牛初乳多肽的制备及其功能研究

Preparation and functional research of bioactive peptides derived from bovine colostrum

目的：以新鲜牛初乳作为原料，研究主要通过分离获得不同区段的蛋白片段并加以收集冻干；并且利用收集的蛋白片段作用于细胞，初步探讨牛初乳中不同区段蛋白对细胞促生长方面的研究。方法：通过超滤膜法分离收集牛初乳各区段蛋白，检测各区段蛋白中IGF-1和TGF-β2的表达情况，并利用WST-8检测牛初乳中不同区段蛋白对人胚成纤维细胞（HFL-1）的促生长作用，同时利用不同剂量的小分子蛋白作用于人胚肾细胞（293）、人正常肝细胞（HL-77021以及HFL-1细胞，初步探讨剂量效应方面的关系。结果：分离获得不同区段的蛋白，在3～10ku的蛋白区段中含有IGF-1，检测浓度为1．25ng／mL；在10～30ku、30ku以上的蛋白区段中含有TGF—β2，检测浓度分别为156pg／mL和257pg／mL，以及3ku以下蛋白片段对细胞有一定的促生长作用，且剂量越大，促生长作用越明显。结论：超滤膜法能够很好地分离牛初乳中各区段蛋白，且牛初乳中小分子蛋白多肽对细胞有一定的促生长作用。

Objective： Taking fresh bovine colostrum as raw material, we can get different fragments of protein derived from bovine colostrums, and these fragments are isolated, collected and freeze-dried. In addition, it is preliminarily discussed that different protein fragments proliferate the cells. Methods： The different protein fragments derived from bovine colostrum are separated and collected by ultrafiltration technology, and the protein IGF-1 and TGF-beta2 in each section have been detected. Then the proliferating function that the different proten fragments promote human embryo fibroblast （HFL-1） growth has been explored by using WST-8 assay, at the same time, the dose-effect relation has been studiedwith different doses of bioactive peptides stimulating various cells including human embryonic kidney cells （293）, human normal liver cells. （HL-7702） and HFL-1 cell. Results： In 3-10 ku protein section, the concentration of IGF-1 is 1.25 ng/mL; in 10-30 ku and above 30 ku protein section, the concentration of TGF-beta2 is respectively 156 pg/mL and 257 pg/mL, and the peptides in the protein fragments under 3 ku have been promoting the cell growth with dose-effect relation, the greater the dose effect is more obvious. Conclusion： Ultrafiltration membrane method can well separate bovine colostrum protein in each section, and it is obvious small molecular protein polypeptide derived from bovine colostrum can promote the growth of cells.