Kollageni

Kollageni is the name for a family of structural proteins that form a major part of the extracellular matrix in animal connective tissues. It provides mechanical strength and resilience to tissues such as skin, bone, cartilage, tendons, ligaments, and blood vessels. The collagen molecule typically consists of three polypeptide chains arranged in a triple helix, giving it high tensile strength. There are many collagen types; the most abundant are type I (skin, bone, tendons), type II (cartilage), type III (reticular fibers in skin and vessels), and type IV (basement membranes). Each type has a distinct distribution and function.

Synthesis begins in specialized cells such as fibroblasts, chondrocytes, and osteoblasts. The genes encoding the collagen chains (COL genes) are transcribed and translated, and the chains undergo post-translational modifications, including hydroxylation of specific proline and lysine residues and glycosylation. Proper folding requires vitamin C. Secreted procollagen molecules are processed and assemble into fibrils in the extracellular space, where cross-links strengthen the fibers.

Functions of kollageni include providing structural support, guiding tissue development, and participating in wound healing and cell signaling. It also plays a role in tissue remodeling and integrity after injury. Degradation by enzymes such as matrix metalloproteinases is a normal part of turnover.

In medicine and nutrition, kollageni is sourced from animal tissues for research, medical applications, and dietary supplements (often as hydrolyzed collagen). Evidence for health benefits, such as improved skin elasticity or joint health, varies by product and condition. Genetic defects in kollageni synthesis or structure can cause disorders such as osteogenesis imperfecta and certain forms of Ehlers-Danlos syndrome.