Fusion of the peptide or protein which we called “tag” into the target protein can increase the expression level, solubility, folding, purification and detection of the recombinant protein. The affinity-tag systems always have the following features:
- One-step adsorption purification
- A minimal effect on tertiary structure and biological activity
- Easy and specific removal to produce the native protein
- Simple and accurate assay of the recombinant protein during purification
- Applicability to a number of different proteins
One strategy for large-scale production of recombinant proteins is to use small peptide labels that do not interfere with the fusion protein. The most commonly used small peptide tags are Flag, HA, His, Myc.
Creative Peptides can provide synthesis of the following peptide tags but are not limited to:
- Flag tag
Flag tag (DYKDDDDK) is a common, well-characterized hydrophilic tag. It is always used in conjunction with antibodies in protein pull-downs to study protein interactions. Flag tag can be incorporated on N-, C- or internal positions of the target protein.
- HA tag
HA tag (YPYDVPDYA) is derived from the human influenza hemagglutinin (HA) molecule corresponding to amino acids 98-106, and it is an ideal tag for co-IP and western blots, with small interference to the function of protein. HA tag has been extensively used as a general epitope tag in expression vectors.
- His tag
His tag (HHHHHH) is the most common affinity tag used to purify proteins. His-Tag purification tag combined with metal chelate affinity chromatography provides a powerful tool for the separation and purification of recombinant proteins.
- Myc tag
Myc tag (EQKLISEEDL) is a small, immunoreactive tag, and can be placed at the N- or C- terminus. Myc tag is a popular epitope tag for detecting the expression of recombinant proteins in yeast, bacteria, insect, and mammalian cell systems.
Creative Peptides has extensive experience in the preparation of peptide-tagged fusion proteins. In the process of tagged peptide synthesis, we are skilled in the use of various markers, and we have expressed and purified a number of peptide-tagged fusion proteins in bacterial, yeast and mammalian cells. If necessary, we can also use spacers to separate the tags from the peptide. Every step of peptide synthesis is subject to Creative Peptides’ stringent quality control. Typical delivery specifications include:
- HPLC chromatogram
- Mass spec analysis
- Synthesis report
- Certificate of Analyses
 Terpe, K. (2003). Overview of tag protein fusions: from molecular and biochemical fundamentals to commercial systems. Applied microbiology and biotechnology, 60(5), 523-533.