常见蛋白质标签总结培训资料

1、常见蛋白质标签总结http:/bbs.bio on.n et/bbs/home.php?mod=space&uid=34800&do=blog&id=38530常见蛋白质标签总结（Flag、HA、cMyc、CBP等）Prote in tags are peptide seque nces gen etically grafted onto a recomb inant prote in. Often these tags are removable by chemical age nts or by en zymatic means, such as proteolysis or intein

2、 splic ing. Tags are attached to prote ins for various purposes.一、氨基酸标签（含小肽标签）A stretch of ami no acids is added to the protein and en ables the recovery of the labelled protein by its unique affinity. Usually its easiest to add the tag to either end of the protein to ensure its accessibility and no

3、t to disturb the protein folding.1. 组氨酸标签（His tag）一般为6个组氨酸，用Ni2+ （Cu2+）亲和层析纯化2. FLAG tag : N-DYKDDDDK -C，recovered with specific antibody3. HA tag： an epitope derived from the In flue nza prote in haemaggluti nin（HA，禽流感病毒血凝素），e.g. N-YPYDVPDYA -C，recovery with an HA an tibody4. MYC tag： an epitope de

4、rived from the huma n proto-on coprote in MYC e.g.N-ILKKATAYIL -C, N-EQKLISEEDL -C，recovery with an MYC an tibody5.SBP tag： Streptavidin Bi ndi ng Peptide,链霉亲合素结合肽，38 ami no acid tag （MDEKTTGWRGGHVVEGLAGELEQLRARLEHHPQGQREP ）， 更多参考在Sigma6. CBP tag：钙调蛋白结合肽（CBP; 26ae）钙调蛋白结合肽与钙调素结合是Ca2+依赖的，这种结合不受标签所处的位置

5、影响（N端和C端均 可），在中性pH条件下使用2mM EGTA可以很方便的将目标蛋白洗 脱下来。这一系统有如下优点：1特异性很高，因为大肠杆菌没有可以 和钙调素结合的蛋白；2与His标签相比可以在强还原性条件下纯化。7. 纤维素结合肽（CBD）:能与纤维素介质特异性的结合，可以在温和的条件下洗脱（乙二醇或低盐条件），pET CBD载体含有纤维素结合肽（CBD）的序列，可方便构建。二、蛋白质标签Rather tha n addi ng on ly a few ami no acids a whole protein is fused to the protein to be purified o

6、r detected. The affin ity of the attached prote in en ables the recovery of the artificial fusion protein. As for the peptides, the protein tag is added to either end of the target protei n.1. GST tag： the small glutathione-S-transferase （GST; 26 kDa，recovery by affinity to substrate glutathione bou

7、nd to a column, e.g. glutathione sepharose2. MBP tag：麦芽糖结合蛋白(MBP; 40kDa)载体：pMAL3. IMPACT ： Intein-Mediated Purification with an affinity Chitin-binding Tag(几丁质结合肽)4. 硫氧还蛋白： Thioredox ins are prote ins that act as an tioxida nts by facilitati nthe reduct ion of other prote ins by cyste ine thiol-disu

8、lfide excha nge.5. Protein A : a 40-60 kDa MSCRAMM surface protein originally found in the.It binds withcell wall of the bacteria Staphylococcus aureus. It has found use in biochemical research because of its ability to bind immunoglobulins. It bind； prote ins from many of mammalia n species, most n

9、o tably IgGthe Fc regi on of immuno globuli ns through in teract ion with the heavy cha in.6. Protein A/G : a recomb inant fusi on protein that comb ines IgG bindingdoma ins of both Protein A and Protein G. Protein A/G contains four Fc bi nding doma ins from Protein A and two from Protein G, yieldi

10、ng a final mass of 50,460 dalt ons. The binding of Prote in A/G is less depe ndent upon pH than Protein A, but otherwise has the additive properties of Protein A an G. Prote in A/G binds to all subclasses of huma n IgG, making it useful for purify ing polycl onal or monoclonal IgG an tibodies whose

11、subclasses have not bee n determ in ed. In additi on, it binds to IgA, IgE, IgM and (to a lesser exte nt) IgD. Prote in A/G also binds to all subclasses of mouse IgG but doej not bind mouse IgA, IgM or serum albumi n.7. GFP :绿色荧光蛋白(GFP; 26.9 kDa) GFP and its variants are the mostcom monly used fluor

12、esce nee tags.三、化学标签biotin - streptavidin （生物素-链霉亲合素）linking amino acids, often lysines, to cofactor and vitamin biotin purification by tight binding to streptavid in-agarose or -beads.Streptavidi n is a 53,000 dalt on tetrameric protein purified from the bacterium Streptomyces avid in ii. It finds wide use in molecular biology through its extraord in arily stro ng affin ity for the vitamin biot in; the dissociati on con sta nt (Kd) of the biotin-streptavidin complex is on the order of 10-15 mol/L, ranking among one of the stron ge