Active Recombinant C. difficile TcdA Protein, His-tagged

• Cat.No.: tcdA-03C
• Product Overview: Recombinant E. coli msyB (Thr2-Arg124) and C. difficile TcdA (Met1-Leu542, Arg184Asn) protein with a 6×His tag at C-terminus was expressed in E. coli.

Specification

• Species: C.difficile
• Source: E.coli
• Tag: His
• ProteinLength: 2-124;1-542 a.a.
• Description: Precursor of a cytotoxin that targets and disrupts the colonic epithelium, inducing the host inflammatory and innate immune responses and resulting in diarrhea and pseudomembranous colitis. TcdA and TcdB constitute the main toxins that mediate the pathology of C.difficile infection, an opportunistic pathogen that colonizes the colon when the normal gut microbiome is disrupted. Compared to TcdB, TcdA is less virulent and less important for inducing the host inflammatory and innate immune responses. This form constitutes the precursor of the toxin: it enters into host cells and mediates autoprocessing to release the active toxin (Glucosyltransferase TcdA) into the host cytosol. Targets colonic epithelia by binding to some receptor, and enters host cells via clathrin-mediated endocytosis. Binding to LDLR, as well as carbohydrates and sulfated glycosaminoglycans on host cells suface contribute to entry into cells. In contrast to TcdB, Frizzled receptors FZD1, FZD2 and FZD7 do not act as host receptors in the colonic epithelium for TcdA. Once entered into host cells, acidification in the endosome promotes the membrane insertion of the translocation region and formation of a pore, leading to translocation of the GT44 and peptidase C80 domains across the endosomal membrane. This activates the peptidase C80 domain and autocatalytic processing, releasing the N-terminal part (Glucosyltransferase TcdA), which constitutes the active part of the toxin, in the cytosol.
• Predicted N Terminal: Thr2 (msyB)
• Bio-activity: Measured by its ability to hydrolyze UDP-Glucose. The specific activity is > 15 pmol/min/μg, as measured under the described conditions.
• Molecular Mass: 79 kDa
• Endotoxin: < 1.0 EU/μg of the protein by the LAL method.
• Purity: > 90%, by SDS-PAGE visualized with Silver Staining and quantitative densitometry by Coomassie® Blue Staining.
• Storage: Use a manual defrost freezer and avoid repeated freeze-thaw cycles.
  6 months from date of receipt, -20 to -70 centigrade as supplied.
  3 months, -20 to -70 centigrade under sterile conditions after opening.
• Storage Buffer: Supplied as a 0.2 μm filtered solution in Tris, NaCl and Glycerol.
• Shipping: The product is shipped with polar packs.

Gene Information

• Gene Name: tcdA toxin A [ Clostridium difficile R20291 ]
• Official Symbol: tcdA
• Synonyms: tcdA; toxin A; toxin A
• Gene ID: 8470358
• Protein Refseq: YP_003217088
• UniProt ID: P16154