Crotalus: A genus of snakes of the family VIPERIDAE, one of the pit vipers, so-called from the pit hollowing out the maxillary bone, opening between the eye and the nostril. They are distinctively American serpents. Most of the 25 recognized species are found in the southwestern United States and northern Mexico. Several species are found as far north as Canada and east of the Mississippi, including southern Appalachia. They are named for the jointed rattle (Greek krotalon) at the tip of their tail. (Goin, Goin, and Zug: Introduction to Herpetology, 3d ed; Moore: Poisonous Snakes of the World, 1980, p335)Crotalid Venoms: Venoms from snakes of the subfamily Crotalinae or pit vipers, found mostly in the Americas. They include the rattlesnake, cottonmouth, fer-de-lance, bushmaster, and American copperhead. Their venoms contain nontoxic proteins, cardio-, hemo-, cyto-, and neurotoxins, and many enzymes, especially phospholipases A. Many of the toxins have been characterized.Crotoxin: A specific complex of toxic proteins from the venom of Crotalus durissus terrificus (South American rattlesnake). It can be separated into a phospholipase A and crotapotin fragment; the latter consists of three different amino acid chains, potentiates the enzyme, and is specifically neurotoxic.Snakes: Limbless REPTILES of the suborder Serpentes.Snake Venoms: Solutions or mixtures of toxic and nontoxic substances elaborated by snake (Ophidia) salivary glands for the purpose of killing prey or disabling predators and delivered by grooved or hollow fangs. They usually contain enzymes, toxins, and other factors.Reptilian Proteins: Proteins obtained from species of REPTILES.Snake Bites: Bites by snakes. Bite by a venomous snake is characterized by stinging pain at the wound puncture. The venom injected at the site of the bite is capable of producing a deleterious effect on the blood or on the nervous system. (Webster's 3d ed; from Dorland, 27th ed, at snake, venomous)Antivenins: Antisera used to counteract poisoning by animal VENOMS, especially SNAKE VENOMS.Viperidae: A family of snakes comprising three subfamilies: Azemiopinae (the mountain viper, the sole member of this subfamily), Viperinae (true vipers), and Crotalinae (pit vipers). They are widespread throughout the world, being found in the United States, Central and South America, Europe, Asia and Africa. Their venoms act on the blood (hemotoxic) as compared to the venom of elapids which act on the nervous system (neurotoxic). (Goin, Goin, and Zug, Introduction to Herpetology, 3d ed, pp333-36)Phospholipases A2: Phospholipases that hydrolyze the acyl group attached to the 2-position of PHOSPHOGLYCERIDES.Phospholipases: A class of enzymes that catalyze the hydrolysis of phosphoglycerides or glycerophosphatidates. EC 3.1.-.L-Amino Acid Oxidase: An enzyme that catalyzes the oxidative deamination of L-amino acids to KETO ACIDS with the generation of AMMONIA and HYDROGEN PEROXIDE. L-amino acid oxidase is widely distributed in and is thought to contribute to the toxicity of SNAKE VENOMS.Bothrops: A genus of poisonous snakes of the VIPERIDAE family. About 50 species are known and all are found in tropical America and southern South America. Bothrops atrox is the fer-de-lance and B. jararaca is the jararaca. (Goin, Goin, and Zug, Introduction to Herpetology, 3d ed, p336)Venoms: Poisonous animal secretions forming fluid mixtures of many different enzymes, toxins, and other substances. These substances are produced in specialized glands and secreted through specialized delivery systems (nematocysts, spines, fangs, etc.) for disabling prey or predator.Disintegrins: A family of polypeptides purified from snake venoms, which contain the arginine-glycine-aspartic acid (RGD) sequence. The RGD tripeptide binds to integrin receptors and thus competitively inhibits normal integrin-ligand interactions. Disintegrins thus block adhesive functions and act as platelet aggregation inhibitors.Phospholipases A: Phospholipases that hydrolyze one of the acyl groups of phosphoglycerides or glycerophosphatidates.

Phosphatidylinositol 3'-kinase and tyrosine-phosphatase activation positively modulate Convulxin-induced platelet activation. Comparison with collagen. (1/124)

In this report we have studied the role of phosphatidylinositol 3'-kinase (PI3-K) and tyrosine phosphatase activation on platelet activation by Convulxin (Cvx). Wortmannin, a specific PI3-K inhibitor, and phenylarsine oxide (PAO), a sulfhydryl reagent that inhibits tyrosine phosphatase (PTPase), block Cvx-induced platelet aggregation, granule secretion, inositol phosphate production, and increase in [Ca2+]i. However, PAO does not inhibit Cvx-induced tyrosine phosphorylation of platelet proteins, including Syk and PLCgamma2, but blocked collagen-induced platelet aggregation as well as tyrosine phosphorylation of PLCgamma2. In contrast, Cvx-induced PLCgamma2 tyrosyl phosphorylation was partially inhibited by wortmannin. We conclude that (i) although Cvx and collagen activate platelets by a similar mechanism, different regulatory processes are specific to each agonist; (ii) mechanisms other than tyrosine phosphorylation regulate PLCgamma2 activity; and (iii) besides protein tyrosine kinases, PI3-K (and PTPase) positively modulate platelet activation by both Cvx and collagen, and this enzyme is required for effective transmission of GPVI-Fc receptor gamma chain signal to result in full activation and tyrosine phosphorylation of PLCgamma2 in Cvx-stimulated platelets.  (+info)

Combining phage display and molecular modeling to map the epitope of a neutralizing antitoxin antibody. (2/124)

Crotoxin is a potent presynaptic neurotoxin from the venom of the rattlesnake Crotalus durissus terrificus. It is composed of the noncovalent and synergistic association of a weakly toxic phospholipase A2, CB, and a nontoxic three-chain subunit, CA, which increases the lethal potency of CB. The A-56.36 mAb is able to dissociate the crotoxin complex by binding to the CA subunit, thereby neutralizing its toxicity. Because A-56.36 and CB show sequence homology and both compete for binding to CA, we postulated that A-56.36 and CB had overlapping binding sites on CA. By screening random phage-displayed libraries with the mAb, phagotopes bearing the (D/S)GY(A/G) or AAXI consensus motifs were selected. They all bound A-56.36 in ELISA and competed with CA for mAb binding, although with different reactivities. When mice were immunized with the selected clones, polyclonal sera reacting with CA were induced. Interestingly, the raised antibodies retained the crotoxin-dissociating effect of A-56.36, suggesting that the selected peptides may be used to produce neutralizing antibodies. By combining these data with the molecular modeling of CA, it appeared that the functional epitope of A-56.36 on CA was conformational, one subregion being discontinuous and corresponding to the first family of peptides, the other subregion being continuous and composed of amino acids of the second family. Phage-displayed peptides corresponding to fragments of the two identified regions on CA reacted with A-56.36 and with CB. Our data support the hypothesis that A-56.36 and CB interact with common regions of CA, and highlight residues which are likely to be critical for CA-CB complex formation.  (+info)

Interaction of the neurotoxic and nontoxic secretory phospholipases A2 with the crotoxin inhibitor from Crotalus serum. (3/124)

Crotalus durissus terrificus snakes possess a protein in their blood, named crotoxin inhibitor from Crotalus serum (CICS), which protects them against crotoxin, the main toxin of their venom. CICS neutralizes the lethal potency of crotoxin and inhibits its phospholipase A2 (PLA2) activity. The aim of the present study is to investigate the specificity of CICS towards snake venom neurotoxic PLA2s (beta-neurotoxins) and nontoxic mammalian PLA2s. This investigation shows that CICS does not affect the enzymatic activity of pancreatic and nonpancreatic PLA2s, bee venom PLA2 and Elapidae beta-neurotoxins but strongly inhibits the PLA2 activity of Viperidae beta-neurotoxins. Surface plasmon resonance and PAGE studies further demonstrated that CICS makes complexes with monomeric and multimeric Viperidae beta-neurotoxins but does not interact with nontoxic PLA2s. In the case of dimeric beta-neurotoxins from Viperidae venoms (crotoxin, Mojave toxin and CbICbII), which are made by the noncovalent association of a PLA2 with a nonenzymatic subunit, CICS does not react with the noncatalytic subunit, instead it binds tightly to the PLA2 subunit and induces the dissociation of the heterocomplex. In vitro assays performed with Torpedo synaptosomes showed a protective action of CICS against Viperidae beta-neurotoxins but not against other PLA2 neurotoxins, on primary and evoked liberation of acetylcholine. In conclusion, CICS is a specific PLA2 inhibitor of the beta-neurotoxins from the Viperidae family.  (+info)

The disulfide bond pattern of catrocollastatin C, a disintegrin-like/cysteine-rich protein isolated from Crotalus atrox venom. (4/124)

The disulfide bond pattern of catrocollastatin-C was determined by N-terminal sequencing and mass spectrometry. The N-terminal disintegrin-like domain is a compact structure including eight disulfide bonds, seven of them in the same pattern as the disintegrin bitistatin. The protein has two extra cysteine residues (XIII and XVI) that form an additional disulfide bond that is characteristically found in the disintegrin-like domains of cellular metalloproteinases (ADAMs) and PIII snake venom Zn-metalloproteinases (SVMPs). The C-terminal cysteine-rich domain of catrocollastatin-C contains five disulfide bonds between nearest-neighbor cysteines and a long range disulfide bridge between CysV and CysX. These results provide structural evidence for a redefinition of the disintegrin-like and cysteine-rich domain boundaries. An evolutionary pathway for ADAMs, PIII, and PII SVMPs based on disulfide bond engineering is also proposed.  (+info)

Shaking up glycolysis: Sustained, high lactate flux during aerobic rattling. (5/124)

Substantial ATP supply by glycolysis is thought to reflect cellular anoxia in vertebrate muscle. An alternative hypothesis is that the lactate generated during contraction reflects sustained glycolytic ATP supply under well-oxygenated conditions. We distinguished these hypotheses by comparing intracellular glycolysis during anoxia to lactate efflux from muscle during sustained, aerobic contractions. We examined the tailshaker muscle of the rattlesnake because of its uniform cell properties, exclusive blood circulation, and ability to sustain rattling for prolonged periods. Here we show that glycolysis is independent of the O(2) level and supplies one-third of the high ATP demands of sustained tailshaking. Fatigue is avoided by rapid H(+) and lactate efflux resulting from blood flow rates that are among the highest reported for vertebrate muscle. These results reject the hypothesis that glycolysis necessarily reflects cellular anoxia. Instead, they demonstrate that glycolysis can provide a high and sustainable supply of ATP along with oxidative phosphorylation without muscle fatigue.  (+info)

A comparison of RAPD versus microsatellite DNA markers in population studies of the massasauga rattlesnake. (6/124)

We compared genetic differentiation among populations of the threatened massasauga rattlesnake (Sistrurus c. catenatus) using two types of nuclear molecular markers: randomly amplified polymorphic DNA (RAPD) markers and microsatellites. Analyses of molecular variance (AMOVA) and G(ST) and F(ST) analyses indicated that levels of among-population differentiation between regional populations (>100 km) were comparable for both markers. However, microsatellites were superior in population assignment tests and at discerning fine-scale genetic differentiation between subpopulations separated by tens of kilometers. These results argue that both types of markers are suitable for defining broad-scale genetic structures in snake populations and can provide important inputs into conservation initiatives of focal taxa. However, our analyses suggest that microsatellites 3re better for detecting structure at limited spatial scales.  (+info)

Insights into population ecology and sexual selection in snakes through the application of DNA-based genetic markers. (7/124)

Hypervariable genetic markers have revolutionized studies of kinship, behavioral ecology, and population biology in vertebrate groups such as birds, but their use in snakes remains limited. To illustrate the value of such markers in snakes, we review studies that have used microsatellite DNA loci to analyze local population differentiation and parentage in snakes. Four ecologically distinct species of snakes all show evidence for differentiation at small spatial scales (2-15 km), but with substantial differences among species. This result highlights how genetic analysis can reveal hidden aspects of the natural history of difficult-to-observe taxa, and it raises important questions about the ecological factors that may contribute to restricted gene flow. A 3-year study of genetic parentage in marked populations of the northern water snake showed that (1) participation in mating aggregations was a poor predictor of genetic-based measures of reproductive success; (2) multiple paternity was high, yet there was no detectable fitness advantage to multiple mating by females; and (3) the opportunity for selection was far higher in males than in females due to a larger variance in male reproductive success, and yet this resulted in no detectable selection on morphological variation in males. Thus genetic markers have provided accurate measures of individual reproductive success in this species, an important step toward resolving the adaptive significance of key features including multiple paternity and reversed sexual size dimorphism. Overall these studies illustrate how genetic analyses of snakes provide previously unobtainable information of long-standing interest to behavioral ecologists.  (+info)

Purification and characterisation of a haemorrhagic fraction from the venom of the Uracoan rattlesnake Crotalus vegrandis. (8/124)

Uracoan rattlesnake (Crotalus vegrandis) venom was subjected to chromatographic, electrophoretic, biochemical and in vivo haemorrhagic analysis. A haemorrhagic toxin (Uracoina-1) active on skin at the site of inoculation in mice was purified by Mono Q2 anion-exchange chromatography and size exclusion (SE) high-performance liquid chromatography. The purified preparation was a protein of M(r) 58,000 as revealed by sodium dodecyl sulphate--polyacrylamide gel electrophoresis under denatured conditions and with silver staining. The use of EDTA, EGTA and 1,10-phenanthroline inhibited haemorrhagic and proteolytic activities. Inhibitors of serine proteinases such as PMSF and TCLK had no effect on the haemorrhagic fraction. Uracoina-1 hydrolyses casein, hide powder azure and fibrinogen have an optimal pH of 8.2. It rapidly digests the A alpha-chain of fibrinogen. Thermal denaturation of Uracoina-1 after exposure at 60 degrees C for 15 min led to inactivation of the haemorrhagic activity. In addition, Uracoina-1 is myotoxic, lacking haemolytic, defibrinating and lethal effects. The N-terminal amino acid sequence (20 residues) was determined.  (+info)

  • Common names: twin-spotted rattlesnake, western twin-spotted rattlesnake, more Crotalus pricei is a venomous pit viper species found in the United States and Mexico. (
  • As serpentes peçonhentas dos gêneros Bothrops e Crotalus têm sido mantidas em cativeiro visando à extração de venenos para a produção de imunobiológicos. (
  • O objetivo do trabalho foi determinar a concentração de proteína total e o perfil eletroforético das proteínas séricas de serpentes Crotalus durissus terrificus (cascavel) criadas em cativeiro. (
  • The generic name Crotalus is derived from the Greek word κρόταλον krótalοn, which means "rattle" or "castanet", and refers to the rattle on the end of the tail which makes this group (genera Crotalus and Sistrurus) so distinctive. (
  • species formerly exclusively referred to the genera Crotalus and Sistrurus. (
  • Here, we demonstrate the utility of Genotyping-in-Thousands by sequencing (GT-seq), a targeted, multiplex amplicon approach, for genotyping minimally-invasive DNA samples from the Western Rattlesnake (Crotalus oreganus), a species-at-risk in British Columbia, Canada. (
  • In addition, other species, such as the Southern Pacific rattlesnake Crotalus oreganus helleri, (formerly Crotalus viridis helleri ), may cause signs and symptoms consistent with typical rattlesnake envenomation combined with signs and symptoms similar to Mojave rattlesnake envenomation. (
  • C. catalinensis has lost its rattle entirely, Crotalus lorenzoensis usually has no rattle, and both Crotalus ruber lucasensis and Crotalus estebanensis exhibit a tendency for rattle loss. (
  • En este trabajo se estudió la capacidad neutralizante de anticuerpos IgG anti-PLA 2 sobre la letalidad inducida por el veneno entero. (
  • La capacidad neutralizante del antisuero se analizó en ratones por inoculación con diluciones de veneno entero preincubado con un volumen adecuado de anticuerpos IgG anti-PLA 2 . (
  • Crotalicidina (Ctn), uma vipericidina relacionada com a catelicidina da glândula de veneno Crotalus durissus terrificus proveniente da América do Sul e seus fragmentos (Ctn1-14 e Ctn15-34) demonstraram atividade antimicrobiana e antifúngica, assim como a catelicidina humana LL-37. (
  • The Santa Catalina Rattlesnake ( Crotalus catalinensis ), also known as the " Santa Catalina Island Rattlesnake ", is a species of venomous Pit viper found on Santa Catalina Island . (
  • Flores-Villela, O. & Gerez, P. Biodiversidad y Conservación en México: Vertebrados y uso de Suelo (Comisión Nacional para el Uso y Conservación de la Biodiversidad, Universidad Nacional Autónoma de México, 1994). (