Collagen is composed of three polypeptide chains forming a triple helix structure, that is, each of the three polypeptide chains is left-handed to form a left-handed helical structure, and then argon bonds with each other to form a strong right-handed supercoil structure (specific of collagen).
Each α-peptide chain consists of up to 300 or more Gly-X-Y triplet repeats (X is usually proline (Pro) and Y is usually hydroxyproline (Hyp)). The three left-handed spiral chains are intertwined into a right-handed spiral structure, that is, the supercoiled structure constitutes a unique "grass-like" triple helix structure of collagen.
