Biological Activities of the Amanita Peptide Toxins

Abstract

The amatoxins, phallotoxins, cycloamanides, and antamanide belong to the special class of secondary metabolites known as cyclic peptides or cyclopeptides – strings of amino acids in which the N and C termini are joined head-to-tail by amide (peptide) bonds (Chap. 2). Cyclic peptides possess many chemical attributes that contribute to high biological activity, including chemical stability, membrane permeability, and rigidity. The importance of these attributes is discussed in more detail in Chap. 7. The focus of this chapter is the specific biological activities of the characterized cyclic peptides of Amanita and other mushrooms. The majority of the studies have concerned the amatoxins, followed by the phallotoxins and, distantly, the other peptides. The organization of this chapter proceeds from the whole organism level to the intraorganismal level, concluding with toxin action at the molecular level.