Abstract:

Acid-soluble collagen (ASC) and pepsin-soluble collagen (PSC) from the skin of farmed Chinese giant
salamander (Andrias davidianus Blanchard) were extracted with 0.5 mol/L acetic acid solution and pepsin at 4 ℃,
respectively, and purified for further property analysis. Results showed that both ASC and PSC contained two α
chains and one β chain (dimer of α chains), indicating them both to be typeⅠ collagen. Among all amino acids in ASC and
PSC, glycine had the largest amount, followed by glutamic and proline, while cystine was the least abundant. The contents
of amino acids in ASC and PSC were 144 and 173 residues/1 000 residues, respectively, and their denaturation temperatures
were 23.5 and 26.5 ℃, respectively. These observations manifested that PSC possessed a better thermal stability than ASC.
In addition, the largest UV absorption of ASC and PSC was observed at 233.0 and 232.0 nm, respectively, which agreed
with the characteristic UV absorption of collagen. Fourier transform infrared (FT-IR) spectra of ASC and PSC were almost
identical. Both collagens had amide Ⅱ and amide Ⅲ, and a series of absorption peaks between them, indicating the existence
of integrated triple helix structure in ASC and PSC.

Key words: Chinese giant salamander, skin, collagen, extraction, physico-chemical properties