Explore chapters and articles related to this topic
Biocatalytic Nanoreactors for Medical Purposes
Published in Peter Grunwald, Pharmaceutical Biocatalysis, 2019
Oscar González-Davis, Chauhan Kanchan, Rafael Vazquez-Duhalt
Glycogen storage disease is an inherited metabolic disorder caused by the absence or deficiency of one of the enzymes responsible for glycogen synthesis, breakdown or glycolysis, mainly within muscles and liver cells (Özen, 2007). The incidence is estimated at 1 case per 20000–43000 live births. There are several types of glycogen storage disease according to the enzyme deficiency. The enzymes involved are glycogen synthase, glucose-6-phosphatase, acid α-glucosidase, glycogen debranching enzyme, glycogen branching enzyme, glycogen phosphorylase, and others.
Metabolic Disorders III
Published in John F. Pohl, Christopher Jolley, Daniel Gelfond, Pediatric Gastroenterology, 2014
Laurie A. Tsilianidis, David A. Weinstein, Roberto Zori
GSD III (Cori disease or Forbes disease) is caused by mutations in the AGL gene on 1p21 resulting in deficient activity of glycogen debranching enzyme. Debranching enzyme has two separate catalytic sites that remove branched outer chains from glycogen. Defects in this enzyme result in the accumulation of structurally abnormal glycogen, called limit dextrin. GSD IIIa affects both liver and muscle and accounts for 85% of patients with GSD III; type IIIb affects only the liver. During infancy and childhood, hepatomegaly and hypoglycemia can be severe. In adolescence and adulthood, the hypoglycemia tends to become milder and a progressive myopathy becomes the predominant feature. A hypertrophic cardiomyopathy can occur, and marked elevations in hepatic transaminases and creatine kinase concentrations are seen prior to commencement of treatment.
Affinity Modification in Biochemistry, Biology, and Applied Sciences
Published in Dmitri G. Knorre, Valentin V. Vlassov, Affinity Modification of Biopolymers, 1989
Dmitri G. Knorre, Valentin V. Vlassov
As an alternative example we present the inactivation of the mammalian glycogen debranching enzyme. This enzyme is known to catalyze two types of reaction: the transfer of the fragments of side chains of branched glycogen to the terminal residue of the main chain (transferase activity EC 2.4.1.25) as well as the hydrolysis of residual branched glucose residue (hydrolase activity EC 3.2.1.33). 1,5-Dimethylarsino-1-thio-β-d-glucopyranoside inactivates both activities. However, the reversible inhibitor (HOC2H4)2NC(CH2OH)3 (bistris) selectively protects glucosidase against inactivation, thus demonstrating that these activities are inherent to different active centers.410
Glycogen phosphorylase B promotes cell proliferation and migration through PI3K/AKT pathway in non-small cell lung cancer
Published in Experimental Lung Research, 2021
Yiyi Zhan, Ru Chen, Tianhai Wang, Shijun Shan, Hongge Zhu
Under hypoxia condition, glycogen is the storage form of glucose in most of the tumor cells.18 Therefore, glycogen metabolism is essential for tumor cell growth under metabolic stress.19 Glycogen phosphorylases, as the rate limited enzymes in glycogen degradation, play key role in cancer progression and has evolved as new targets for cancer therapy.20 In NSCLC, glycogen phosphorylase regulates nuclear glycogenolysis, and controls epigenetic regulation for cell growth.21 Glycogen debranching enzyme, another enzyme responsible for glycogen degradation, has been reported as a critical regulator of NSCLC.22 Recently, PYGB, one of the three isoforms of glycogen phosphorylase in mammals, was shown to be highly expressed in NSCLC.23 However, the functional role as well as the mechanism of PYGB in NSCLC remain enigmatic. In this study, we investigated the impact of PYGB on NSCLC and the mechanism of PYGB contributing to proliferation, migration, and invasion.