ABSTRACT
This chapter deals with some basic aspects and hypotheses concerning the structure/function relationships of pardaxin. When applied in large doses and/or prolonged applications, to more restricted and specific interferences with membranal functions that are mediated by proteins such as ionic channels, carrier molecules, and membrane-bound enzymes. The vast majority of excitatory neurotoxic effect were reproduced by pardaxin--the toxin derived from the P. marmoratus secretion. This concerns the ichthyotoxic, hemolytic, and excitatory action on a nerve muscle preparation as well as the cytolytic, heart-cell-depolarizing, enzyme-blocking, and fish-gill-histopathologic activities. The concentration of pardaxin in the overall system was in the range of 0.2 - 0.3 µg/mL of medium. In this experiment the effect of pardaxin was compared with that of melittin--a low-molecular-weight, strongly basic and amphipatic protein derived from bee venom, well-known to interact hydrophobically with phospholipid bilayers and biologic membranes and to possess cytolytic activity.
