(Also see Matrix Metalloproteinase Inhibitors)
Mammalian collagenases belong to the family of metalloproteinases that specifically cleave collagen. On a dry weight basis, collagen constitutes over 70% of skin weight. Collagenases have a unique ability to degrade native collagen that is normally resistant to breakdown by other proteases. They catalyze a single proteolytic cleavage in the helical collagen chains, resulting in two fragments that are subsequently accessible to less specific proteases. Collagenases are produced by macrophages, fibroblasts, and keratinocytes that are involved in the wound-healing process. In normal healthy subjects, even during wound healing, the activity of endogenous collagenases is low and is sufficient for the removal of dead tissue. However, in patients with chronic non-healing wounds and ulcers, there may be impairment of endogenous collagenase production leading to insufficient removal of dead tissue. Such conditions warrant the application of bacterial collagenases to clean the wound and begin the healing process. Collagenases also play an important role in separating cells from their anchors. They dissolve desmosomes and thereby enable cells to migrate on a matrix of fibronectin. Fibroblast migration also requires these proteases to enable fibroblasts to move within the wound.