002/adma.201904625.

Abstract. Biological nanoparticles found in living systems possess distinct molecular architectures and diverse functions. Glycogen is a unique biological polysaccharide nanoparticle fabricated by nature through a bottom-up approach. 

Roach PJ, Depaoli-Roach AA, Hurley TD, Tagliabracci VS. Glycogen and its metabolism: some new developments and old themes. Biochem J. 2012 Feb 1;441(3):763-87. doi: 10.1042/BJ20111416. 

Abstract. There has been debate over the relative importance of allosteric compared with covalent control of the key biosynthetic enzyme, glycogen synthase, as well as the relative importance of glucose entry into cells compared with glycogen synthase regulation in determining glycogen accumulation. 

Prats C, Graham TE, Shearer J. The dynamic life of the glycogen granule. J Biol Chem. 2018 May 11;293(19):7089-7098. doi: 10.1074/jbc.R117.802843. 

Abstract. In this Minireview, we review the literature to follow the dynamic life of a glycogen granule in a multicompartmentalized system, i.e. the cell, and how and where glycogen granules appear and the factors governing its degradation. 

Bollen M, Keppens S, Stalmans W. Specific features of glycogen metabolism in the liver. Biochem J. 1998 Nov 15;336 ( Pt 1)(Pt 1):19-31. doi: 10.1042/bj3360019.

Abstract. Although the general pathways of glycogen synthesis and glycogenolysis are identical in all tissues, the enzymes involved are uniquely adapted to the specific role of glycogen in different cell types. In liver, where glycogen is stored as a reserve of glucose for extrahepatic tissues, the glycogen-metabolizing enzymes have properties that enable the liver to act as a sensor of blood glucose and to store or mobilize glycogen according to the peripheral needs. 

Blows JM, Calder PC, Geddes R, Wills PR. The structure of placental glycogen. Placenta. 1988 Sep-Oct;9(5):493-500. doi: 10.1016/0143-4004(88)90021-5. 

Abstract. Glycogen was purified from human term placenta and its structural features investigated. The beta-amylolysis limit and average chain lengths indicated that some degradation of the glycogen had occurred prior to its extraction. The sedimentation coefficient distribution of the purified glycogen showed that it contained a significant proportion of aggregated material. Diffusion coefficient measurements allowed calculation of the molecular weight distribution. The placental glycogen contained a significant proportion of high molecular weight material, although not as much as liver or skeletal muscle glycogens. Because the high molecular weight glycogen of liver and skeletal muscle is associated with the lysosome it is likely that this is also true of the large placental glycogen. Lysosomal glycogen is degraded hydrolytically to glucose and so placental glycogen may be involved in fetal glucose homeostasis.

Panduro J, Vigh-Larsen JF, Ermidis G, Póvoas S, Schmidt JF, Søgaard K, Krustrup P, Mohr M, Randers MB. Acute arm and leg muscle glycogen and metabolite responses to small-sided football games in healthy young men. Eur J Appl Physiol. 2022 Jun 1. doi: 10.1007/s00421-022-04970-y.

Abstract. Studies have indicated upper body involvement during football, provoking long-term muscular adaptations. This study aimed at examining the acute metabolic response in upper and lower body skeletal muscle to football training organized as small-sided games.

Marr L, Biswas D, Daly LA, Browning C, Vial SCM, Maskell DP, Hudson C, Bertrand JA, Pollard J, Ranson NA, Khatter H, Eyers CE, Sakamoto K, Zeqiraj E. Mechanism of glycogen synthase inactivation and interaction with glycogenin. Nat Commun. 2022 Jun 11;13(1):3372. doi: 10.1038/s41467-022-31109-6.

Abstract. We describe the 2.6 Å resolution cryo-EM structure of phosphorylated human GS revealing an autoinhibited GS tetramer flanked by two GN dimers.

outsifeli P, Varma U, Daniels LJ, Annandale M, Li X, Neale JPH, Hayes S, Weeks KL, James S, Delbridge LMD, Mellor KM. Glycogen-autophagy: Molecular machinery and cellular mechanisms of glycophagy. J Biol Chem. 2022 May 30:102093. doi: 10.1016/j.jbc.2022.102093.

Abstract. Here, we review the current evidence of glycophagy involvement in homeostatic cellular metabolic processes and of molecular mediators participating in glycophagy flux, We integrate information from a variety of settings including cell lines, primary cell culture systems, ex vivo tissue preparations, genetic disease models and clinical glycogen disease states.