tropocollagen

The rate the fibroblasts produce tropocollagen is proportional to these stimuli.

Examples of such universal building blocks include alpha-helices, beta-sheets or tropocollagen molecules.

What is left is known as tropocollagen.

This is synthesised intracellularly as tropocollagen and then exported, forming fibrils.

Registration peptides are cleaved and tropocollagen is formed by procollagen peptidase.

The two collagenases act synergistically by cleaving tropocollagen (the 'collagen molecule') at different points.

The tropocollagen or collagen molecule is a subunit of larger collagen aggregates such as fibrils.

The tropocollagen subunits spontaneously self-assemble, with regularly staggered ends, into even larger arrays in the extracellular spaces of tissues.

This enzyme acts on lysines and hydroxylysines producing aldehyde groups, which will eventually undergo covalent bonding between tropocollagen molecules.

These tropocollagen molecules are intercalated with the mineral phase (hydroxyapatite, a calcium phosphate) forming fibrils that curl into helicoids of alternating directions.

Formation of Tropocollagen: Once outside the cell, membrane bound enzymes known as collagen peptidases, remove the "loose ends" of the procollagen molecule.

After secretion from the cell, the terminal peptides are cleaved by procollagen N- and C-proteinases, and the tropocollagen molecules spontaneously assemble into insoluble fibrils.

Multiple tropocollagen molecules form collagen fibrils, via covalent cross-linking (aldol reaction) by lysyl oxidase which links hydroxylysine and lysine residues.

- Butler, William T.; and Cunningham, Leon W.: Evidence for the Linkage of a Disaccharide to Hydroxylysine in Tropocollagen.

There is some covalent crosslinking within the triple helices, and a variable amount of covalent crosslinking between tropocollagen helices forming well organized aggregates (such as fibrils).

Collagen's insolubility was a barrier to the study of monomeric collagen until it was found that tropocollagen from young animals can be extracted because it is not yet fully crosslinked.

If collagen is sufficiently denatured, e.g. by heating, the three tropocollagen strands separate partially or completely into globular domains, containing a different secondary structure to the normal collagen polyproline II (PPII), e.g. random coils.

The process of hydrolysis involves not only breaking down the molecular linkages in the triple helix of collagen trimers called tropocollagen but significantly reducing the molecular weight (or molecular mass) of collagen monomers to short chains of polypeptides.