Glycoproteins and Proteoglycans X

Question 1

Glycoproteins - def

**

Answer 1

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

Question 2

Proteoglycans - def

**

Answer 2

polysaccahrides attached to core protein

can have as much as 95% carb

Question 3

Carbohydrate - types

Answer 3

Simple sugars
Modified suagars (like adding amino groups)
Polysaccharides

Question 4

Simple Sugars

Answer 4

monosaccharides

i.e. glucose, mannose, galactose

Question 5

Modified sugars

Answer 5

principal = hexosamines (N added to C2)

Question 6

Polymers

Answer 6

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

Question 7

Glycosylation

Answer 7

attaching carbs
not template driven
Can use N or O linkages

Question 8

known N and O linkages

**

Answer 8

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

Question 9

Glycolysation - functional impact

Answer 9

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

Question 10

Glycosylation - critical for

Answer 10

Naturally occurring proteins in higher concentrations

Biopharmaceuticals

Question 11

Blood Group Substances (naturally occurring protein)

Answer 11

Different carbohydrates recognized for blood group definition

Question 12

aberrant glycosylation

Answer 12

Can affect whether substrate get recognized by enzyme

Question 13

aberrant glycosylation patterns of proeints

Answer 13

can be analyzed and validates as potential biomarkers of disease

Question 14

Biopharm - i.e.

Answer 14

Erythropoitein, Myozyme

Question 15

degradation of glycoprotiens - pthwy

Answer 15

sugars removed from non-reducing end, by lysosomes.

Opposite of construction

Question 16

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

Answer 16

KNOW

Question 17

I cell disease - a.k.a, def

***

Answer 17

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

Question 18

Mucolipidosis - physcial manifesations

***

Answer 18

corenal clouding
short stature
umbilical hernias.

Question 19

proteoglycans

Answer 19

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

Question 20

GAG - a.k.a, types

**

Answer 20

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

Question 21

Disaccharide repeating unit

Answer 21

uronic acid and amino sugar

negative charge

Question 22

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

Answer 22

KNOW

Question 23

Proteoglycans - role

**

Answer 23

support/connective tissue
mechanical
diffusion

Question 24

Proteoglycans - location

Answer 24

intracellular compartment, cell surface or in ECM

Question 25

Classes of Proteoglycans | ***

Answer 25

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

Question 26

Hyaluronate/Hyaluronic Acid - def, fxn

Answer 26

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

Question 27

Heparin

Answer 27

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

Question 28

Lubricin

Answer 28

Major lube in joint - boundary lubricant

Question 29

degradation of proteoglycans

Answer 29

one at a time

Question 30

Mucopolysaccharidoses - def | ***

Answer 30

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

Question 31

Mucopolysaccharidoses - i.e. | ***

Answer 31

Hunter | Hurler + Scheie

Question 32

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

Answer 32

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

Question 33

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

Answer 33

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