等电点法纯化太平洋鳕鱼皮胶原蛋白及其结构特性研究

Purification of Collagen from Pacific Cod Skin by Isoelectric Precipitation Processing and Its Structure Properties

为研究等电点法纯化鳕鱼皮胶原的可行性,通过测定溶解度和Zeta电位来确定鳕鱼皮胶原的等电点。将粗提胶原溶液的pH调至等电点,后经离心、复溶、透析、冻干等步骤得到了等电点纯化后的胶原干品。采用SDS-PAGE法检验产品的胶原纯度;采用红外光谱、X-射线衍射、紫外光谱法对胶原的结构性质进行了研究。最后对等电点沉淀的工艺进行了单因素实验。结果显示鳕鱼皮胶原的等电点为6.83,且在该等电点下纯化得到的产品纯度较高。光谱学结果显示胶原的三螺旋结构仍保持完整。单因素实验结果显示最优条件为:pH6.8、沉淀6 h、6 mg/m L的胶原浓度,此时回收率可达85%,纯度可达90%以上。至此,确定了等电点沉淀是一种纯化胶原蛋白的有效方法。

In order to study the feasibility ofisoelectric precipitation method for the purification of collagen from Pacific cod skin,the isoelectric point of the collagen from cod skin was determined by the solubility and the Zeta potential methods.The pH of the crude collagen solution was adjusted to its isoelectric point,and then the collagen was centrifuged,redissolved,dialysed and lyophilized.The SDS-PAGE method was used to determine the purity of the product. The structure properties of collagen were detected by Fourier transform infrared spectroscopy,X-ray diffraction and ultraviolet absorption spectrum.In the end,the process of isoelectric precipitation was optimized by single-factor test.It was found that the isoelectric point of Pacific cod skin collagen was 6.83 and the product was of high purity. The results of spectroscopic properties showed that the triple helix structure of collagen remained intact.The recovery rate was 85% and the purity was over 90% under the optimized condition of pH6.8,6 h and 6 mg/m L collagen concentration. Based on these results,the isoelectric precipitation method is an effective method for purifying collagen.