Collagen/Elastin Flashcards
Which is the main structural protein of the extracellular matrix?
Collagen
Collagen type 1 can be found in
Bone, skin, tendons
Collagen type 2 can be found in
Cartilage
Collagen type 3 can be found in
Blood vessels, granulation tissue, uterus
Collagen type 4 can be found in
Basement Membrane
Collagen structure
Three alpha chains linked by disulfide bonds (also hydrogen bonds)
Steps in Collagen synthesis (6 steps)
- Synthesis of individual alpha chains
- Hydroxylation of Proline and Lysine
- Glycosilation of hydroxyproline = Procollagen
- Exocytosis of procollagen
- Cleavage of terminal regions
- Cross-linking between collagen molecules
Which step of collagen synthesis needs Vit C?
Hydroxilation of proline and lysine
Hydroxilation of proline and lysine needs ____________
Vitamin C
Osteogenesis imperfecta affects which type of Collagen?
Type 1
Clinical features of Osteogenesis imperfecta
Bone fragility + Blue sclera + Dental problem/Hearing loss
Osteogenesis imperfecta inheritance pattern
Autosomal Dominant
Ehlers Danlos affects which type of Collagen
Type 3 (Also Type 5)
Ehlers Danhlos Clinical features
Hypermobile joints and Hyperextensible skin
Type 5: More vascular compromise
Merkes Syndrome is caused by
Poor copper absorption = Decreased collagen synthesis
Merkes Syndrome clinical features
Brittle hair + Cognitive impairment
What is elastin?
Large and very stretchy protein commonly found in connective tissue
Sites where you can find Elastin
Skin, blood vessels, lungs and Ligament flava
What action does Alpa-1- Antitrypsin do?
Increases elastase activity = Decrease elastin
Syndrome characterized by defective fibrillin?
Marfan Syndrome
Patient with Marfanoid Habitus + Pectus carinatum + Aortic incompetence. Diagnosis
Marfan Syndrome
Marfan syndrome pathogenesis:
Defective fibrillin (Decreased production of sheath around elastin)
Lens abnormality associated to Marfan Syndrome
Superotemporal/Temporal Lens subluxation
Marfan Syndrome inheritance pattern
Autosomal dominant
