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pulmonary mechanic and lung histology injury induced by crotalus durissus terrificus snake venom.in the present work we investigated the effects of crotalus durissus terrificus venom (cdtv) on the pulmonary mechanic events [static and dynamic elastance, resistive (deltap1) and viscoelastic pressures (deltap2)] and histology after intramuscular injection of saline solution (control) or venom (0.6 microg/g). the static and dynamic elastance values were increased significantly after 3 h of venom inoculation, but were reduced at control values in the other periods studied. the deltap1 values th ...200818457854
the venom of south american rattlesnakes inhibits macrophage functions and is endowed with anti-inflammatory properties.the injection of crotalus durissus terrificus venom into the foot pad of mice did not induce a significant inflammatory response as evaluated by oedema formation, increased vascular permeability and cell migration. the subcutaneous injection of the venom, or its addition to cell cultures, had an inhibitory effect on the spreading and phagocytosis of resident macrophages, without affecting the viability of the cells. this effect was not observed when the venom was added to cultures of thioglycoll ...199618475692
crotalphine, a novel potent analgesic peptide from the venom of the south american rattlesnake crotalus durissus terrificus.we have shown that the venom of the south american rattlesnake crotalus durissus terrificus induces a long-lasting antinociceptive effect mediated by activation of kappa- and delta-opioid receptors. despite being mediated by opioid receptors, prolonged treatment with the crotalid venom does not cause the development of peripheral tolerance or abstinence symptoms upon withdrawal. in the present study, we have isolated and chemically characterized a novel and potent antinociceptive peptide respons ...200818495297
biological and biochemical characterization of new basic phospholipase a(2) bmtx-i isolated from bothrops moojeni snake venom.bmtx-i, an asp49 phospholipase a(2), was purified from bothrops moojeni venom after only one chromatographic step using reverse-phase hplc on mu-bondapak c-18 column. a molecular mass of 14238.71da was determined by maldi-tof mass spectrometry. amino acid analysis showed a high content of hydrophobic and basic amino acids as well as 14 half-cysteine residues. the bmtx-i pla(2) had a sequence of 121 residues of amino acids: dlwqfnkmik kevgklpfpf ygaygcycgw ggrgekpkdg tdrccfvhdc cykkltgcpk wddrysy ...200818501940
antineurotoxic activity of galactia glaucescens against crotalus durissus terrificus venom.ethanolic extract of leaves of galactia glauscescens (gge) at concentration of 100 and 500 microg/ml prevented the neuromuscular paralysis induced by crotalus durissus terrificus venom on mouse phrenic nerve-diaphragm preparation.200818505705
modulation of the pharmacological effects of enzymatically-active pla2 by btl-2, an isolectin isolated from the bryothamnion triquetrum red alga.an interaction between lectins from marine algae and pla2 from rattlesnake was suggested some years ago. we, herein, studied the effects elicited by a small isolectin (btl-2), isolated from bryothamnion triquetrum, on the pharmacological and biological activities of a pla2 isolated from rattlesnake venom (crotalus durissus cascavella), to better understand the enzymatic and pharmacological mechanisms of the pla2 and its complex.200818534036
anti-snake venom properties of schizolobium parahyba (caesalpinoideae) aqueous leaves extract.many medicinal plants have been recommended for the treatment of snakebites. the aqueous extracts prepared from the leaves of schizolobium parahyba (a plant found in mata atlantica in southeastern brazil) were assayed for their ability to inhibit some enzymatic and biological activities induced by bothrops pauloensis and crotalus durissus terrificus venoms as well as by their isolated toxins neuwiedase (metalloproteinase), bnsp-7 (basic lys49 pla(2)) and cb (pla(2) from crotoxin complex). phosph ...200818567056
radicicol improves regeneration of skeletal muscle previously damaged by crotoxin in mice.this work investigates the influence of heat shock proteins (hsps) on necrosis and subsequent skeletal muscle regeneration induced by crotoxin (ctx), the major component of crotalus durissus terrificus venom. mice were treated with radicicol, a hsp inductor, followed by an intramuscular injection of ctx into the gastrocnemius muscle. treated groups were sacrificed 1, 10 and 21 days after ctx injection. muscle histological sections were stained with toluidine blue and assayed for acid phosphatase ...200818573269
pro- and anti-inflammatory cytokines release in mice injected with crotalus durissus terrificus venom.the effects of crotalus durissus terrificus venom (cdt) were analyzed with respect to the susceptibility and the inflammatory mediators in an experimental model of severe envenomation. balb/c female mice injected intraperitoneally presented sensibility to cdt, with changes in specific signs, blood biochemical and inflammatory mediators. the venom induced reduction of glucose and urea levels and an increment of creatinine levels in serum from mice. significant differences were observed in the tim ...200818604304
random volumetric mri trajectories via genetic algorithms.a pseudorandom, velocity-insensitive, volumetric k-space sampling trajectory is designed for use with balanced steady-state magnetic resonance imaging. individual arcs are designed independently and do not fit together in the way that multishot spiral, radial or echo-planar trajectories do. previously, it was shown that second-order cone optimization problems can be defined for each arc independent of the others, that nulling of zeroth and higher moments can be encoded as constraints, and that i ...200818604305
secretory phospholipases a(2) isolated from bothrops asper and from crotalus durissus terrificus snake venoms induce distinct mechanisms for biosynthesis of prostaglandins e2 and d2 and expression of cyclooxygenases.the effects of myotoxin iii (mt-iii), a phospholipase a(2) (spla2) from bothrops asper snake venom, and crotoxin b (cb), a neurotoxic and myotoxic spla2 from the venom of crotalus durissus terrificus, on cyclooxygenases (coxs) expression and biosynthesis of prostaglandins (pgs) were evaluated, together with the mechanisms involved in these effects. upon intraperitoneal injection in mice, both spla(2)s promoted the synthesis of pgd2 and pge2, with a different time-course. mt-iii, but not cb, indu ...200818619987
aminopeptidase activities, oxidative stress and renal function in crotalus durissus terrificus envenomation in mice.acute renal failure is a serious condition of crotalus bites, which could be treated with statins. the effects of crotalus durissus terrificus venom (vcdt) and simvastatin on renal function, oxidative stress and representative plasma, urinary and renal aminopeptidase (ap) activities were evaluated in mice. eighty percent ld50 of vcdt caused hyperuricemia and urinary hypoosmolality (100%) and hypercreatinemia (60%). plasma neutral, pyroglutamyl and dipeptidyl iv and renal soluble and membrane-bou ...200818619992
prospection, structural analysis and phylogenetic relationships of endogenous gamma-phospholipase a(2) inhibitors in brazilian bothrops snakes (viperidae, crotalinae).during the last 20 years, there have been an increasing number of reports on endogenous phospholipase a(2) inhibitors (plis) in the sera of snakes. these studies have demonstrated the existence of three different structural classes of plis (alpha, beta and gamma). the gamma class members are potent inhibitors of phospholipases a(2) (pla(2)) from the venom of viperidae snakes. these enzymes, together with the mammalian pro-inflammatory pla(2), belong to the iia class of the pla(2)-superfamily. al ...200818620721
immunization with cdna of a novel p-iii type metalloproteinase from the rattlesnake crotalus durissus durissus elicits antibodies which neutralize 69% of the hemorrhage induced by the whole venom.zinc-dependent metalloproteinases play a key role in the hemorrhage induced by viperid bite envenoming. in this work we report the cloning and sequencing of the cdna from a novel p-iii type metalloproteinase from crotalus durissus durissus venom glands. the recombinant plasmid was used for dna immunization in mice using accelerate dna-coated microparticles with the gene gun system. the results showed that there is no significant difference in the efficiency of the immunization in mice when gold ...200818621072
cytotoxic effects of crotamine are mediated through lysosomal membrane permeabilization.crotamine, one of the main toxic components of crotalus durissus terrificus venom, is a small non-enzymatic basic polypeptide, which causes hind limb paralysis and necrosis of muscle cells. it is well-known that several toxins penetrate into the cytosol through endocytosis, although in many cases the mechanism by which this occurs has not been fully investigated. recently, using low concentrations of crotamine, we demonstrated the uptake of this toxin into actively proliferative cells via endocy ...200818662711
increase of the cytotoxic effect of bothrops jararacussu venom on mouse extensor digitorum longus and soleus by potassium channel blockers and by na(+)/k(+)-atpase inhibition.we investigated the myotoxicity of bothrops jararacussu crude venom and other cytolytic agents on mouse isolated extensor digitorum longus (edl) and soleus (sol) muscles, which present distinct properties: edl is a fast-twitch, white muscle with predominantly glycolytic fibers, while sol is slow-twitch, red muscle with predominantly oxidative fibers. muscles were exposed to b. jararacussu crude venom (25 microg/ml) and other crotaline venoms (agkistrodon contortrix laticinctus; crotalus viridis ...200818675839
intraspecies differences in hemostatic venom activities of the south american rattlesnakes, crotalus durissus cumanensis, as revealed by a range of protease inhibitors.crotalus durissus cumanensis is an endemic rattlesnake found in venezuela and colombia. in this study, a comparative analysis of hemorrhagic, coagulation and fibrino(geno)lytic activities in the presence or absence of protease inhibitors was performed with venoms of the same species crotalus durissus cumanensis, from seven geographical regions of venezuela (lagunetica, santa teresa, carrizales, guarenas, anzoátegui, margarita and maracay). lagunetica, carrizales and anzoátegui venoms induced hem ...200818685436
crotalphine induces potent antinociception in neuropathic pain by acting at peripheral opioid receptors.neuropathic pain is an important clinical problem and it is usually resistant to the current therapy. we have recently characterized a novel analgesic peptide, crotalphine, from the venom of the south american rattlesnake crotalus durissus terrificus. in the present work, the antinociceptive effect of crotalphine was evaluated in an experimental model of neuropathic pain induced in rats by chronic constriction of sciatic nerve. the effect of the peptide was compared to that induced by the crude ...200818703042
the analgesic effect of crotoxin on neuropathic pain is mediated by central muscarinic receptors and 5-lipoxygenase-derived mediators.crotoxin (ctx), a neurotoxin isolated from the venom of the south american rattlesnake crotalus durissus terrificus, induces analgesia. in this study, we evaluated the antinociceptive effect of ctx in a model of neuropathic pain induced by rat sciatic nerve transection. hyperalgesia was detected 2 h after nerve transection and persisted for 64 days. immersion of proximal and distal nerve stumps in ctx solution (0.01 mm for 10 s), immediately after nerve transection, blocked hyperalgesia. the ant ...200818778727
peptidase activities in crotalus durissus terrificus semen. 200818784247
bothrops jararaca fibrinogen and its resistance to hydrolysis evoked by snake venoms.fibrinogen is an essential protein involved in several steps of hemostasis, being associated with the final steps of the blood coagulation mechanism. herein, we describe the purification and characterization of a reptile fibrinogen, obtained from bothrops jararaca plasma. native b. jararaca fibrinogen showed a molecular mass of 372 kda, and the reduced and alkylated fibrinogen molecule showed three chains of 71, 60 and 55 kda, which are similar to the molecular masses of human and bovine aalpha, ...200818805500
anti-platelet effect of cumanastatin 1, a disintegrin isolated from venom of south american crotalus rattlesnake.disintegrins have been previously described in the venom of several snake families inhibiting signal transduction, cell-cell interactions, and cell-matrix interactions and may have therapeutic potential in heart attacks, thrombotic diseases, and cancers. this investigation describes the first disintegrin isolated from south american crotalus venom (venezuelan rattlesnake crotalus durissus cumanensis), which inhibits platelet adhesion to matrix proteins. c. d. cumanensis crude venom was first sep ...200918835011
mitochondrial dysfunction induced by pancreatic and crotalic (crotalus durissus terrificus) phospholipases a2 on rabbit proximal tubules suspensions.in the present study we show that phospholipases a2 isolated from porcine pancreas (pp-pla2) and crotalus durissus terrificus snake venom (sv-pla2) induced dose-dependent increases of ldh release from rabbit proximal tubules in suspension. both porcine and crotalic pla(2)s induced increases in non-esterified fatty acid (nefa) levels (microg of nefa/mg of tubule protein). it was observed that the nefa levels in the pellets were higher than in the supernatant for both pla2, and were dose-dependent ...200818835290
renal and vascular effects of the natriuretic peptide isolated from crotalus durissus cascavella venom.crotalus durissus cascavella is a snake that is usually found in the scrublands of northeast brazil. the components of its venom may have effects on the vascular and renal systems. recently, a new bradykinin inhibitory peptide has been identified in the venom of the crotalinae family. the aim of the present study was to investigate the renal and vascular effects of the natriuretic peptide isolated from the venom of crotalus durissus cascavella (np2_casca). the chromatographic profile showed the ...200818835291
expression of mrnas coding for vap1/crotastatin-like metalloproteases in the venom glands of three south american pit vipers assessed by quantitative real-time pcr.snake venom metalloproteases encompass a large family of toxins, with approximately 200 members already catalogued, which exhibit a diversity of structures and biological functions. from this relatively large number, only a dozen examples of apoptosis-inducing metalloproteases, like vap1 and 2 from the venom of crotalus atrox, are known. since most vap1-like toxins ever characterized were purified from the venom of viperidae species inhabiting diverse places on earth, we investigate the expressi ...200818926840
physiological importance of the coronary arterial blood supply to the rattlesnake heart.the reptilian heart consists of a thick inner spongy myocardium that derives its oxygen and nutrient supply directly from the blood within the ventricular cavity, which is surrounded by a thin outer compact layer supplied by coronary arteries. the functional importance of these coronary arteries remains unknown. in the present study we investigate the effects of permanent coronary artery occlusion in the south american rattlesnake (crotalus durissus) on the ability to maintain heart rate and blo ...200818978223
neutralization of venom-induced hemorrhage by equine antibodies raised by immunization with a plasmid encoding a novel p-ii metalloproteinase from the lancehead pitviper bothrops asper.in this work, the cdna encoding a novel p-ii type metalloproteinase from bothrops asper venom glands was cloned, sequenced and used for dna immunization of animals with accelerated dna-coated tungsten microparticles and the helius gene gun system. specific antibodies against b. asper venom antigens were induced in mice co-immunized with the plasmid encoding the p-ii metalloproteinase together with an expression plasmid encoding the murine il-2. similarly, specific antibodies against b. asper ven ...200919013207
enzymatic and structural characterization of new pla2 isoform isolated from white venom of crotalus durissus ruruima.this work reports the structural and enzymatic characterization of a new spla2 from the white venom of crotalus durissus ruruima, nominated pla2a. the homogeneity of the pla2a fraction and its molecular mass were initially evaluated by sds-page and confirmed by maldi-tof spectrometry, indicating a molecular mass of 14,299.34da. structural investigation, through circular dichroism spectroscopy, revealed that pla2a has a high content of alpha helix and beta-turn structures, 45.7% and 35.6% respect ...200919013478
seasonal variation of peptidase activities in the reproductive tract of crotalus durissus terrificus.seasonal quantitative patterns of acid (apa), basic (apb), puromycin-sensitive (apn-ps) and puromycin-insensitive neutral (apn-pi), cystyl (cap), dipeptidyl iv (dppiv), type-1 pyroglutamyl (pap-i) and prolyl-imino (pip) aminopeptidases and prolyl oligopeptidase (pop) activities in soluble (sf) and solubilized membrane-bound (mf) fractions from ductus deferens, vagina and uterus were studied to evaluate their relationships with the reproductive cycle and the extensive long-term spermatozoa storag ...200919027015
the unequal influences of the left and right vagi on the control of the heart and pulmonary artery in the rattlesnake, crotalus durissus.autonomic control of the cardiovascular system in reptiles includes sympathetic components but heart rate (f(h)), pulmonary blood flow (q(pul)) and cardiac shunt patterns are primarily controlled by the parasympathetic nervous system. the vagus innervates both the heart and a sphincter on the pulmonary artery. the present study reveals that whereas both the left and right vagi influence f(h), it is only the left vagus that influences pulmonary vascular resistance. this is associated with the fac ...200919088220
antigenic, microbicidal and antiparasitic properties of an l-amino acid oxidase isolated from bothrops jararaca snake venom.venoms from the bee apis mellifera, the caterpillar lonomia achelous, the spiders lycosa sp. and phoneutria nigriventer, the scorpions tityus bahiensis and tityus serrulatus, and the snakes bothrops alternatus, bothrops jararaca, bothrops jararacussu, bothrops moojeni, bothrops neuwiedi, crotalus durissus terrificus, and lachesis muta were assayed (800mug/ml) for activity against staphylococcus aureus. venoms from b. jararaca and b. jararacussu showed the highest s. aureus growth inhibition and ...200919101583
functional and structural analysis of two fibrinogen-activating enzymes isolated from the venoms of crotalus durissus terrificus and crotalus durissus collilineatus.fibrinogen-activating enzymes, widely distributed in crotalidae and viperidae venoms, are single-chain glycosylated serine proteases that display high macromolecular selectivity and are often referred to as thrombin-like enzymes (tles). tles serve as structural models to extend our understanding of the structure-function relationships of blood coagulation factors, have been clinically used for the treatment of thrombotic diseases, and are used as tools in clinical assays. the combination of gel ...200919129947
peptidase activities in the semen from the ductus deferens and uterus of the neotropical rattlesnake crotalus durissus terrificus.to understand the role of peptidases in seminal physiology of crotalus durissus terrificus, intra- and inter-seasonal activity levels of acid (apa), basic (apb), puromycin-sensitive (apn-ps) and puromycin-insensitive neutral (apn-pi), cystyl (cap), dipeptidyl-iv (dppiv), type-1 pyroglutamyl (pap-i) and prolyl-imino (pip) aminopeptidases as well as prolyl endopeptidase (pop) were evaluated in soluble (sf) and/or membrane-bound (mf) fractions of semen collected from the ductus deferens of the male ...200919225781
crotalus durissus collilineatus venom gland transcriptome: analysis of gene expression profile.crotalus durissus rattlesnakes are responsible for the most lethal cases of snakebites in brazil. crotalus durissus collilineatus subspecies is related to a great number of accidents in southeast and central west regions, but few studies on its venom composition have been carried out to date. in an attempt to describe the transcriptional profile of the c. durissus collilineatus venom gland, we generated a cdna library and the sequences obtained could be identified by similarity searches on exist ...200919230843
inhibition of snake venoms and phospholipases a(2) by extracts from native and genetically modified eclipta alba: isolation of active coumestans.we genetically modified eclipta alba using agrobacterium rhizogenes lba 9402, with the aim of producing secondary metabolites with pharmacological properties against phospholipase a(2) and the myotoxic activities of snake venom. extracts from in natura aerial parts and roots, both native and genetically modified (in vitro), were prepared and analysed by high-performance liquid chromatography. in natura materials showed the coumestan wedelolactone at higher concentration in the aerial parts, whil ...200919320636
cloning of serine protease cdnas from crotalus durissus terrificus venom gland and expression of a functional gyroxin homologue in cos-7 cells.gyroxin is one of main serine proteases of crotalus durissus terrificus venom, representing about 2% of the protein content in the crude venom. it is a 33 kda glycoprotein with 3.8% by weight of sugar moiety. this toxin induces hemotoxicity in mice and a neurological condition called barrel rotation syndrome. in the present work, we report the molecular cloning of five new nucleotide sequences from a cdna library of the venom glands of a single specimen of c. d. terrificus. these sequences have ...200919341755
semen collection and evaluation in free-ranging brazilian rattlesnakes (crotalus durissus terrificus).two hundred-ninety species of reptiles are estimated to need urgent action for conservation, with at least 113 threatened species worldwide. the international union for conservation of nature and natural resources (iucn) red list of threatened species includes 80 species of snakes, with six native brazilian species, a number likely to be an underestimation. some authors believe that assisted reproduction would be an important tool to improve reproduction in captivity of some reptiles. an efficie ...200719360568
snake venomics and antivenomics of bothrops colombiensis, a medically important pitviper of the bothrops atrox-asper complex endemic to venezuela: contributing to its taxonomy and snakebite management.the taxonomic status of the medically important pitviper of the bothrops atrox-asper complex endemic to venezuela, which has been classified as bothrops colombiensis, remains incertae cedis. to help resolving this question, the venom proteome of b. colombiensis was characterized by reverse-phase hplc fractionation followed by analysis of each chromatographic fraction by sds-page, n-terminal sequencing, maldi-tof mass fingerprinting, and collision-induced dissociation tandem mass spectrometry of ...200919457355
effect of umbelliferone (7-hydroxycoumarin, 7-hoc) on the enzymatic, edematogenic and necrotic activities of secretory phospholipase a2 (spla2) isolated from crotalus durissus collilineatus venom.flavonoids, coumarins and other polyphenolic compounds are powerful antioxidants both in hydrophilic and lipophylic environments with diverse pharmacological properties including anti-inflammatory activity. despite being widely used as powerful therapeutic agents for blood coagulation disorders, more specifically to control some serine protease enzymes, the mechanism of anti-inflammatory activity of coumarins is unknown, unlike that of flavonoids. although their controlling effect on serine prot ...200919470355
expression of human recombinant antibody fragments capable of partially inhibiting the phospholypase activity of crotalus durissus terrificus venom.crotoxin is the main toxic component of the south american rattlesnake crotalus durissus terrificus venom. it is composed of two different subunits: ca, crotapotin, and cb (basic subunit of cortoxin isolated from c. d. terrificus), a weakly toxic phospholipase a(2) with high enzymatic activity. the phospholipases a(2) are abundant in snake venoms and are responsible for disruption of cell membrane integrity via hydrolysis of its phospholipids. however, in addition to their normal digestive actio ...200919486333
intraspecific variation of the crotamine and crotasin genes in crotalus durissus rattlesnakes.crotamine is a small basic myotoxin peptide of crotalus durissus venom, with beta-defensin scafold and variable concentration in individual venoms. the crotamine gene was mapped to the end of chromosome 2 and the signal intensity differed significantly between the two homologues. in contrast to crotamine, the paralogous crotasin gene is scarcely expressed in the venom glands. in this study, we analyzed the crotamine concentrations in the venoms of a total of 23 rattlesnakes from diverse brazilia ...200919523505
neutralization of bothrops mattogrossensis snake venom from bolivia: experimental evaluation of llama and donkey antivenoms produced by caprylic acid precipitation.polyspecific bothropic/crotalic and bothropic/lachesic antivenoms were produced in bolivia by immunizing two donkeys with the venoms of bothrops mattogrossensis and crotalus durissus terrificus and one llama with the venoms of b. mattogrossensis and lachesis muta. these antivenoms are currently being used for snakebite envenomation in bolivia. the rationale for using these animals is that donkeys and llamas are better adapted than horses to the high altitudes in south america and constitute good ...201019647761
biochemical and biological characterization of a pla2 from crotoxin complex of crotalus durissus cumanensis.a new pla2 (cdcum6) from crotoxin complex of colombian crotalus durissus cumanensis rattlesnake was purified using molecular exclusion chromatography and rp-hplc. the molecular mass of cdcum6 was determined by sds-page approximately 14 kda and confirmed by maldi-tof (14321.98 da). the enzyme showed km 6.0 mm, vmax 3.44 nmol/min, optimum ph was 8.0 and temperature was between 30 and 45 degrees c, and it had a strict requirement of ca2+ for its activity. the n-terminal sequence of pla2 was slvqf e ...200919673100
identification of continuous interaction sites in pla(2)-based protein complexes by peptide arrays.crotoxin (ca.cb) is a beta-neurotoxin from crotalus durissus terrificus snake venom that is responsible for main envenomation effects upon biting by this snake. it is a heterodimer of an acidic protein (ca) devoid of any biological activity per se and a basic, enzymatically active, pla(2) counterpart (cb). both lethal and enzymatic activities of crotoxin have been shown to be inhibited by cnf, a protein from the blood of c. d. terrificus snakes. cnf replaces ca in the ca.cb complex, forming a st ...200919733616
biological and biochemical characterization of two new pla2 isoforms cdc-9 and cdc-10 from crotalus durissus cumanensis snake venom.this work reports the purification, biological characterization and amino acid sequence of two new basic pla(2) isoforms, cdc-9 and cdc-10, purified from the crotalus durissus cumanensis venom by one step analytical chromatography reverse phase hplc. the molecular masses of the pla(2) were 14,175+/-2.7 da for cdc-9 and 14,228+/-3.5 da for cdc-10 both deduced by primary structure and confirmed by maldi-tof. the isoforms presented an amino acid sequence of 122 amino acid residues, being cdc-9: slv ...201019747981
crystallization and preliminary x-ray diffraction analysis of crotoxin b from crotalus durissus collilineatus venom.crotoxin b is a basic phospholipase a(2) found in the venom of several crotalus durissus ssp. rattlesnakes and is one of the subunits that constitute crotoxin, the main component of the venom of these snakes. this heterodimeric toxin is related to important envenomation effects such as neurological disorders, myotoxicity and renal failure. although crotoxin was first crystallized in 1938, the first structural data only became available in 2007 (for crotoxin b from c. durissus terrificus) and sho ...200919851009
snake venomics of the central american rattlesnake crotalus simus and the south american crotalus durissus complex points to neurotoxicity as an adaptive paedomorphic trend along crotalus dispersal in south america.we report a comparative venomic and antivenomic characterization of the venoms of newborn and adult specimens of the central american rattlesnake, crotalus simus, and of the subspecies cumanensis, durissus, ruruima, and terrificus of south american crotalus durissus. neonate and adult c. simus share about 50% of their venom proteome. the venom proteome of 6-week-old c. simus is predominantly made of the neurotoxic heterodimeric phospholipase a(2) (pla(2) crotoxin) (55.9%) and serine proteinases ...201019863078
phylogenetic analyses based on small subunit rrna and glycosomal glyceraldehyde-3-phosphate dehydrogenase genes and ultrastructural characterization of two snake trypanosomes: trypanosoma serpentis n. sp. from pseudoboa nigra and trypanosoma cascavelli from crotalus durissus terrificus.we sequenced the small subunit (ssu) rrna and glycosomal glyceraldehyde-3-phosphate dehydrogenase (ggapdh) genes of two trypanosomes isolated from the brazilian snakes pseudoboa nigra and crotalus durissus terrificus. trypanosomes were cultured and their morphometrical and ultrastructural features were characterized by light microscopy and scanning and transmission electron microscopy. phylogenetic trees inferred using independent or combined ssu rrna and ggapdh data sets always clustered the sn ...200919883449
crotoxin is responsible for the long-lasting anti-inflammatory effect of crotalus durissus terrificus snake venom: involvement of formyl peptide receptors.in the present study, it was investigated which components are responsible for the anti-inflammatory properties of crotalus durissus terrificus venom (cdtv). the effect of crotoxin, as well as of other cdtv components was evaluated on edema, cell migration and alterations in leukocyte-endothelium interactions induced by carrageenan. crotoxin (40 microg kg(-1)) was injected at different time periods before or after the injection of carrageenan (15 mg kg(-1)) into the mouse hind paw, peritoneum or ...201020034508
effect of mikania glomerata (asteraceae) leaf extract combined with anti-venom serum on experimental crotalus durissus (squamata: viperidae) envenomation in rats.crotalic envenomation represents the highest number of deaths when compared to other snakebite envenomations of medical interest. crotalic venom has important characteristics such as neurotoxicity, myotoxicity, nephrotoxicity, and clotting and hemolytic action. we evaluated the clinical and laboratory aspects of crotalus durissus terrificus experimental envenomation in wistar rats treated with antivenom and the aqueous extract of the plant mikania glomerata. the animals were divided into three g ...200920073325
crotoxin: novel activities for a classic beta-neurotoxin.crotoxin, the main toxin of south american rattlesnake (crotalus durissus terrificus) venom, was the first snake venom protein to be purified and crystallized. crotoxin is a heterodimeric beta-neurotoxin that consists of a weakly toxic basic phospholipase a(2) and a non-enzymatic, non-toxic acidic component (crotapotin). the classic biological activities normally attributed to crotoxin include neurotoxicity, myotoxicity, nephrotoxicity and cardiotoxicity. however, numerous studies in recent year ...201020109480
crotoxin potentiates l-type calcium currents and modulates the action potential of neonatal rat cardiomyocytes.crotoxin (ctx), the major component of the venom from the south american rattlesnake (crotalus durissus terrificus) has diverse toxic effects, including pre-synaptic neurotoxicity. among these, the effect of ctx in the heart is the least understood. in this study, we explored the effect(s) of ctx on the electrophysiological activity of neonatal rat cardiomyocytes (nrcm). by using patch, voltage-, and current-clamping techniques, we found that, in nrcm, ctx strongly potentiates l-type ca2+ curren ...201020122949
a new fibrin sealant from crotalus durissus terrificus venom: applications in medicine.fibrin sealant, a widely available tissue adhesive, has been used since 1940 in a variety of clinical applications. commercially available fibrin sealant products are synthesized from bovine thrombin and human fibrinogen, which may transmit infectious diseases, and recipients may also develop antibodies against bovine thrombin. bearing these disadvantages in mind, a new fibrin sealant was developed in 1989 by a group of researchers from the center for the study of venoms and venomous animals, in ...200920183534
snake venomic of crotalus durissus terrificus--correlation with pharmacological activities.the snake venomic of crotalus durissus terrificus was analyzed by 2-d and 1-d electrophoresis and subsequent ms/ms and enzymatic assays. the venomic of the south american rattlesnake comprises toxins from seven protein families: phospholipases a(2), serine proteinases, ecto-5'-nucleotidases, metalloproteinases, nerve growth factors, phosphodiesterases, and glutaminyl cyclase. the venom toxin composition correlates with the clinical manifestation of the crotalinae snake bites and explains patholo ...201020205475
structural and pharmacological characterization of the crotamine isoforms iii-4 (myx4_crocu) and iii-7 (myx7_crocu) isolated from the crotalus durissus cumanensis venom.two major crotamine isoforms (iii-4 and iii-7) were obtained combining two chromatographic steps on molecular exclusion chromatography (sephadex g-75) and ion-exchange column (protein pack sp 5pw) of the rattlesnake crotalus durissus cumanensis venom. the "in vivo" myotoxic effect of the venom, its "in vitro" cytotoxicity in myoblasts and myotubes (c2c12) and the neurotoxic and edema-forming activity were characterized. the molecular masses of the crotamine isoforms were 4907.94 da (iii-4) and 4 ...201020206199
effect of the synthetic coumarin, ethyl 2-oxo-2h-chromene-3-carboxylate, on activity of crotalus durissus ruruima spla2 as well as on edema and platelet aggregation induced by this factor.we show that ethyl 2-oxo-2h-chromene-3-carboxylate (eocc), a synthetic coumarin, irreversibly inhibits phospholipase a(2) (spla2) from crotalus durissus ruruima venom (spla2r) with an ic(50) of 3.1 +/- 0.06 nmol. eocc strongly decreased the v(max) and k(m), and it virtually abolished the enzyme activity of spla2r as well as spla2s from other sources. the edema induced by spla2r + eocc was less than that induced by spla2r treated with p-bromophenacyl bromide, which was more efficient at neutraliz ...201020223257
lipoic acid effects on renal function, aminopeptidase activities and oxidative stress in crotalus durissus terrificus envenomation in mice.crotalus durissus terrificus envenomation has been associated with direct nephrotoxicity, rhabdomyolysis, hyperuricemia, urinary hypoosmolality, alterations in aminopeptidase activities (ap) and oxidative stress. this study evaluated the effects of lipoic acid (la) on renal function, lethality, ap and gssg/gsh in mice injected with c. d. terrificus venom (vcdt). the doses and routes of administration of la and vcdt promoted no systemic myotoxicity. la did not alter significantly the lethality of ...201020398689
cdna and deduced primary structure of basic phospholipase a2 with neurotoxic activity from the venom secretion of the crotalus durissus collilineatus rattlesnake.to illustrate the construction of precursor complementary dnas, we isolated mrnas from whole venom samples. after reverse transcription polymerase chain reaction (rt-pcr), we amplified the cdna coding for a neurotoxic protein, phospholipase a2 d49 (pla2 d49), from the venom of crotalus durissus collilineatus (cdc pla2). the cdna encoding cdc pla2 from whole venom was sequenced. the deduced amino acid sequence of this cdna has high overall sequence identity with the group ii pla2 protein family. ...201020401434
snake venomics and antivenomics of crotalus durissus subspecies from brazil: assessment of geographic variation and its implication on snakebite management.we report the comparative proteomic and antivenomic characterization of the venoms of subspecies cascavella and collilineatus of the brazilian tropical rattlesnake crotalus durissus. the venom proteomes of c. d. collilineatus and c. d. cascavella comprise proteins in the range of 4-115 kda belonging to 9 and 8 toxin families, respectively. collilineatus and cascavella venoms contain 20-25 main toxins belonging to the following protein families: disintegrin, pla(2), serine proteinase, cysteine-ri ...201020542151
new nanostructured silica adjuvant (sba-15) employed to produce antivenom in young sheep using crotalus durissus terrificus and apis mellifera venoms detoxified by cobalt-60.equine antivenom is considered the only treatment for animal-generated envenomations, but it is costly. the study aimed to produce apis mellifera (africanized honeybee) and crotalus durissus terrificus (c.d.t.) antivenoms using nanostructured silica (sba-15) as adjuvant and cobalt-60 ((60)co)-detoxified venoms utilizing young sheep. natural and (60)co-irradiated venoms were employed in four different hyperimmunization protocols. thus, 8 groups of 60- to 90-d-old sheep were hyperimmunized, enzyme ...201020563926
snake venomics of bothriechis nigroviridis reveals extreme variability among palm pitviper venoms: different evolutionary solutions for the same trophic purpose.we report the proteomic characterization and biological activities of the venom of the black-speckled palm pitviper, bothriechis nigroviridis, a neotropical arboreal pitviper from costa rica. in marked contrast to other bothriechis species investigated, the venom of b. nigroviridis does not possess detectable zn(2+)-dependent metalloproteinases, and is uniquely characterized by a high content of crotoxin-like pla(2) and vasoactive peptides. these data suggest that different evolutionary solution ...201020590130
gyroxin increases blood-brain barrier permeability to evans blue dye in mice.gyroxin is a serine protease enzyme component of the south american rattlesnake (crotalus durissus terrificus) venom. this toxin displays several activities, including the induction of blood coagulation (fibrinogenolytic activity), vasodilation and neurotoxicity, resulting in an effect called barrel rotation. the mechanisms involved in this neurotoxic activity are not well known. because gyroxin is a member of a potentially therapeutic family of enzymes, including thrombin, ancrod, batroxobin, t ...201120637222
successful treatment of south american rattlesnake (crotalus durissus terrificus) envenomation with crotalidae polyvalent immune fab (crofab™). 201120658221
the heart of the south american rattlesnake, crotalus durissus.most anatomical and physiological studies of the sauropsid heart have focused on species with extraordinary physiologies, and detailed anatomical descriptions of hearts from sauropsids with more common physiologies are therefore warranted. here, we present a comprehensive study of the cardiac anatomy of the south american rattlesnake (crotalus durissus). the cardiovascular physiology of this species has been investigated in a number of studies, whereas only a few cursory studies exist on the car ...201020730920
k+(atp) channels-independent analgesic action of crotalus durissus cumanensis venom.the effect was investigated of the k+ channel blocker, glibenclamide, on the ability of crotalus durissus cumanensis venom (cdcm) to promote peripheral antinociception. this was measured by formalin-induced nociception in male swiss mice. cdcm (200 and 300 microg/kg) produced an antinociceptive effect during phase 2 in the formalin test. the effect of cdcm (200 microg/kg) was unaffected by the atp-sensitive k+ channel blocker glibenclamide (2 mg/kg). these results suggest that cdcm is effective ...201020734950
in vitro antiophidian properties of dipteryx alata vogel bark extracts.extracts from dipteryx alata bark obtained with different solvents (hexane, dichloromethane, ethyl acetate and methanol) were mixed in vitro with bothrops jararacussu (bjssu, 40 μg/ml) and crotalus durissus terrificus (cdt, 15 μg/ml) snake venoms, and applied to a mouse phrenic nerve-diaphragm preparation to evaluate the possible neutralization of venom effects. cdt venom neurotoxic effect was not inhibited by any of the extracts, while the neurotoxic and myotoxic actions of bjssu venom were dec ...201020877202
quercetin as an inhibitor of snake venom secretory phospholipase a2.as polyphenolic compounds isolated from plants extracts, flavonoids have been applied to various pharmaceutical uses in recent decades due to their anti-inflammatory, cancer preventive, and cardiovascular protective activities. in this study, we evaluated the effects of the flavonoid quercetin on crotalus durissus terrificus secretory phospholipase a2 (spla2), an important protein involved in the release of arachidonic acid from phospholipid membranes. the protein was chemically modified by trea ...201021056032
effects of low molecular weight sulfated galactan fragments from botryocladia occidentalis on the pharmacological and enzymatic activity of spla2 from crotalus durissus cascavella.low molecular weight fragments of sulfated galactans (boc-5 and boc-10) from the red algae botryocladia occidentalis significantly inhibited crotalus durissus cascavella spla2 enzymatic activity. equimolar ratios of spla2 to boc-5 or boc-10 resulted in allosteric inhibition of spla2. under the conditions tested, we observed that both boc-5 and boc-10 strongly decreased edema, myonecrosis, and neurotoxicity induced by native spla2.201021061146
biological versatility of crotamine--a cationic peptide from the venom of a south american rattlesnake.molecules isolated from animals, insects, plants or microorganisms can provide prototypes for design of biopharmaceutical products. some venom toxins and their derivatives are used in medicine, while others provide templates for development of new drugs.201021062230
comparison of the effect of crotalus simus and crotalus durissus ruruima venoms on the equine antibody response towards bothrops asper venom: implications for the production of polyspecific snake antivenoms.antivenoms are preparations of immunoglobulins purified from the plasma of animals immunized with snake venoms. depending on the number of venoms used during the immunization, antivenoms can be monospecific (if venom from a single species is used) or polyspecific (if venoms from several species are used). in turn, polyspecific antivenoms can be prepared by purifying antibodies from the plasma of animals immunized with a mixture of venoms, or by mixing antibodies purified from the plasma of anima ...201021130107
immunomodulatory effects of crotoxin isolated from crotalus durissus terrificus venom in mice immunised with human serum albumin.crotalus durissus terrificus venom and its main component, crotoxin (ctx), have the ability to down-modulate the immune system. certain mechanisms mediated by cells and soluble factors of the immune system are responsible for the elimination of pathogenic molecules to ensure the specific protection against subsequent antigen contact. accordingly, we evaluated the immunomodulatory effects of ctx on the immune response of mice that had been previously primed by immunisation with human serum albumi ...201121223974
determination of sphingomyelinase-d activity of loxosceles venoms in sphingomyelin/cholesterol liposomes containing horseradish peroxidase.based on degradation of sphingomyelin/cholesterol liposomes containing entrapped horseradish peroxidase, we evaluated the sphingomyelinase-d (smase-d) activity of scorpion, spider and snake venoms by monitoring spectrophotometrically the product of oxidation of hrp released. the results indicate that loxosceles crude venoms (loxosceles intermedia, loxosceles laeta, loxosceles gaucho and loxosceles similis) displayed smase-d activity in a concentration-dependent manner. furthermore, this activity ...201121236288
modulation of the pharmacological activities of secretory phospholipase a2 from crotalus durissus cascavella induced by naringin.in this work we have characterized the action of the naringin, a flavonoid found in grapefruit and known for its various pharmacological effects, which include antioxidant blood lipid lowering and anticancer activity, on the structure and biochemical activities of a secretory phospholipase a (spla2) from crotalus durissus cascavella, an important protein involved in the releasinge of arachidonic acid in phospholipid membranes. spla2 was incubated with naringin (mol:mol) at 37 °c and a discrete r ...201121245808
in vitro antibacterial and hemolytic activities of crotamine, a small basic myotoxin from rattlesnake crotalus durissus.crotamine, a myotoxin from the venom of south american rattlesnake, is structurally related to +¦-defensins, antimicrobial peptides (amps) found in vertebrate animals. here, we tested the antibacterial properties of crotamine and found that it killed several strains of escherichia coli, with the mics ranging from 25 to 100 ++g mlôü+-¦. time-kill and bacterial membrane permeabilization assays revealed that killing of bacteria by crotamine occurred within 1 h and reached the maximum by 2 h. additi ...201121386851
role of a novel tetrodotoxin-resistant sodium channel in the nitrergic relaxation of corpus cavernosum from the south american rattlesnake crotalus durissus terrificus.coitus in snakes may last up to 28 hours; however, the mechanisms involved are unknown.201121477017
the inhibitory effect of camellia sinensis extracts against the neuromuscular blockade of crotalus durissus terrificus venom.in geographically isolated populations where intensive medical care or serum therapy is not easily accessible snake envenomation is a major cause for concern. the aim of the present study was to test camellia sinensis extracts, theaflavin and epigallocatechin (two of the main c. sinensis components) against the irreversible neuromuscular blockade induced by crotalus durissus terrificus venom in mouse phrenic-nerve diaphragm preparations. a quantitative histological study was also performed. the ...201021544176
evaluation of anti-inflammatory activity of derivatives from aerial parts of baccharis uncinella.context: species of baccharis exhibit antibiotic, antiseptic, and wound-healing properties, and have been used in the traditional medicine of south america for the treatment of inflammation, headaches, diabetes, and hepatobiliary disorders. objective: to investigate the anti-inflammatory activity of organic phases from etoh extract of the aerial parts of baccharis uncinella dc (asteraceae). materials and methods: the crude etoh extract from the aerial parts of b. uncinella was subjected to parti ...201121554002
abdominal hyperalgesia in secretory phospholipase a(2)-induced rat pancreatitis: distinct roles of nk(1) receptors.we investigated the potential of secretory phospholipase a(2) (spla(2))-induced pancreatitis to promote abdominal hyperalgesia, as well as to depolarize sensory fibres in vitro using a grease-gap technique. pancreatitis was induced by the injection of spla(2) from crotalus durissus terrificus (spla(2)cdt, 300μgkg(-1)) venom into the common bile duct of rats. pancreatic inflammatory signs, serum amylase levels and abdominal hyperalgesia were evaluated in rats treated or not with sr140333, a tachy ...201121565534
effects of the crotalus durissus terrificus snake venom on hepatic metabolism and oxidative stress.snake venoms present different action mechanisms because of their complex composition, represented mainly by toxins and enzymes. this work aimed to investigate the effects of the crotalus durissus terrificus(cdt) venom in the liver. wistar rats were inoculated intraperitoneally with saline (control) or cdt venom. after 3, 4, or 6 h, the following parameters were analyzed: (a) hepatic function, (b) oxidative stress parameters, and (c) the metabolism of alanine in the isolated perfused liver. plas ...201121671311
crotoxin and phospholipases a₂ from crotalus durissus terrificus showed antiviral activity against dengue and yellow fever viruses.dengue is the most important arbovirus in the world with an estimated of 50 million dengue infections occurring annually and approximately 2.5 billion people living in dengue endemic countries. yellow fever is a viral hemorrhagic fever with high mortality that is transmitted by mosquitoes. effective vaccines against yellow fever have been available for almost 70 years and are responsible for a significant reduction of occurrences of the disease worldwide; however, approximately 200,000 cases of ...201221723310
evaluation of the genotoxicity of crotalus durissus terrificus snake venom and its isolated toxins on human lymphocytes.in the present study, experiments were carried out to evaluate the mutagenic potential and genotoxic effects of crotalus durissus terrificus snake venom and its isolated toxins on human lymphocytes, using the micronucleus and comet assays. significant damage to dna was observed for crotoxin and crotapotin (ca). basic phospholipase a(2) (cb) and crotamine did not present any mutagenic potential when evaluated by the micronucleus test. c. d. terrificus crude venom was able to induce the formation ...201121723956
hypotensive effects of the crotalus durissus cascavella venom: involvement of no.crotalus durissus cascavella is a snake native of northeastern brazil. the aim of the study was to investigate the effects of c. d. cascavella venom on rat mean arterial pressure and vascular reactivity in the mesenteric vascular bed. the venom evoked a dose-dependent decrease in mean arterial pressure, cardiac and respiratory frequency with increased plasma nitrite levels. l-name (10 mg/kg) blunted both the hypotension and increased nitrite production observed after the venom administration. to ...201121815429
allopurinol reduces the lethality associated with acute renal failure induced by crotalus durissus terrificus snake venom: comparison with probenecid.acute renal failure is one of the most serious complications of envenoming resulting from crotalus durissus terrificus bites. this study evaluated the relevance of hyperuricemia and oxidative stress and the effects of allopurinol and probenecid in renal dysfunction caused by direct nephrotoxicity of c. d. terrificus venom.201121909449
anti-tumor activity of crtx in human lung adenocarcinoma cell line a549.to assess the cytotoxic effect of crotoxin (crtx), a potent neurotoxin extracted from the venom of the pit viper crotalus durissus terrificus, in human lung adenocarcinoma a549 cells and investigated the underlying mechanisms.201121946324
the peripheral l-arginine-nitric oxide-cyclic gmp pathway and atp-sensitive k+ channels are involved in the antinociceptive effect of crotalphine on neuropathic pain in rats.crotalphine, a 14 amino acid peptide first isolated from the venom of the south american rattlesnake crotalus durissus terrificus, induces a peripheral long-lasting and opioid receptor-mediated antinociceptive effect in a rat model of neuropathic pain induced by chronic constriction of the sciatic nerve. in the present study, we further characterized the molecular mechanisms involved in this effect, determining the type of opioid receptor responsible for this effect and the involvement of the ni ...201122126967
anti-snake venom activities of extracts and fractions from callus cultures of sapindus saponaria.context: sapindus saponaria l. (sapindaceae) bark, root, and fruits are used as sedatives and to treat gastric ulcer and also demonstrate diuretic and expectorant effects. objective: the anti-snake venom properties of callus of s. saponaria are investigated here for the first time. materials and methods: in vitro cultivated callus of sapindus saponaria were lyophilized, and the extracts were prepared with different solvents, before submitting to phytochemical studies and evaluation of the an ...201122133075
immunohistochemical and functional characterization of nitric oxide signaling pathway in isolated aorta from crotalus durissus terrificus.we characterized the nitric oxide (no)-cyclic gmp-phosphodiesterase-5 (pde5) pathway in crotalus durissus terrificus aorta. concentration responses curves to acetylcholine (ach), sodium nitroprusside (snp), bay41-2272 (soluble guanylyl cyclase [sgc] stimulator), bay60-2770 (sgc activator) and tadalafil (pde5 inhibitor) were constructed in phenylephrine (10 μm)-precontracted tissues with intact (e(+)) or denuded (e(-)) endothelium. ach (0.0001-10 μm) and snp (0.0001-10 μm) relaxed aorta, which we ...201222134054
the natural cell-penetrating peptide crotamine targets tumor tissue in vivo and triggers a lethal calcium-dependent pathway in cultured cells.our goal was to demonstrate the in vivo tumor specific accumulation of crotamine, a natural peptide from the venom of the south american rattlesnake crotalus durissus terrificus, which has been characterized by our group as a cell penetrating peptide with a high specificity for actively proliferating cells and with a concentration-dependent cytotoxic effect. crotamine cytotoxicity has been shown to be dependent on the disruption of lysosomes and subsequent activation of intracellular proteases. ...201122142367
inflammatory mediators release in urine from mice injected with crotalus durissus terrificus venom.in this study, we investigated in groups of female balb/c mice injected with crotalus durissus terrificus venom (cdt) the renal function based on creatinine clearance, percentage of fractional excretion cytokines and histological examination of renal tissue. cdt caused renal alterations that induced proteinuria during the initial hours post-venom and reduced creatinine clearance 15 min. up to 2 hours post-venom administration. in urine from mice injected with cdt induced a decrease in il-4 level ...201122174490
crotamine, a small basic polypeptide myotoxin from rattlesnake venom with cell-penetrating properties.crotamine, a low molecular weight cationic polypeptide from the venom of the south american rattlesnake crotalus durissus terrificus is a natural cell-penetrating peptide with functional versatility. the presence of nine lysine residues and three disulfide bonds renders crotamine highly compact, stable and positively charged. topologically, crotamine adopts an ancient β-defensin fold that is found in diverse families of endogenous and venom polypeptides dedicated to host defense. crotamine is un ...201122204433
clinical safety evaluation of f(ab')₂ antivenom (crotalus durissus-bothrops asper) administration in dogs.antivenoms consisting of selective antigen binding antibody fragments, or f(ab')(2), are becoming more popular in human and veterinary medicine, owing to their preferred kinetics, tissue distribution, and removal of the fc binding portion of igg. consequences of antivenom administration can include acute and delayed reactions, dependent, in part, on the antivenom's donor source, purity, and composition. this study evaluated an equine-derived polyvalent f(ab')(2) pit viper antivenom in healthy do ...201122316205
envenomations by bothrops and crotalus snakes induce the release of mitochondrial alarmins.skeletal muscle necrosis is a common manifestation of viperid snakebite envenomations. venoms from snakes of the genus bothrops, such as that of b. asper, induce muscle tissue damage at the site of venom injection, provoking severe local pathology which often results in permanent sequelae. in contrast, the venom of the south american rattlesnake crotalus durissus terrificus, induces a clinical picture of systemic myotoxicity, i.e., rhabdomyolysis, together with neurotoxicity. it is known that mo ...201222363828
relationship between the structure and the enzymatic activity of crotoxin complex and its phospholipase a2 subunit: an in silico approach.crotoxin, one of the major toxins of south american rattlesnake crotalus durissus subspecies, is an heterodimeric complex composed of two distinct subunits: a basic phospholipase a(2) (pla(2), cb) and an acidic nontoxic catalytically inactive protein, crotapotin (ca). it's well known that cb has a high enzymatic activity; however the molecular aspects that determine this fact remain unknown. in this study, an in silico approach was used to predict the ca structure by homology modeling, and the c ...201222481077
characterization of two vasoactive peptides isolated from the plasma of the snake crotalus durissus terrificus.incubation of plasma from the snake crotalus durissus terrificus (cdtp) with trypsin generated two hypotensive peptides. the primary structure of the peptides was established for two sequences as: (ser-ile-pro-gln-ala-pro-thr-ser-asn-leu-ile-glu-ala-thr-lys) and (lys-pro-asp-ala-asn-gln-val-leu-ile-gln-val-ile-gly-val). these peptides display homology with fragments of albumin from trimeresurus flavoviridis. bolus intra-arterial injection of the purified or the synthetic peptide produced a stron ...201222483415
[experimental efficacy of igy antibodies produced in eggs against the venom of the peruvian snake bothrops atrox].to develop an immunization protocol in order to produce avian igy immunoglobulins against bothrops atrox peruvian snake venom and to evaluate its neutralizing capacity.201222510909
crystallographic characterization of functional sites of crotoxin and ammodytoxin, potent β-neurotoxins from viperidae venom.this review will focus on a description of the three-dimensional structures of two β-neurotoxins, the monomeric pla(2) ammodytoxin from vipera ammodytes ammodytes, and heterodimeric crotoxin from crotalus durissus terrificus, and a detailed structural analysis of their multiple functional sites. we have recently determined at high resolution the crystal structures of two natural isoforms of ammodytoxin (atxa and atxc) (saul et al., 2010) which exhibit different toxicity profiles and different an ...201222683534
lmrtx, a basic pla₂ (d49) purified from lachesis muta rhombeata snake venom with enzymatic-related antithrombotic and anticoagulant activity.a basic phospholipase a₂ (lmrtx) isoform was isolated from lachesis muta rhombeata snake venom and partially characterized. the venom was fractionated by molecular exclusion chromatography in ammonium bicarbonate buffer followed by reverse-phase hplc on a c-5 discovery® bio wide column. from liquid chromatography-electrospray ionization/mass spectrometry, the molecular mass of lmrtx was measured as 14.277.50 da. the amino acid sequence showed a high degree of homology between pla₂ lmrtx from l. ...201222750534
microbiological evaluation of different strategies for management of snakes in captivity.keeping snakes in captivity to produce venom for scientific research and production of inputs is now a worldwide practice. maintaining snakes in captivity involves capture, infrastructure investments, management techniques, and appropriate qualified personnel. further, the success of the project requires knowledge of habitat, nutrition, and reproduction, and control of opportunistic infections. this study evaluated the management of snakes in three types of captivity (quarantine, intensive, and ...201222852856
antiplasmodial effect of the venom of crotalus durissus cumanensis, crotoxin complex and crotoxin b.the antiplasmodial activity of phospholipases a(2) (pla(2)) isolated from different animals has been studied. we explored the in vitro anti plasmodium falciparum effect of a fraction containing crotoxin, crotoxin b and whole venom of the rattlesnake crotalus durissus cumanensis. fraction ii (crotoxin complex) was obtained by size exclusion chromatography, whereas crotoxin b was purified by rp-hplc. the whole venom is active against the parasite at concentrations of 0.17±0.03 μg/ml, fraction ii a ...201222884508
kinetic characterization of gyroxin, a serine protease from crotalus durissus terrificus venom.this work describes for the first time the characterization of the enzymatic features of gyroxin, a serine protease from crotalus durissus terrificus venom, capable to induce barrel rotation syndrome in rodents. measuring the hydrolysis of the substrate zfr-mca, the optimal ph for proteolytic cleavage of gyroxin was found to be at ph 8.4. increases in the hydrolytic activity were observed at temperatures from 25 °c to 45 °c, and increases of nacl concentration up to 1 m led to activity decreases ...201222898589
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