Tropoelastin.

Tropoelastin is a 60-72 kDa alternatively spliced extracellular matrix protein and a key component of elastic fibres. It is found in all vertebrates except for cyclostomes. Secreted tropoelastin is tethered to the cell surface, where it aggregates into organised spheres for cross-linking and incorporation into growing elastic fibres. Tropoelastin is characterised by alternating hydrophobic and hydrophilic domains and is highly flexible. The conserved C-terminus is an area of the molecule of particular biological importance in that it is required for both incorporation into elastin and for cellular interactions. Mature cross-linked tropoelastin gives elastin, which confers resilience and elasticity on a diverse range of tissues. Elastin gene disruptions in disease states and knockout mice emphasise the importance of proper tropoelastin production and assembly, particularly in vascular tissue. Tropoelastin constructs hold promise as biomaterials as they mimic many of elastin's physical and biological properties with the capacity to replace damaged elastin-rich tissue.