Separated And Purified Of Insulin-like Growth Factor-Ⅰ In Bovine Colostrums

Insulin-like Growth Factors(IGFs) and Insulin precursors have high degree of homology in the structure;IGFs has some of the functions and features of Insulin.Bases on molecular structure, IGFs will be divided into two categories of IGF-â… and IGF-â…¡.So far,more research is IGF-â… , molecular weight of 7649D,the pI was 8.4.Bovine colostrums are the milk that the cows secreted after delivery within 3-7 days.It is not only rich in nutrients,but also contains a large number of bioactive substances.Recent studies show that IGF-â… exists in cells and large presences in the bovine colostrums;it is the most important of bovine colostrums Growth Factor.In this study,the insulin-like growth factor-â… (IGF-â… )was separated and purified from bovine colostrums.Especially,the study focused on the optimization of pretreatment conditions in the separation to access high level of IGF-â… .Include the Skim Milk Preparation and the Whey Preparation,Removal of IGF-binding protein and Decompression Enrichment.Process the obtainning rude IGF-â… for ultrafiltration,and optimization the conditions of different pH and temperature.Pure the rude IGF-â… through Chromatography on Sephadex G-50,and improve the separation conditions.Purification effect was tested by SDS-PAGE in each process.The content of IGF-â… in each process was detected by radio-immunoassay(RIA).This study obtain the whole methods of separation and purification the insulin-like growth factor-â… (IGF-â… )in bovine colostrums.The content of IGF-â… in final isolates was 1915.56ng/ml, is approximately 114 times than in bovine colostrums.The yield of IGF-â… on final is 27.23%. Provide the basis for follow-up work to further purify with scale and high-level production of IGF-â… in the future.