Isolation and partial characterization of basement membrane-like collagens from bovine thoracic aorta

Collagen polymorphism was investigated in the bovine thoracic aortic media after extraction by a technique involving reduction of disulfide bonds followed by limited pepsin digestion. Type I, III, IV and V collagens were all fractionated from each other in the native state by differential salt precipitation both in acidic and neutral conditions. Type IV and V collagen were both found to be similar, if not identical, to the same collagens isolated from other tissues, the Type IV collagen fraction clearly containing two different alpha-sized components. The possible function of the different collagen types in aortic structure is briefly discussed.