Most authors have classified collagens based on their supramolecular structures in two main classes: the fibrillar collagens and the nonfibrillar collagens.(Vuorio E, de Crombugghe B. 1990; Hulmes D. 1992) In addition, type VIII and type VI collagens are described below, but they have not yet been classified. - 6 -
Table 1. Collagen types α Chains Tissue Distribution Ⅰ α1(Ⅰ), α2(Ⅰ) Most connective tissues, eg, bone, tendon, skin, lung, cornea, sclera, vascular system Ⅱ α1(Ⅱ) Cartilage, vitreous humour, embryonic cornea Ⅲ α1(Ⅲ) Ⅳ α1(Ⅳ), α2(Ⅳ), α3(Ⅳ) Basement membranes α4(Ⅳ), α5(Ⅳ) V α1(V), α2(V), α3(V) Extensible connective tissues, eg, skin, lung, vascular system Tissues containing collagen Ⅱ, quantitatively minor componet VI α1(VI), α1(VI), α1(VI) Most connective tissues, including cartilage VII α1(VII) Basement-membrane-associate anchoring fibrils VIII α1(VIII), α2(VIII) Product of endothelial and various tumor cell lines IX α1(IX), α2(IX), α3(IX) Tissues containing collagen Ⅱ, quantitatively minor componet X α1(X) Hypertrophic zone of cartilage XI α1(XI), α2(XI), α2(XI) XII α1(XII) XIII α1(XIII) XIV α1(XIV) Tissues containing collagen Ⅱ, quantitatively minor componet Tissues containing collagen Ⅰ, quantitatively minor componet Quantitatively minor collagen, eg, found in skin and intestine Tissues containing collagen Ⅰ, quantitatively minor componet - 7 -