title: Crystallization and preliminary X-ray diffraction analysis of a Lys49-phospholipase A2 complexed with caffeic acid, a molecule with inhibitory properties against snake venoms.
abstract: Phospholipases A(2) (PLA(2)s) are one of the main components of bothropic venoms; in addition to their phospholipid hydrolysis action, they are involved in a wide spectrum of pharmacological activities, including neurotoxicity, myotoxicity and cardiotoxicity. Caffeic acid is an inhibitor that is present in several plants and is employed for the treatment of ophidian envenomations in the folk medicine of many developing countries; as bothropic snake bites are not efficiently neutralized by conventional serum therapy, it may be useful as an antivenom. In this work, the cocrystallization and preliminary X-ray diffraction analysis of the Lys49-PLA(2) piratoxin I from Bothrops pirajai venom in the presence of the inhibitor caffeic acid (CA) are reported. The crystals diffracted X-rays to 1.65 Å resolution and the structure was solved by molecular-replacement techniques. The electron-density map unambiguously indicated the presence of three CA molecules that interact with the C-terminus of the protein. This is the first time a ligand has been observed bound to this region and is in agreement with various experiments previously reported in the literature.
authors.affiliation: Departamento de Física e Biofísica, Instituto de Biociências, UNESP-Universidade Estadual Paulista, Botucatu-SP, Brazil.
authors.forename: Patrícia S
authors.initials: PS
authors.lastname: Shimabuku
authors.forename: Carlos A H
authors.initials: CA
authors.lastname: Fernandes
authors.forename: Angelo J
authors.initials: AJ
authors.lastname: Magro
authors.forename: Tássia R
authors.initials: TR
authors.lastname: Costa
authors.forename: Andreimar M
authors.initials: AM
authors.lastname: Soares
authors.forename: Marcos R M
authors.initials: MR
authors.lastname: Fontes
mesh_terms: D000818:Animals; D017837:Bothrops / Q000378:metabolism*; D002109:Caffeic Acids / Q000378:metabolism*; D003435:Crotalid Venoms / Q000737:chemistry*; D003460:Crystallization; D018360:Crystallography, X-Ray / Q000379:methods; D054501:Group II Phospholipases A2 / Q000737:chemistry*; D008024:Ligands; D008958:Models, Molecular; D010741:Phospholipases A / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding
chemical_list: D002109:Caffeic Acids; D003435:Crotalid Venoms; D008024:Ligands; D010741:Phospholipases A; D054501:Group II Phospholipases A2; C040048:caffeic acid