Phospholipases A 2 (PLA 2 ) are a group of enzymes that hydrolyze phospholipids at the sn -2 position, being present in all nature. In venomous animals, these proteins assume a special role, being able to exert diverse pharmacological effects. In this work, authors identified a new isoform of PLA 2 in the venom of Porthidium hyoprora , which was isolated through sequential chromatographic steps and named PhTX-III. The enzyme was characterized biochemically and structurally. Structural studies using mass spectrometry confirmed an acidic secretory PLA 2 , family IIA, with molecular mass of 13,620.9Da and identification of 86% of its primary sequence. PhTX-III did not exhibit myotoxic, anticoagulant or antibacterial effects, often present in this class of enzymes. Although, it was capable of initiate inflammatory response, with local edema and release of cytokines IL-1α, IL-6 and TNF-α, probably due to mast cell degranulation. Highlights ? A new acidic PLA 2 was isolated from Porthidium hyoprora venom, named PhTX-III. ? The protein presented high sequential homology with other acidic PLA 2 . ? PhTX-III did not present many classic toxic effects of PLA 2 . ? PhTX-III caused inflammatory effects upon injection with elevated cytokines count. ? Inflammatory effects caused probably due to mast cell degranulation.
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