Coral Snake Venom Research Articles

Prey specificity, comparative lethality and compositional differences of coral snake venoms

Toxicities of crude venoms from 49 coral snake ( Micrurus sp.) populations, representing 15 nominal taxa, were examined in both laboratory mice and in native prey animals and compared with data gathered from two non-micrurine elapids and a crotalid, which served as outgroups. These venoms were further compared on the basis of 23 enzymatic activities. Both toxicities and enzymatic activities were analyzed with respect to natural prey preferences, as determined from stomach content analyses and literature reports. Venoms of nearly all Micrurus for which prey preferences are known, are more toxic to natural prey than to non-prey species. Except for amphisbaenians, prey are more susceptible to venoms of Micrurus that feed upon them, than to venoms of those that eat other organisms. All venoms were more toxic i.v.>i.p.>i.m. Route-specific differences in toxicity are generally greatest for preferred prey species. Cluster analyses of venom enzymatic activities resulted in five clusters, with the fish-eating M. surinamensis more distant from other Micrurus than even the crotalid, Bothrops moojeni. Ophiophagous and amphisbaenian-eating Micrurus formed two close subclusters, one allied to the outgroup species Naja naja and the other to the fossorial, ophiophagous Bungarus multicinctus. Prey preference is shown to be the most important determinant of venom composition in Micrurus.

Cloning and Characterization of an α-Neurotoxin-Type Protein Specific for the Coral Snake Micrurus corallinus

During the cloning of abundant cDNAs expressed in the Micrurus corallinus coral snake venom gland, we cloned an α-neurotoxin homologue cDNA (nxh1). Two others isoforms were also cloned (nxh3 and nxh7, respectively). The nxh1 cDNA codes for a potential coral snake toxin with a signal peptide of 21 amino acids plus a predicted mature peptide with 57 amino acids. The deduced protein is highly similar to known toxic three-finger α-neurotoxins, with four deduced S–S bridges at the same conserved positions. This is the first cDNA coding for a three-finger related protein described so far for coral snakes. However, the predicted protein does not possess some of the important amino acids for the nicotinic acetylcholine receptor interaction. This protein was expressed in Escherichia coli as a His-tagged protein that allowed the rapid purification of the recombinant protein. This protein was used to generate antibodies which recognized the recombinant protein in Western blot and also a single band present in the M. corallinus venom, but not in the venom of 10 other Micrurus species.

Coral snakes of the Americas: biology, identification, and venoms

Part 1 General Information: Overview. Part 2 Form and Distinguishing Features: External Features Internal Features. Part 3 Biology and Evolution: Ecology Feeding and Food Reproduction Enemies and Defense Mimicry - Imitation Fellowships Biogeography, Origin and Evolution. Part 4 Venoms and Snakebite: Venoms in Biology and Their Value Studies of Coral Snake Venom Chemical and Biological Characteristics of Venom Coral Snake Bite Accidents. Part 5 Identification, Description and Distribution By Countries: Identification Description of Species and Subspecies with Keys to the Subspecies Distribution by Countries. Appendices: Scientific and Common Names of Coral Snakes Summary of the Composition of Coral Snake Venom.

Coral snake mimicry: live snakes not avoided by a mammalian predator.

The occurrence of coral snake coloration among unrelated venomous and non-venomous New World snake species has often been explained in terms of warning coloration and mimicry. The idea that snake predators would avoid coral snakes in nature seems widely established and is postulated in many discussions on coral snake mimicry. However, the few workers that have tested a potential aposematic function of the conspicuous colour pattern focused exclusively on behaviour of snake predators towards coloured abstract models. Here we report on behaviour of temporarily caged, wild coatis (Nasua narica) when confronted with co-occurring live snakes, among which were two species of venomous coral snakes. Five different types of responses have been observed, ranging from avoidance to predation, yet none of the coatis avoided either of the two coral snake species or other species resembling these. As in earlier studies coatis appeared to avoid coral snake models, our findings show that results from studies with abstract snake models cannot unconditionally serve as evidence for an aposematic function of coral snake coloration.

Evolution of coloration, urotomy and coral snake mimicry in the snake genusScaphiodontophis(Serpentes: Colubridae)

The Neotropical hinged-tooth, coral snake mimics of the genus Scaphiodontophis are characterized by extremely long and disproportionately thick tails that are extremely fragile. Both the coloration and tail structure are putative antipredator devices. While all examples have components of the coloration that match those of the venomous coral snakes (family Elapidae), the range of variation is extreme, leading to controversy on the status of various populations, including nine named taxa. Individual, ontogenetic and geographic variation in scutellation and head, body and tail coloration were analysed to evaluate population status and possible evolutionary trends based on a sample of 183 examples from Mexico, Central America and Colombia. Variation in subcaudal counts show population differences (higher in Mexico and upper Central America) but are not congruent with geographic variation in coloration. Generally snakes from north of Nicaragua and from central and eastern Panama have a pattern of dyads (black-light-black bands separating red bands), those from Atlantic slope Nicaragua to western Panama a pattern of monads (light-black-light bands separating the red ones) and those from Colombia have both pattern types on the same snake. The dyads and/or monads may be present the length of the body and tail, restricted to the anterior part of the body or on the entire body or on the anterior part of the body and on the tail. Two or more of these variants may occur at a single geographic locality or only a single one may be present. Head and nuchal colour patterns (Z, A, V, and Du) are relatively consistent geographically. The Atlantic slope Guatemala, Belize and Honduras population have the A pattern, those of Nicaragua, Costa Rica and western Panama the V pattern, and those in Colombia a Du pattern. Other populations have the Z coloration. Intermediate conditions in coloration of the body and tail and head and neck are found at localities intermediate between the main pattern types, indicating intergradation among adjacent populations. Consequently, we regard these snakes as representative of a single species, Scaphiodontophis annulatus Duméril and Bibron and the eight other names applied to various populations and individuals as synonyms. Analysis of colour pattern leads us to the conclusion that the tricolour pattern evolved from a uniform one through a lineate-spotted condition (usually present on the non-tricolour portions of the snake) through a bicolour red and black pattern to the dyadal condition. The monadal pattern in turn was derived from the dyadal one. The data further indicates that tricolour components first appeared anteriorly and progressively expanded posteriorly. The evolutionary sequence for the head and nuchal pattern appears to be A → Z → V → Du S. annulatus has a series of jaw and tooth specializations designed for rapid processing of hard-bodied prey found during diurnal foraging in the leaf-litter. Urotomy in this species involves intervertebral tail-breakage (pseudoautotomy) without regeneration. Evidence is presented supporting the long-tail multiple break hypothesis as applicable to Scaphiodontophis and other snakes with similar tail morphology (specialized pseudoautotomy). This is in contrast to snakes with similar tail morphology (specialized pseudoautotomy). This is in contrast to Coniophanes and other snakes with a high incidence of urotomy having long but unspecialized tails (unspecialized pseudoautotomy) without multiple breaks over time. All Scaphiodontophis colour patterns have a general resemblance to that of venomous coral snakes and offer protection from generalizing predators having innate or other triggered responses to coral snake colours. The aposematic effect is enhanced by tail thrashing and head twitching behaviours. The characteristic foraging pose of S. annulatus , which tends to expose the head and anterior body, makes even the incomplete tricolour pattern effective as an antipredator defense. No evidence supports the idea that tail thrashing or the incomplete tricolour pattern directs the predator attacks to the tail to expedite pseudoautotomy. Coral snake mimicry and specialized pseudoautotomy are shown not to be co-evolved and pseudautotomy seems to have evolved long before mimetic coloration in this genus.

Evolution of coloration, urotomy and coral snake mimicry in the snake genus Scaphiodontophis (Serpentes: Colubridae)

The Neotropical hinged-tooth, coral snake mimics of the genusScaphiodontophisare characterized by extremely long and disproportionately thick tails that are extremely fragile. Both the coloration and tail structure are putative antipredator devices. While all examples have components of the coloration that match those of the venomous coral snakes (family Elapidae), the range of variation is extreme, leading to controversy on the status of various populations, including nine named taxa. Individual, ontogenetic and geographic variation in scutellation and head, body and tail coloration were analysed to evaluate population status and possible evolutionary trends based on a sample of 183 examples from Mexico, Central America and Colombia. Variation in subcaudal counts show population differences (higher in Mexico and upper Central America) but are not congruent with geographic variation in coloration. Generally snakes from north of Nicaragua and from central and eastern Panama have a pattern of dyads (black-light-black bands separating red bands), those from Atlantic slope Nicaragua to western Panama a pattern of monads (light-black-light bands separating the red ones) and those from Colombia have both pattern types on the same snake. The dyads and/or monads may be present the length of the body and tail, restricted to the anterior part of the body or on the entire body or on the anterior part of the body and on the tail. Two or more of these variants may occur at a single geographic locality or only a single one may be present. Head and nuchal colour patterns (Z, A, V, and Du) are relatively consistent geographically. The Atlantic slope Guatemala, Belize and Honduras population have the A pattern, those of Nicaragua, Costa Rica and western Panama the V pattern, and those in Colombia a Du pattern. Other populations have the Z coloration. Intermediate conditions in coloration of the body and tail and head and neck are found at localities intermediate between the main pattern types, indicating intergradation among adjacent populations. Consequently, we regard these snakes as representative of a single species,Scaphiodontophis annulatusDumeril and Bibron and the eight other names applied to various populations and individuals as synonyms. Analysis of colour pattern leads us to the conclusion that the tricolour pattern evolved from a uniform one through a lineate-spotted condition (usually present on the non-tricolour portions of the snake) through a bicolour red and black pattern to the dyadal condition. The monadal pattern in turn was derived from the dyadal one. The data further indicates that tricolour components first appeared anteriorly and progressively expanded posteriorly. The evolutionary sequence for the head and nuchal pattern appears to be A → Z → V → DuS. annulatushas a series of jaw and tooth specializations designed for rapid processing of hard-bodied prey found during diurnal foraging in the leaf-litter. Urotomy in this species involves intervertebral tail-breakage (pseudoautotomy) without regeneration. Evidence is presented supporting the long-tail multiple break hypothesis as applicable toScaphiodontophisand other snakes with similar tail morphology (specialized pseudoautotomy). This is in contrast to snakes with similar tail morphology (specialized pseudoautotomy). This is in contrast toConiophanesand other snakes with a high incidence of urotomy having long but unspecialized tails (unspecialized pseudoautotomy) without multiple breaks over time. AllScaphiodontophiscolour patterns have a general resemblance to that of venomous coral snakes and offer protection from generalizing predators having innate or other triggered responses to coral snake colours. The aposematic effect is enhanced by tail thrashing and head twitching behaviours. The characteristic foraging pose ofS. annulatus, which tends to expose the head and anterior body, makes even the incomplete tricolour pattern effective as an antipredator defense. No evidence supports the idea that tail thrashing or the incomplete tricolour pattern directs the predator attacks to the tail to expedite pseudoautotomy. Coral snake mimicry and specialized pseudoautotomy are shown not to be co-evolved and pseudautotomy seems to have evolved long before mimetic coloration in this genus.

Experimental Studies of Coral Snake Mimicry: Generalized Avoidance of Ringed Snake Patterns by Free-Ranging Avian Predators

Summary 1. Plasticine snake replicas were used to demonstrate that free-ranging avian predators generalize avoidance of Coral Snake ringed patterns to similar patterns, supporting the argument that the convergence on ringed and banded patterns among neotropical snakes is a result of the mimetic advantage of resembling venomous Coral Snakes. 2. The study was conducted at a tropical dry forest site in Costa Rica, where only one species of Coral Snake occurs. The Coral Snake has a tricolour (red-yellow-blackyellow-red) ringed pattern and no snakes at the site have bicolour (red-black) ringed patterns. Neither tricolour nor bicolour ringed replicas were attacked by birds, whereas an unmarked brown replica was. 3. The avoidance of the bicolour ringed pattern is attributable to generalized avoidance of Coral Snake-like patterns. No red-and-black ringed prey have been observed at the site, so birds could not have learned specific avoidance of the bicolour pattern. Historical biogeographical evidence suggests that the avifauna at the site did not evolve in the presence of red-and-black ringed snakes, so it is unlikely that birds evolved a specific innate avoidance of the bicolour ringed pattern.

Reverse Biology Applied toMicrurus corallinus, a South American Coral Snake

AbstractLittle is known about the coral snakes venom components. Clarification of the primary structure of polypeptidic toxins was hampered until now by the lack of enough venom for protein purification and chemistry. Using the Reverse Biology approach, several potential Micrurus corallinus toxins were characterized by cDNA cloning. The deduced proteins shared homology with known snake toxins, such as α-neurotoxins, phospholipase A2, natriuretic peptides and lectins. To our knowledge, these are the first complete primary structure characterization of coral snake venom toxins.

Local effects induced by venoms from five species of genus Micrurus sp. (coral snakes)

Venoms from five species of Micrurus (coral snakes) from Brazil (Amazonas State) were tested for the following effects: edematogenic, myotoxic, coagulant, hemorrhagic and phospholipase A2 (PLA2) detection. None of the venoms tested presented coagulant activity. The presence of PLA2 was detected by ELISA in the venoms of M. spixii, M. averyi and M. lemniscatus. The myotoxicity was estimated by the increase in the serum creatine kinase level and by histological analysis. All venoms, except that from M. surinamensis, induced intense edematogenic and myotoxic effects. The venom of M. averyi showed hemorrhagic activity which was confirmed by histopathological analysis. This is the first evidence of such an effect by coral snake venom.

DIFFERENTIAL AVOIDANCE OF CORAL SNAKE BANDED PATTERNS BY FREE-RANGING AVIAN PREDATORS IN COSTA RICA.

Empirical studies of mimicry have rarely been conducted under natural conditions. Field investigations of some lepidopteran systems have provided a bridge between experiments examining artificial situations and the mimicry process in nature, but these systems do not include all types of mimicry. The presence of dangerous or deadly models is thought to alter the usual rules for mimicry complexes. In particular, a deadly model is expected to protect a wide variety of mimics. Avoidance of different types of mimics should vary according to how closely they resemble the model. Coral snake mimicry complexes in the neotropics may provide natural systems in which these ideas can be examined, but there is no direct evidence that the patterns of venomous coral snakes or potential mimics are avoided in the wild. Plasticine replicas of snakes were used to assess the frequency of avian predation attempts as a function of color pattern. Avian predators left identifiable marks on the replicas, the position of which indicated that replicas were perceived as potentially dangerous prey items by birds. The number of attacks on unmarked brown replicas was greater than that on tricolor coral snake banded replicas. This result was true whether replicas were placed on natural or plain white backgrounds, suggesting that coral snake banded patterns function aposematically. In a separate experiment, replicas representing all six patterns of proposed coral mimics at the study site were attacked less often than unmarked brown replicas. Within these six banded patterns, some were attacked significantly more often than others. This study provides direct field evidence that coral snake banded patterns are avoided by free-ranging avian predators and supports theoretical predictions about mimicry systems involving deadly models.

The colouration of the venomous coral snakes (family Elapidae) and their mimics (families Aniliidae and Colubridae)

The bright coloured, highly venomous coral snakes, Leptomicrurus, Micrurus and Micruroides (family Elapidae) and a series of harmless or mildly toxic mimics form an important component of the snake fauna of the Americas. Coral snake patterns are defined as any dorsal pattern found in any species of venomous coral snake and/or any dorsal pattern containing a substantial amount of red, pink or orange distributed so as to resemble that of some species of venomous coral snake. The components of coral snake colouration are described and four principal dorsal patterns are recognized: unicolour, bicolour, tricolour and quadricolour. The tricolour patterns may be further clustered based on the number of black bands or rings separating the red ones as: monads, dyads, triads, tetrads or pentads. A detailed classification of all coral snake colour patterns is presented and each pattern is illustrated. The taxonomic distribution of these patterns is surveyed for mimics and the 56 species of highly venomous coral snakes. Among the latter, the most frequent encountered patterns are tricolour monads, tricolour triads and bicolour rings, in that order. No venomous coral snakes have a tricolour dyad, tricolour tetrad or quadricolour pattern. As many as 115 species of harmless or mildly toxic species, c. 18% of all American snakes, are regarded as coral snake mimics. The colouration and behavioural traits of venomous coral snakes combine to form a significant antipredator defence of an aposematic type. The mimics in turn receive protection from predators that innately or through learning avoid coral snake colour patterns. The precise resemblances in colouration between sympatric non-coral snakes and venomous coral snakes and the concordant geographic variation between the two strongly support this view. Batesian mimicry with the highly venomous coral snakes as the models and the other forms as the mimics is the favoured explanation for this situation. It is further concluded that a number of species in the genera Elaphe, Farancia, Nerodia and Thamnophis, although having red in their colouration, should not be included in the coral snake mimic guild.

Comparative enzymatic composition of brazilian coral snake ( Micrurus) venoms

1. 1. Venoms of 11 coral snake taxa, including Micrurus albicinctus, M. corallinus, M. frontalis altirostris, M. f. brasiliensis, M. f. frontalis, M. fulvius fulvius, M. ibiboboca, M. lemniscatus ssp., M. rondonianus, M. spixii spixii, and M. surinamensis surinamensis, were examined for 13 enzymatic activities. 2. 2. These were compared with venoms of three outgroup taxa: Naja naja kaouthia, Bungarus multicinctus, and Bothrops moojeni. 3. 3. Enzyme activity levels in Micrurus venoms were highly variable from species to species. 4. 4. All venoms possessed phospholipase activity. 5. 5. Protease activity against synthetic or dyed natural substrates was generally negligible in all elapid venoms examined. By contrast, most Micrurus venoms displayed ample l-leucine aminopeptidase activity. 6. 6. Venom of M.s. surinamensis was significantly different from those of its congeners in most assays.

Comparative chromatography of Brazilian coral snake ( Micrurus venoms

1. 1. Elution profiles of 11 coral snake venoms, including those of Micrurus albicinctus, M. corallinus, M. frontalis altirostris, M. f. brasiliensis, M. f. frontalis, M. fulvius fulvius, M. ibiboboca, M. lemniscatus ssp., M. rondonianus, M. spixii spixii and M. surinamensis surinamensis, were compared using high performance gel filtration and reverse phase media. 2. 2. Micrurus venom profiles were compared with those of “outgroup” taxa Bothrops moojeni, Naja naja kaouthia and Bungarus multicinctus. 3. 3. Purified elapid venom constituents were also chromatographed under identical conditions in order to suggest possible identities of Micrurus venom constituents. 4. 4. Masses of various components were confirmed by mass spectrometry. 5. 5. Phospholipase constituents in three venoms were positively identified based on their reverse phase chromatograms. 6. 6. Venoms of M. rondonianus and M. s. surinamensis are shown to be significantly different in their peptide composition from other Micrurus venoms.

The status of Pliocercus and Urotheca (Serpentes: Colubridae), with a review of included species of coral snake mimics

The generic name Urotheca Bibron, 1843 is revived for a group of Neotropical colubrid snakes diagnosed by a long, thickened but fragile tail and the presence of a specialized naked pocket on the asulcate surface of the hemipenial capitulum. Urotheca includes those species previously placed in the lateristriga group of the genus Rhadinaea and the coral snake mimics usually referred to the genus Pliocercus. The many names based upon the coral snake mimics are shown to represent two species at most: Urotheca elapoides, a bicolour (red and black) or tricolour (red, yellow and black) banded or ringed form found in Mexico and northern Central America and U. euryzona, which is usually bicolour (red, yellow or white and black) and ranges from Nicaragua to western Ecuador. Coloration in U. elapoides resembles closely that of sympatric species of venomous coral snakes. Local variation in coloration and a geographic trend in the colour of the light rings (usually red in the north, white to the south) in U. euryzona parallels similar colour variation in the sympatric venomous coral snake Micrurus mipartitus. These patterns of variation add strong support to the idea that the two species are mimics of the highly venomous coral snakes. Urotheca, including the non-mimetic species U. decipiens, U. fulmceps, U. guentheri, U. lateristriga, U. multilineata and U. pachyura, shares the characteristic of a very long and disproportionately thickened and fragile tail with the coral snake mimics of the distantly related genus Scapkiodontophis. Members of both genera have a very high proportion (about 50%) of the tails broken indicating a probable predator escape device. Breakage is intercentral, with a calcified cap developing over the tip of the distal surface of the new terminal vertebra unlike the situation in many lizards where there is an intracentral fracture septum and the tail is regenerated.

Coral snake venoms: mode of action and pathophysiology of experimental envenomation

Coral snakes, the New World Elapidae, are included in the genera Micniroides and Micrurus. The genus Mlcrurus comprises nearly all coral snake species and those which are responsible for human snake-bite accidents. The following generalizations concerning the effects induced by their venoms, and their venom-properties can be made. Coral snake venoms are neurotoxic, producing loss of muscle strenght and death by respiratory paralysis. Local edema and necrosis are not induced nor blood coagulation or hemorrhages. Proteolysis activity is absent or of very low grade. They display phospholipase A2 activity. Nephrotoxic effects are not evoked. The main toxins from elapid venoms are postsynaptic and presynaptic neurotoxins and cardiotoxins. Phospholipases A2 endowed with myonecrotic or cardiotoxin-like properties are important toxic components from some elapid venoms. The mode of action of Micrurus frontalis, M. lemniscatus, M. corallinus and M. fulvius venoms has been investigated in isolated muscle preparations and is here discussed. It is shown that while M. frontalis and M. lemniscatus venoms must contain only neurotoxins that act at the cholinergic end-plate receptor (postsynaptic neurotoxins), M. corallinus venom also inhibits evoked acetylcholine release by the motor nerve endings (presynaptic neurotoxin-like effect) and M. fulvius induces muscle fiber membrane depolarization (cardiotoxin-like effect). The effects produced by M. corallinus and M. fulvius venoms in vivo in dogs and M. frontalis venom in dogs and monkeys are also reported.

Local effects induced by coral snake venoms: Evidence of myonecrosis after experimental inoculations of venoms from five species

The local effects induced by intramuscular inoculations of venoms from six species of coral snakes were studied in mice. Venoms of Micrurus nigrocinctus nigrocinctus, M. n. mosquitensis, M. alleni, M. frontalis, M. carinicauda and M. surinamensis induced prominent myonecrosis which was observed histologically. From a morphological point of view all these venoms induced a similar pattern of myonecrosis, characterized by a conspicuous alteration of the intracellular structure. This myotoxic activity was corroborated by an increase in plasma creatine kinase levels 3 hr after i.m. injection of M. n. nigrocinctus, M. n. mosquitensis, M. frontalis and M. carinicauda venoms. M. mipartitus venom did not induce myonecrosis. None of the venoms induced edema or hemorrhage at the site of injection.

The venomous coral snakes (genus Micrurus) of Costa Rica.

Four species of venomous coral snakes ( Micrurus ) occur in Costa Rica. The single bicolor species, M. mipartitus has previously been defined as two subspecies; however, variations in diagnostic characters clemonstrate dinal shift that precludes recognition of geographic races. Presence of the tricolor M. clarki is concluded from but a single Costa Rican specimen, although the species is otherwise definitely known from adjacent areas in Panama. Variation among tricolor coral snakes allied to M. nigrocinctus suggests the presence of three populations that occupy southwestern Pacific Costa Rica, northwestern Pacific Costa Rica and western Nicaragua, and Atlantic lowland Costa Rica. Gradual intergradation in the Pacific lowlanels, as well as more complex intergrading patterns in the Meseta Central and Arenal regions and over a broad arca of Nicaragua, eliminate the value of subspecific designations. Where M. nigrocinctus occurs sympatrically with populations of the closely related M. alleni , they can be constently distinguished by differences in head cap patterns and segmental counts. Micrurus alleni is composed of three allopatric populations in the Atlantic lowlands of Costa Rica anel Nicaragua, the southwestern Pacific lowlands of Costa Rica and adjacent southwestern Panama, and Pacific lowland Darien in eastern Panama. Becaust of limited information on variation among these populations we prefer not to apply the trinomials.

Neuromuscular blockade of chick biventer cervicis nerve-muscle preparations by a fraction from coral snake venom

Neuromuscular blockade of chick biventer cervicis nerve-muscle preparations by a fraction from coral snake venom

Fractionation of coral snake venom. Preliminary studies on the separation and characterization of the protein fractions.

Abstract Lyophilized coral snake ( Micrurus f.fulvius ) venom was fractionated into six homogeneous and one heterogeneous fractions (labelled F-FVII in order of their elution) using CM-cellulose columns eluted with phosphate buffers (pH 6·0–9·0). Identification of each fraction on starch gel electrophoresis revealed that fractions I through VI migrated as homogeneous proteins. FVII was composed of four separate migrating units. All of the migrating units present in the crude venom were accounted for in the seven fractions. FIII, VI and VII each accounting for approximately 25 per cent of the recovery weight, were equally toxic, and were as toxic as the crude venom. All three possessed a strong anticoagulant activity. FIV and V present in moderate amounts, were toxic at concentrations 10 times that of the crude venom and possessed a weak anticoagulant activity. FII was toxic at concentrations 20 times that of the crude venom while FI was not toxic. All seven fractions exhibited a strong phospholipase A activity and hemolyzed red cells. None of the fractions nor the crude venom hemolyzed red cells without ovolecithin. None of the fractions or crude venom were proteolytic.

Fractionation of coral snake venom—Preliminary studies on the separation and characterization of the protein fractions

Fractionation of coral snake venom—Preliminary studies on the separation and characterization of the protein fractions