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Virus proteins are useful!

Posted by Klaus Herick on Sep 23, 2020 1:25:29 PM

 

Parts of them are used as epitope tags

Epitope tags, i.e. short peptide tags are commonly used, versatile, and convenient tools for multiple capture and detection applications including immunofluorescence, immunoprecipitation, affinity purification, and Western blotting.

Among those epitope tags, several tags are from virus protein origin, because they likely have unique sequences. Hence, they might have less issues with cross reactivity of antibodies potentially detecting host cell protein background.

Below, an overview of peptide tags that are of virus origin is shown:

  • E2 tag / E2 epitope tag
    Applications: Detection and purification
    Sequence: SSTSSDFRDR
    Size: 10 AA, 1.2 kDa
    Tag location: N-, C-terminal or internal
    Origin: transactivator protein E2 of bovine papilloma-virus type-1

  • HA tag
    Applications: Purification and detection
    Sequence: YPYDVPDYA
    Size: 9 AA, 1.1 kDa
    Tag location: N-, C-terminal or internal
    Origin: amino acids 98–106 of the major surface protein glycoprotein hemagglutinin of influenza virus
    Comment: Not suitable for detection or purification of proteins from apoptotic cells because it is cleaved by Caspase-3 / Caspase-7

  • HSV tag
    Applications: Purification
    Sequence: QPELAPEDPED
    Size: 11 AA, 1.2 kDa
    Tag location: C-terminal
    Origin: aa 290–300 of glycoprotein D, a major surface protein of herpes simplex virus type 1 (HSV-1)

  • T7 tag
    Applications: Purification and increased expression
    Sequence: MASMTGGQQMG
    Size: 11 AA, 1.2 kDa
    Tag location: N-, C-terminal or internal
    Origin: N-terminal 11 residues of the major capsid protein gp 10 of T7 phage

  • VSV-G-tag
    Applications: Detection and purification
    Sequence: YTDIEMNRLGK
    Size: 11 AA, 1.3 kDa
    Tag location: C-terminal
    Origin: C terminal aa of virus envelope glycoprotein of vesicular stomatitis virus G

  • V5-tag
    Sequence: GKPIPNPLLGLDST
    Size: 14 AA, 1.4 kDa
    Tag location: N-, C-terminal or internal
    Origin: P and V proteins of Simian virus 5 (SV5) of the Rubulavirus genus in the Paramyxoviridae family

 

References

Kimple, M.E. et al (2013): Overview of Affinity Tags for Protein Purification
Curr Protoc Protein Sci. 2013; 73: Unit–9.9, DOI 10.1002/0471140864.ps0909s73
and references therein

Boriana Marintcheva, B. (2018) in Harnessing the Power of Viruses, chapter: Viral Tools for Protein Expression and Purification, Academic Press, DOI 10.1016/C2015-0-05654-4

Terpe, K. (2003): Overview of tag protein fusions: from molecular and biochemical fundamentals to commercial systems, Appl Microbiol Biotechnol. 60:523–533, DOI 10.1007/s00253-002-1158-6

Photo by CDC on Unsplash.

 

Topics: epitope tag

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