Epitope Tag Antibodies
These antibodies are highly specific monoclonal and polyclonal antibodies to common epitope tags, including FLAG, GST, HA, His and Myc. The antibodies are all available with the option to be conjugated to an array of Alexa Fluor Dyes and enzymes.
This is a 15 residue biotin-acceptor peptide 1, GLNDIFEAQKIEWHE, that allows for biotinylation of the recombinant protein as biotin ligase catalyzes the linking of biotin to the Avi-Tag. The biotinylated tagged recombinant protein can be purified with Streptavidin Resin.
The Calmodulin Binding Protein tag is derived from muscle myosin ligh-chain kinase and is a 26 amino acid (~4kD) peptide, KRRWKKNFIAVSAANRFKKISSSGAL. The tag has high affinity for Calmodulin allowing tagged recombinant proteins to be purified with Calmodulin resin.
Disulfide bond oxidoreductase (DsbA) is the key enzyme of periplasmic oxidoreductive system. It facilitates correct disulfide bond formation via intra- and intermolecular catalysis. In biotechnological applications, target proteins having multiple disulfide bonds (enterokinase catalytic subunit, proinsulin) were fused at the C terminus of DsbA to enhance disulfide bond formation as well as stabilize unfolded target protein via its polypeptide binding site. (Malik A. 3 Biotech. 2016;6(1):44. doi:10.1007/s13205-016-0397-7)
These are 10-amino acids (epitope E2a: SSTSSDFRDR)- and 12 amino acids (epitope E2b: GVSSTSSDFRDR)-long peptides derived from the E2 protein of bovine papillomavirus type 1.
Fluorescent Protein Tags (GFP, eGFP, eCFP, RFP and eYFP-Tags)
These protein tags are fluorescent proteins that fluoresce as green (GFP, eGFP), cyan (CFP), red (RFP) and yellow (YFP). Tagging a recombinant protein with these tags allows its detection by fluorescent microscopy.
This epitope tag is an 8 amino acid peptide, DYKDDDDK (1012 Da). The small tag makes it idea for localization studies using antibodies against the tag. The recombinant protein can also be purified with antibodies against the tag.
This epitope tag represents amino acid residues, CEEEEYMPME, of middle T-antigen of mouse polyomavirus.
Glutathione S-Transferase (GST) tags are large (220 amino acids; 26kD) and can be used to purify tagged recombinant proteins on Glutathione Resin, due to the high affinity of GST for glutathione.
This tag is derived from the human influenze hemagglutinin (HA), a surface glycoprotein and consists of amino acids 98-106, YPYDVPDYA. Many recombinant proteins have been engineered to express the HA tag, which does not appear to interfere with the bioactivity or the biodistribution of the recombinant protein. This tag facilitates the detection, isolation, and purification of the protein of interest.
Also known as a polyhistidine tag is a string of histidine amino acids, typically 6 (4-10), placed at the N or C terminal of recombinant proteins. The His-Tag allows the purification of tagged recombinant proteins via immobilized metal affinity chromatography (IMAC).
This tag is a short 12 amino acid tag derived from Herpes Simplex Virus that can be engineered to the N or C terminus of recombinant proteins. THe amino acid sequence is SQPELAPEDPED.
The recognized KT3 epitope represents the amino acid sequence KPPTPPPEPET derived from the Simian Virus 40 (SV40) large T-antigen.
Luciferase from the firefly has become one of the more widely used reporter proteins for the study of gene expression. Luciferase catalyzes a bioluminescent reaction which requires the substrate luciferin as well as Mg2+ and ATP. Mixing these reagents with the cell extract containing luciferase, results in a flash of light that decays rapidly. This light can be detected by a luminometer. The total light emission is proportional to the luciferase activity of the sample.
The Maltose Binding Protein has been used as a protein tag as it is used to increae the solubility of recombinant proteins expressed in bacterial systems. In addition, the MBP-tag can be used for purification of recombinant proteins as it binds to amylose resins and can be eluted with maltose.
A polypeptide protein tag derived from the c-myc gene product and is a 10 amino acid (1202Da) peptide, EQKLISEEDL.
The Nano-tag is a new streptavidin-binding peptide for both the purification and the detection of Nano-tagged proteins. This peptide possesses nanomolar-affinity for streptavidin and therefore is termed Nano-tag. The nano-tags have two types, Nano-tag15 (MDVEAWLGARVPLVET) and Nano-tag9 (MDVEAWLGAR), which bind to streptavidin with dissociation constants of 4 nM and 17 nM, respectively
S-tag is the name of an oligopeptide derived from pancreatic ribonuclease A (RNase A). If RNase A is digested with subtilisin, a single peptide bond is cleaved, but the resulting two products remain weakly bound to each other and the protein, called ribonuclease S, remains active although each of the two products alone shows no enzymatic activity. The N-terminus of the original RNase A, also called S-peptide, consists of 20 amino acids KETAAAKFERQHMDS. S Tag antibody can recognize C-terminal, internal, and N-terminal S-tagged proteins.
S1 tag, with sequence NANNPDWDF, is derived from the hepatitis B virus preS1 region. S1 tag is widely used in various protein expression systems. This antibody can detect the over-expressed fusion proteins containing S1 epitope tag.
A synthetic peptide of eight amino acids (WSHPQFEK) that exhibits affinity towards Strep-Tactin®, a specifically engineered streptavidin.
T7 tag is an epitope tag composed of an 11-residue peptide (MASMTGGQQMG)encoded from the leader sequence of the T7 bacteriophage gene10, which encodes a T7 major capsid protein.
The TAP (Tandem Affinity Purification) method is an affinity purification method for the isolation of TAP-tagged proteins along with associated proteins. The TAP tag historically consists of a calmodulin binding peptide (CPB), a tobacco etch virus (TEV) protease cleavage site, and Protein A. However, additional tag combinations have been used with the TAP method including the combination of FLAG tags and HA tags.
Thioredoxin is a class of small redox proteins known to be present in all organisms. It plays a role in many important biological processes, including redox signaling. The thioredoxin (Trx) fusion E. coli expression system is available to offer soluble expression of normally insoluble or difficult to express proteins. It was reported that a number of mammalian cytokines and growth factors, when expressed as C-terminal trxA fusion proteins, stayed remarkably soluble in the E. coli cytoplasm under certain conditions.
The V5 epitope tag is derived from a small epitope (Pk) present on the P and V proteins of the paramyxovirus of simian virus 5 (SV5). The V5 tag antibody can be helpful in detecting the recombinant proteins, some of which include transmembrane and secreted proteins fusion protein. This V5-tag antibody is prepared by immunizing synthetic peptide GKPIPNPLLGLDST coupled to KLH.
The fusiogenic envelope G glycoprotein of the vesicular stomatitis virus (VSV-G) that has been used to pseudotype retrovirus and lentivirus vectors can be used alone as an efficient vehicle for gene transfer. The VSV-G epitope tag is commonly engineered onto the N- or C- terminus of a protein of interest so that the tagged protein can be analyzed and visualized using immunochemical methods.