An internet database of crotaline venom found in the United States

Comparative study of anticoagulant and procoagulant properties of 28 snake venoms from families Elapidae, Viperidae, and purified Russell's viper venom-factor X activator (RVV-X)

Snake venoms consist of numerous molecules with diverse biological functions used for capturing prey. Each component of venom has a specific target, and alters the biological function of its target. Once these molecules are identified, characterized, and cloned; they could have medical applications. The activated clotting time (ACT) and clot rate were used for screening procoagulant and anticoagulant properties of 28 snake venoms. Crude venoms from Daboia russellii siamensis, Bothrops asper, Bothrops moojeni, and one Crotalus oreganus helleri from Wrightwood, CA, had procoagulant activity. These venoms induced a significant shortening of the ACT and showed a significant increase in the clot rate when compared to the negative control. Factor X activator activity was also measured in 28 venoms, and D. r. siamensis venom was 5-6 times higher than those of B. asper, B. moojeni, and C. o. helleri from Wrightwood County. Russell's viper venom-factor X activator (RVV-X) was purified from D. r. siamensis venom, and then procoagulant activity was evaluated by the ACT and clot rate. Other venoms, Crotalus atrox and two Naja pallida, had anticoagulant activity. A significant increase in the ACT and a significant decrease in the clot rate were observed after the addition of these venoms; therefore, the venoms were considered to have anticoagulant activity. Venoms from the same species did not always have the same ACT and clot rate profiles, but the profiles were an excellent way to identify procoagulant and anticoagulant activities in snake venoms.

A novel quantitative proteomics reagent based on soluble nanopolymers

Bi-functionalized dendrimers leads to highly efficient quantitative proteomics and the determination of protease activities in snake venoms.

Characterization and identification of disintegrins inCrotalushorridusvenom by liquid chromatography and tandem matrix-assisted laser desorption ionization - quadrupole ion trap time-of-flight (MALDI-QIT-TOF) mass spectrometry

Two disintegrins were purified from the venom of Crotalus horridus by multiple-dimension liquid chromatography (MDLC) (specifically C18 reverse phase (RP) high-performance liquid chromatography followed by size exclusion chromatography (SEC), and anion exchange chromatography (SCX)). Both disintegrins were subjected to mass spectrometry to determine their intact molecular mass, the number of disulfide linkages, and protein sequence, respectively. These disintegrins were named horrdistatin 1 (nominal mass, 7231 Da) and horrdistatin 2 (nominal mass, 7451 Da), and had IC50(inhibitory concentrations) of 12.5 and 16.2 nmol/L (at 50%), respectively. For sequence confirmation from the C-terminal end, both disintegrins were derivatized using chemical-assisted fragmentation (CAF) and subsequently unzipped via collision-induced dissociation (CID) by matrix-assisted laser desorption – ionization – quadrupole ion trap time-of-flight (MALDI-QIT-TOF) mass spectrometry.Key words: disintegrins, mass spectrometry, snake venom, Timber rattlesnake, Crotalus horridus.

The efficacy of two antivenoms against the venom of North American snakes

Mortality due to snake envenomation is not a major problem in the United States with approximately 8-12 deaths per year, but envenomation is a serious problem that can result in functional disability, loss of extremities, and a costly recovery. Physicians encounter different clinical situations with each new snakebite victim because of the geographical variations in snake venoms. The best and most acceptable form of treatment is the use of antivenom; however, it must be administered as soon as possible since it is not so effective at reducing local signs of envenomation such as necrosis. The antivenom in the United States is in short supply, expensive and may not even be the most effective for neutralizing all North American snake venoms. In this study, we tested two antivenoms. The first was a Crotalidae Polyvalent Fab fragment with Ovine origin (FabO) manufactured in London, and the second was Antivipmyn, a Mexican manufactured antivenom that is F(ab')(2) fragment produced in horse (Fab(2)H). The efficacy of the two antivenoms was tested with 15 different snake venoms found in North America. Three different assays were used to test the efficacy of the antivenoms, the in vivo serum protection test (ED(50)), antihemorrhagic and anticoagulant. The Fab(2)H antivenom was most effective in neutralizing the hemorrhagic activity of 78% of the hemorrhagic venoms used in this study. In the ED(50) assay, the Fab(2)H antivenom was effective in neutralizing all venoms used in this study, while FabO neutralized all but C. m. molossus venom. However, in most cases, FabO required less antivenom than Fab(2)H antivenom to neutralize three LD(50).

Cross reactivity of three antivenoms against North American snake venoms

The antivenom in the United States today is in short supply, expensive and may not even be the most effective in neutralizing venoms from snakes in certain geographical locations. The ED(50) is considered to be the best indicator of antivenom efficacy, however, other tests are needed. In this study, three antivenoms (Antivipmyn (Fab(2)H), Crotalidae Polyvalent Immune Fab (Ovine) (FabO) and UCV (FabV) were used to test the effectiveness of neutralization of eight venoms (Agkistrodon piscivorus piscivorus, Bothrops asper, Crotalus adamanteus, C. durissus durissus, C. horridus atricaudatus, C. h. horridus, C. atrox, and C. molossus molossus). Four different assays were used to study the efficacy of the antivenoms: the antihemorrhagic, antigelatinase, antifibrinolytic and antihide powder azure. Fab(2)H antivenom was more effective in neutralizing the enzymatic activities of these eight venoms than FabO and FabV antivenoms.

The effects of Western Diamondback Rattlesnake (Crotalus atrox) venom on the production of antihemorrhagins and/or antibodies in the Virginia opossum (Didelphis virginiana)

Opossums are animals that are naturally resistant to the proteolytic effects of Crotalid venoms. Opossums possess proteinase inhibitors in their sera that bind to and neutralize hemorrhagic and other proteolytic activity in many snake venoms. The proteinase inhibitors are not antibodies since they have different molecular weights (60kDa) and pI (4.2). The purpose of this study was to determine if opossums were capable of producing antibodies against venom and/or increasing the production of proteinase inhibitors (specifically antihemorrhagins). Five different venom immunization protocols were used to determine the effects of the venom in the opossums. The dosages ranged from 1mg of venom per immunization to 350mg/kg body weight of venom per immunization. The antihemorrhagic response was increased, but there is no evidence to suggest that an opossum can produce antibodies against venom. The lack of an antibody response is most likely due to the natural proteinase inhibitors clearing the venom from the opossum's body before an antibody response can occur.