Synthesis
Collagen is an excellent example of the production of a complex protein structure from a simple amino acid chain. It is made in cells such as fibroblasts:
- individual polypeptide chains are synthesized on membrane-bound ribosomes according to mRNA templates; this is the pro-alpha chain
- a signal peptide on the polypeptide ensures that the chain is passed into the lumen of the endoplasmic reticulum
- proline and lysine residues on the chain are hydroxylated
- some hydroxylysine residues may be glycosylated
- a triple alpha helix of 3 polypeptide chains forms spontaneously; this is procollagen:
- hydroxyproline forms interchain hydrogen bonds
- hydroxylysine cross-links collagen molecules
- procollagen is secreted into the extracellular space where proteolytic enzymes cleave the terminal peptides
- resulting tropocollagen molecules spontaneously combine with other tropocollagen molecules to form linear array within collagen fibril
- collagen fibrils orientate themselves along the line of collagen fibre made from several collagen fibrils
Related pages
Create an account to add page annotations
Annotations allow you to add information to this page that would be handy to have on hand during a consultation. E.g. a website or number. This information will always show when you visit this page.