Glycogen debranching enzyme at Duke University suggest that the human AGL gene contains at minimum 2 promotor regions, sites where the transcription of the gene begins, that result in differential expression of isoform, different forms of the same protein, mRNAs in a manner that is specific for different tissues. When GDE activity is compromised, the body cannot effectively release stored glycogen, type III Glycogen Storage Disease (debrancher deficiency), an autosomal recessive disorder, can result. In GSD III glycogen breakdown is incomplete and there is accumulation of abnormal glycogen with short outer branches. Most patients exhibit GDE defiency in both liver and muscle (TypeIIIa),
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