Description_x000D_ General description_x000D_ Product is not activated. If activation is required, see Kaslow, et al., for suggested conditions._x000D_ Application_x000D_ The toxin is released from B. pertussis in an inactive form. When the pertussis toxin B oligomer binds to the cell membrane, the S1 subunit of its A protomer becomes activated, perhaps through the action of glutathione and ATP. A protocol for activating pertussis toxin in vitro is given by Kaslow, et al._x000D_ Biochem/physiol Actions_x000D_ Pertussis toxin catalyzes the ADP-ribosylation of the α subunits of the heterotrimeric guanine nucleotide regulatory proteins Gi, Go, and Gt. This prevents the G protein heterotrimers from interacting with receptors, thus blocking their coupling and activation. Since the Gα subunits remain in their GDP-bound, inactive state, they are unable to inactivate adenylyl cyclase or open K+ channels._x000D_ Features and Benefits_x000D_ This compound is a featured product for Cyclic Nucleotide research. Click here to discover more featured Cyclic Nucleotide products. Learn more about bioactive small molecules for other areas of research at sigma.com/discover-bsm._x000D_ This compound is featured on the G Proteins (Heterotrimeric) page of the Handbook of Receptor Classification and Signal Transduction. To browse other handbook pages, click here._x000D_ Physical form_x000D_ Lyophilized powder containing sodium chloride and sodium phosphate buffer salts