Chemistry
Collagen is composed of a triple helix, which generally consists of two identical chains (α1) and an additional chain that differs slightly in its chemical composition (α2). The amino acid composition of collagen is atypical for proteins, particularly with respect to its high hydroxyproline content. The most common motifs in the amino acid sequence of collagen are glycine-proline-X and glycine-X-hydroxyproline, where X is any amino acid other than glycine, proline or hydroxyproline. The average amino acid composition for fish and mammal skin is given.
| Amino Acid | Abundance in Mammal Skin (Residues/1000) | Abundance in Fish Skin (Residues/1000) |
|---|---|---|
| Asp | 47 | 47 |
| Hyp | 95 | 67 |
| Thr | 19 | 26 |
| Ser | 36 | 46 |
| Glu | 74 | 76 |
| Pro | 126 | 108 |
| Gly | 329 | 339 |
| Ala | 109 | 114 |
| Val | 22 | 21 |
| Met | 6 | 13 |
| Ile | 11 | 11 |
| Leu | 24 | 23 |
| Tyr | 3 | 3 |
| Phe | 13 | 14 |
| Hyl | 6 | 8 |
| Lys | 29 | 26 |
| His | 5 | 7 |
| Arg | 49 | 52 |
Read more about this topic: Collagen
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