点带石斑鱼鱼皮和鳞片胶原蛋白的提取及理化性质的研究

以点带石斑鱼为原料,分别从鱼皮和鱼鳞中提取酸溶性胶原蛋白,并研究其纯度、热变性温度、溶解度等理化性质.结果表明:(1)鱼皮和鱼鳞中胶原蛋白的提取率分别为76.21%和2.50%;(2)经紫外可见光谱扫描、傅里叶转换红外光谱和氨基酸分析,确定所提取的胶原蛋白是Ⅰ型胶原蛋白,具有完整的三螺旋结构;(3)SDS-PAGE电泳测定证明鱼皮和鱼鳞胶原蛋白均含有α1、α2、β和γ链,α1、α2链的相对分子质量分别为2.79×105和2.87×105,纯度分别为91%和85%;(4)鱼皮、鱼鳞胶原蛋白的热变性温度分别为40.16和42.06℃;(5)等电点分别为7.12和7.15;(6)两者在酸性pH(2～4)时具有高的溶解度,并且当NaCl的质量浓度分别为10和20 g/L时,溶解度最高.

Extraction and physicochemical characteristics of collagen from skin and scales of Epinephelus malabaricus

Acid soluble collagen extracted from skin and scales of Epinephelus malabaricus was studied on its physicochemical properties, including the purity, the thermal denaturation temperature and the solubility, etc. The results showed that： （ 1 ） The extraction rate in skin and scales was 76.21% and 2.50%, respectively. （2） By UV and visible spectra scan, FFIR and analysis of amino acid, the collagen was proved to be protein I with integrate triple-helix structure. （3） SDSPAGE showed that both collagens contained 2 alpha components （α1 and α2）, β and y components were also found in both collagens, and the molecular weight of αl chain and α2 chain was 278.72 and 286.92, and the purity of 91% and 85%, respectively. （4） Thermal denaturation temperature was 40.16℃ and 42.06℃ for skin and scales, respectively. （5） From zeta potential analysis, net charge of zero was found at pH 7.12 and 7.15 for skin and scales, respectively. （6） Both collagens exhibited high solubility in acidic pH （2-4） and in the presence of NaC1 at concentration of 10 and 20 g/L for skin and scales, respectively.