GAGs and Glycoproteins

Question 1

GAGs

Answer 1

Mucopolysaccharides

N acetylated and acidic sugar dimer chain

Long unbranched and - charge

• pump out water (synovial fluid)
• high viscosity when solubilized

Associated with core proteins

Amino group is acetylated-remove + charge=keep total charge negative

Make up

• ECM (bound to collagens and elastics-molecular sieve)
• ground substance (bind a lot to water)

Question 2

Acidic GAG sugars

Answer 2

Glucaronic acid (GlcUA)
Iduronic acid (IdUA)
Galactose (gal)

Question 3

N acetylated amino sugars

Answer 3

N-acetyl galactosamine (GalNAC)
N-acetylglucosamine (GlcNAC)
Glucosamine (GlcN)

Question 4

What links GAG to core protein?

Answer 4

Trihexoside (Gal, gal, xylose) linkage to serine of protein

Question 5

Sanfilippo Syndrome

• Enzyme
• affects deg of…?
• Sx

Answer 5

Four enzymes
Hep sulfate
Severe nervous system disorder/profound MR

Question 6

Sly Syndrome

• Enzyme
• affects deg of…?
• Sx

Answer 6

Beta glucuonidase def
Derm/Hep sulfate affected
Hepatosplenomegaly, SM deformity, short, corneal clouding, mental deficiency

Question 7

phosphotransferase+what if def

Answer 7

adds M6P tag

Def=I cell

Question 8

I cell disease

• enzyme
• pathway/DX
• Sx

Answer 8

• No phophotransferase
• Build up of acid hydrolyses in blood (normally only found in lysosomes)
• Skel abnormalites, restricted, movement, dysmorphic facial features, severe psychomotor impairment)