Collagen: Difference between revisions

Hydrogen bonds are also an important inter-tropocollagen force which holds the tropocollagens together in the fiber segment. As shown above, <font color="gold">Hyp</font> is the outer most residue on the <scene name='Collagen/Pros_position_tropo/1'>surface</scene> of the triple helix, and the hydroxyl groups are the atoms that extend out the most from the surface.  The hydrogen bonds are formed between the hydroxyl hydrogen of a Hyp and a backbone carbonyl oxygen.  As the peptides in a tropocollagen twist about each other they come into <scene name='Collagen/Hlite_c_k_peptides/1'>close contact</scene> with particular peptides in adjacent tropocollagens and then move away from them. The two peptide highlighted in spacefill are located in two different tropocollagens.  Notice that in this case, they make contact with each other in the middle of the strands, and a hydrogen bond is located at this point of contact.  The <scene name='Collagen/Inter-hbonds1/2'>hydrogen bond</scene> consist of the oxygen of a carbonyl of a Hyp in a <font bold="" color="blue"><strong>peptide</strong></font> of one tropocollagen and the hydroxyl hydrogen of a Hyp in a <font color="gold"><strong>peptide</strong></font> of another tropocollagen.  Another example shows <scene name='Collagen/Hlite_k_o/1'>two peptides</scene> from two different tropocollagens making contact at the ends of the fiber segment, and of course it is within these regions where the inter-tropocollagen attractions occur. At one end a <scene name='Collagen/Inter-hbond2/4'>hydrogen bond</scene> is formed between a hydrogen of Hyp in one <font color="gold"><strong>peptide</strong></font> and an oxygen of a Gly carbonyl in the second <font color="red"><strong>peptide</strong></font>. At the other end of the two peptides a <scene name='Collagen/Inter-hbond3/2'>Hyp carbonyl oxygen</scene> donates its electrons to a Hyp hydroxyl hydrogen. Show the <scene name='Collagen/2nd_view_hbond3/2'>hydrogen bond</scene> in the context of the six peptides of the two tropocollagens. The above examples of hydrogen bonding illustrate that Hyp plays a central role in maintaining the structures of both the tropocollagen and the collagen fiber.  Without the proper amount of vitamin C in their diets humans can not make Hyp, and therefore can not make stable collagen and strong bones.