B. pertussis Pertussis Toxin Subunit, A Protomer

Nature

Native

Tag/Conjugate

Unconjugated

Alternative Names

Bordetella pertussis toxin

Format

Lyophilized power, sealed under vacuum

Preservative

None

Storage

Store at 4°C prior to reconstitution. This product may be frozen following reconstitution.

Reconstitution

Each vial, when reconstituted with 500 μl of sterile water, contains 10.0 μg of soluble protein in 10 mM tris, 0.1 mM Na2EDTA, 0.03% CHAPS at pH 8.0. Handle the product gently; do not vortex.

Antigen Description

Pertussis toxin (PTX) is produced by Bordetella pertussis, the bacterium responsible for whooping cough. Pertussis toxin is a multi-component protein composed of six non-covalently bound subunits ranging in molecular weight from approximately 9 to 28 kDa. These subunits are designated as S1, S2, S3, S4 and S5 and occur in native pertussis toxin in a ratio of 1:1:1:2:1, where the subunit S4 is present in two copies. The largest subunit S1, also called the A protomer, is responsible for the ADP-ribosyltransferase activity; the A protomer alone will transfer the ADP ribose from NAD+ to α subunits of G proteins of the class Gαi, Gαo or Gαt. The crystal structure of PTX reveals a pyramid-like shape with the A protomer situated on top of the S5 subunit which rests on two dimers, S2-S4 and S3-S4. Together the five subunit platform is called the B oligomer and under certain conditions PTX dissociates into just two parts, the enzymatic A protomer and the five subunit, binding complex, the B oligomer. This B oligomer allows PTX to enter most cells, attaching to glycan residues present on receptor proteins including TLR4 and glycoprotein Ib. After entering the cell via receptor-mediated endocytosis, PTX is transported retrogradely via the endosomal pathway and Golgi complex to the endoplasmic reticulum. A protomer is released from the toxin and translocates through the membrane of the endoplasmic reticulum where the toxin inactivates the target membrane-bound G proteins.