Fibrous Proteins Flashcards
What is purpose of collagen?
Provides body structure by protecting and supporting soft tissues
What is the mutation that causes Ehlers-Daners syndrome?
Identifiable mutation in COL5A1 or COL5A2, which encodes the type V collagen
What gender does EDS disproportionally affect?
Women
What is osteogenesis imperfecta
Brittle bone disease–numerous fractures and bone deformity
What is the mutation that causes in Osteogenesis imperfecta
Mutation of Glycine in the Gly-X-Y triplet to Ala, Val, Ser
What is the role of collagen in bone formation?
Organic phase–collagen
Inorganic phase– Hydroxylapatite
What are the four molecules that make up collagen?
Glycine, Alanine, Hydroxylysine, Proline and 4-Hydroxyproline
How does the collagen triple helix stabilize?
Inter-chain H bonding between a Glycine residue on one chain and a Proline residue of another chain within the helix
What kind of bond stabilizes the triple helix(tropocollagen)
Inter-strand disulfide bonds
What is the purpose of the procollagen N-terminal polypeptide?
It is the feedback control of net collagen synthesis and regulates growth factor activity in extracellular matrix
Why is hydroxylation of lysine important?
Sugar attachment–as a carbohydrate can stabilize the collagen
Why is hydroxylation of proline important?
Two reasons: 1) Triple helix stability 2) Fibril(mini-Fiber) Stability
Why is ascorbate essential?
serves as a cofactor for lysine and proline hydroxylases.(Also known as Vitamin C)
What is the disease that is due to a deficiency of Vitamin C?
Scurvy
Deficiency in Vitamin C prevents what chemical process?
Proline Hydroxylation
What enzyme converts lysine to allysine?
Lysyl Oxidase
Why is it important to form crosslinks in collagen?
Mainly for strength and stability throughout the body.
Which two amino acids form crosslinks in collagen?
Lysine and Histidine
T/F: There are disulfide cross links in mature collagen
FALSE
T/F: Elastin is highly hydrophobic
TRUE
What is desmosine made up of?
4 Lysine residues
Mutations in fibrillin gene cause what syndrome?
Marfan’s
Which has more entropy, the relaxed state or the stretched state?
Relaxed because there are different ways of arranging the polymer chain
What is Supravalvular Aortic Stenosis caused by?
SVAS is due to mutations in elastin or decrease of elastin production
What are some problems associated with Williams Syndrome?
Heart and Blood Vessel defects(Hypertension, Hypercalcemia)
What do fibulins help assemble?
Tropoelastin
What do fibulins facilitate?
Binding of Lysyl oxidase to the elastin fibril
