Exotoxin A is one of the toxic proteins released by pathogenic strains of Pseudomonas aeruginosa.
It is secreted as a proenzyme with a molecular weight of 66kD.
Like diphtheria toxin, exotoxin A is translocated into susceptible mammalian cells.
Covalent alteration of the molecule occurs, rendering it enzymatically active.
The intact toxin can be activated 20- to 50-fold in vitro by treatment with urea and dithiothreitol.
Exotoxin A catalyzes the transfer of the adenosine diphosphate ribose moiety of oxidized nicotinamide adenine dinucleotide onto elongation factor 2(3): NAD + EF-2 ® ADP-ribose-EF-2 + nicotinamide + H+.
This ADP-ribosylation of EF-2 blocks polypeptide assembly on the surface of the ribosome.
As a result, this molecule is cytopathic for a number of cultured cell lines and is toxic to animals.
Although exotoxin A and diphtheria toxin have identical enzymatic activity, they exhibit distinct target cell specificities and are immunologically unrelated.
In crude preparations or in purified material which has been stored, lower molecular weight peptides with ADP-ribosylating activity may be present.
Similarly, after reduction and limited proteolytic cleavage with chymotrypsin, a 26,000D fragment that has enzymatic activity may be separated.
This fragment alone is not toxic to intact cells.
Applications:Suitable for use in ELISA and Western Blot.
Other applications not tested.
Recommended Dilutions:Western Blot: 1:200,000Optimal dilutions to be determined by the researcher.
Titer:ELISA: The titer measures at mid-point was 1:178,000 using 2ug coating of Endotoxin A.
Storage and Stability:Lyophilized and reconstituted products are stable for 12 months after receipt at -20°C.
Reconstitute with sterile ddH2O.
Aliquot to avoid repeated freezing and thawing.
Store at -20°C.
For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap.
Further dilutions can be made in assay buffer.
仕様
Size：500ul
Host：goat
Grade：Serum
Purity：Serum.
Form：Supplied as a sterile-filtered lyophilized powder. Reconstitute with 500ul sterile ddH2O. Do not vortex.
Specificity：Recognizes Pseudomonas aeruginosa Exotoxin A.
