Tropokollagens

Tropokollagens is the precursor molecule to collagen, the most abundant protein in mammals. It is a soluble tropocollagen molecule that is secreted by fibroblasts and other connective tissue cells. Tropocollagen is composed of three polypeptide chains, known as alpha chains, that are wound around each other in a triple helix structure. Each alpha chain contains a high proportion of the amino acids glycine, proline, and hydroxyproline.

After secretion, tropocollagen molecules assemble into larger collagen fibrils. This assembly process involves covalent cross-linking between tropocollagen molecules, which increases the tensile strength of the resulting collagen fibers. These fibers are then further organized to form the various types of collagen found in connective tissues. Tropocollagen is essential for the structural integrity of skin, bones, tendons, ligaments, and other tissues. The synthesis and assembly of tropocollagen are tightly regulated processes. Defects in tropocollagen structure or assembly can lead to various connective tissue disorders.