The amino acid sequences of many snake venom PLA2s and the crystal structure of a number of them have been reported. Such structural characterization has revealed a relatively high identity in many of their sequences and a conserved structural scaffold. Nevertheless, these enzymes display anmpressive array of pharmacological/toxicological activities which have originated through a process of ‘accelerated evolution’, particularly in residues located in the surface of these molecules (Nakashima et al., 1993; Kini and Chan, 1999). Venom PLA2s therefore represent an intriguing puzzle from the structure–function standpoint.