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. 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. 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 molcule fairly resistant to attack by other molcules. | 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 molcule fairly resistant to attack by other molcules. This hydrogen bonding occurs when the NH of a glycine residue forms a peptide bond with the C=0 of an adjacent residue. The overall molecule is approxiametly 300nm long and 1.5-2nm in diameter. | ||
==Function== | ==Function== | ||
