Crystal structure of a phospholipase A(2) homolog complexed with p-bromophenacyl bromide reveals important structural changes associated with the inhibition of myotoxic activity

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Crystallization and preliminary X-ray diffraction analysis of crotoxin B from Crotalus durissus collilineatus venom

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Crystallization and preliminary X-ray crystallographic studies of a Lys49-phospholipase A(2) homologue from Bothrops pirajai venom complexed with rosmarinic acid

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Molecular cloning and biochemical characterization of a myotoxin inhibitor from Bothrops alternatus snake plasma

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Orpotrin: A novel vasoconstrictor peptide from the venom of the Brazilian Stingray Potamotrygon gr. orbignyi

Characterization of the peptide content of venoms has a number of potential benefits for basic research, clinical diagnosis, development of new therapeutic agents, and production of antiserum. In order to analyze in detail the peptides and small proteins of crude samples, techniques such as chromatography and mass spectrometry have been employed. The present study describes the isolation, biochemical characterization, and sequence determination of a novel peptide, named Orpotrin from the venom of Potamotrygon gr. orbignyi. The natural peptide was shown to be effective in microcirculatory environment causing a strong vasoconstriction. The peptide was fully sequenced by de novo amino acid sequencing with mass spectrometry and identified as the novel peptide. Its amino acid sequence, HGGYKPTDK, aligns only with creatine kinase residues 97-105, but has no similarity to any bioactive peptide. Therefore, possible production of this peptide from creatine kinase by limited proteolysis is discussed. Taken together, the results indicate the usefulness of this single-step approach for low molecular mass compounds in complex samples such as venoms. (c) 2006 Elsevier B.V. All rights reserved.

Anti-hemorrhagic Activity of Four Brazilian Vegetable Species Against Bothrops jararaca Venom

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Kinetics of venom and antivenom serum levels, clinical evaluation and therapeutic effectiveness in dogs inoculated with Crotalus durissus terrificus venom

This work evaluated the clinical and therapeutic aspects as well as serum levels of venom and antivenom IgG by enzyme-linked immunosorbent assay (ELISA) in experimental envenomation of dogs with Crotalus durissus terrificus venom. Twenty-eight mixed breed adult dogs were divided into four groups of seven animals each, Group I: only venom; Group II, venom + 50 ml of anti-bothropic-crotalic serum (50mg) + fluid therapy; Group III, venom + 50 ml of anti-bothropic-crotalic serum + fluid therapy + urine alkalination; Group IV, 50 ml of anti-bothropic-crotalic serum. The lyophilized venom of Crotalus durissus terrificus was reconstituted in saline solution and subcutaneously inoculated at the dose of 1mg/kg body weight. The dogs presented clinical signs of local pain, weakness, mandibular ptosis, mydriasis, emesis and salivation. The venom levels detected by ELISA ranged from 0 to 90ng/ml, according to the severity of the clinical signs. Serum antivenom ranged from 0 to 3ug/ml and was detected for up to 138h after treatment. ELISA results showed the effectiveness of the serum therapy for the venom neutralization.

Co-60 gamma irradiation prevents Bothrops jararacussu venom neurotoxicity and myotoxicity in isolated mouse neuromuscular junction

The ability of gamma radiation from Co-60 (2000 Gy) to attenuate the toxic effects of Bothrops jararacussu venom was investigated on mouse neuromuscular preparations in vitro. A comparative study between the effects of native and irradiated venoms was performed on both phrenic-diaphragm (PD) and extensor digitorum longus (EDL) preparations by means of myographic, biochemical and morphological techniques. Native venom (10 and 20 mug/ml) induced a concentration-dependent paralysis of both directly and indirectly evoked contractions on PD preparations. At 20 mug/ml, it also caused a pronounced myotoxic effect on the EDL muscle preparation that was characterized by an increase of creatine kinase release and by several morphological changes of this preparation. By contrast, irradiated venom, even at concentrations as high as 40 mug/ml, induced neither paralyzing nor myotoxic effects. It was concluded that Co-60 gamma radiation is able to abolish both the paralyzing and the myotoxic effects of B. jararacussu venom on the mouse neuromuscular junction. These findings support the hypothesis that gamma radiation could be an important toot to improve antisera production by reducing toxicity while preserving immunogenicity. (C) 2002 Elsevier B.V. Ltd. All rights reserved.

Natural history of the South American water snake Helicops leopardinus (Colubridae : Hydropsini) in the pantanal, Central Brazil

The South American water snake Helicops leopardinus is very abundant in the Pantanal wetlands of Central Brazil. We studied the biology of this species based on specimens collected by local workers in the Paraguay River. Females attained greater body lengths and had larger heads than males, but the latter had longer tails. Helicops leopardinus fed on a wide variety of fishes (70% of the total prey items) and frogs, with fishes of the order Gymnotiformes (33.34%) and frogs of the family Hylidae (23.34%) representing the most common prey items. There was relatively lows diet overlap between the sexes and between juveniles and adults. Mean litter size was 6.6 and ranged from 4-11. The reproductive cycle was seasonal, with birth occurring late in the wet season (simultaneous with the flooding of the Paraguay River), facilitating dispersal of young snakes by floating vegetation. Floating vegetation may be a critical habitat for H. leopardinus, and management plans for their maintenance need to be developed.

New record of Haplometroides intercaecalis (Digenea, Plagiorchiidae) infecting a Brazilian snake

Phalotris matogrossensis (Serpentes, Colubridae) was reported as a new host for Haplometroides intercaecalis ( Digenea, Plagiorchiidae). The host snake was obtained from the municipality of Anastacio, state of Mato Grosso do Sul, Brazil. One specimen of H. intercaecalis was recovered from the esophagus of the host and identified by the intercecal position of the vitellaria in the pre-acetabular region. This paper describes the second report of the occurrence of this trematode in fossorial snakes of the genus Phalotris in the state of Mato Grosso do Sul, Brazil.

Occurrence of Microcerella halli (Engel) (Diptera, Sarcophagidae) in snake carrion in southeastern Brazil

Occurrence of Microcerella halli (Engel) (Diptera, Sarcophagidae) in snake carrion in southeastern Brazil. The occurrence of 27 second-instar larvae of the flesh fly Microcerella halli (Engel, 1931) (Diptera, Sarcophagidae) in a carcass of a snake usually called as Urutu, Bothrops alternatus (Dumeril, Bibron & Dumeril, 1854) (Serpentes, Viperidae, Crotalinae) is reported. The snake was kept in captivity in a snake farm in Morungaba, São Paulo state, Brazil. Descriptions of reptile carcass colonization by insects and general biological data of this flesh fly are scarce and this necrophagic behavior is described for the first time in literature.

Natural history of the coral snake Micrurus Pyrrhocryptus Cope 1862 (Elapidae) from semideciduous forests of western Brazil.

Coral snakes in the genus Micrurus are widely distributed in the Neotropics, with more than 50 species already described in this region. They are primarily ground or leaf litter dwellers, feed on snakes or other elongate vertebrates, and tend to reproduce during the rainy season. We present data on the biology of Micrurus pyrrhocryptus from two semideciduous forests of Mato Grosso do Sul state, western Brazil. Two snake species were consumed: the dipsadid Sibynomorphus lavillai and the typhlopid Typhlops brongersmianus. Sexual dimorphism is marked in M. pyrrhocryptus. with males attaining larger sizes and having longer tails. Activity was concentrated in the wet season, when reproduction occurs. The defensive behavior in this species is similar to that displayed by other Micron's, although less pronounced.

Rhabdias filicaudalis n. sp. (Nematoda: Rhabdiasidae) from the snake Spilotes pullatus (Serpentes: Colubridae) in Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Comparative biochemical studies of myotoxic phospholipase A(2) from Bothrops venom

Venoms from Bothrops jararacussu, Bothrops asper, Bothrops atrox, Bothrops pirajai, Bothrops moojeni, Bothrops alternatus and Bothrops (Bothriopsis) bilineata were fractionated using a simplified procedure based on ion-exchange chromatography on CM-Sepharose at pH 8.0 or reverse phase HPLC. The resulting elution profiles showed important differences in the myotoxin content of these venoms. The venoms from B. alternatus, B. atrox and Bothriopsis bilineata did not contain the major myotoxin found in the other venoms. The amino acid sequence of the first 50 residues of the N-terminal region of the PLA(2)-like myotoxins showed a homology of 90-96% with other bothropic myotoxins. All of the myotoxins isolated induced rat paw edema, increased the level of plasma creatine kinase and produced myonecrosis together with polymorphonuclear cell infiltration.

Predation on the lizard Ameiva ameiva (Sauria: Teiidae) by a coral snake Micrurus frontalis (Serpentes: Elapidae) in Brazil.

We report a case of elapid predation on a lizard in Brazilian Savannah. A subterranean coral snake (Micrurus frontalis) was found preying a green lizard (Ameiva ameiva) in Southeastern Brazil.