Anti-PA anthrax mAbs [W1](MABL-2587)

MABL-2587

neutralizing, ELISA

Engineer antibody

Bacillus anthracis

W1

Recombinant Antibody

This antibody recognizes protective antigen (PA) of anthrax toxin. W1 antibody targets a conformational epitope formed by C-terminal amino acids 614–735 of PA (Chen et al., 2006; pmid: 16453257). W1 is thought to recognize the same neutralizing epitope as another anti-PA antibody W2 as they both competed with each other in binding to PA and have the same CDRs (Chen et al., 2006; pmid: 16453257). PA is a component of the anthrax toxin and binds to a receptor (ATR) in sensitive eukaryotic cells, thereby facilitating the translocation of the enzymatic toxin components, edema factor and lethal factor, across the target cell membrane.

protective antigen; PA; Anthrax toxins translocating protein; PA-83; PA83; anthrax toxin

P13423

The original scFv version of this antibody was isolated from a phage display library generated from immunized chimpanzees.

The original scFv version of this antibody was confirmed to strongly bind anthrax protective antigen (PA) via ElISA (Chen et al., 2006; pmid: 16453257). This format was further shown to inhibit the effects of anthrax toxin. To perform subsequent tests, W1 clone was turned into an IgG1 version. This format of W1 exhibited very potent neutralizing activity against PA in the the RAW264.7 cell-based in vitro assay (its neutralizing capabilities were 15-fold higher than of the popular murine anti-PA clone 14B7 (Chen et al., 2006; pmid: 16453257). Furthermore, W1 had one of the highest affinities against anthrax PA ever recorder (Kd = 4e-11 mol/L) (Chen et al., 2006; pmid: 16453257). Finally, IgG1 version of this antibody fully protected rats from anthrax toxin challenge even when the antibody had been injected 1 week before the toxin challenge, demonstrating its slow dissociation rate crucial in potential clinical use (Chen et al., 2006; pmid: 16453257). W1 can be also combined with anti-LF antibodies, such as LF11H to produce synergistic protective effect against the anthrax toxin (Chen et al., 2009; pmid: 19528217). This confirms that W1 antibody can be further researched as a potential therapeutic agent as PA entry inhibitor for use in the emergency prophylaxis against and treatment of anthrax as well as a post-exposure therapy (Manish et al., 2020; pmid: 32729741). This clone can be also potentially used in the development of protective therapies against bioterrorism and biological warfare where anthrax toxins have been used (Bouzianas, 2009; pmid: 19781945).

Chen et al. Efficient Neutralization of Anthrax Toxin by Chimpanzee Monoclonal Antibodies against Protective Antigen J Infect Dis. 2006 Mar 1; 193(5): 625–633. PMID:16453257

Describes the generation and characterization of anti-PA and anti-LF anthrax antibodies.

100 μg Purified antibody.

1 mg/ml.

Protein A affinity purified

PBS with 0.02% Proclin 300.

Store at 4⁰C for up to 3 months. For longer storage, aliquot and store at - 20⁰C.