Structure and function comparison of Micropechis ikaheka snake venom phospholipase A2 isoenzymesLok, S.M., Gao, R., Rouault, M., Lambeau, G., Gopalakrishnakone, P., Swaminathan, K.
(2005) FEBS J 272: 1211-1220
- PubMed: 15720395
- DOI: https://doi.org/10.1111/j.1742-4658.2005.04547.x
- Primary Citation of Related Structures:
1OZY, 1P7O, 1PWO
- PubMed Abstract:
Comparison of the crystal structures of three Micropechis ikaheka phospholipase A2 isoenzymes (MiPLA2, MiPLA3 and MiPLA4, which exhibit different levels of pharmacological effects) shows that their C-terminus (residues 110-124) is the most variable. M-Type receptor binding affinity of the isoenzymes has also been investigated and MiPLA4 binds to the rabbit M-type receptor with high affinity. Examination of surface charges of the isoenzymes reveals a trend of increase in positive charges with potency. The isoenzymes are shown to oligomerize in a concentration-dependent manner in a semi-denaturing gel. The C-termini of the medium (MiPLA4) and highly potent (MiPLA2) isoenzyme molecules cluster together, forming a highly exposed area. A BLAST search using the sequence of the most potent MiPLA2 results in high similarity to Staphylococcus aureus clotting factor A and cadherin 11. This might explain the myotoxicity, anticoagulant and hemoglobinuria effects of MiPLA2s.
Institute of Molecular and Cell Biology, Singapore.