MW L5 Proteases Flashcards

1
Q

RA is mediated by

A

MMP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

MMP is secreted by

A

tissue cells - synovial fibroblasts, chondrocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Inflammatroy cytokines are particularly derived from macrophages e.g. (2)

A

TNFa

IL1b

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

………….. and ………….cells help maintain cytokine production

A

T and B lymphocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

2 e.g. of natural proteases

A

collagenase

elastase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Synovial fibroblasts secrete

A
  • cytokines
  • Enzymes
  • mediators (PGE2)
  • Matrix materials
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Synovial fibroblasts ‘………….’ T-cells and exhibit ‘………….’ phenotype

A

nurse

malignant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Cartilage is made up of …..

A

cells and extracellular matrix:

  • fibrous protein - collagen
  • proteoglycan
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is proteoglycan

A

chondroitin sulphate linked to aggrecan core

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

proteoglycans are …….. and bind to water

A

charged

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what happens to proteoglycans in raised intra-articular pressure in RA

A

displaced and lost

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

proteoglycans have a …………….. structure

A

open - highly accessible thus sensitive to breakdown by several proteinase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Collagen or proteoglycans is lost quicker

A

proteoglycans

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Native collagen is only susceptible to

A

collagenases - after initial damage other enzymes can continue degreading

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

4 families of proteolytic enzymes

A

MMP
Serine proteinases
Cysteine proteinases
Aspartate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

MMP1,8, and 13 are

A

collagenases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

MMP2 is

A

gelatinase A

18
Q

MMP3 is

A

stromelysin 1

19
Q

MMP are active at ……….pH and require……..

A

neutral

Zn

20
Q

MMPs are inhibited by

21
Q

MMPs are activated by the removal of ……… by …………….

A

propeptide (hence Cys motif) by sereine proteases

22
Q

………. terminus is important in substrate specificity and regulation

23
Q

When inactive MMP is

A

folded up with Cys on Zn catalyst stopping function

24
Q

Serine and Cys proteinases e.g.

A

Neutrophil elastase
cathepsin G
kallikrein

25
Serine and Cys proteases break down
Elastin Laminin Chondroitin sulfate and proteoglycans (involved in antigen processing)
26
Endogenous inhibitor of Serine and Cys proteinases by ............ which are inactivated by ...........
Serpins | oxidation
27
3 synthetic MMP inhibitors
Peptidomimetics Non-peptidomimetics Tetracycline and derivatives
28
Peptidomimetics are
small hydroxamic-acid-based molecules mimic substrate recognition site inhibit MMP
29
are Peptidomimetics specific?
no
30
Peptidomimetics e.g.
Batimastat and merimastat
31
Non-peptidomimetics e.g.
tanomastat and prinomastat
32
Non-peptidomimetics are
based on confirmation of the MMP active site
33
Tetracycline works by
inhibiting synthesis and activity of MMP
34
What are MMP inhibitors not used?
lack of specificity s/e (ongoing trials for ser and cys protease inhibitors)
35
ROS are produced by
infiltrating leukocytes and tissue resident cells
36
what catalyses the formation of superoxide
NADPH
37
What decomposes to for OH- and HOCl-
H202
38
Reactive nitrogen species formed from ................
NOS derived NO combining with oxygen species
39
RA undergoes cycles of .......... and ..........
hypoxia and reperfusion - oxidative stress - superoxide is generated
40
Effects of ROS
- DNA damage - activate inflam gene transcription (NFKB) - amino acid modifications - matrix modifications - cell apoptosis and necrosis
41
What sort of amino acid modifications does ROS make
make host proteins immunogenic | inactivation of serpins