Abstract: Acid-soluble collagen (ASC) was prepared from the body wall of Urechis unicinctus through extraction with 0.5 mol/L acetic acid followed by precipitation with 0.9 mol/L NaCl and its physical and chemical properties were primarily studied. Ultraviolet spectral analysis showed that the characteristic absorption wavelength of ASC was 228 nm, suggesting that it is a typical collagen. Amino acid composition analysis indicated that ASC was a typical type Ⅰcollagen. SDS polyacrylamide gel electrophoresis (SDS-PAGE) suggested that ASC contained two alpha chains (α1 and α2), one β chain and oneγ chain. It also contained disulfide bonds. Fourier-transform infrared (FTIR) spectral analysis revealed the existence of helical arrangements in the collagen. The thermal denaturation temperature (td) and the thermal shrinkable temperature (ts) were 33.6 and 67.5 ℃, respectively.

Key words: Urechis unicinctus, collagen, extraction, characterization