HA-tag Protein Expression and Purification Basics

HA-tag Basics

What is an HA-tag?

An HA-tag is derived from the human influenza hemagglutinin (HA) molecule corresponding to amino acids 98-106. It has been extensively used as a general epitope tag in expression vectors. The HA-tag does not appear to interfere with the bioactivity or the biodistribution of the recombinant HA-tagged protein.

What is the HA-tag peptide's nucleotide and amino acid sequence?

The HA tag's nucleotide sequence is: 5' TAC CCA TAC GAT GTT CCA GAT TAC GCT 3' or 5' TAT CCA TAT GAT GTT CCA GAT TAT GCT 3'

The HA tag's amino acid sequence is: YPYDVPDYA

What is the molecular weight of the HA-tag?

The molecular weight of the HA-tag (YPYDVPDYA-tag) peptide is 1102.15 Da.

HA-tagged Protein Purification

Why use an HA-tag for protein expression and production?

Adding an HA-tag to a protein's C- or N-terminus can facilitate its detection, isolation, and purification by HA-tag specific antibodies. Sino Biological has developed HA-tag specific antibodies for ELISA, Western Blotting, Immonofluorecence, and Immunoprecipitation detection of the HA-tagged protein. It can also be conjugated to agarose beads for HA-tagged protein affinity purification.

How do you purify HA-tagged proteins?

HA-tagged recombinant protein can be affinity purified directly from a cell culture lysate or supernatant. The HA-tagged protein binds to the HA-tag specific monoclonal antibody conjugated on an agarose gel. After washing away residual impurities, bound HA-tag proteins can be eluted off the affnity column by high concentration of the HA-tag peptide or by low pH buffer.

How do I cleave of the HA-tag after purification?

In some applications, it is desirable to remove the HA-tag, for example, for protein crystallization. To allow cleavage of the HA-tag, a protease cleavage site needs to be engineered between the tag and the protein. An EK cleavage site behind the HA-tag (HA-EK site-protein structure) can allow complete removal of the HA-tag and the cleavage site, leaving no additional amino acids after the specific cleavage of the HA-tag. For more information on the cleavage site and tag removal by EK and HRV-3C protease, please refer to: Enterokinase (EK), HRV-3C (human rhinovirus protease).

HA-tag Protein Production & Purification Service

Full services From gene cloning/synthesis to purified proteins
Host Cells Choices of expression hosts:
Transient transfection in HEK293 cells
Transient transfection in CHO cells
Stable expression in CHO cells
Yeast cell expression system
Insect cell/baculovirus expression system
E. coli. microbial expression system
HA Tag Design HA-tag (YPYDVPDYA-tag) at N- or C-terminus
Cleavage Site Option to design a cleavage site between the tag and protein
Selection of cleavage protease enzyme: Enterokinase (EK), HRV-3C (human rhinovirus protease), TEV
Purification HA (YPYDVPDYA) tag specific antibody conjugated affinity column
HA-tag affinity purification resin
Deliverable Purified recombinant proteins (quantities to be specified by customer)
Quality Specification typically >90% purity by SDS page
Typical Timeline 8-12 weeks

HA-tag (YPYDVPDYA-tag) has been widely used in recombinant protein expression and production. The HA-tag allows simple and efficient affinity purification of the tagged protein using HA-tag specific antibody conjugated to agarose-beads. The HA-tag (YPYDVPDYA-tag) also can be used for detection in western blot by using a HA-tag-specific antibody. HA-tag can be added to either C- or N-terminus of a protein for expression in virtually all expression systems.

Sino Biological has successfully produced many proteins with the HA-tag and purified with HA-tag affinity chromatography. We are highly experienced in designing the HA-tag according to the protein structure and handle any problems arising from protein purification process.

Sino Biological has also developed highly sensitive HA-tag (YPYDVPDYA -tag) specific antibodies for detection in western blot, ELISA assay, Immunofluorescence, and Immunoprecipitation. We have also developed our own HA-tag affinity purification resin. For more information on our HA-tag (YPYDVPDYA -tag) epitope antibodies, please refer to: Tag antibodies. The HA-tag antibodies can be purchased directly from our website.

Our track-records in the past years on the successful production of about 6,000 recombinant protein bulks and over 12,000 antibodies have attracted top-10 multi-national pharmaceutical customers as well as small biotech companies worldwide through word-of-mouth, as we have not done much business development or advertisement in the past. In addition, we are starting to promote our protein production services to all research institutions and companies worldwide, as we believe more customers can benefit greatly from our capacity and experience.

How do you submit a request for protein production service?

If you are interested in using our protein production services to support your antibody discovery and development program, please contact us by leaving an on-line message or send us your detailed request to CRO-service@sinobiological.com. Based on the quantity and quality requirement of your request, a formal quote will be send back to you for your review, comment, and/or acceptance.

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