Exotoxins are secreted products, usually of bacteria but sometimes protozoa and fungi. They can act in a number of ways:
• Inhibition of protein synthesis. Corynebacterium diphtheriae, the cause of diphtheria, produces a toxin that causes ADP-ribosylation elongation factor-2, thereby stopping protein synthesis. It is extremely potent and one molecule of toxin is capable of killing a cell. Escherichia coli, Vibrio cholerae and Bordatella pertussis (the cause of whooping cough) also produce toxins that cause ADP-ribosylation of proteins. (more…)
