Levels of persistent organic pollutants and residual pattern of DDTs in small cetaceans from the coast of São Paulo, Brazil

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

A new species of Pseudopaludicola Miranda-Ribeiro, 1926 (Anura: Leiuperidae) from the state of Mato Grosso, Brazil, with comments on the geographic distribution of Pseudopaludicola canga Giaretta & Kokubum, 2003.

A new species of Pseudopaludicola is described from the state of Mato Grosso, western Brazil. The new species inhabits the transition zone between Brazilian Cerrado and Amazon rainforest in northern Mato Grosso, and is characterized by its medium size (snout-vent length 12-17 mm), lack of T-shaped terminal phalanges, toe tips not expanded laterally, presence of two antebrachial tubercles, and smooth upper eyelids. The advertisement call of the new species consists of a series composed of 11-74 non-pulsed notes. Mean dominant frequency is 3938 Hz. Each note presents a slight ascendant frequency modulation in its first half, and another ascendant modulation in its last half. We also present new data on the distribution and conservation status of Pseudopaludicola canga.

Crystallization of bothrombin, a fibrinogen-converting serine protease isolated from the venom of Bothrops jararaca

Bothrombin, a snake-venom serine protease, specifically cleaves fibrinogen, releasing fibrinopeptide A to form non-crosslinked soft clots, aggregates platelets in the presence of exogeneous fibrinogen and activates blood coagulation factor VIII. Bothrombin shares high sequence homology with other snake-venom proteases such as batroxobin (94% identity), but only 30 and 34% identity with human alpha-thrombin and trypsin, respectively. Single crystals of bothrombin have been obtained and X-ray diffraction data have been collected at the Laboratorio Nacional de Luz Sincrotron to a resolution of 2.8 Angstrom. The crystals belong to the space group P2(1)2(1)2(1), with unit-cell parameters a = 94.81, b = 115.68, c = 155.97 Angstrom.

Purification, characterization and crystallization of Jararacussin-I, a fibrinogen-clotting enzyme isolated from the venom of Bothrops jararacussu

A fibrinogen-clotting enzyme, Jararacussin-I, was purified from the venom of Bothrops jararacussu by a combination of ion exchange chromatography using Resource 15S resin and affinity chromatography using Benzamidine Sepharose 6B resin. Jararacussin-I displays a molecular mass of 28 kDa as estimated by sodium dodecyl sulphate-PAGE and possesses an isoetectric point of 5.0. The coagulant specific activity of the enzyme was determined to be 45.8 NIH U/mg using bovine fibrinogen as the substrate and the esterase specific activity was determined to be 258.7 U/mg. The protease inhibitors, benzamidine and DTT inhibited the esterase specific activity by 72.4 and 69.7%, respectively. The optimal temperature and pH for the degradation of both chains of fibrinogen and esterase specific activity were determined to be 37 degreesC and 7.4-8.0, respectively. The enzyme was inactivated at both 4 and 75 T. Single crystals of Jararacussin-I were obtained and complete three-dimensional X-ray diffraction data was collected at the Brazilian National Synchrotron Source (LNLS) to a resolution of 2.4 Angstrom. (C) 2002 Published by Elsevier B.V. Ltd.

Initial structural analysis of an alpha(4)beta(4) C-type lectin from the venom of Crotalus durissus terrificus

Convulxin, an alphabeta C-type lectin, is a potent platelet activator isolated from the venom of the South American rattlesnake Crotalus durissus terrificus. It is a 26.5 kDa alphabeta heterodimer consisting of two homologous disulfide-linked chains. The crystals belong to space group I4, with unit-cell parameters a = b = 131.61, c = 121.85 Angstrom, and diffraction data were collected to 2.7 Angstrom. The structure was solved by molecular replacement and the asymmetric unit contains two alphabeta heterodimers, each of which forms a disulfide-linked cyclic alpha(4)beta(4) tetramer in the unit cell. These alpha(4)beta(4) tetramers are stacked to form a large solvent channel.

Crystallization and preliminary diffraction data of a platelet-aggregation inhibitor from the venom of Agkistrodon piscivorus piscivorus (North American water moccasin)

Applaggin (Agkistrodon piscivorus piscivorus platelet-aggregation inhibitor) is a potent inhibitor of blood platelet aggregation derived from the venom of the North American water moccasin, the protein consists of 71 amino acids, is rich in cysteines, contains the sequence-recognition site of adhesion proteins at positions 50-52 (Arg-Gly-Asp) and shares high sequence homology with other snake-venom disintegrins such as echistatin, kistrin and trigramin, Single crystals of applaggin have been grown and X-ray diffraction data have been collected to a resolution of 3.2 Angstrom. The crystals belong to space group P4(1)2(1)2 (or its enantiomorph), with unit-cell dimensions a = b = 63.35, c = 74.18 Angstrom and two molecules per asymmetric unit. Molecular replacement using models constructed from the NMR structures of echistatin and kistrin has not been successful in producing a trial structure for applaggin.

Amino acid sequence of a myotoxic Lys49-phospholipase A(2) homologue from the venom of Cerrophidion (Bothrops) godmani

The complete amino acid sequence of myotoxin II (godMT-II), a myotoxic phospholipase A( 2 )(PLA(2)) homologue from the venom of the Central American crotaline snake Cerrophidion (Bothrops) godmani, was determined by direct protein sequencing methods. GodMT-II is a class II PLA, showing a Lys instead of Asp at position 49. An additional substitution in the calcium binding loop region (Asn instead of Tyr at position 28) suggests the lack of enzymatic activity observed in this toxin is due to loss of its ability to bind the co-factor Ca2+, since the residues involved in forming the catalytic network of PLA(2)s (His-48, Tyr-52 and Asp-99) an conserved in godMT-II. This myotoxin shows highest sequence homology with other Lys-49 PLA(2)s from Bothrops, Agkistrodon and Trimeresurus species, suggesting that they constitute a conserved family of proteins, yet in contrast presents lower homology with Bothrops asper myotoxin III, a catalytically-active PLA(2). The C-terminal region of godMT-II, which is rich in cationic and hydrophobic residues, shares high sequence homology to the corresponding region in the myotoxin II from B. asper, which has been proposed to play an important role in the Ca2+-independent membrane damaging activity. (C) 1998 Elsevier B.V. B.V. All rights reserved.

Structure of a Lys49 phospholipase A(2) homologue isolated from the venom of Bothrops nummifer (jumping viper)

Lys49-Phospholipase A(2) (Lys49-PLA(2)) homologues damage membranes by a Ca2+-independent mechanism which does not involve catalytic activity, We have solved the structure of myotoxin-I, a Lys49-PLA(2) homologue isolated from the venom of Bothrops nummifer (jumping viper) at 2.4 Angstrom resolution using molecular replacement techniques. The final model has been refined to a final R-factor of 18.4% (R-free = 23.2%), and shows excellent geometry, the myotoxin-I from Bothrops nummifer is dimeric in the crystalline state as has been observed for other Lys49-PLA(2) homologues. In addition, a continuous electron density in the active site and substrate binding channel could be successfully modeled as a fatty-acid molecule. (C) 1999 Elsevier B.V. Ltd, All rights reserved.

Crystal structure of the platelet activator convulxin, a disulfide-linked alpha(4)beta(4) cyclic tetramer from the venom of Crotalus durissus terrificus

Convulxin (CVX), a C-type lectin, isolated from the venom of the South American rattlesnake Crotalus durissus terrificus, causes cardiovascular and respiratory disturbances and is a potent platelet activator which hinds to platelet glycoprotein GPVI. The structure of CVX has been solved at 2.4 Angstrom resolution to a crystallographic residual of 18.6% (R-free =26.4%). CVX is a disulfide linked heterodimer consisting of homologous alpha and beta chains. The heterodimers are additionally linked by disulfide bridges to form cyclic alpha(4)beta(4)heterotetramers. These domains exhibit significant homology to the carbohydrate-binding domains of C-type lectins, to the factor IX-binding protein (IX-bp), and to flavocetin-A (Fl-A) but sequence and Structural differences are observed in both the domains in the putative Ca2+ and carbohydrate binding regions. (C) 2003 Elsevier B.V. All rights reserved.

Crystallization of the Lys49 PLA(2) homologue, myotoxin II, from the venom of Atropoides nummifer

Myotoxin H, a Lys49 catalytically inactive phospholipase A(2) homologue from Atropoides nummifer venom, was purified, characterized and crystallized. The crystals belongs to the tetragonal system, space group P4(3)2(1)2, with unit cell parameters (a=b=68.66 and c=63.87 Angstrom). Diffraction data were collected to a resolution of 2.32 Angstrom. The crystal structure is currently being determined using molecular replacement techniques. (C) 2004 Elsevier B.V. All rights reserved.

Purification, biochemical and functional characterization of miliin, a new thiol-dependent serine protease isolated from the latex of Euphorbia milii

Miliin, a new thiol-dependent serine protease purified from the latex of Euphorbia milii possesses a molecular weight of 79 kDa, an isoelectric point of 4.3 and is optimally active at 60 degrees C in the pH range of and 7.5-11.0. Activity tests indicate that milliin is a thiol-dependent serine protease.

Crystal Structure of Bucain, a Three-Fingered Toxin from the Venom of the Malayan Krait (Bungarus candidus)

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

Purification, crystallization and preliminary X-ray diffraction analysis of a class P-III metalloproteinase (BmMP-III) from the venom of Bothrops moojeni

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Two new species of phytoseiid mites (Acari: Phytoseiidae) from the State of São Paulo, Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

A new genus of dipnoiformes from the Cretaceous of Brazil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)