大黄鱼血清IgM的纯化及其特性分析

AbstractIgM is an important component of fish-specific immune system,which plays animportant role in fish response to exogenous stimuli and pathogen infection.Thispassage through collecting blood from tail vein of large yellow croaker culture,aftercentrifugation to obtain serum,use salting out saturated ammonium sulfate toextracted the serum IgM,and then using Protein A specific binding immunoglobulinmolecular homeostatic region,the crude extract was further purified by Protein Anucleophilic chromatography column.The purified protein after freeze-dringconcentration and suspension,the concentration of the purified protein used theBradford kit to determined,the result of concentration is about 0.5mg/ml.The purityand molecular weight of IgM was checked by SDS-PAGE,the obtained IgM showedobviously two main bands with the molecular weight of 70 kDa and 30 kDa,this isconsistent with the size of the heavy and light chains of fish IgM,indicating that theIgM obtained from purification is large yellow croaker;And the purified protein doesnot contain other bands,indicating the purity is high and does not contain impurities.In conclusion,The crude extraction of saturated ammonium sulfate combined withProtein A affinity purification can obtain A better purification effect of serum IgMfrom yellow croaker.Through characteristic analysis of IgM purified from the serumof Large yellow croaker will help to deepen the understanding of the immune systemof the yellow croaker.Key words:Large yellow croaker;Salting out;affinity chromatography;IgM