Structural highlights
Function
PA2B5_NOTSC Snake venom phospholipase A2 (PLA2) that inhibits neuromuscular transmission by blocking acetylcholine release from the nerve termini. Notechis II-5 is less toxic than notexin but has a higher specific phospholipase activity. PLA2 catalyzes the calcium-dependent hydrolysis of the 2-acyl groups in 3-sn-phosphoglycerides.
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
The three-dimensional structures of the class II anticoagulant phospholipase A2 (PLA2) toxin RVV-VD from the venom of Russell's viper, Vipera russelli russelli, and the class I neurotoxic PLA2 Notechis II-5 from the, Australian tiger snake, Notechis scutatus scutatus, were determined to 2.2 A and 3.0 A resolution, respectively. Both enzymes are monomeric and consist of 121 and 119 residues, respectively. A comparison of ten class I/II PLA2 structures showed, among other differences, that the beta-sheet of these enzymes (residues 76-83) is about 90 degrees less twisted in class I than in class II PLA2s. This, along with the insertion of some residues in the region 57-59 in class I enzymes (the elapid loop), could be the main reason for the significant difference in the anticoagulant and (presynaptic) neurotoxic properties between the two classes of PLA2. It seems apparent from sequence and structural comparisons that the toxic site of PLA2 responsible for the strong anticoagulancy of these toxins consists of a negatively charged part, Glu53, together with a positively charged ridge of lysine residues free for intermolecular interactions. These lysines differ between the two classes of PLA2.
The three-dimensional structures of two toxins from snake venom throw light on the anticoagulant and neurotoxic sites of phospholipase A2.,Carredano E, Westerlund B, Persson B, Saarinen M, Ramaswamy S, Eaker D, Eklund H Toxicon. 1998 Jan;36(1):75-92. PMID:9604284[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Carredano E, Westerlund B, Persson B, Saarinen M, Ramaswamy S, Eaker D, Eklund H. The three-dimensional structures of two toxins from snake venom throw light on the anticoagulant and neurotoxic sites of phospholipase A2. Toxicon. 1998 Jan;36(1):75-92. PMID:9604284
