Venom Phospholipase A2 Research Articles

INHIBITORY ACTIVITY OF LUPEOL FROM Cryptolepis oblongifolia (MEINS) SCHLTR ON PARTIALLY PURIFIED PHOSPHOLIAPASE A2 VENOM OF Naja nigricollis (ELAPIDAE)

The research is design to provide scientific evidence for the use of Cryptolepis oblongifolia in traditional treatment of inflammation and also to examine whether it have some snake venom phospholipase A2 inhibition potential. A triterpene was isolated from C. oblongifolia using column chromatography and identified via spectroscopic means. The inhibitory activity of the isolate on phospholipase A2 (PLA2) of Naja nigricollis venom was evaluated. The proton nuclear magnetic resonance (1H NMR) of the isolated compound showed the presence of olefinic protons while the carbon nuclear magnetic resonance (13C NMR) showed the presence of exomethylene carbon atoms. By comparison with the reported literature the compound was found to be lupeol, the inhibitory activity of the isolate on PLA2 of Naja nigricollis venom showed that, the isolate inhibits the PLA2 at dose dependent manner with inhibition binding constant (ki) of 0.015 mg/ml. The activity of the compound isolated supports the local usage of C. oblongifolia in traditional treatment of inflammation.

Full sequencing and comparison of five venom metalloproteases of Trimeresurus gracilis: The PI-enzyme is most similar to okinalysin but the PIII-enzyme is most similar to Crotalus venom enzymes

The cDNAs encoding the Zn+2-metalloproteases (SVMPs) of Trimeresurus gracilis (abbreviated as Tgc), a pitviper endemic to Taiwan, were cloned from venom glands and sequenced. The amino-acid sequences of five novel SVMPs, including one P-III, three P-II and one P-I class enzymes, were thus deduced and subjected to BLAST-analyses. The P-III enzyme (designated as Tgc-PIII) is structurally most similar to the PIII-SVMPs of New World pitvipers but not similar to the PIII-SVMP of Ovophis okinavensis. Sequence-similarity analysis of 22 homologous PIII-SVMPs reveal three major structural subtypes of the pitviper PIII-SVMPs, which possibly have different substrate specificities. In addition, Tgc-PIII and the PI-class SVMP (named Tgc-MP) were isolated from the venom and verified by mass spectrometry. All the three deduced sequences of PII-SVMPs (Tgc-PIIs) contain an abnormal Zn+2-binding-site in their catalytic-domain, and an identical “long-disintegrin” domain. The predicted 85-residues disintegrin, gracilisin, bears high similarities to some long-disintegrins of the New-World pitvipers and salmosin3. By BLAST search and comparison, Tgc-MP is 96% similar to okinalysin, the hemorrhagic PI-SVMP of O. okinavensis, rather than any other PI-SVMPs in the databanks. Our results confirm the fast evolution of Tgc-SVMPs as well as their structural similarities to different SVMP-classes of the New-World pitvipers and of O. okinavensis, respectively. The implications of our findings are discussed along with our previous sequence comparisons of venom phospholipases A2 and ten venom serine proteases of Tgc.

Bee Venom Phospholipase A2 Reduces Tau Phosphorylation through Inhibition of GSK3β Expression

Bee Venom Phospholipase A2 Reduces Tau Phosphorylation through Inhibition of GSK3β Expression

Isolation and Antibacterial Activity of Honey Bee Venom Bioactive from Apis cerana

Honey bee venom from Apis species has garnered considerable attention in medicine due to its bioactive, which have antimicrobial activity. This research aims to isolate bioactive melittin and phospholipase A2 (PLA2) of honey bee venom from Indonesian Apis cerana and examine the antibacterial activity of these bioactive. Honey bee venoms were isolated from four locations using an electric shock method and purified using Fast Protein Liquid Chromatography. Purified protein was analyzed by SDS PAGE and measured by the Lowry method. Further, the antibacterial activity of melittin and PLA2 against Gram-positive (Staphylococcus aureus and Salmonella typhi) and Gram-negative (Escherichia coli) bacteria was defined by inhibition zone. Our results show that the average of all bee venoms obtained from four locations with eight sampling times was 17.1 mg proteins. Melittin was purified using gradient steps with 55%, 90%, and 100% elution buffer, while PLA2 was purified using 55% elution buffer. Melittin and PLA2 showed molecular weights of less than 7.5 kDa and 19 kDa, respectively. Protein concentrations in melittin and PLA2 were 95

Monoclonal-Based Antivenomics Reveals Conserved Neutralizing Epitopes in Type I PLA2 Molecules from Coral Snakes.

For over a century, polyclonal antibodies have been used to treat snakebite envenoming and are still considered by the WHO as the only scientifically validated treatment for snakebites. Nevertheless, moderate innovations have been introduced to this immunotherapy. New strategies and approaches to understanding how antibodies recognize and neutralize snake toxins represent a challenge for next-generation antivenoms. The neurotoxic activity of Micrurus venom is mainly due to two distinct protein families, three-finger toxins (3FTx) and phospholipases A2 (PLA2). Structural conservation among protein family members may represent an opportunity to generate neutralizing monoclonal antibodies (mAbs) against family-conserved epitopes. In this work, we sought to produce a set of monoclonal antibodies against the most toxic components of M. altirostris venom. To this end, the crude venom was fractionated, and its major toxic proteins were identified and used to generate a panel of five mAbs. The specificity of these mAbs was characterized by ELISA and antivenomics approaches. Two of the generated mAbs recognized PLA2 epitopes. They inhibited PLA2 catalytic activity and showed paraspecific neutralization against the myotoxicity from the lethal effect of Micrurus and Naja venoms' PLA2s. Epitope conservation among venom PLA2 molecules suggests the possibility of generating pan-PLA2 neutralizing antibodies.

Venom composition and pain-causing toxins of the Australian great carpenter bee Xylocopa aruana

Most species of bee are capable of delivering a defensive sting which is often painful. A solitary lifestyle is the ancestral state of bees and most extant species are solitary, but information on bee venoms comes predominantly from studies on eusocial species. In this study we investigated the venom composition of the Australian great carpenter bee, Xylocopa aruana Ritsema, 1876. We show that the venom is relatively simple, composed mainly of one small amphipathic peptide (XYTX1-Xa1a), with lesser amounts of an apamin homologue (XYTX2-Xa2a) and a venom phospholipase-A2 (PLA2). XYTX1-Xa1a is homologous to, and shares a similar mode-of-action to melittin and the bombilitins, the major components of the venoms of the eusocial Apis mellifera (Western honeybee) and Bombus spp. (bumblebee), respectively. XYTX1-Xa1a and melittin directly activate mammalian sensory neurons and cause spontaneous pain behaviours in vivo, effects which are potentiated in the presence of venom PLA2. The apamin-like peptide XYTX2-Xa2a was a relatively weak blocker of small conductance calcium-activated potassium (KCa) channels and, like A. mellifera apamin and mast cell-degranulating peptide, did not contribute to pain behaviours in mice. While the composition and mode-of-action of the venom of X. aruana are similar to that of A. mellifera, the greater potency, on mammalian sensory neurons, of the major pain-causing component in A. mellifera venom may represent an adaptation to the distinct defensive pressures on eusocial Apidae.

Structural basis of the myotoxic inhibition of the Bothrops pirajai PrTX-I by the synthetic varespladib

Varespladib (LY315920) is a potent inhibitor of human group IIA phospholipase A2 (PLA2) originally developed to control inflammatory cascades of diseases associated with high or dysregulated levels of endogenous PLA2. Recently, varespladib was also found to inhibit snake venom PLA2 and PLA2-like toxins. Herein, ex vivo neuromuscular blocking activity assays were used to test the inhibitory activity of varespladib. The binding affinity between varespladib and a PLA2-like toxin was quantified and compared with other potential inhibitors for this class of proteins. Crystallographic and bioinformatic studies showed that varespladib binds to PrTX-I and BthTX-I into their hydrophobic channels, similarly to other previously characterized PLA2-like myotoxins. However, a new finding is that an additional varespladib binds to the MDiS region, a particular site that is related to muscle cell disruption by these toxins. The present results further advance the characterization of the molecular interactions of varespladib with PLA2-like myotoxins and provide additional evidence for this compound as a promising inhibitor candidate for different PLA2 and PLA2-like toxins.

In silico screening of the phytochemicals present in Clitoria ternatea L. as the inhibitors of snake venom phospholipase A2 (PLA2)

Millions of people suffer from snake bite envenomation, and its management is a challenge, even today. Medicinal plants have attracted the researcher’s attention for their outstanding advantages in treating many diseases, including snake venom poisoning. Clitoria ternatea L, is a plant popularly known for its various pharmacological effects especially, anti-snake venom property. However, the molecular mechanism behind this is poorly understood. It is reported that snake venom PLA2 is an extensively studied toxic factor. This study is meant to screen the compound’s capability to act as inhibitors of the Daboia russelli snake venom PLA2 through molecular docking and dynamics studies. Our results show that among the 27 compounds taken for the study, only Kaempferol showed good interaction profile with the conserved catalytic active site residues, His48 and Asp49. The pharmacophore features of the compound also demonstrate its exact fitting at the binding pocket. Further RMSD, RMSF, Rg, and hydrogen bond analysis confirmed the stable binding of Kaempferol with PLA2 through molecular dynamic simulations for 100 ns. In addition, the MM/PBSA binding free energy calculation of the complex was also affirming the docking results. The binding free energy (BFE) of Kaempferolis better than the reference compound. ADME and Lipinski’s rule of five reveals its drug like properties. Communicated by Ramaswamy H. Sarma

The edematogenic effect of Micrurus lemniscatus venom is dependent on venom phospholipase A2 activity and modulated by non-neurogenic factors

Coral snakes mainly cause neurotoxic symptoms in human envenomation, but experimental studies have already demonstrated several pharmacological activities in addition to these effects. This investigation was carried out with the aim of evaluating (1) non-neurogenic mechanisms involved in the inflammatory response induced by Micrurus lemniscatus venom (MLV) in rat hind paws, (2) participation of PLA2 in this response, and (3) neutralizing efficiency of commercial anti-elapid antivenom on edema. MLV promoted a rapid, significant increase in vascular permeability, influx of leukocytes, and disorganization of collagen bundles, as demonstrated by histological analysis. Several pretreatments were applied to establish the involvement of inflammatory mediators in MLV-induced edema (5 µg/paw). Treatment of animals with chlorpromazine reduced MLV-induced edema, indicating participation of TNF-α. However, the inefficiency of other pharmacological treatments suggests that eicosanoids, leukotrienes, and nitric oxide have no role in this type of edema formation. In contrast, PAF negatively modulates this venom-induced effect. MLV was recognized by anti-elapid serum, but this antivenom did not neutralize edema formation. Chemical modification of MLV with p-bromophenacyl bromide abrogated the phospholipase activity and markedly reduced edema, demonstrating PLA2 participation in MLV-induced edema. In conclusion, the non-neurogenic inflammatory profile of MLV is characterized by TNF-α-mediated edema, participation of PLA2 activity, and down-regulation by PAF. MLV induces an influx of leukocytes and destruction of collagen fibers at the site of its injection.

The relative efficacy of chemically diverse small-molecule enzyme-inhibitors against anticoagulant activities of Black Snake (Pseudechis spp.) venoms

Snakebite remains a worldwide public health burden and a severely neglected tropical disease. Recent research has begun to focus on the potential use of repurposed small-molecule enzyme-inhibitors as early treatments to neutralise the effects of snake venoms. Black snakes (Pseudechis spp.) are a widespread and dangerously venomous group found throughout Australia and New Guinea. Utilising validated coagulation assays, our study assessed the efficacy of two chemically different small molecule inhibitors, a phospholipase A2 inhibitor (varespladib) and a metalloproteinase inhibitor (prinomastat), in vitro neutralisation of the anticoagulant prothrombinase-inhibiting activity of venom from seven species within the Pseudechis genus (P. australis, P. butleri, P. coletti, P. guttatus, P. papuanus, P.rossignolii, P. sp (NT).). Varespladib was shown to be highly effective at neutralising this anticoagulant activity for all seven species, but with P. coletti notably less so than the others. In contrast, prinomastat showed strong neutralisation for five out of the seven species, but was ineffective at neutralising the activity of P. coletti or P. rossignolii venoms. This suggests that varespladib binds to a highly conserved site but that prinomastat binds to a more variable site. These results build upon recent literature indicating that metalloproteinase inhibitors have cross-neutralising potential towards snake venom phospholipase A2 toxins, but with higher degrees of variability that PLA2-specific inhibitors. An important caveat is that these are in vitro tests and while suggestive of potential clinical utility, in vivo animal testing and clinical trials are required as future work.

Efficient heterologous expression in Pichia pastoris, immobilization and functional characterization of a scorpion venom secreted phospholipase A2

Industrial processes have expanded with the ability to clone and express recombinant immobilized enzymes in microorganisms such as Pichia pastoris that have commercially attractive amounts of the appropriate genes. This report describes the overexpression in Pichia pastoris, immobilization, and functional characterization of a secreted phospholipase A2 from scorpion venom Scorpio maurus: rPLA2(-5). After 48 h of culture, the recombinant rPLA2(-5) was secreted into the culture medium and expressed at about 9 mg/L. Comparative analyses of the kinetics and hydrolysis of rPLA2(-5) monolayers at various surface pressures were conducted with the same form produced in Escherichia coli. As a second part of the study, rPLA2(-5) overexpressed in Pichia pastoris was immobilized by adsorption on CaCO3, with about 78 percent of the activity. In comparison to the free enzyme, rPLA2(-5) was studied for stability. Immobilization improved the thermal stability of rPLA2(-5) and even the stability at acidic pH. Moreover, we found that the immobilization improved the stability of rPLA2(-5) towards bile salts, Tween 80, Triton X-100, and SDS, as well as its stability towards many organic solvents. Until now, this is the first study to describe the overexpression and immobilization of a scorpion venom phospholipase A2 that possesses an interesting stability characteristic that makes it useful for a wide range of biotechnological applications.

Interpopulational variation and ontogenetic shift in the venom composition of Lataste's viper (Vipera latastei, Boscá 1878) from northern Portugal

Lataste's viper (Vipera latastei) is a venomous European viper endemic to the Iberian Peninsula, recognised as medically important by the World Health Organization. To date, no comprehensive characterisation of this species' venom has been reported. Here, we analysed the venoms of juvenile and adult specimens of V. latastei from two environmentally different populations from northern Portugal. Using bottom-up venomics, we produced six venom proteomes (three per population) from vipers belonging to both age classes (i.e., two juveniles and four adults), and RP-HPLC profiles of 54 venoms collected from wild specimens. Venoms from juveniles and adults differed in their chromatographic profiles and relative abundances of their toxins, suggesting the occurrence of ontogenetic changes in venom composition. Specifically, snake venom metalloproteinase (SVMP) was the most abundant toxin family in juvenile venoms, while snake venom serine proteinases (SVSPs), phospholipases A2 (PLA2s), and C-type lectin-like (CTLs) proteins were the main toxins comprising adult venoms. The RP-HPLC venom profiles were found to vary significantly between the two sampled localities, indicating geographic variability. Furthermore, the presence/absence of certain peaks in the venom chromatographic profiles appeared to be significantly correlated also to factors like body size and sex of the vipers. Our findings show that V. latastei venom is a variable phenotype. The intraspecific differences we detected in its composition likely mirror changes in the feeding ecology of this species, taking place during different life stages and under different environmental pressures. SignificanceLataste's viper (Vipera latastei) is a medically important viper endemic to the Iberian Peninsula, inhabiting different habitats and undergoing a marked ontogenetic dietary shift. In the current study, we report the first proteomic analysis of V. latastei venom from two environmentally different localities in northern Portugal. Our bottom-up venomic analyses show that snake venom serine proteinases (SVSPs), phospholipases A2 (PLA2s), and C-type lectin-like (CTLs) proteins are the major components of adult V. latastei venom. The comparative analysis of young and adult venoms suggests the occurrence of ontogenetic shift in toxin abundances, with snake venom metalloproteinases (SVMPs) being the predominant toxins in juvenile venoms. Moreover, geographic venom variation between the two studied populations is also detected, with our statistical analyses suggesting that factors like body size and sex of the vipers are possibly at play in its determination.Our work represents the first assessment of the composition of V. latastei venom, and the first step towards a better understanding of the drivers behind its variability.

The Unusual Metalloprotease-Rich Venom Proteome of the Australian Elapid Snake Hoplocephalus stephensii.

The Australasian region is home to the most diverse elapid snake radiation on the planet (Hydrophiinae). Many of these snakes have evolved into unique ecomorphs compared to elapids on other continents; however, their venom compositions are poorly known. The Australian elapid Hoplocephalus stephensii (Stephen’s banded snake) is an arboreal snake with a unique morphology. Human envenoming results in venom-induced consumption coagulopathy, without neurotoxicity. Using transcriptomics and a multi-step fractionation method involving reverse-phase high-performance liquid chromatography, sodium dodecyl sulfate polyacrylamide gel electrophoresis and bottom-up proteomics, we characterized the venom proteome of H. stephensii. 92% of the total protein component of the venom by weight was characterized, and included all dominant protein families and 4 secondary protein families. Eighteen toxins made up 76% of the venom, four previously characterized and 14 new toxins. The four dominant protein families made up 77% of the venom, including snake venom metalloprotease (SVMP; 36.7%; three identified toxins), phospholipase A2 (PLA2; 24.0%; five identified toxins), three-finger toxin (3FTx; 10.2%; two toxins) and snake venom serine protease (SVSP; 5.9%; one toxin; Hopsarin). Secondary protein families included L-amino acid oxidase (LAAO; 10.8%; one toxin), natriuretic peptide (NP; 0.8%; two toxins), cysteine-rich secretory protein (CRiSP; 1.7%; two toxins), c-type lectin (CTL; 1.1%; one toxin), and one minor protein family, nerve growth factor (NGF; 0.8%; one toxin). The venom composition of H. stephensii differs to other elapids, with a large proportion of SVMP and LAAO, and a relatively small amount of 3FTx. H. stephensii venom appeared to have less toxin diversity than other elapids, with only 18 toxins making up three-quarters of the venom.

Non-compartmental toxicokinetic studies of the Nigerian Naja nigricollis venom.

Snakebite envenoming (SBE) is a neglected public health problem, especially in Asia, Latin America and Africa. There is inadequate knowledge of venom toxicokinetics especially from African snakes. To mimic a likely scenario of a snakebite envenoming, we used an enzyme-linked immunosorbent assay (ELISA) approach to study the toxicokinetic parameters in rabbits, following a single intramuscular (IM) administration of Northern Nigeria Naja nigricollis venom. We used a developed and validated non-compartmental approach in the R package PK to determine the toxicokinetic parameters of the venom and subsequently used pharmacometrics modelling to predict the movement of the toxin within biological systems. We found that N. nigricollis venom contained sixteen venom protein families following a mass spectrometric analysis of the whole venom. Most of these proteins belong to the three-finger toxins family (3FTx) and venom phospholipase A2 (PLA2) with molecular weight ranging from 3 to 16 kDa. Other venom protein families were in small proportions with higher molecular weights. The N. nigricollis venom was rapidly absorbed at 0.5 h, increased after 1 h and continued to decrease until the 16th hour (Tmax), where maximum concentration (Cmax) was observed. This was followed by a decrease in concentration at the 32nd hour. The venom of N. nigricollis was found to have high volume of distribution (1250 ± 245 mL) and low clearance (29.0 ± 2.5 mL/h) with an elimination half-life of 29 h. The area under the curve (AUC) showed that the venom remaining in the plasma over 32 h was 0.0392 ± 0.0025 mg h.L−1, and the mean residence time was 43.17 ± 8.04 h. The pharmacometrics simulation suggests that the venom toxins were instantly and rapidly absorbed into the extravascular compartment and slowly moved into the central compartment. Our study demonstrates that Nigerian N. nigricollis venom contains low molecular weight toxins that are well absorbed into the blood and deep tissues. The venom could be detected in rabbit blood 48 h after intramuscular envenoming.

Traces of Bothrops snake venoms in necrotic muscle preclude myotube formation in vitro

Deficient skeletal muscle regeneration, which often leads to permanent sequelae, is a common clinical finding in envenomations caused by snakes of the family Viperidae, such as those of Bothrops alternatus and B. diporus in South America. The causes of such poor muscle regenerative outcome are still incompletely understood. Using a murine experimental model of envenomation by the venoms of these two species, we assessed whether traces of venom components that remain in muscle tissue days after envenomation affect myoblasts and myotube formation in culture. The kinetics of drop in venom concentration in the tissue was assessed by ELISA and Western blot, and by the quantification of venom phospholipase A2 activity. A rapid drop of venom components was observed in muscle, although a band of 58–63 kDa remained even 168 h after venom injection, and venom phospholipase A2 activity was detected in muscle tissue days after envenomation. Muscle homogenates from envenomated animals were cytotoxic to myoblasts in culture and inhibited the formation of myotubes even in conditions where homogenates were devoid of cytotoxicity. These deleterious effects were abrogated when homogenates were incubated with antivenom. Our findings agree with previous observations with the venom of Bothrops asper and provide further evidence that one of the causes of the poor skeletal muscle regeneration after Bothrops sp venom-induced myonecrosis is the deleterious action on myogenic cells of traces of venom components remaining in the tissue.

Viperidae snake venom phospholipase A2 . Biochemical targets for the action of protein in the human blood circulatory system. Part 1 (review of literature)

Snake venoms have been fervently studied for decades for two reasons: 1) high death rate due to snake bites; 2) numerous components of snake venoms prove useful in medicine and treatment of diverse pathologies. Snake venom phospholipases A2 are among the most aggressive toxic proteins often playing the main role in immobilization and killing of snakebite victims. These enzymes catalyze the hydrolysis of glycerophospholipids to produce lysoglycerophospholipids and free fatty acids. But the diversity of phospholipase A2 effects is not limited to their catalytic action. In this review (Part 1), we describe the features of the structure and properties of Viperidae snake venom phospholipase A2 .

Bee venom phospholipase A2 ameliorates amyotrophic lateral sclerosis by increasing regulatory T cell population

Bee venom phospholipase A2 ameliorates amyotrophic lateral sclerosis by increasing regulatory T cell population

Exploring the potent inhibitor β-stigmasterol from Pittosporum dasycaulon Miq. leaves against snake venom phospholipase A2 protein through in vitro and molecular dynamics behavior approach

β-Stigmasterol, responsible for antivenom activity against abundant PLA2 protein of Viper (Daboia russelii) and Cobra (Naja naja) venom, was identified, characterized, and isolated from Pittosporum dasycaulon leaves extract. The compound purity was checked by RP-HPLC analysis, and structure was elucidated by FTIR and NMR analysis, followed by in-vitro as well as in-silico studies. The structural stability of the docked complexes was evaluated by molecular dynamic simulation, and the binding free energies were calculated by MM-PBSA analysis. The in-vitro analysis revealed that the isolated compound β-SS is effective against D. russelii PLA2 (IC50 40.903 ± 0.479 μg/mL) than N. naja venom PLA2 (42.340 ± 0.11 μg/mL). The in-silico approaches helps to conclude that the β-SS-PLA2 D. russelii complex showed a stable conformation with a reduced degree of flexibility throughout the dynamics simulation time period with high-affinity docking energy −10.60 kcal/mol than β-SS-PLA2 N. naja complex, which observed docking energy of −10.39 kcal/mol.

Photoprotective and therapeutic effects of Apamin, Melittin and Phospholipase A2 on human keratinocyte cell line

The aim of this study is to determine the protective and therapeutic properties of bee venom components Apamin, Melittin and Phospholipase A2 against UV damage on the human keratinocyte cell line. Cosmetic and therapeutic effects of bee venom have been reported in previous studies, but it is not known which components of the venom have the most effect. For this purpose, firstly, an in vitro UV damage model was designed. Components of bee venom were tested at a different concentration. Cell viability, cytotoxicity and apoptotic processes were analyzed on the designed model. As a result, it has been observed that Apamin demonstrated a significant protective effect against UV-induced cell death at all concentrations. Photoprotective effects of Melittin were observed in all concentration time periods and its photoprotective effects were increased as the concentration increased. Our results were indicated that Phospholipase A2 could be used as a photoprotective and phototherapy agent. This study is the first to show the protective and therapeutic properties of bee venom components against UV damage. As a result, it has been shown that these components can be successful photoprotective and phototherapeutic agents against UV-induced damage, but more detailed studies should be conducted to minimize their toxic effects on cells.

Biochemical and proteomic analyses of venom from a new pit viper, Protobothrops kelomohy.

Background: A new pit viper, Protobothrops kelomohy, has been recently discovered in northern and northwestern Thailand. Envenoming by the other Protobothrops species across several Asian countries has been a serious health problem since their venom is highly hematotoxic. However, the management of P. kelomohy bites is required as no specific antivenom is available. This study aimed to investigate the biochemical properties and proteomes of P. kelomohy venom (PKV), including the cross-neutralization to its lethality with antivenoms available in Thailand.Methods: PKV was evaluated for its neutralizing capacity (ER50), lethality (LD50), procoagulant and hemorrhagic effects with three monovalent antivenoms (TAAV, DSAV, and CRAV) and one polyvalent (HPAV) hematotoxic antivenom. The enzymatic activities were examined in comparison with venoms of Trimeresurus albolabris (TAV), Daboia siamensis (DSV), Calloselasma rhodostoma (CRV). Molecular mass was separated on SDS-PAGE, then the specific proteins were determined by western blotting. The venom protein classification was analyzed using mass spectrometry-based proteomics.Results: Intravenous LD50 of PKV was 0.67 µg/g. ER50 of HPAV, DSAV and TAAV neutralize PKV at 1.02, 0.36 and 0.12 mg/mL, respectively. PKV exhibited procoagulant effect with a minimal coagulation dose of 12.5 ± 0.016 µg/mL and hemorrhagic effect with a minimal hemorrhagic dose of 1.20 ± 0.71 µg/mouse. HPAV was significantly effective in neutralizing procoagulant and hemorrhagic effects of PKV than those of TAAV, DSAV and CRAV. All enzymatic activities among four venoms exhibited significant differences. PKV proteome revealed eleven classes of putative snake venom proteins, predominantly metalloproteinase (40.85%), serine protease (29.93%), and phospholipase A2 (15.49%).Conclusions: Enzymatic activities of PKV are similarly related to other viperid venoms in this study by quantitatively hematotoxic properties. Three major venom toxins were responsible for coagulopathy in PKV envenomation. The antivenom HPAV was considered effective in neutralizing the lethality, procoagulant and hemorrhagic effects of PKV.