A new C-type animal lectin isolated from Bothrops pirajai is responsible for the snake venom major effects in the isolated kidney

Crosstalk of Inflammation and Coagulation in Bothrops Snakebite Envenoming: Endogenous Signaling Pathways and Pathophysiology

Snakebite envenoming represents a major health problem in tropical and subtropical countries. Considering the elevated number of accidents and high morbidity and mortality rates, the World Health Organization reclassified this disease to category A of neglected diseases. In Latin America, Bothrops genus snakes are mainly responsible for snakebites in humans, whose pathophysiology is characterized by local and systemic inflammatory and degradative processes, triggering prothrombotic and hemorrhagic events, which lead to various complications, organ damage, tissue loss, amputations, and death. The activation of the multicellular blood system, hemostatic alterations, and activation of the inflammatory response are all well-documented in Bothrops envenomings. However, the interface between inflammation and coagulation is still a neglected issue in the toxinology field. Thromboinflammatory pathways can play a significant role in some of the major complications of snakebite envenoming, such as stroke, venous thromboembolism, and acute kidney injury. In addition to exacerbating inflammation and cell interactions that trigger vaso-occlusion, ischemia-reperfusion processes, and, eventually, organic damage and necrosis. In this review, we discuss the role of inflammatory pathways in modulating coagulation and inducing platelet and leukocyte activation, as well as the inflammatory production mediators and induction of innate immune responses, among other mechanisms that are altered by Bothrops venoms.

Heparin prevents the cytotoxic activity of Bothrops jararacussu and Apis mellifera venoms in renal cells

Envenomation by Bothrops snakes and Apis mellifera bee may imply systemic disorders which affect well-perfused organs such as kidneys, a process that can lead to acute renal failure. Nevertheless, there is scarce information regarding a direct renal cell effect and the putative antagonism by antivenoms. Here the cytotoxic effect of B. jararacussu and A. mellifera venoms was evaluated in the renal proximal tubule cell line LLC-PK1, as well as the antagonism of this effect by heparin. B. jararacussu venom showed significant cytotoxicity as assessed by LDH release and MTT reduction, with a sharp decline of the cell number after 180 min (>90% at 50 μg/mL). A. mellifera venom produced a much faster and potent cytotoxic activity, conferring almost no viable cells after 15 min at 25 μg/mL. Phase contrast microscopy revealed that while B. jararacussu venom induced a progressive loss of cell adhesion and detachment, A. mellifera venom promoted a rapid plasma membrane disruption and nuclear condensation suggestive of necrotic cell death. Pre-incubation of both venoms with heparin for 30 min significantly reduced cytotoxicity. Our results demonstrate direct toxicity of B. jararacussu and A. mellifera venoms toward renal cells but with distinct kinetics and cell pattern, suggesting different mechanisms of action. In addition, the antagonistic, cytoprotective effect of heparin ascribes such compound as a promising drug for preventing renal failure from envenomation.

A Transcriptomic Approach to the Recruitment of Venom Proteins in a Marine Annelid

The growing number of known venomous marine invertebrates indicates that chemical warfare plays an important role in adapting to diversified ecological niches, even though it remains unclear how toxins fit into the evolutionary history of these animals. Our case study, the Polychaeta Eulalia sp., is an intertidal predator that secretes toxins. Whole-transcriptome sequencing revealed proteinaceous toxins secreted by cells in the proboscis and delivered by mucus. Toxins and accompanying enzymes promote permeabilization, coagulation impairment and the blocking of the neuromuscular activity of prey upon which the worm feeds by sucking pieces of live flesh. The main neurotoxins ("phyllotoxins") were found to be cysteine-rich proteins, a class of substances ubiquitous among venomous animals. Some toxins were phylogenetically related to Polychaeta, Mollusca or more ancient groups, such as Cnidaria. Some toxins may have evolved from non-toxin homologs that were recruited without the reduction in molecular mass and increased specificity of other invertebrate toxins. By analyzing the phylogeny of toxin mixtures, we show that Polychaeta is uniquely positioned in the evolution of animal venoms. Indeed, the phylogenetic models of mixed or individual toxins do not follow the expected eumetazoan tree-of-life and highlight that the recruitment of gene products for a role in venom systems is complex.

Bothrops pauloensis snake venom-derived Asp-49 and Lys-49 phospholipases A2 mediates acute kidney injury by oxidative stress and release of inflammatory cytokines

The envenomation caused by the Bothrops pauloensis snake leads to severe local and systemic effects including acute kidney injury. In this study, we investigated the renal effects by phospholipases A2 (PLA2s), divided into two main subgroups, Asp-49 and Lys-49, isolated from the Bothrops pauloensis snake venom (BpV) in isolated rat kidney system. Both PLA2s (3 μg/mL), added alone to the perfusion system and analyzed for 120 min, had significant effects on isolated rat kidney. Asp-49 reduced Glomerular Filtration Rate (GFR) at 60, 90 and 120 min, and the percentage of total tubular sodium transport (%TNa⁺) and potassium transport (%TK⁺) at 120 min. Lys-49 increased Perfusion Pressure (PP) at 120 min and reduced GFR, %TNa⁺ and the percentage of total tubular chloride transport (%TCl^-) at 60, 90 and 120 min. Cytokine release in the kidney tissues were increased with Asp-49 PLA2 (IL-10) and Lys-49 PLA2 (TNF-α, IL-1β, IL-10). Both increased MPO activity. Asp-49 PLA2 decreased Glutathione (GSH) and increased nitrite levels, while Lys-49 PLA2 increased Malondialdehyde (MDA), GSH and nitrite levels. Histological analysis of the perfused kidneys revealed the presence of glomerular degeneration and atrophy, deposit of proteinaceous material in Bowman's space and intratubular with both PLA2s. These findings indicated that both PLA2s modified the functional parameters in an isolated perfused kidney model with increased oxidative stress and cytokine release. PLA2s are one of the components at high concentration in BpV and our results provide important knowledge about their involvement with the nephrotoxic mechanism.

Comprehensive Proteome Reveals the Key Lethal Toxins in the Venom of Jellyfish Nemopilema nomurai

Jellyfish stings are a major threat to human beings in coastal areas of the world. Each year, hundreds of thousands of victims are stung by venomous jellyfish. Nemopilema nomurai is a dangerous species with a large number of victims including many deaths. N. nomurai venom is a complex cocktail that is rich in proteins and peptides, and it is secreted by nematocysts for prey or defense. Previous studies have identified hundreds of toxins in the venom of N. nomurai; however, it is unclear which toxin(s) is responsible for lethality. Herein, we isolated the lethal fraction (NnLF) from N. nomurai venom with multiple chromatography. NnLF showed strong lethality to mice, and the toxicology results were consistent with the clinical symptoms of dead patients after N. nomurai sting, which indicated that NnLF contained the key lethal toxins in the venom. Subsequently, proteomic analysis was performed to identify the toxins in NnLF, and a total of 13 toxin homologues were identified, including phospholipase, potassium channel inhibitor, hemolysin, thrombin, etc. Moreover, in vitro toxicity assays further verified the phospholipase A₂ and hemolytic activity of NnLF. These results revealed that cell membrane-targeted toxins, including channel-forming toxins, potassium channel inhibitors, and especially phospholipases, played very important roles in the lethality of N. nomurai sting. Moreover, blood toxins such as thrombin-like toxin and hemolysins might be synergistically involved in lethality. These findings advance the understanding of lethality caused by N. nomurai sting and will be significant for the development of drugs to treat this jellyfish sting in the future.

Effect of BjcuL, a lectin isolated from Bothrops jararacussu, on human peripheral blood mononuclear cells

BjcuL is a C-type lectin with specificity for the binding of β-d-galactose units isolated from Bothrops jararacussu venom. It triggers cellular infiltration in post capillary venules, increases edema and vascular permeability in murine models, contributes to in vitro neutrophil activation and modulates macrophage functional activation towards an M1 state. The purpose of this study was to investigate the effect of BjcuL on human peripheral blood mononuclear cells (PBMCs) activation with a focus on PBMCs proliferation and inflammatory mediators release. Results showed that BjcuL is not toxic to PBMCs, that BjcuL inhibits PBMCs proliferation and that it stimulates PBMCs to produce superoxide anion and hydrogen peroxide, primarily via lymphocyte stimulation, but does not stimulate the production of nitric oxide and PGE₂. These results demonstrate that BjcuL has an immunomodulatory effect on PBMCs. Further studies are needed to confirm the immunomodulatory effect of BjcuL, to elucidate the molecular mechanisms of action responsible for its effects and to determine its potential application as an immunopharmacological and biotechnological tool.

Snake venom galactoside-binding lectins: a structural and functional overview

Snake venom galactoside-binding lectins (SVgalLs) comprise a class of toxins capable of recognizing and interacting with terminal galactoside residues of glycans. In the past 35 years, since the first report on the purification of thrombolectin from Bothrops atrox snake venom, several SVgalLs from Viperidae and Elapidae snake families have been described, as has progressive improvement in the investigation of structural/functional aspects of these lectins. Moreover, the advances of techniques applied in protein-carbohydrate recognition have provided important approaches in order to screen for possible biological targets. The present review describes the efforts over the past 35 years to elucidate SVgalLs, highlighting their structure and carbohydrate recognition function involved in envenomation pathophysiology and potential biomedical applications.

L-Aminoacid Oxidase from Bothrops leucurus Venom Induces Nephrotoxicity via Apoptosis and Necrosis

Acute renal failure is a common complication caused by Bothrops viper envenomation. In this study, the nefrotoxicity of a main component of B. leucurus venom called L-aminoacid oxidase (LAAO-Bl) was evaluated by using tubular epithelial cell lines MDCK and HK-2 and perfused kidney from rats. LAAO-Bl exhibited cytotoxicity, inducing apoptosis and necrosis in MDCK and HK-2 cell lines in a concentration-dependent manner. MDCK apoptosis induction was accompanied by Ca2+ release from the endoplasmic reticulum, reactive oxygen species (ROS) generation and mitochondrial dysfunction with enhanced expression of Bax protein levels. LAAO-Bl induced caspase-3 and caspase-7 activation in both cell lines. LAAO-Bl (10 μg/mL) exerts significant effects on the isolated kidney perfusion increasing perfusion pressure and urinary flow and decreasing the glomerular filtration rate and sodium, potassium and chloride tubular transport. Taken together our results suggest that LAAO-Bl is responsible for the nephrotoxicity observed in the envenomation by snakebites. Moreover, the cytotoxic of LAAO-Bl to renal epithelial cells might be responsible, at least in part, for the nephrotoxicity observed in isolated kidney.

Galatrox is a C-type lectin in Bothrops atrox snake venom that selectively binds LacNAc-terminated glycans and can induce acute inflammation

Previous studies indicate that snake venom contains glycan-binding proteins (GBPs), although the binding specificity and biological activities of many of these GBPs is unclear. Here we report our studies on the glycan binding specificity and activities of galatrox, a Bothrops atrox snake venom-derived GBP. Glycan microarray analysis indicates that galatrox binds most strongly to glycans expressing N-acetyllactosamine (LacNAc), with a significant preference for Galβ1-4GlcNAcβ over Galβ1-3GlcNAcβ compounds. Galatrox also bound immobilized laminin, a LacNAc-dense extracellular matrix component, suggesting that this GBP can bind LacNAc-bearing glycoproteins. As several endogenous mammalian GBPs utilize a similar binding LacNAc binding preference to regulate neutrophil and monocyte activity, we hypothesized that galatrox may mediate B. atrox toxicity through regulation of leukocyte activity. Indeed, galatrox bound neutrophils and promoted leukocyte chemotaxis in a carbohydrate-dependent manner. Similarly, galatrox administration into the mouse peritoneal cavity induced significant neutrophil migration and the release of pro-inflammatory cytokines IL-1α and IL-6. Exposure of bone marrow-derived macrophages to galatrox induced generation of pro-inflammatory mediators IL-6, TNF-α, and keratinocyte-derived chemokine. This signaling by galatrox was mediated via its carbohydrate recognition domain by activation of the TLR4-mediated MyD88-dependent signaling pathway. These results indicate that galatrox has pro-inflammatory activity through its interaction with LacNAc-bearing glycans on neutrophils, macrophages and extracellular matrix proteins and induce the release of pro-inflammatory mediators.

Jellyfish venomics and venom gland transcriptomics analysis of Stomolophus meleagris to reveal the toxins associated with sting

Jellyfish Stomolophus meleagris is a very dangerous animal because of its strong toxicity. However, the composition of the venom is still unclear. Both proteomics and transcriptomics approaches were applied in present study to investigate the major components and their possible relationships to the sting. The proteomics of the venom from S. meleagris was conducted by tryptic digestion of the crude venom followed by RP-HPLC separation and MS/MS analysis of the tryptic peptides. The venom gland transcriptome was analyzed using a high-throughput Illumina sequencing platform HiSeq 2000 with de novo assembly. A total of 218 toxins were identified including C-type lectin, phospholipase A₂ (PLA₂), potassium channel inhibitor, protease inhibitor, metalloprotease, hemolysin and other toxins, most of which should be responsible for the sting. Among them, serine protease inhibitor, PLA₂, potassium channel inhibitor and metalloprotease are predominant, representing 28.44%, 21.56%, 16.06% and 15.14% of the identified venom proteins, respectively. Overall, our combined proteomics and transcriptomics approach provides a systematic overview of the toxins in the venom of jellyfish S. meleagris and it will be significant to understand the mechanism of the sting.

BIOLOGICAL SIGNIFICANCE

Jellyfish Stomolophus meleagris is a very dangerous animal because of its strong toxicity. It often bloomed in the coast of China in recent years and caused thousands of people stung and even deaths every year. However, the components which caused sting are still unknown yet. In addition, no study about the venomics of jellyfish S. meleagris has been reported. In the present study, both proteomics and transcriptomics approaches were applied to investigate the major components related to the sting. The result showed that major component included C-type lectin, phospholipase A₂, potassium channel inhibitor, protease inhibitor, metalloprotease, hemolysin and other toxins, which should be responsible for the effect of sting. This is the first research about the venomics of jellyfish S. meleagris. It will be significant to understand the mechanism of the biological effects and helpful to develop ways to deal with the sting.

Isolation and biochemical characterization of a new thrombin-like serine protease from Bothrops pirajai snake venom

This paper presents a novel serine protease (SP) isolated from Bothrops pirajai, a venomous snake found solely in Brazil that belongs to the Viperidae family. The identified SP, named BpirSP-39, was isolated by three chromatographic steps (size exclusion, bioaffinity, and reverse phase chromatographies). The molecular mass of BpirSP-39 was estimated by SDS-PAGE and confirmed by mass spectrometry (39,408.32 Da). The protein was able to form fibrin networks, which was not observed in the presence of serine protease inhibitors, such as phenylmethylsulfonyl fluoride (PMSF). Furthermore, BpirSP-39 presented considerable thermal stability and was apparently able to activate factor XIII of the blood coagulation cascade, unlike most serine proteases. BpirSP-39 was capable of hydrolyzing different chromogenic substrates tested (S-2222, S-2302, and S-2238) while Cu(2+) significantly diminished BspirSP-39 activity on the three tested substrates. The enzyme promoted platelet aggregation and also exhibited fibrinogenolytic, fibrinolytic, gelatinolytic, and amidolytic activities. The multiple alignment showed high sequence similarity to other thrombin-like enzymes from snake venoms. These results allow us to conclude that a new SP was isolated from Bothrops pirajai snake venom.

Isolation, functional, and partial biochemical characterization of galatrox, an acidic lectin from Bothrops atrox snake venom

Snake venom lectins have been studied in regard to their chemical structure and biological functions. However, little is known about lectins isolated from Bothrops atrox snake venom. We report here the isolation and partial functional and biochemical characterization of an acidic glycan-binding protein called galatrox from this venom. This lectin was purified by affinity chromatography using a lactosyl-sepharose column, and its homogeneity and molecular mass were evaluated by high-performance liquid chromatography, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry. The purified galatrox was homogeneous and characterized as an acidic protein (pI 5.2) with a monomeric and dimeric molecular mass of 16.2 and 32.5 kDa, respectively. Alignment of N-terminal and internal amino acid sequences of galatrox indicated that this protein exhibits high homology to other C-type snake venom lectins. Galatrox showed optimal hemagglutinating activity at a concentration of 100 μg/ml and this effect was drastically inhibited by lactose, ethylenediaminetetraacetic acid, and heating, which confirmed galatrox's lectin activity. While galatrox failed to induce the same level of paw edema or mast cell degranulation as B. atrox crude venom, galatrox did alter cellular viability, which suggested that galatrox might contribute to venom toxicity by directly inducing cell death.

Characterisation of a mannose-binding C-type lectin from Oxyuranus scutellatus snake venom

C-type lectins are calcium-dependent sugar binding proteins and are distributed ubiquitously amongst vertebrate organisms. As part of a wider study on Australian snake venom components, we have identified and characterised a C-type lectin from the venom of Oxyuranus scutellatus (Australian coastal taipan) with mannose-binding activity. This protein exhibited a subunit molecular mass of 15 kDa and was found to bind mannose and also bind to and agglutinate erythrocytes in a Ca(2+)-dependent manner. cDNA transcripts coding for C-lectin proteins were cloned and sequenced from six Australian elapid snake species and an antibody generated against the O. scutellatus mannose-binding C-lectin identified C-lectin proteins in the venom of 13 Australian elapid snakes by immunoblotting. Experimental evidence and molecular modelling also suggest that this protein exhibits a unique dimeric structure. This is the first confirmed example of a snake venom C-lectin with mannose-binding activity.

Induction of inflammatory cell accumulation by TM-N49 and promutoxin, two novel phospholipase A(2)

Local inflammation is a prominent characteristic of snakebite wound. Snake venom phospholipase A(2)s (PLA(2)s) are one of the main components which contribute to accumulation of inflammatory cells. We have isolated TM-N49 and promutoxin from Protobothrops mucrosquamatus venom and investigated their ability in induction of cell accumulation by using an in vivo mouse model. The results showed that both TM-N49 and promutoxin are potent stimuli for induction of neutrophil, lymphocyte, macrophage and eosinophil accumulation in the mouse peritoneum. The TM-N49- and promutoxin-induced inflammatory cell accumulation was inhibited by pretreatment of animals with cyproheptadine, terfenadine and Ginkgolide B, indicating that histamine and PAF is likely to contribute to the cells accumulation. Pre-injection of antibodies against adhesion molecules ICAM-1, CD18, CD11a and L-selectin showed that ICAM-1 is a key adhesion molecule of TM-N49- and promutoxin-induced lymphocyte, macrophage and eosinophil accumulation; CD18 and CD11a plays an important role in the migration of neutrophils, eosinophils and macrophages; and L-selectin is involved in the neutrophil and eosinophil accumulation. In conclusion, induction of inflammatory cell accumulation by TM-N49 and promutoxin confirms that group II PLA(2)s is pivotal stimulus for cell infiltration, through which they participate in the formation of snakebite inflammation.

Structure–function inferences based on molecular modeling, sequence-based methods and biological data analysis of snake venom lectins

Lectins are a structurally and functionally diverse group of proteins from different sources, capable to recognize and bind specifically carbohydrates. Several snake venoms contain calcium-dependent true lectins (SVLs) that recognize galactose. Herein, in order to enlighten some of the structure-function relationships of snake venom lectins (SVLs), we constructed theoretical models for 10 SVLs based on the Crotalus atrox lectin (CaL), the only SVL crystal structure available, and compared with other animal and plant lectins, and C-type lectin-like proteins (CLPs) that do not bind carbohydrates. Although these are theoretical structures, we could identify some SVL features, including: (i) a singular intrachain disulfide bond (Cys(38)-Cys(133)) that is not present in CLPs; (ii) a significant reorientation (39-41A) of the 80's loop position that folds back to the globular domain, assists the carbohydrate recognition domain (CRD), and orients the dimer formation, even in BfL-1 and BfL-2, which did not present the Cys(86) interchain; (iii) a CRD presenting a negative and concave surface that allows the interaction with the specific saccharide hydroxyl groups and calcium ion; (iv) the role of water molecules in some interchain interactions, similar to other animal and plant lectins; and (v) the inability of forming oligomers in contrast to CaL and some CLPs, such as convulxin.

Purification, characterization and cytokine release function of a novel Arg-49 phospholipase A(2) from the venom of Protobothrops mucrosquamatus

Group IIA phospholipase A(2) (PLA(2)) are major components in Viperidae/Crotalidae venom. In the present study, a novel PLA(2) named promutoxin with Arg at the site 49 has been purified from the venom of Protobothrops mucrosquamatus by chromatography. It consists of 122 amino acid residues with a molecular mass of 13,656 Da assessed by MALDI-TOF. It has the structural features of snake venom group IIA PLA(2)s, but has no PLA(2) enzymatic activity. Promutoxin shows higher amino acid sequence identity to the K49 PLA(2)s (72-95%) than to D49 PLA(2)s (52-58%). Promutoxin exhibits potent myotoxicity in the animal model with as little as 1 microg of promutoxin causing myonecrosis and myoedema in the gastrocnemius muscle of mice. Promutoxin is also able to stimulate the release of IL-12, TNFalpha, IL-6 and IL-1beta from human monocytes, and induce IL-2, TNFalpha and IL-6 release from T cells, indicating that this snake venom group IIA PLA(2) is actively involved in the inflammatory process in man caused by snake venom poisoning.

Simple affinity chromatographic procedure to purify β-galactoside binding lectins

Affinity chromatography based on the commercial resin Sepharose CL-6B was used to isolate new C1-beta-type lectins from crude preparations of snake venoms (Bothrops jararaca, Bothrops jararacussu, Bothrops newiedi, Bothrops moojeni, Lachesis muta rhombeata). Most of the C-type lectins could be eluted with almost 100% recovery using the competitor isopropyl-beta-D-thiogalactoside (IPTG) or through Ca2+ sequestration with EDTA. The lectin yield varied considerably among the different snake species, but B. newiedi venom was a particularly rich source of lectin, retaining 2.7 mg of lectin by milliliter of resin in saturating conditions. C1-alpha-lectins from Crotalus durisus terrificus venom, from the jack fruit (jacalin) and from bread fruit seeds extract (frutalin) had no affinity, either with or without Ca2+ added, for Sepharose CL-6B, showing that the resin is specific for C1-beta-type lectins. Sepharose CL-6B used as galactose-affinity chromatography provides a simple and fast method for isolating C-type beta-galactoside binding lectins from crude sample preparations.

Purification and biological effects of C-type lectin isolated from Bothrops insularis venom

Bothrops insularis is a snake from Queimada Grande Island, which is an island located about 20 miles away from the southeastern coast of Brazil. Compared to other Brazilian species of Bothrops, the toxinology of B. insularis is still poorly understood. Its C-type lectin is involved in several biological processes including anticoagulant and platelet-modulating activities. We purified the C-type lectin (BiLec) from Bothrops insularis venom and investigated its effect in the isolated kidney. BiLec was purified after two chromatographic steps; firstly, the whole venom was submitted to an HPLC molecular exclusion chromatography followed by a second purification through affinity chromatography. B. insularis lectin (BiLec) was studied as to its effect on the renal function of isolated perfused rat kidneys with the use of six Wistar rats. The concentration of 10mug/mL increased perfusion pressure (PP; control(60)=108.27+/-4.9; BiLec(60)=112.9+/-5.4 mmHg; *p<0.05) and renal vascular resistance (RVR; control(60)=5.38+/-0.51; BiLec(60)=6.01+/-0.57 mmHg; *p<0.05). The urinary flow reduced significantly at 90 and 120 min of perfusion (UF; control(120)=0.160+/-0.020; BiLec(120)=0.082+/-0.008 mL g(-1) min(-1); *p<0.05). Glomerular filtration rate (GFR; control(120)=0.697+/-0.084; BiLec(120)=0.394+/-0.063 mL g(-1) min(-1); *p<0.05) diminished only at 120 min. BiLec did not change the percentage of sodium (TNa(+)), potassium (TK(+)) and chloride tubular transport (TCl(-)). The histological alterations probably reflected direct injury on glomerular and tubular renal cells, as demonstrated by the rise in permeability of glomerular endothelial cells, revealed by the presence of a proteinaceous material in the Bowman space. We postulate that the C-type lectin B. insularis promoted its effects probably through interactions with endothelial cells or through the release of other mediators by tubular, mesangial and endothelial cells.

Biological activities of a lectin from Bothrops jararacussu snake venom

Snake venoms contain saccharide-binding lectins. In this work, we examined the biological activities of a lectin (BjcuL) purified from Bothrops jararacussu snake venom by chromatography on non-derivatized Sepharose 4B and Sephacryl S-200 HR. The protein, a homodimer with subunits of 14.5 kDa, gave a single immunoprecipitin line in immunoelectrophoresis and cross-reacted in ELISA with antivenoms raised against Bothrops spp. (lanceheads), Micrurus spp. (coral snakes), Crotalus durissus terrificus (South American rattlesnake), and arthropod (Loxosceles gaucho, Phoneutria nigriventer and Tityus serrulatus) venoms. BjcuL agglutinated human formaldehyde-fixed erythrocytes at > or = 100 ng/ml and was inhibited by lactose and EDTA (> or = 2 mM) and high concentrations (> 100 mM) of glucose and sucrose, but not by N-acetylglucosamine. BjcuL had no direct hemolytic activity and was devoid of esterase, PLA2 and proteolytic activities. The lectin (up to 200 microg/ml) did not aggregate human platelet-rich plasma (PRP) or washed platelets (WP), nor did it alter the aggregation induced by ADP in PRP or by thrombin in WP. When injected into mouse hind paws, BjcuL (10-100 microg/paw) caused edema and increased vascular permeability, with a maximum effect after 1h that persisted for up to 6 h (edema) or gradually decreased after the peak interval (vascular permeability). No hemorrhage was observed in BjcuL-injected paws. In anesthetized rats, B. jararacussu venom (200 microg/kg, i.v.) produced sustained hypotension (maximum decrease of approximately 60%) whereas a similar dose of BjcuL decreased the blood pressure by approximately 15%, with a rapid return to the resting level.