Collagen Structure & Function: Difference between revisions
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The triple-helical domain of collagens consist of three distinct α-chains. 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 of 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. 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 of 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>PMID: 7695699 </ref>. | 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>PMID: 7695699 </ref>. | ||
The image on the right-hand side has each side chain colored a different color to shown how each individual protein chain interacts with the others to form the overall molecule. The active sites have also been illustrated to point out their positions in the triple-helix. | |||
==Function== | ==Function== | ||
