Flashcards in Glycosylation Deck (32):
1
hexose example
glucose
2
pentose exmaple
ribose
3
aldehyde example
glucose
4
ketone example
ribose
5
three sugars that are stereoisomers of the same structure
glucose, galactose and mannose
6
glycosidic linkage
-formed by what carbon
-requirement for reaction to take place
-formed by the anomeric carbon
-this anomeric carbon must be activated with UDP prior to the linkage being formed
7
alpha maltose
two glucose moleculse
8
alpha lactose
galactose and glucose
9
sucrose
fructose and glucose
10
amylopectin vs amylose
amylose is a straight chain polysaccharide whereas amylopectin is a branched polysaccharide
11
glucose vs glycogen
-glucose is a single saccharide
-glycogen is a branched polysaccharide with alpha 1,4 linkages between the straight chain monomers and alpha 1,6 linkages at the branch points
12
chondroitin
-GAG
-bone, cartilage, cornea formation
13
keratin sulfate
-GAG
-cornea connective tissue
14
dermatan sulfate
-GAG
-binds LDL to plasma walls
15
heparan sulfate
-GAG
-aortic wall, basement membrane
16
heparin
-GAG
-anticoagulant
17
hyaluronic acid
-GAG
-cell migration, lubricant
-not covalently attached to a protein
18
GAG general structure
-long linear polysaccharides
-repeating disaccharide units
-considerable negative charge (including sulfate)
19
glycolipids
-example
-
-gangliosides
-come from sugar modifications of lipids
20
glycation
-HbA1c
-non-enzymatic glycosylation of proteins
-formation of HbA1c
-simple chemical reaction of sugar and protein side chains
21
enzymatic glycosylation (conjugation)
-added to
-requirement
-specificity
-occurs to add sugars to other sugars, proteins, or lipids
-requires prior activation of sugar which is accomplished by formation of sugar nucleotides
-enzymes are specific for each different sugar being added as well as the accepting sugar molecule
22
where is the sugar of glycoproteins located
-except for O-GlcNac, they are located either in the lumen of the ER, the extracellular side of the plasma membrane , or secreted
23
O-linked glycoprotein
-largely built on Ser/Thr residues
-built one sugar at a time
24
N-linked glycoprotein
-built on Asp
-initially added to the protein in a 14 sugar block
-constructed on a dilochol phosphate lipid
-initial transfer to N is usually cotranslational in the ER
25
similaritry between construction of N and O linked glycoproteins
-they are both processed as the glycoprotein traffics from the Er through the golgi
26
glycoprotein and polysaccharide breakdown
-occurs in the lysosome with the help of many different types of enzymes
-when these enzymes fail you can get lysosomal storage diseases (mucopolysaccharidoses)
27
pompe disease
single lysosomal enzyme disease defect
28
proteoglycans
-made of over 90% sugar
-important structural components
-part of the matrix that makes up tissue structure
-found in cartilage, dentin or predentin
-hydrated so they can provid cushion
-charged so they can bind substances like growth factors and chemokines.cytokines
29
biological recognition
-often involves glycosylation
-protein recognition of carbohydrate structures usually involves a lectin domain
-deficiency disease 2)
30
examples of uses of carbs in major bodily functions
-blood type
-infection
-cell contacts
carbohydrate structures underlie the differences in ABO blood type groups, contribute to the ability of viruses (flu) or bacteria (H. pylori) to infect, and mediate cell-cell contacts (leukocyte adhesion
31
chaperon mediated protein folding
-facilitated by carbohydrate binding in the ER
32