Collagen vs. Keratin

Main Difference

The main difference between Collagen and Keratin is that the protein complex consisting of three collagen chains and Keratin is a one of a family of fibrous structural proteins; protein that protects epithelial cells from damage or stress.

• Collagen

  Collagen is the main structural protein in the extracellular space in the various connective tissues in the body. As the main component of connective tissue, it is the most abundant protein in mammals, making 25% to 35% of the whole-body protein content. Collagen consists of amino acids wound together to form triple-helices of elongated fibrils. It is mostly found in fibrous tissues such as tendons, ligaments, and skin.

  Depending upon the degree of mineralization, collagen tissues may be rigid (bone), compliant (tendon), or have a gradient from rigid to compliant (cartilage). It is also abundant in corneas, blood vessels, the gut, intervertebral discs, and the dentin in teeth. In muscle tissue, it serves as a major component of the endomysium. Collagen constitutes one to two percent of muscle tissue and accounts for 6% of the weight of strong, tendinous, muscles. The fibroblast is the most common cell that creates collagen. Gelatin, which is used in food and industry, is collagen that has been irreversibly hydrolyzed. Collagen has many medical uses in treating complications of the bones and skin.

  The name collagen comes from the Greek κόλλα (kólla), meaning “glue”, and suffix -γέν, -gen, denoting “producing”. This refers to the compound’s early use in the process of boiling the skin and tendons of horses and other animals to obtain glue.

• Keratin

  Keratin () is one of a family of fibrous structural proteins. It is the key structural material making up hair, nails, horns, claws, hooves, and the outer layer of human skin. Keratin is also the protein that protects epithelial cells from damage or stress. Keratin is extremely insoluble in water and organic solvents. Keratin monomers assemble into bundles to form intermediate filaments, which are tough and form strong unmineralized epidermal appendages found in reptiles, birds, amphibians, and mammals. The only other biological matter known to approximate the toughness of keratinized tissue is chitin.