Collagen Flashcards
Collagen is the most abundant protein in what
most vertebrates in connective tissue
Collagen helix is unique and distinct from an alpha helix, how?
Left-handed
3 residues per turn
Coiled coil
3 alpha chains are twisted around each other and this super helical twist is right handed
Collagen alpha chain has what residue in what position
glycine in every 3rd position
Collagen alpha chain has a high percentge of what other residues
Mainly Proline + Hydroxyproline and Lysine
Why does glycine lie in the centre of the triple helix
Due to its size
What is the amino acid sequence of collage
Repeat of Gly-X-Y
X is proline
Y is hydroxyproline
What is the basic unit of the collagen structure
Tropocollagen
What stabilises the tropocollagen triple helix
Hydrogen bonding between the 3 alpha chains
What amino acid provides for more hydrogen bonding
Hydroxyproline
How are tropocollagen molecules packed
Side by side in an overlapping fashion and are cross linked
The tropocollagen molecules are cross linked via what
Lysine residues
Cross linked tropocollagen forms what
Collagen fibre
What gives collagen fibre its strength
cross linking via lysine residues of the tropocollagen
Collagen fibrils are what
supramolecular assemblies consisting of triple-helical collagen molecules
What is the rigid and brittle nature of aging due to
accumulation of covalent cross link
