Collagen Structure & Function: Difference between revisions
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The triple-helical domain of collagens consist 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 as hydroxyproline. The presence of hydroxyproline in the Y position contributes to the stability of the helical form. | The triple-helical domain of collagens consist 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 as hydroxyproline. The presence of hydroxyproline in the Y position contributes to the stability of the helical form. | ||
These three chains are then twisted around one another in a rope-like manner to produce the overall tightly packed triple-helical form of the molecule. The interaction of α-chains is stabilized via interchain hydrogen bonding making the molecule fairly resistant to attack by other molcules. This hydrogen bonding occurs when the amino group (NH) of a glycine residue forms a peptide bond with the carbonyl (C=0) of an adjacent residue. The overall molecule is approxiametly 300nm long and 1.5-2nm in diameter.<ref name="collalike" | These three chains are then twisted around one another in a rope-like manner to produce the overall tightly packed triple-helical form of the molecule. The interaction of α-chains is stabilized via interchain hydrogen bonding making the molecule fairly resistant to attack by other molcules. This hydrogen bonding occurs when the amino group (NH) of a glycine residue forms a peptide bond with the carbonyl (C=0) of an adjacent residue. The overall molecule is approxiametly 300nm long and 1.5-2nm in diameter..<ref name="collalike" />. | ||
The image on the right-hand side has each side chain colored a different color to shown how each individual <scene name='Sandbox_168/Helices/1'>α-helices</scene> interact with the others to form the overall molecule. The <scene name='Sandbox_168/Myscene/1'>active sites</scene> | The image on the right-hand side has each side chain colored a different color to shown how each individual <scene name='Sandbox_168/Helices/1'>α-helices</scene> interact with the others to form the overall molecule. The <scene name='Sandbox_168/Myscene/1'>active sites</scene> | ||
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. | ||