MW L5 Proteases Flashcards
RA is mediated by
MMP
MMP is secreted by
tissue cells - synovial fibroblasts, chondrocytes
Inflammatroy cytokines are particularly derived from macrophages e.g. (2)
TNFa
IL1b
………….. and ………….cells help maintain cytokine production
T and B lymphocytes
2 e.g. of natural proteases
collagenase
elastase
Synovial fibroblasts secrete
- cytokines
- Enzymes
- mediators (PGE2)
- Matrix materials
Synovial fibroblasts ‘………….’ T-cells and exhibit ‘………….’ phenotype
nurse
malignant
Cartilage is made up of …..
cells and extracellular matrix:
- fibrous protein - collagen
- proteoglycan
what is proteoglycan
chondroitin sulphate linked to aggrecan core
proteoglycans are …….. and bind to water
charged
what happens to proteoglycans in raised intra-articular pressure in RA
displaced and lost
proteoglycans have a …………….. structure
open - highly accessible thus sensitive to breakdown by several proteinase
Collagen or proteoglycans is lost quicker
proteoglycans
Native collagen is only susceptible to
collagenases - after initial damage other enzymes can continue degreading
4 families of proteolytic enzymes
MMP
Serine proteinases
Cysteine proteinases
Aspartate
MMP1,8, and 13 are
collagenases
MMP2 is
gelatinase A
MMP3 is
stromelysin 1
MMP are active at ……….pH and require……..
neutral
Zn
MMPs are inhibited by
TIMPa
MMPs are activated by the removal of ……… by …………….
propeptide (hence Cys motif) by sereine proteases
………. terminus is important in substrate specificity and regulation
C
When inactive MMP is
folded up with Cys on Zn catalyst stopping function
Serine and Cys proteinases e.g.
Neutrophil elastase
cathepsin G
kallikrein