品名:List Labs Pertussis Toxin from B. pertussis, Lyophilized in Buffer
中文名:百日咳毒素
規格:50 ug
純度:>95%
形式:lyophilized powder
儲存溫度:2-8°C
描述:
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-S4Together 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.5 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.