Structural highlights
Function
[PA2B8_DABRR] Snake venom phospholipase A2 (PLA2) that shows weak neurotoxicity and medium anticoagulant effects by binding to factor Xa (F10) and inhibiting the prothrombinase activity (IC(50) is 130 nM) (PubMed:18062812). It also damages vital organs such as lung, liver and kidney, displays edema-inducing activities when injected into the foot pads of mice and induces necrosis of muscle cells when injected into the thigh muscle. Has a low enzymatic activity. PLA2 catalyzes the calcium-dependent hydrolysis of the 2-acyl groups in 3-sn-phosphoglycerides.[1] [2] [3]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
Type IIA secretory phospholipase A2 (PLA2) enzymes catalyze the hydrolysis of the sn-2 ester bond of glycerophospholipids to release fatty acids and lysophospholipids. In order to elucidate the role of PLA2 in inflammatory disorders and to determine the mode of binding of non-steroidal anti-inflammatory drugs (NSAIDs) to PLA2, the detailed three-dimensional structure of a complex formed between a group IIA PLA2 from Daboia russelli pulchella and 2-[(2,6-dichlorophenyl)amino]benzeneacetic acid (diclofenac) has been determined. The preformed complex was crystallized by equilibrating the protein solution against a mixture of 0.20 M ammonium sulfate and 30% PEG 4000. The crystals belong to space group P4(3), with unit-cell parameters a = b = 53.0, c = 48.4 A. The structure was solved by the molecular-replacement method and refined to R(cryst) and R(free) factors of 0.192 and 0.211, respectively, using reflections to 2.7 A resolution. The structure showed that diclofenac occupies a very favourable position in the centre of the substrate-binding hydrophobic channel that allows a number of intermolecular interactions. The binding mode of diclofenac involved crucial interactions with important residues for substrate recognition such as Asp49, His48 and Gly30. In addition, it included three new interactions involving its Cl atoms with Phe5, Ala18 and Tyr22. It also showed an extensive network of hydrophobic interactions involving almost all of the residues of the substrate-binding hydrophobic channel. The binding affinity of diclofenac was determined using surface plasmon resonance, which gave an equilibrium constant of 4.8 +/- 0.2 x 10(-8) M.
Specific binding of non-steroidal anti-inflammatory drugs (NSAIDs) to phospholipase A2: structure of the complex formed between phospholipase A2 and diclofenac at 2.7 A resolution.,Singh N, Jabeen T, Sharma S, Somvanshi RK, Dey S, Srinivasan A, Singh TP Acta Crystallogr D Biol Crystallogr. 2006 Apr;62(Pt 4):410-6. Epub 2006, Mar 18. PMID:16552142[4]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Faure G, Gowda VT, Maroun RC. Characterization of a human coagulation factor Xa-binding site on Viperidae snake venom phospholipases A2 by affinity binding studies and molecular bioinformatics. BMC Struct Biol. 2007 Dec 6;7:82. PMID:18062812 doi:http://dx.doi.org/10.1186/1472-6807-7-82
- ↑ Kasturi S, Rudrammaji LM, Gowda TV. Antibodies to a phospholipase A2 from Vipera russelli selectively neutralize venom neurotoxicity. Immunology. 1990 Jun;70(2):175-80. PMID:2115497
- ↑ Tsai IH, Lu PJ, Su JC. Two types of Russell's viper revealed by variation in phospholipases A2 from venom of the subspecies. Toxicon. 1996 Jan;34(1):99-109. PMID:8835338
- ↑ Singh N, Jabeen T, Sharma S, Somvanshi RK, Dey S, Srinivasan A, Singh TP. Specific binding of non-steroidal anti-inflammatory drugs (NSAIDs) to phospholipase A2: structure of the complex formed between phospholipase A2 and diclofenac at 2.7 A resolution. Acta Crystallogr D Biol Crystallogr. 2006 Apr;62(Pt 4):410-6. Epub 2006, Mar 18. PMID:16552142 doi:10.1107/S0907444906003660
