Glycogen storage disease type I similar, but Ib incurs a few additional problems (described below). Glycogen in liver and (to a lesser degree) kidneys serves as a form of stored, rapidly accessible glucose, so that the blood glucose level can be maintained between meals. For about 3 hours after a carbohydrate-containing meal, high insulin levels direct liver cells to take glucose from the blood, to convert it to glucose-6-phosphate (G6P) with the enzyme glucokinase, and to add the G6P molecules to the ends of chains of glycogen (glycogen synthesis). Excess G6P is also shunted into production of triglycerides and exported for storage in adipose tissue
Glycogen phosphorylase the subunit interface that is not present in the rabbit muscle glycogen phosphorylase (RMGP) normally used in studies. This site was not sensitive to the same inhibitors as those at the AMP allosteric site, and most success has been had synthesizing new inhibitors that mimic the structure of glucose, since glucose-6-phosphate is a known inhibitor of HLGP and stabilizes the less active T-state. These glucose derivatives have had some success in inhibiting HLGP, with predicted Ki values as low as 0.016 mM. Mutations in the muscle isoform of glycogen phosphorylase (PYGM) are associated with glycogen storage disease type V (GSD