Study On Cytotoxic Activity Of Gln49-PLA₂ From Agkistrodon Blomhoffii Ussurensis Snake Venom

Gln49-PLA2 was purified and separated from Agkistrodon blomhoffii ussurensis snake venom. The molecular mass of protein was about 16 kDa, which showed myotoxicity and significant anticoagulant activity, but lacked the phospholipase A2 activity. The study of effect on cells growth and expression of proteins in cells showed that the protein possesed cytotoxity activity.The results of MTT on MCF-7, Hela, ECV-304, K562 and HL60 cells showed that Gln49-PLA2 possesed cytotoxity depending on time and dose;IC50 on K562 and MCF-7 cells were 13μmol/L and 1.2μmol/L.Under IC50, presence of K562 cell debris and MCF-7 detachment from wall of culture flask, which showed that Gln49-PLA2 inhibited growth of the cells and possessed cytotoxity activity.The results of LDH assey showed that Gln49-PLA2 induced leakage of lactate dehydrogenase in cells. Maximal apoptosis rates were about 20% and decrease of mitochondrial membrane potential affected by different concentrations of Gln49- PLA2 in K562 and MCF-7 cells. During the process of K562 apoptosis induced by Gln49-PLA2, there was not changement of Bcl-2 expression, which showed that Bcl-2 did not play important role on regulating K562 apoptosis;In MCF-7 cells, Bcl-2 expression decreased, Caspase-3 and Caspase-8 expression increased according to increasing dose of Gln49-PLA2, which indicated that this protein induced apoptosis of MCF-7 cells through Death Receptor Route and Mitochondrial Route.