Background: For many decades, research on snake venom toxinology focused mainly on the
venoms of Viperidae and Elapidae species, which were traditionally the only ones considered as venomous.
However, much less interest has been given to the venom produced by opisthoglyphous colubrid
snakes, since they were typically considered of no clinical relevance.
Objective: The aim of this work is to perform a preliminary biochemical and venomic characterization
of the venom of the colubrid snake Phalotris lemniscatus, a species that has been responsible for two
relevant cases of envenomation in Uruguay.
Methods: We extracted venom from collected specimens and performed different biochemical and proteomic
assays to understand its toxin composition.
Results: We found that the venom of P. lemniscatus is composed of protein families typically present in
snake venoms, such as metallo and serine preoteases, L-amino acid oxidases, phospholipases A2s, Ctype
lectines-like, Kunitz-type proteins and three-finger toxins. Activity assays demonstrated a highly
active gelatinolytic component as well as a potent capability to induce blood coagulation.
Conclusion: The results indicate that the venom of P. lemniscatus contains hemotoxic activities and
components that resemble those found in Viperidae (Bothrops) snakes and that can induce a clinically
relevant accident. Further studies are needed to better understand the venom composition of this colubrid
snake and its most active compounds.