Collagen Synthesis Flashcards
Where is collagen forms
Osteoblast of bones and chondrocytes
Steps in biosynthesis of collagen (7)
Formation of pro alpha chain Hydroxilation Glucosylation Assembly and secretion of procollagen Extracellular cleavage of procollagen Formation of collagen fibrils Crosslonk formation
Where does pro collagen forms?
In cisternae of RER
What happen during pro collagen forms?
N terminal actvas signal to be exported and also lead polypeptide to the cisterna of RER
3 pro ollagenchains assemble forms disulgide cross links in C terminal
Helical structure middle
Non helicalin terminals
What is tropocollagen
Tripocollagen is a subunitvof larger collagen aggregates such as fibrils
They made up of 3 polyoeptide cbains and forming left handed helix
Left handed helicals twisted togetger in to right handed coil - super helix
Quaternary structure of collagen stabilize by
Hydrogen bonds
Quater staggered arrangmebts of collagen
Each collagen fibrils overlaps with other approximately 3/4 of a molecule
What happen in hydroxilation
In y location of Gly-x-Y hydroxylation of proline and lysine takes place
Enzymes- prolylhydroxylase and lisylhydroxylase
Requires molecular O and vitaminC
They enhance tge cross links and strengthen collagen
What haopen in glycosylation
Hydroxyl lusine can be further modified wuth glucose and galactose
What happen in cross link formation?
Lysyl oxidade oxidatively deaminates(remove animo group) sone lysil and hydroxylysyl residues giving rise to aldehyde groups
This cross links with neighbour lysyl & hydroxyl residues & forms covalent cross lonks
This provides the tensile strengh
When there is deficiency in crossink formation what would hapeen(disease )
Scurvy
How maby types of collagen are there
4
What is the most common type of collagen
Type 1
Where we can find type 1 collagen
Skin Bone Blood Tendon Vessels CorneA
What are the disseases of collagen
Ehlers-Danlos symdrom(circus man)
Brittle bone disease(osteogenesis imperfecta)
