ABSTRACT
The clostridia are some of the most prolific producers of proteins that are able to act on eukaryotic cell membranes. Many of these proteins have served as prototypic molecules for basic studies on the modes of action, structures, and roles in disease of bacterial toxins. For example, pioneering work with the Clostridium perfringens α-toxin in the 1940s [1] showed for the first time that a bacterial toxin could also have an enzymatic mode of action (in this case a phospholipase C activity). However, while some clostridial toxins have been well characterized over the past 50 years, the basis of toxicity of others is only poorly understood, and it seems likely that there are membrane active toxins still awaiting discovery. This duality of an increasingly detailed knowledge of some toxins, and a lack of understanding of many others, make this field one that is both at the leading edge and still maturing. In this chapter, the properties of a range of membrane active toxins produced by the clostridia are reviewed. It is hoped that this will provide a basis for future studies by researchers.
