单环刺螠体壁胶原蛋白的提取及其理化性质

Extraction and Physical and Chemical Properties of Collagen from Urechis unicinctus

采用0.5mol/L醋酸提取,结合NaCl沉淀法从单环刺螠(Urechis unicinctus)的体壁中提取酸溶性胶原蛋白(ASC),并对其理化性质作初步研究。紫外光谱分析表明ASC的特征吸收波长位于228nm,初步推断所提取的蛋白为典型的胶原蛋白;氨基酸组成分析表明ASC为典型的Ⅰ型胶原蛋白;聚丙烯酰胺凝胶电泳(SDS-PAGE)结果表明ASC有两条不同的α链(α1和α2链)、β链和γ链,其胶原蛋白中含有二硫键;傅里叶红外光谱(FTIR)分析表明其存在三螺旋结构;示差扫描量热仪(DSC)分析表明热变性温度(td)和热收缩温度(ts)分别为33.6℃和67.5℃。

Acid-soluble collagen （ASC） was prepared from the body wall of Urechis unicinctus through exlraction with 0.5 mol/L acetic acid followed by precipitation with 0.9 mol/L NaCI 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 I collagen. SDS polyacrylamide gel electrophoresis （SDS- PAGE） suggested that ASC contained two alpha chains （α1 and α2）, one β chain and one γ 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.