虾夷扇贝外套膜胶原蛋白的提取与表征

为探索虾夷扇贝Patinopecten yessoensis加工副产物的高附加值利用,从副产物外套膜中提取经济价值较高的胶原蛋白,并对其理化性质(分子量、溶解性、黏度、紫外吸收、氨基酸组成)和结构特性(圆二色谱、傅里叶红外光谱)进行研究。结果表明:外套膜干基中胶原蛋白含量为13.16%;外套膜胶原蛋白分子主要由α亚基和少量的β、γ亚基组成,外套膜胶原蛋白为典型的Ⅰ型胶原;酸溶性胶原蛋白(ASC)和酶溶性胶原蛋白(PSC)均富含甘氨酸、谷氨酸、脯氨酸和羟脯氨酸;胶原蛋白的变性温度约为20℃,与其他物种有所差异;PSC的溶解度高于ASC,二者的等电点均在pH为4左右,且二者的盐溶性变化趋势相似;红外光谱表明,PSC和ASC二级结构间有细微差异,但胃蛋白酶没有影响胶原蛋白的三螺旋结构;圆二色谱显示,ASC的三级结构比PSC的更加稳定,温度升高会影响二者的三级结构。

Extraction and characterization of collagen from yesso scallop Patinopecten yessoensis mantle

The mantle collagen were extracted and its physicochemical properties including molecular weight,solubility,viscosity,ultraviolet (UV) absorption,and amino acid composition and structural characteristics (CD,FT-IR) were studied in yesso scallop Patinopecten yessoensis in order to explore the high value-added use of scallop byproducts.The results showed that there was 13.16％ of collagen in dry mantle.Collagen molecules were primarily consisted of α subunit and a small amount of β,γsubunits,and the peptide molecular weight was reduced because the pepsin removed the telopeptide of subunits.Mantle collagen was characterized by a typical type I collagen,whose acid soluble collagen (ASC) and enzymatic soluble collagen (PSC) were rich in glycine,glutamic acid,proline and hydroxyproline.The collagen had denatured temperature of about 20 ℃,and was different from collagens of other species in that PSC had a higher solubility than ASC did.They had isoelectric point of pH 4 and the similar salt solubility.Fourier transform infrared spectroscopy revealed that there was subtle difference in secondary structure between PSC and ASC.However,pepsin did not affect the triple helical structure of the collagen.Circular dichroism spectrum indicated that the ASC had more stable tertiary structure than PSC and that increase in temperature undermined the tertiary structure.