Phospholipase A2

Phospholipase A2 (PLA2) is an enzyme which releases fatty acids from glycerol. It is found in mammals and in snake venoms. PLA2 releases arachidonic acid from membranes causing inflammation and pain. PLA2 from the snake Bothrops jararacussu is called bothropstoxin (BTX) and from Bothrops pirajai – piratoxin (PTX). The viperotoxin (VTX) is a heterodimer of very homologous PLA2 called RV-4/RV-7. The intracellular PLA2 – cystolic PLA2 (cPLA2) – are larger than the secreted PLA2 and contains the targeting C2 domain. The pro-phosphlipase (PPLA2) is a pancreatic PLA2 whose 7-mer N-terminal peptide is being cleaved off to produce the active PLA2. The PLA2 contains many isozymes which are ordered by groups and named accordingly, ie., group I is PLA2G1. The images at the left and at the right correspond to one representative PLA2, i.e. the crystal structure of Phospholipase A2 from Naja naja sagittifera (1yxh). For details on Lys49 snake-venom PLA2 see Anum-II. For PLA2 complex see Diclofenac binding to Phospholipase A2.

Crystal structure of porcine pancreatic phospholipase A₂ in complex with 2-methoxycyclohexa-2-5-diene-1,4-dione ^[1]

possesses anti-inflammatory activity. The binding of curcumin with PLA₂ was studied using X-ray crystallography. Since the electron density found in the active site did not match with curcumin, (the photo-degraded product of curcumin) in the unexplained electron density. To understand the , molecular docking studies was carried out. with respect to the ligand position and identified that of PLA₂ with a binding energy -16.81 Kcal/mol. The binding mode is in such a manner that it can prevent the entry of substrate to the hydrophobic active site. These studies indicate that curcumin can be act as an inhibitor to PLA₂.