[32P]ADP-ribosylation of proteins catalyzed by cholera toxin and related heat-labile enterotoxins.

摘要: Publisher Summary This chapter describes the [32P] adenosine di phosphate (ADP)-ribosylation of proteins catalyzed by cholera toxin and related heat-labile enterotoxins. Cholera enterotoxins some enteric bacteria are multimeric that catalyze identical ADP-ribosylations form. The entire multimer (A5B) allows ADP-ribosylation to take place inside whole cells but for work with cell fractions its fragment A1 is required this must be separated from rest molecule. A2 reduction linking disulfide. Its activity increased further presence sodium dodecyl sulfate (SDS) separates noncovalent association other components probably also prevents aggregation. most sensitive assay involves measuring rise in adenylate cyclase as a consequence ADP-ribosylation. It evident these enzymes not active intact they vitro, neither natural inhibitory mechanism nor sufficiently selective artificial inhibitor has been identified.