Identify the major collagen classes and types of collagen included in each class
• Fibril-forming (interstitial)—types I, II, III, V, XI. Being the most abundant collagen class, these collagens form the extracellular fabric of the major connective tissues. They have the same tensile strength as steel wire.
• Fibril-associated collagens with interrupted triple helices (FACIT)—types IX, XII, XIV, XVI, XIX, XXI. These collagens are associated with the fibril-forming (interstitial) collagens and occur in the same tissues.
• Collagens with specialized structures or functions:
Basement membrane collagen—type IV.
Short-chain collagens—types VIII, X.
Nonfibrillar collagens—types VI, VII, XIII, XV, XVII, XVIII.