Collagen Structure & Function: Difference between revisions
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The triple-helical domain structure of collagens consists of three distinct α-chains and earns collagen the name "tropocollagen".<ref name="collalike">PMID:7695699</ref>. Each of these chains contain a characteristic L-handed amino acid sequence of polyproline, often termed as polyproline type II helix <ref>PMID: 19344236</ref>. The proper folding of each of these chains requires a glycine residue to be present in every third position in the polypeptide chain. For example, each α-chain is composed of multiple triplet sequences of of Gly-Y-Z in which Y and Z can be any amino acid. Y is commonly found as proline and Z is usually present as hydroxyproline. The presence of hydroxyproline in the Y position is also thought to contribute to the stability of the helical form.<ref name="collalike" />. | The triple-helical domain structure of collagens consists of three distinct α-chains and earns collagen the name "tropocollagen".<ref name="collalike">PMID:7695699</ref>. Each of these chains contain a characteristic L-handed amino acid sequence of polyproline, often termed as polyproline type II helix <ref>PMID: 19344236</ref>. The proper folding of each of these chains requires a glycine residue to be present in every third position in the polypeptide chain. For example, each α-chain is composed of multiple triplet sequences of of Gly-Y-Z in which Y and Z can be any amino acid. Y is commonly found as proline and Z is usually present as hydroxyproline (Figure 1.). The presence of hydroxyproline in the Y position is also thought to contribute to the stability of the helical form.<ref name="collalike" />. | ||
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have also been illustrated to point out their positions in the triple-helix. | have also been illustrated to point out their positions in the triple-helix. | ||
[[Image:collagen_(alpha_chain).jpg | thumb |'''Figure 1.''' Amino Acid residues in collagen. Gly, Pro and Hydroxyproline residues present in a collagen molecule <ref name="residues"/>.]] | [[Image:collagen_(alpha_chain).jpg | thumb |'''Figure 1.''' Amino Acid residues in collagen. Gly, Pro and Hydroxyproline residues present in a collagen molecule <ref name="residues"/>.]] | ||
==Function== | ==Function== | ||