Collagen is the predominant protein in the animal body, constituting approximately 30% of total proteins (Birk & Bruckner, 2005; Unlua et al. 2014). It is an extracellular matrix protein that can interact directly or indirectly with cells to modify cellular activity. At least 27 different types of collagen have been identified, respectively named types I to XXVII (Birk & Bruckner, 2005). StructureCollagen is characterized by the right-handed triple helical stem structure which is formed of three left-handed helical polypeptide chains. Although the triple helical structure is the main characteristic of collagen, some globular proteins are identified as collagen due to the repeating triplets and the small triple helical rod (Prockop & Kivirikko 1995). Each polypeptide chain consists of repeating triplets (Gly-XY), where X and Y are, with high frequency, proline (Pro) and hydroxyproline (Hyp) respectively (Prockop & Kivirikko 1995; Ogawa et al. 2003) . Glycine in three amino acids is very essential. The small side chain of glycine allows the side chain of proline and...