Collagen: Difference between revisions

Proteopedia Page Contributors and Editors (what is this?)Proteopedia Page Contributors and Editors (what is this?)

Ala Jelani, Karl Oberholser, Eran Hodis, Tilman Schirmer, Judy Voet, David Canner, Jaime Prilusky, Michal Harel, Alexander Berchansky, Eric Martz

Revision as of 22:37, 21 May 2012 view source Karl Oberholser (talk \| contribs) 1,665 edits No edit summary ← Older edit		Revision as of 23:41, 18 July 2012 view source Karl Oberholser (talk \| contribs) 1,665 edits No edit summary Newer edit →
Line 24:		Line 24:
	=== Intra-tropocollagen Attractions ===		=== Intra-tropocollagen Attractions ===

	Intra-tropocollagen attractions are primarily hydrogen bonds formed between the peptides in the triple helix. The three polypeptide chains are <scene name='Collagen/Intra-hbonds/4'>staggered</scene> in position by one residue, that is, a <span style="color:limegreen;background-color:black;font-weight:bold;">Pro</span> on Chain A is at the same level along the triple helix axis as a <font color="#ff0000">Gly</font> on Chain B and a <span style="color:gold;background-color:black;font-weight:bold;">Hyp</span> on Chain C. This staggered arrangement not only <scene name='Collagen/Intra-hbonds2/6'>aligns</scene> a <font color="#ff0000">Gly</font> backbone NH (imino group) with a <span style="color:limegreen;background-color:black;font-weight:bold;">Pro</span> backbone O (carbonyl oxygen) on one of the other peptides but also brings the two groups close enough so that a <scene name='Collagen/Intra-hbonds6/2'>hydrogen bond</scene> can form between the imino hydrogen and the carbonyl oxygen. This alignment occurs with Gly in each of the three peptides so that the Gly imino hydrogens of Chain A form <scene name='Collagen/Hbonds_a_to_b/6'>hydrogen bonds</scene> (<span style="color:orange;background-color:black;font-weight:bold;">orange</span>) with the Pro carbonyl oxygens on Chain B, and likewise Gly of <scene name='Collagen/Hbonds_a_to_b/5'>Chain B to Pro of Chain C</scene> (<span style="color:gold;background-color:black;font-weight:bold;">yellow</span>) and Gly of <scene name='Collagen/~~Intra-hbonds5~~/1'>Chain C to Pro of Chain A</scene> (<span style="color:limegreen;background-color:black;font-weight:bold;">green</span>). The force of these hydrogen bonds extending the length of the tropocollagen add up to a strong attractive force which mantain the integrity of the tropocollagen. Since the main chain N atoms of both Pro and Hyp residues lack H atoms, only Gly can provide hydrogen to form these hydrogen bonds.		Intra-tropocollagen attractions are primarily hydrogen bonds formed between the peptides in the triple helix. The three polypeptide chains are <scene name='Collagen/Intra-hbonds/4'>staggered</scene> in position by one residue, that is, a <span style="color:limegreen;background-color:black;font-weight:bold;">Pro</span> on Chain A is at the same level along the triple helix axis as a <font color="#ff0000">Gly</font> on Chain B and a <span style="color:gold;background-color:black;font-weight:bold;">Hyp</span> on Chain C. This staggered arrangement not only <scene name='Collagen/Intra-hbonds2/6'>aligns</scene> a <font color="#ff0000">Gly</font> backbone NH (imino group) with a <span style="color:limegreen;background-color:black;font-weight:bold;">Pro</span> backbone O (carbonyl oxygen) on one of the other peptides but also brings the two groups close enough so that a <scene name='Collagen/Intra-hbonds6/2'>hydrogen bond</scene> can form between the imino hydrogen and the carbonyl oxygen. This alignment occurs with Gly in each of the three peptides so that the Gly imino hydrogens of Chain A form <scene name='Collagen/Hbonds_a_to_b/6'>hydrogen bonds</scene> (<span style="color:orange;background-color:black;font-weight:bold;">orange</span>) with the Pro carbonyl oxygens on Chain B, and likewise Gly of <scene name='Collagen/Hbonds_a_to_b/5'>Chain B to Pro of Chain C</scene> (<span style="color:gold;background-color:black;font-weight:bold;">yellow</span>) and Gly of <scene name='Collagen/Hbonds_c_to_a/1'>Chain C to Pro of Chain A</scene> (<span style="color:limegreen;background-color:black;font-weight:bold;">green</span>). The force of these hydrogen bonds extending the length of the tropocollagen add up to a strong attractive force which mantain the integrity of the tropocollagen. Since the main chain N atoms of both Pro and Hyp residues lack H atoms, only Gly can provide hydrogen to form these hydrogen bonds.