Molecule of the Month: Phospholipase A2
Phospholipase A2 breaks membrane lipids, forming molecules that contribute to inflammation and pain signaling.
Small and Steady
Inside and Out
Exploring the Structure
Venom Phospholipase A2
Two venom phospholipases are shown here, one from bee venom (PDB entry 1poc) and one from cobra venom (1pob). The structures of these two enzymes are quite different, but they share a very similar collection of active site amino acids, including a histidine that attacks the lipid bond that is cleaved and an aspartate that coordinates the calcium ion. These structures have an analog of the phospholipid bound in the active site, showing how everything lines up to perform the reaction in these two different enzymes. To explore these structures in more detail, click on the image for an interactive Jmol.
Topics for Further Discussion
- Some forms of phospholipase A2 associate into larger assemblies, although it is not known if these have a biological function. Take a look at entry 1psh to see a trimeric form of cobra toxin.
- Structures of many types of phospholipase are available in the PDB archive, including some with trial inhibitors. Try searching for “Phospholipase A2” in the main PDB site.
November 2019, David Goodsellhttp://doi.org/10.2210/rcsb_pdb/mom_2019_11