Human Collagen Type IV protein purified from human placenta.

Collagen Type IV is a type of collagen found primarily in the skin within the basement membrane zone which is the specialized sheet-like extracellular matrix of multicellular tissues that exists around certain cell types (e.g., skeletal muscle cells, smooth muscle cells, heart muscle cells, and adipocytes). Basement membranes also exist between connective tissues and epithelial cells, endothelial cells, or Schwann cells. It consists of a protomer fiber made up of three α chains, each about 180 kDa. Six different genes encode for various α subunits of Collagen Type IV. It is the most important structural collagen of the basement membrane, and it entails key signaling potential, which is important for various physiological and pathological functions.