Why are some proteins fused to tags? Do protein tags affect protein activity?

Most GenScript recombinant proteins are tag-free. Protein tags however, are useful for several different purposes.

1. Protein tags are useful for protein purification.

2. Tags are used for protein detection in Western blot or ELISA when the specific antibodies are not available.

3. The Fc tag stabilizes molecules, which may increase the half-life of the linked products. Since the Fc fragment tends to dimerize, it helps the linked protein, particularly receptors, to form biologically active dimers.

Protein tags may or may not affect the protein’s activity. For some applications, small tags, such as the His-tag, may not affect protein activity and do not need to be removed. For example, there are more than 100 structures of His-tagged proteins in the Protein Data Bank. This indicates that the small His-tag often does not interfere with correct protein folding. Additionally, tested activity results are listed on our protein web pages. If you have concerns about tags interfering with protein activity and there is no activity data online, please feel free to contact us for latest information at product@genscript.com .