Snake venom Lys49 myotoxins: from phospholipases A2 to non-enzymatic membrane disruptors
artículo original
Fecha
2012-09Autor
Lomonte, Bruno
Rangel Hasbún, José Andrés
Metadatos
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Snake venoms often contain toxins that cause a rapid necrosis of skeletal muscle fibers,
referred to as myotoxins. The most common among them are phospholipases A2 (PLA2s),
enzymes that have two independent evolutionary origins in snake venoms. Within the
group II PLA2s found in viperid venoms, a particular subgroup emerged, in which the
otherwise conserved Asp49 of their catalytic center is replaced by Lys49. These intriguing
proteins, referred to as Lys49 myotoxins, lost the ability to catalyze phospholipid hydrolysis,
but still induce myonecrosis by a non-enzymatic mechanism based on membrane
permeabilization as the critical event. Such mechanism is only partially understood. This
review briefly describes the general structural and functional characteristics of the Lys49
myotoxins, and summarizes four proposed models of their functional “toxic site”. Finally, it
discusses some novel insights into their mode of action, in particular examining arguments
and experimental observations that could shed light on the possible nature of their
membrane target on skeletal muscle cells, which remains elusive.
External link to the item
10.1016/j.toxicon.2012.02.007Colecciones
- Microbiología [1171]