INTERNAL LYSINE PALMITOYLATION IN ADENYLATE-CYCLASE TOXIN FROM BORDETELLA-PERTUSSIS

A number of bacterial protein toxins, including adenylate cyclase (AC) toxin from Bordetella pertussis, require the product of an accessory gene in order to express their biological activities. In this study, m ass spectrometry was used to demonstrate that activated, wild-type AC toxin was modified by amide-linked palmitoylation on the epsilon-amino group of lysine 983. This modification was absent from a mutant in wh ich the accessory gene had been disrupted. A synthetic palmitoylated p eptide corresponding to the tryptic fragment (glutamine 972 to arginin e 984) that contained the acylation blocked AC toxin-induced accumulat ion of adenosine 3',5'-monophosphate, whereas the nonacylated peptide had no effect.