Collagen evolution of collagens was a fundamental step in the early evolution of life, supporting the coalescence of multicellular life forms. Collagen D-banding is viable as periodic formation of ridging on all fibrils forming collagen. D-bands are created due to the semi-crystalline formation of the collagen within the fibrils. The pattern exhibited by D-banding is consistently independent of fibril diameter. When undergoing deformation, collagen fibrils may lose their D-banding, making the disappearance of the d-bands an indicator of the type of damage undergone by then tendon fibrils. Collagen Collagen is the main structural protein in the extracellular space in the various
Elastin-like polypeptides oxidase. One of the major reasons that elastin can withstand high levels of stress in the body without experiencing any physical deformation is that the underlying tropoelastin contains domains that are highly hydrophobic. These hydrophobic domains, consisting overwhelmingly of alanine, proline, glycine, and valine, tend towards instability and disorderliness, ensuring that the elastin does not lock into any specific confirmation. Thus, ELPs consisting of the Val-Pro-Gly-X-Gly monomeric units, which bear resemblance to the repetitive tropoelastin hydrophobic domains, are highly disordered below their T Even above their T in their aggregated state, ELPs are only partially ordered. This is due to