This gene encodes an alpha chain for one of the low abundance fibrillar collagens. Laminins bind other ECM components such as collagens and nidogens. The hemopexin domain is important to facilitate the cleavage of triple helical interstitial collagens. The ECM consists mainly of proteoglycan and collagens. Type II and type XI collagens compose the fibrils present in cartilage. The collagen fibrils are made of a mixture of type I and type V collagens. Specific collagens become altered in composition and ratios. The primary function of MMP-8 is the degradation of type I, II and III collagens. This gene encodes an RGD-containing protein that binds to type I, II and IV collagens. Specifically, MMP-1 breaks down the interstitial collagens, types I, II, and III. Its autophosphorylation is achieved by all collagens so far tested (type I to type VI). Collagens are the most abundant protein in the ECM. Its composition varies between cells, but collagens are the most abundant protein in the ECM. Collagens I-IV bind this region with high affinity, while collagen V binds only weakly.