Glycoproteins and Proteoglycans X Flashcards Preview

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Flashcards in Glycoproteins and Proteoglycans X Deck (33):
1

Glycoproteins - def
****

proteins that covalently attach carbohydrate chains EXCEPT polymers of repeating units
Carb chains - short, unbranched
varying amounts and concentrations of carb

2

Proteoglycans - def
****

polysaccahrides attached to core protein
can have as much as 95% carb

3

Carbohydrate - types

Simple sugars
Modified suagars (like adding amino groups)
Polysaccharides

4

Simple Sugars

monosaccharides
i.e. glucose, mannose, galactose

5

Modified sugars

principal = hexosamines (N added to C2)

6

Polymers

putting sugars linked with glycosidic bonds
, Di-, Tri-, Oligo- and Poly-
i.e. maltose, lactose
put together by glycosyltransferases
taken apart by glycosidades

7

Glycosylation

attaching carbs
not template driven
Can use N or O linkages

8

known N and O linkages
****

N-glycosyl to asparagine
O glycosyl to serine or theorine
O glycosyl to hydroxylysine

9

Glycolysation - functional impact

Increase protein solubility
guide protein folding
provide some protections from proteolytic degradation to the polypeptide backbone
+other regulation events

10

Glycosylation - critical for

Naturally occurring proteins in higher concentrations
Biopharmaceuticals

11

Blood Group Substances (naturally occurring protein)

Different carbohydrates recognized for blood group definition

12

aberrant glycosylation

Can affect whether substrate get recognized by enzyme

13

aberrant glycosylation patterns of proeints

can be analyzed and validates as potential biomarkers of disease

14

Biopharm - i.e.

Erythropoitein, Myozyme

15

degradation of glycoprotiens - pthwy

sugars removed from non-reducing end, by lysosomes.
Opposite of construction

16

Enzyme deficiency results in progressive accumulation of aspartylglucosamine in tissues, spinal fluid and urine

KNOW

17

I cell disease - a.k.a, def
***

Mucolipidosis, Lysosomal Storage disorder with UDP-N-acetylglucosamine-I-phosphotransferase deficiency
*enzyme that puts sugar on glycoproteins

18

Mucolipidosis - physcial manifesations
***

corenal clouding
short stature
umbilical hernias.

19

proteoglycans

carbs with protein core
high anionic charge - basophilic (blue)
disaccharide repeating unit + sulfate (negative charge)

20

GAG - a.k.a, types
****

**glycosaminoglycans
Chonroitin Sulfate (most commoon, i.e. aggrecan)
Dermatan Sulfate
Hepran Sulfate
Keretan Sulfate
Heparin (huge clusters of negative charge = coagulant)
Hyaluronic acid

21

Disaccharide repeating unit

uronic acid and amino sugar
negative charge

22

Aggrecan loss from the cartilage ECM is an early and sustained feature of OA

KNOW

23

Proteoglycans - role
****

support/connective tissue
mechanical
diffusion

24

Proteoglycans - location

intracellular compartment, cell surface or in ECM

25

Classes of Proteoglycans
***

Large aggregating proteoglycans *(i.e.AGGRECAN)
small leucine-rich proteoglycans (SLRP)
basement membrane proteoglycans

26

Hyaluronate/Hyaluronic Acid - def, fxn

GAG - not proteoglycan
co ploymer of Nacetyleglucoamine and Glucuronic Acid
shock absorgber, lubricant

27

Heparin

unlike other GAG's, intracelluar component of mast cell
used to contract thrombosis(clot)

28

Lubricin

Major lube in joint - boundary lubricant

29

degradation of proteoglycans

one at a time

30

Mucopolysaccharidoses - def
***

genetic disorder of excessive accumulation and excretion of the oligosaccharides of proteoglycans

31

Mucopolysaccharidoses - i.e.
***

Hunter
Hurler + Scheie

32

Hunter - Accumulated products, Deficient enzyme, cleaves
***

Accumulated products - heparin sulfate, dermatan sulfate
Deficient enzyme - Iduronate sufatase
*cleaves sulfate from hylauronic acid

33

Hurlers + Scheie - Accumulated products, Deficient enzyme, cleaves
***

Accumulated products - heparin sulfate, dermatan sulfate
Deficient enzyme - alpha-L-Iduronidase
*Cleaves hylauronic acid