Protein as the main executor of lifeactivity, its function and biological function research gradually thorough.Sohow to separate and study a particular protein?The wide application of protein tagtechnology can effectively solve the problem of which many researchers ontorture.At present, some peptide and protein are widely used in a largeproduction of recombinant protein, fusionexpressionthem with purpose protein, inorder to protein expression, detection, tracer and purification.Such peptidesor proteins, named Protein tag. Such asMyC, His, GST, HA, etc. Tag antibody cancombined with the corresponding high specific fusion peptides or proteins, forprotein purification and analysis of the testing purpose protein.At present,the cloud cloning launched a series of protein tag antibodies, let you face calmlywith protein test.
First a brief introduction of seriesprotein tag.
HA protein tag.Tag sequenceYPYDVPDYA, whichfrom influenza virusred blood cells of lectin surface antigen determinant, 9 AA,small influence on exogenoustarget proteinspatial structure, easy to build intoa tag fusion protein to N or C terminal. Can be detected with Anti - HA antibodyand ELISA.
MYC protein tag.MYC protein tag is a smalllabel containing 11 AA sequence (Glu - Gln - Lys - Leu - IIe - Ser - Glu - Glu- Asp –Leu).This 11 amino acids as antigen epitope expressed in differentprotein framework but still can recognize its corresponding antibody.Myc taghas been successfully used in Western blot, immunoprecipitation and flowcytometry, can use to detect recombinant protein expression in target cell.
FLAG.Flag tag protein coded8 AA hydrophilicpeptide (DYKDDDDK), whilecarrier built Kozak sequencemade with Flag of fusionprotein expression in eukaryotic expression system is more efficient.
GST.Glutathione thioltransferase play animportant role in the process of detoxification, it is 26 KD.As GST highlysoluble, can increase soluble of foreign proteins, in addition GST fusionexpression system is widely applied in all kinds of fusion protein expression,can improve the expression quantity.GST tag protein can directly use reducedGlutathione agarose gel affinity resinfrom the bacteria pyrolysis liquidtopurify.And GST protein tags can elute under mild, modified condition, so keep proteinantigenicity and biological activity.But GST under degeneration will losecombinationability with glutathione resin, so can't adddenaturantin purification buffer,such as: guanidine hydrochloride or urea.
H6. His-Tag (HHHHHH), there are 6histidine, can be inserted at the end of the target protein C or N terminal.Dueto H6 small molecular weight, will not affect the function of the targetprotein, and can be purified under denature or nonionic surfactant condition, haveno space steric effect, often used in protein - protein, protein - DNAinteraction research.
Each protein tag has its advantages anddisadvantages, the specific choice depends on your application.
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