Pertussis Toxin is a protein-based AB5-type exotoxin produced by the bacterium Bordetella pertussis, which causes whooping cough. Pertussis Toxin inhibits G protein-coupled receptor (GPR) signaling through Gi proteins[1][2][3].
CRM197 is a genetically detoxified diphtheria toxin. It is expressed as a soluble, correctly folded ~58kDa recombinant protein in the cytoplasm of E. coli and then produced to >99% purity.