title: At the interface: crystal structures of phospholipases A2.
abstract: The protein content of many snake venoms often includes one or more phospholipases A2 (PLA2). In recent years a growing number of venoms from snakes of Agkistrodon, Bothrops and Trimeresurus species have been shown to contain a catalytically inactive PLA2-homologue in which the highly conserved aspartic acid at position 49 (Asp49) is substituted by lysine (Lys49). Although demonstrating little or no catalytic activity, these Lys49-PLA2s disrupt membranes by a Ca2+-independent mechanism of action. In addition, this family of PLA2s demonstrates myotoxic and cytolytic pharmacological activities, however the structural bases underlying these functional properties are poorly understood. Through the application of X-ray crystallography in combination with biophysical and bioinformatics techniques, we are studying structure/function relationships of Lys49-PLA2s. We here present results of a systematic X-ray crystallographic and amino acid sequence analysis study of Lys49 PLA2s and propose a model to explain the Ca2+-independent membrane damaging activity.
authors.affiliation: Department of Physics, IBILCE-UNESP, Sao Jose do Rio Preto SP, Brazil.
authors.forename: R J
authors.initials: RJ
authors.lastname: Ward
authors.forename: W F
authors.initials: WF
authors.lastname: de Azevedo
authors.forename: R K
authors.initials: RK
authors.lastname: Arni
mesh_terms: D017836:Agkistrodon; D000818:Animals; D017837:Bothrops; D002118:Calcium / Q000378:metabolism; D003435:Crotalid Venoms / Q000737:chemistry* / Q000201:enzymology; D018360:Crystallography, X-Ray; D019281:Dimerization; D008958:Models, Molecular; D010741:Phospholipases A / Q000737:chemistry* / Q000494:pharmacology; D054467:Phospholipases A2; D011487:Protein Conformation; D017421:Sequence Analysis; D017841:Trimeresurus
chemical_list: D003435:Crotalid Venoms; D010741:Phospholipases A; D054467:Phospholipases A2; D002118:Calcium