Collagen is the key structural protein that is found within the extracellular matrix that can be found in the different connective tissues within the body. As the chief connective tissue component, it is the protein that is the most abundant in mammals, making up from 25 percent to 35 percent of the protein content within the entire body.
Collagen is made up of amino acids that bind together to form what is known as a collagen helix. This is a triple helix of the elongated fibril. It is usually located within the connective tissue, for example, in the skin, ligaments, tendons, bones, and cartilage.
Based on the level of mineralization, collagen tissues can either be compliant, such as the tendon, or they can be rigid, like bone. In some cases, for example, with regard to cartilage, they can have a gradient from rigid to compliant.
Collagen is abundant in the dentin in the teeth, intervertebral discs, the gut, blood vessels, and the corneas.
With regard to muscle tissue, it acts as a major element of the endomysium. Collagen makes up between one and two percent of muscle tissue, as well as accounting for approximately six percent of the weight of tendinous, strong muscles.
The most common cell that generates collagen is the fibroblast. You may have also heard of Gelatin, which is used in industry and food, is collagen that has been hydrolyzed irreversibly.
We have seen collagen used in the medical sector in many ways, including treating complications of the skin and bones.