1poa

INTERFACIAL CATALYSIS: THE MECHANISM OF PHOSPHOLIPASE A2

spinqualitylabelsall models 1poa, resolution 1.50Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1poa is a 1 chain structure with sequence from Naja atra. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.5Å Ligands: CA Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function PA2A1_NAJAT Snake venom phospholipase A2 (PLA2) that has high affinity for muscarinic acetylcholine receptors mAChRs (CHRM) and has the ability to activate them. In guinea-pig ileum, produces an onset and dose-dependent contraction. Has also weak anticoagulant 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 A chemical description of the action of phospholipase A2 (PLA2) can now be inferred with confidence from three high-resolution x-ray crystal structures. The first is the structure of the PLA2 from the venom of the Chinese cobra (Naja naja atra) in a complex with a phosphonate transition-state analogue. This enzyme is typical of a large, well-studied homologous family of PLA2S. The second is a similar complex with the evolutionarily distant bee-venom PLA2. The third structure is the uninhibited PLA2 from Chinese cobra venom. Despite the different molecular architectures of the cobra and bee-venom PLA2s, the transition-state analogue interacts in a nearly identical way with the catalytic machinery of both enzymes. The disposition of the fatty-acid side chains suggests a common access route of the substrate from its position in the lipid aggregate to its productive interaction with the active site. Comparison of the cobra-venom complex with the uninhibited enzyme indicates that optimal binding and catalysis at the lipid-water interface is due to facilitated substrate diffusion from the interfacial binding surface to the catalytic site rather than an allosteric change in the enzyme's structure. However, a second bound calcium ion changes its position upon the binding of the transition-state analogue, suggesting a mechanism for augmenting the critical electrophile. Interfacial catalysis: the mechanism of phospholipase A2.,Scott DL, White SP, Otwinowski Z, Yuan W, Gelb MH, Sigler PB Science. 1990 Dec 14;250(4987):1541-6. PMID:2274785 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Phospholipase A2 3D structures

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