title: Purification, sequencing and structural characterization of the phospholipase A1 from the venom of the social wasp Polybia paulista (Hymenoptera, Vespidae).
abstract: The biochemical and functional characterization of wasp venom toxins is an important prerequisite for the development of new tools both for the therapy of the toxic reactions due to envenomation caused by multiple stinging accidents and also for the diagnosis and therapy of allergic reactions caused by this type of venom. PLA(1) was purified from the venom of the neotropical social wasp Polybia paulista by using molecular exclusion and cation exchange chromatographies; its amino acid sequence was determined by using automated Edman degradation and compared to the sequences of other vespid venom PLA(1)'s. The enzyme exists as a 33,961.40 Da protein, which was identified as a lipase of the GX class, liprotein lipase superfamily, pancreatic lipases (ab20.3) homologous family and RP2 sub-group of phospholipase. P. paulista PLA(1) is 53-82% identical to the phospholipases from wasp species from Northern Hemisphere. The use restrained-based modeling permitted to describe the 3-D structure of the enzyme, revealing that its molecule presents 23% alpha-helix, 28% beta-sheet and 49% coil. The protein structure has the alpha/beta fold common to many lipases; the core consists of a tightly packed beta-sheet constituted of six-stranded parallel and one anti-parallel beta-strand, surrounded by four alpha-helices. P. paulista PLA(1) exhibits direct hemolytic action against washed red blood cells with activity similar to the Cobra cardiotoxin from Naja naja atra. In addition to this, PLA(1) was immunoreactive to specific IgE from the sera of P. paulista-sensitive patients.
authors.affiliation: Department of Biology, Institute of Biosciences of Rio Claro, Center of the Study of Social Insects, University of São Paulo State (UNESP), Av. 24A no. 1515, Bela Vista, Rio Claro, SP CEP 13506-900, Brazil.
authors.forename: Lucilene D
authors.initials: LD
authors.lastname: Santos
authors.forename: Keity S
authors.initials: KS
authors.lastname: Santos
authors.forename: Bibiana M
authors.initials: BM
authors.lastname: de Souza
authors.forename: Helen A
authors.initials: HA
authors.lastname: Arcuri
authors.forename: Edécio
authors.initials: E
authors.lastname: Cunha-Neto
authors.forename: Fabio Morato
authors.initials: FM
authors.lastname: Castro
authors.forename: Jorge Elias
authors.initials: JE
authors.lastname: Kalil
authors.forename: Mario S
authors.initials: MS
authors.lastname: Palma
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D006801:Humans; D015151:Immunoblotting; D007073:Immunoglobulin E; D008958:Models, Molecular; D008969:Molecular Sequence Data; D054466:Phospholipases A1 / Q000737:chemistry* / Q000378:metabolism; D011487:Protein Conformation; D014862:Wasp Venoms / Q000201:enzymology*; D014863:Wasps / Q000201:enzymology*
chemical_list: D014862:Wasp Venoms; D007073:Immunoglobulin E; D054466:Phospholipases A1