in membranes of cells which had been pretreated in vivo with pertussis toxin , the 40 kda band was no longer a substrate for either pertussis or cholera toxin in vitro , whereas in membranes from cholera-toxin-pretreated cells the 40 kda band was still a substrate for fresh cholera toxin in vitro and for pertussis toxin .
C0007603
membranes
C0007634
cells