What's the big fuss? - Extra Reading

Hi ALL! This is possibly our last post for this blog!

So I'm sure that most of you are wondering why Andersen's disease results in so much trouble despite it only affect one enzyme - Glycogen Branching Enzyme (GBE). 

So let me show you guys why...

This picture here shows that by breaking down glycogen* using glycogen phosphorylase (GPase), you get Glucose-1-Phosphate (G-1-P_ which is essential for forming Glucose-6-Phosphate (G-6-P) via an enzyme called phosphoglucomutase. I am sure all of you know the purpose of G-6-P which is to form glucose during glycolysis! 

Hence without glycogen due to a defect in GBE, the cell is unable to produce G-1-P and hence unable to produce G-6-P. This is a huge problem for the cell as there is now a lack of glucose and an accumulation of polyglucosan bodies (refer to previous blogpost if you're curious!). This is the reason why the liver suffers so much in Andersen's disease :(

For those of you curious about how G-1-P is converted to G-6-P, it's actually via phosphorylation of Serine residue (due to it having an -OH or hydroxyl group) and it giving away a phosphate group on the other end of the residue (from Carbon-1). Thus it "switches" from G-1-P to G-6-P. 

*Glycogen contains alpha-1,4 & alpha-1,6 glycosidic linkages in its structure. The former can be broken down by GPase but the latter requires a debranching enzyme to break the linkage and in the process of doing so, produce glucose as well! 

It's been a really fun & great journey to blog about Andersen's disease and raising awareness by this project but all good things come to an end!

Thank you all for reading the long posts and tolerating our puns!

Sources:
https://41.media.tumblr.com/9b616d62d45c6ed6b107bd52029fb47c/tumblr_mi21tzNxTT1s5zd05o1_500.jpg
http://mahmrabeh.weebly.com/uploads/9/4/9/7/9497973/_9440992.gif