Clostridium difficile Toxin B

Native toxin B purified from C. difficile strain VPI10463 (toxinotype 0)

Inactivates Rho (and Rho family small GTPases). Causes disregulation of the actin cytoskeleton, cell rounding, cytotoxicity, and altered cellular signaling.

Clostridium difficile is a bacteria that causes antibiotic-associated pseudomembranous colitis. This bacterium produces two high molecular weight exotoxins, toxin A and B. Toxin B is more effective than toxin A in disrupting human colonic epithelium in vitro.

Clostridium difficile Toxin A and B, cation-dependent UDP-glucose glucosyltransferases, are cellular toxins that inactivate Rho (and Rho family small GTPases) through monoglucosylation of these family members. Effects of this monoglucosylation include disregulation of the actin cytoskeleton, cell rounding, cytotoxicity, and altered cellular signaling. Rho proteins are monoglucosylated by Toxin A and B using UDP-glucose as a cosubstrate. Rho, Rac and Cdc42 are included in the Rho subfamilies targeted by both toxins. Low molecular mass GTP-binding proteins that are not modified by Toxin A and B include Ras, Rab, Arf, or Ran subfamilies as well as heterotrimeric G proteins.

Inactivates Rho (and Rho family small GTPases). Causes disregulation of the actin cytoskeleton, cell rounding, cytotoxicity, and altered cellular signaling.

Toxin B is 100-1,000-fold more cytotoxic than toxin A in inducing rounding-up of cells and destruction of the actin cytoskeleton.

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Contents of the 50 μg SKU when reconstituted in 250 μL sterile distilled water will contain Toxin B at a concentration of approximately 0.2 mg/mL in 0.05 M Hepes, 0.15 M sodium chloride and 5% sucrose.

Contents of the 2 μg SKU when reconstituted in 100 μL sterile distilled water will contain Toxin B at a concentration of approximately 0.02 mg/mL in 0.05 M Hepes, 0.15 M sodium chloride and 5% sucrose.

After reconstitution, the reconstituted liquid can be frozen at -80 °C to -20 °C to extend stability to 1 year; however every freeze/thaw cycle wil cause increased aggregation. Avoid multiple freeze/thaw cycles and multiple temperature fluctuations.
Mixing: Swirl or pipette gently to mix. Vortexing may promote aggregation.