New C. difficile proteins improve discovery and detection
May 14, 2014
What is Clostridium Difficile?
Clostridium difficile is the causative agent of antibiotic-associated diarrhea and pseudomembranous colitis. It produces two major exotoxins, Toxin A and Toxin B; however, about 10% of strains isolated from patients with colitis also contain genes, coding for a unique ADP-ribosylating toxin, CDT Binary Toxin. Additionally, Clostridium difficile produces and secretes a glutamate dehydrogenase (cdGDH).
List Labs offers four new products in the C. difficile family
New product offerings from List Labs cover other proteins produced concurrently with the exotoxins. These proteins are valuable as alternate markers allowing more sensitive or more accurate determination of C. difficile infections (CDI).
These new products, all related to C. difficile, will be of interest to diagnostic developers, vaccine manufacturers, as well as, to those doing research in infectious diseases. List Labs is notably offering antigens and antibodies for two C. difficile proteins which are present in C. difficile infections. These products add to our C. difficile reagents which also include the main virulence factors Toxin A and Toxin B, and the antibodies: Goat Anti-Toxin A, Chicken Anti-Toxin B and Chicken Anti-Toxin B.
The first two products are components of CDT Binary Toxin, an ADP-ribosyltransferase. This toxin is composed of two independently produced components, the enzymatic subunit A, CdtA, and the binding and translocation subunit B, CdtB, which mediates cell entry of CdtA. CDT Binary Toxin causes depolymerization of the actin cytoskeleton and formation of microtubule-based membrane protrusions,resulting in cell rounding and cell death, and it is suggested to be involved in enhanced bacterial adhesion and colonization of hypervirulent C. difficile strains. The cell surface receptor has been identified as lipolysis stimulated lipoprotein receptor (LSR).
CDT Binary Toxin, A Subunit (CDTa), Product # 157, is recombinantly expressed in E. coli and purified using affinity chromatography. The affinity tag has subsequently been cleaved from the protein prior to packaging. Binary toxin A subunit has been tested in an in vitro ADP-ribosylation assay. It is non-toxic and unable to penetrate cells in the absence of the B subunit binding and translocation domain. Expression and purification of the A subunit from a recombinant setting ensures that there is no possible contamination with the B subunit.
1) #157A, Binary Toxin from Clostridium difficile A Subunit 20 ug, price $350
CDT Binary Toxin, B Subunit (CDTb), Product # 158, is recombinantly expressed in E. coli, purified using affinity chromatography and the affinity tag cleaved. Prior to packaging, the B subunit is nicked with trypsin for activation. The B subunit of the Binary Toxin is non-toxic, and does not contain any enzymatic activity.
2) #158A, Binary Toxin from Clostridium difficile B Subunit 40 ug, price $350
The next products are chicken antibodies: Chicken Anti-CDT Binary B subunit antibodies, with and without biotin. Antibodies have been raised against C. difficile Binary Toxin B Subunit and affinity purified on an antigen column, Product # 758. These antibodies are suitable for use in Western Blot assays and ELISAs as an effective probe for C. difficile Binary Toxin B Subunit. Additionally, purified antibody has been labeled with biotin, Product # 759, providing antibodies for both capture and detection.
3) #758A, Anti – C. difficile Binary Toxin B Subunit (Chicken IgY) 0.1 mg, price $290
4) #759A, Biotinylated Anti – C. difficile Binary Toxin B Subunit (Chicken IgY) 0.1 mg, price $315
Use of CDT on subconfluent Caco-2 cells is described by Schwan et al, 2009. Toxin –induced cellular processes were observed on these cells after one hour treatment with CDT Binary Toxin, a mixture of 20 ng/ml of CDTa and 40 ng/ml of CDTb.
Use our new Citations Finder to see additional citations of how C. Difficile from List Labs has been used in research.
- Schwan C., Stecher B., Tzivelekidis T., van Ham M., Rohde M., Hardt WD., Wehland J., Aktories K., (2009) Clostridium difficile Toxin CDT Induces Formation of Microtubule-Based Protrusions and Increases Adherence of Bacteria. PLoS Pathog 5(10): e1000626. PMID: 19834554