Small peptides, big world: biotechnological potential in neglected bioactive peptides from arthropod venoms

Until recently, a toxinologist's tasks involved the search for highly toxic or lethal toxins in animal venoms that could explain the harmful effects in clinically observed symptoms. Most of these toxins were put on evidence using a function to structure approach, in which a biological phenomena observation usually guided the isolation and characterization of the causative molecule. Paving this way, many toxins were promptly purified because of their readily observed effect. Nevertheless, small molecules with micro-effects that are not easily visualized can be relatively neglected or poorly studied. This situation has changed now with the advent of the sensitivity, resolution and accuracy of techniques such as mass spectrometry and proteomic approaches used in toxinology. Taking advantage of these methodologies, small peptides with 'newly exploited' biological activities such as vasoactive, hormone-like, antimicrobial and others have been recently given much more attention, enlarging the known repertoire of bioactive molecules found in animal venoms. This article aims to review current knowledge on small biologically active peptides (<3 kDa) found in arthropod venoms and discuss their potentialities as new drug candidates or therapeutic lead compounds.