Tryptophan as a Functional Replacement for ADP-ribose-arginine in Recombinant Proteins
Bacterial toxins such as cholera toxin and diphtheria toxin catalyze the ADP-ribosylation of important cellular target proteins in their human hosts, thereby, as in the case of cholera toxin, irreversibly activating adenylyl cyclase. In this reaction, the toxin transfers the ADP-ribose moiety of Nicotinamide Adenine Dinucleotide (NAD) to an acceptor amino acid in a protein or peptide. ADP-ribosylation leads to a peptide/protein with altered biochemical or pharmacological properties. Mammalians proteins catalyze reactions similar to the bacterial toxins.