Question

One of the ingredients present in the venom of Indian spectacled cobra, Naja naja is phospholipase A2(PLA2). We have discussed the site of action of PLA2 in a glycerophospholipid. PLA2 from cobra venom thus degrades the glycerophospholipids present in the cell membrane leading to cell lysis releasing its cytoplasmic contents.

a. Explain taking an example of any glycerophospholipid present in the cell membranes, how action of PLA2 brings out lysis

Answer 1

Phospholipase A2 hydrolyzes the bond between the second fatty acid and the glycerol molecule in a phospholipid molecule. As a result, the process leads to the release of arachidonic acid activating the recruitment of immune cells that activate the lysis of the host cells. Therefore, the effect of phospholipase A2 is mediated by arachidonic acid that activates cytotoxic immune cells (i.e., T killers) that stimulate cell lysis.