| comparative chromatography of brazilian coral snake (micrurus) venoms. | 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. micrurus venom profiles were compared with those of "outgroup" taxa bothrops moojeni, naja naja kaouthia and bungarus multicinctus. 3 ... | 1991 | 1756614 |
| analysis of the efficacy of taiwanese freeze-dried neurotoxic antivenom against naja kaouthia, naja siamensis and ophiophagus hannah through proteomics and animal model approaches. | in southeast asia, envenoming resulting from cobra snakebites is an important public health issue in many regions, and antivenom therapy is the standard treatment for the snakebite. because these cobras share a close evolutionary history, the amino acid sequences of major venom components in different snakes are very similar. therefore, either monovalent or polyvalent antivenoms may offer paraspecific protection against envenomation of humans by several different snakes. in taiwan, a bivalent an ... | 2017 | 29244815 |
| salmonella serovar distribution in cobras (naja kaouthia), snake-food species, and farm workers at queen saovabha snake park, thailand. | the purpose of the current study was to investigate the prevalence and serovar distribution of salmonella isolates in cobras and their environment at a snake park. a total of 166 fecal or intestinal samples were examined, comprising 39 samples from captive cobras (naja kaouthia), 70 from recently wild-caught cobras, 19 from wild-caught cobras that had been kept on the farm for over 3 months, 18 from mice (mus musculus), 12 from frogs (hoplobatrachus rugulosus), and 8 from farm workers. specific ... | 2012 | 22362530 |
| molecular events associated with macrovipera lebetina obtusa and montivipera raddei venom intoxication and condition of biomembranes. | studies on the interaction of snake venom and organized lipid interfaces have been conducted using a variety of systems, including blms, suvs and guvs. the present study was undertaken to elucidate how the plastic properties (namely, its microviscosity, thickness, permeability) of model membranes from native lipids of different tissues of rats change in the course of macrovipera lebetina obtusa (mlo), montivipera raddei (mr) and naja kaouthia (nk) venoms processing. the presence of viper venom i ... | 2012 | 22366201 |
| thermal stabilization of anti-α-cobratoxin single domain antibodies. | there is an unmet need for snake antivenoms that can be stored ready to use near the point of care. to address that need we have taken two anti-α-cobratoxin single domain antibodies and increased their thermal stability to improve their ambient temperature shelf-life. the anti-α-cobratoxin single domain antibodies c2 and c20 were first isolated, and demonstrated to be toxin neutralizing by richard et al., 2013 (richard, g., meyers, a.j., mclean, m.d., arbabi-ghahroudi, m., mackenzie, r., hall, j ... | 2017 | 28209480 |
| antivenom cross-neutralization of the venoms of hydrophis schistosus and hydrophis curtus, two common sea snakes in malaysian waters. | sea snake envenomation is a serious occupational hazard in tropical waters. in malaysia, the beaked sea snake (hydrophis schistosus, formerly known as enhydrina schistosa) and the spine-bellied sea snake (hydrophis curtus, formerly known as lapemis curtus or lapemis hardwickii) are two commonly encountered species. australian csl sea snake antivenom is the definitive treatment for sea snake envenomation; it is unfortunately extremely costly locally and is not widely available or adequately stock ... | 2015 | 25690691 |
| bindings of cobra venom phospholipases a2 to micelles of n-hexadecylphosphorylcholine. | bindings of cobra venom phospholipases a2 to micelles of n-hexadecylphosphorylcholine were studied by the tryptophyl fluorescence method at 25 degrees c and ionic strength 0.1. the data were analyzed by assuming that the micellar surface has multiple binding sites for the enzyme and these sites are identical and mutually independent. the enzyme binding site was found to accommodate a constant number of substrate (monomer) molecules, n = 10, 5 or 13 for n. naja atra apoenzyme and its ca2+ complex ... | 1983 | 6619110 |
| alpha-neurotoxins of naja atra and naja kaouthia snakes in different regions. | recent studies have shown that there are geographic variation of alpha-neurotoxins in naja kaouthia, but the cause is not clear yet. in this work, venoms were collected from adult naja atra in zhejiang province and naja kaouthia in yunnan province, well identified by morphological characters and cytochrome b gene analysis in summer season to avoid age and seasonal variation in the venom composition. then alpha-neurotoxins were purified and cloned from these two kinds of snakes. three alpha-neuro ... | 2003 | 12897961 |
| participation of an ionizable group with pk 8.55 in the reaction of p-bromophenacyl bromide with his 48 of cobra venom phospholipases a2. | the chemical reaction of p-bromophenacyl bromide (bpb) with his 48 of cobra venom phospholipases a2 (n. naja siamensis, n. naja kaouthia, and n. naja atra) was studied at 25 degrees c and ionic strength 0.1 by following the decreases in the fluorescence intensity of 8-anilino-1-naphthalene sulfonate (ans) and/or in the enzymatic activity. the effect of the bpb concentration on the pseudo-first-order rate constant, chi obs, was studied for the n. naja atra enzyme and the dissociation constants of ... | 1982 | 7096315 |
| direct cloning of a target gene from a pool of homologous sequences: complete cdna sequence of a weak neurotoxin from cobra naja kaouthia. | selective cloning of the cdna coding for a weak neurotoxin (wtx) from cobra n. kaouthia including the 5'- and 3'-non-translated regions (ntr) is described. the known amino acid sequence of wtx was used together with the nucleotide sequence of a weak neurotoxin nnam2 from cobra naja atra, to design wtx-specific primers for direct amplification of an internal wtx cdna fragment by rt- pcr. the sequence of the complete wtx cdna was determined in sequencing runs on internal pcr products, cloned 3'- a ... | 2003 | 12716062 |
| changes in body temperature pattern in vertebrates do not influence the codon usages of alpha-globin genes. | codon usages are known to vary among vertebrates chiefly due to variations in isochore structure. under the assumption that marked differences exist in isochore structure between warm-blooded and cold-blooded animals, the variations among vertebrates were previously attributed to an adaptation to homeothermy. however, based on data from a turtle species and a crocodile (archosauromorpha), it was recently proposed that the common ancestors of mammals, birds and extent reptiles already had the "wa ... | 2002 | 12207041 |
| neutralization of the principal toxins from the venoms of thai naja kaouthia and malaysian hydrophis schistosus: insights into toxin-specific neutralization by two different antivenoms. | antivenom neutralization against cobra venoms is generally low in potency, presumably due to poor toxin-specific immunoreactivity. this study aimed to investigate the effectiveness of two elapid antivenoms to neutralize the principal toxins purified from the venoms of the thai monocled cobra (naja kaouthia, nk-t) and the malaysian beaked sea snake (hydrophis schistosus, hs-m). in mice, n. kaouthia monovalent antivenom (nkmav) neutralization against nk-t long neurotoxin (lntx) and cytotoxin was m ... | 2016 | 27023606 |
| cobra venom contains a pool of cysteine-rich secretory proteins. | a large family of cysteine-rich secretory proteins (crisps) includes proteins of different origin, the function of the majority of crisps being unknown. for crisps isolated from snake venom, two types of activities were found: two proteins blocked cyclic nucleotide-gated ion channels, several others blocked potassium-stimulated smooth muscle contraction. thus, snake crisps represent potentially valuable tools for studies of ion channels, which makes promising a search for new crisps. here we rep ... | 2005 | 15670767 |
| elucidating the biogeographical variation of the venom of naja naja (spectacled cobra) from pakistan through a venom-decomplexing proteomic study. | naja naja is a medically important species that is distributed widely in south asia. its venom lethality and neutralization profile have been reported to vary markedly, but the understanding of this phenomenon has been limited without a comprehensive venom profile for the pakistani n. naja. this study set to investigate the venom proteome of pakistani n. naja applying reverse-phase hplc, sds-page, mass spectrometry and data-mining approaches. the venom enzymatics and antigen binding activities w ... | 2017 | 29278784 |
| combined venomics, antivenomics and venom gland transcriptome analysis of the monocoled cobra (naja kaouthia) from china. | we conducted an omics-analysis of the venom of naja kaouthia from china. proteomics analysis revealed six protein families [three-finger toxins (3-ftx), phospholipase a2(pla2), nerve growth factor, snake venom metalloproteinase (svmp), cysteine-rich secretory protein and ohanin], and venom-gland transcriptomics analysis revealed 28 protein families from 79 unigenes. 3-ftx (56.5% in proteome/82.0% in transcriptome) and pla2(26.9%/13.6%) were identified as the most abundant families in venom prote ... | 2017 | 28263888 |
| thrombolytic protein from cobra venom with anti-adhesive properties. | a metalloproteinase anticoagulant toxin of molecular weight 66 kda has been purified from the venom of indian monocled cobra (naja kaouthia). this toxin named as nkv 66 cleaved fibrinogen in a dose and time dependent manner. the digestion process was specific to aα chain and cleaved fibrinogen to peptide fragments. nkv 66 completely liquefied the fibrin clots developed in vitro in 18 h. plasma recalcification time and thrombin time were significantly prolonged following treatment of plasma with ... | 2016 | 26558696 |
| venom-gland transcriptome and venom proteome of the malaysian king cobra (ophiophagus hannah). | the king cobra (ophiophagus hannah) is widely distributed throughout many parts of asia. this study aims to investigate the complexity of malaysian ophiophagus hannah (moh) venom for a better understanding of king cobra venom variation and its envenoming pathophysiology. the venom gland transcriptome was investigated using the illumina hiseq™ platform, while the venom proteome was profiled by 1d-sds-page-nano-esi-lcms/ms. | 2015 | 26358635 |
| structure-function relationship of three neurotoxins from the venom of naja kaouthia: a comparison between the nmr-derived structure of nt2 with its homologues, nt1 and nt3. | three homologous short-chain neurotoxins, named nt1, nt2 and nt3, were purified from the venom of naja kaouthia. nt1 has an identical amino acid sequence to cobrotoxin from naja naja atra [biochemistry 32 (1993) 2131]. nt3 shares the same sequence with cobrotoxin b [j. biochem. (tokyo) 122 (1997) 1252], whereas nt2 is a novel 61-residue neurotoxin. tests of their physiological functions indicate that nt1 shows a greater inhibition of muscle contraction induced by electrical stimulation of the ne ... | 2002 | 11904231 |
| use of split-free nano-liquid chromatography-mass spectrometry/high resolution mass spectrometry interface to improve the detection of α-cobratoxin in equine plasma for doping control. | cobra (naja naja kaouthia) venom contains a toxin called α-cobratoxin (α-cbtx) containing 71 amino acids (mw 7821 da) with a reported analgesic power greater than morphine. in 2013, the first analytical method for the detection of α-cbtx in equine plasma was developed by bailly-chouriberry et al, allowing the confirmation of the presence of α-cbtx at low concentrations (1-5 ng/ml or 130-640 fmol/ml) in plasma samples. to increase the method sensitivity and therefore to improve the detection of α ... | 2017 | 29232492 |
| biological activities of peristrophe bivalvis extracts: promising potential for anti-snake venoms against naja kaouthia and trimeresurus albolabris venoms. | this study evaluates the in vitro anti-snake venom potential of peristrophe bivalvis (pb) extracts against naja kaouthia (nk) and trimeresurus albolabris (ta) venoms, including inhibition of cytotoxic effects and enzymatic activities, and the binding-precipitation of extracts and venom proteins analysis. in addition, the antioxidant, cytotoxic and in vivo acute oral toxic activities of pb extracts are also reported. the in vitro cytotoxic and enzymatic analysis reveals that the ethanol extracts ... | 2016 | 25942501 |
| new paradoxical three-finger toxin from the cobra naja kaouthia venom: isolation and characterization. | a new three-finger toxin nakoroxin was isolated from the cobra naja kaouthia venom, and its complete amino acid sequence was established. nakoroxin belongs to the group of "orphan" toxins, data on the biological activity of which are practically absent. nakoroxin shows no cytotoxicity and does not inhibit the binding of α-bungarotoxin to nicotinic acetylcholine receptors of muscle and α7 types. however, it potentiates the binding of α-bungarotoxin to the acetylcholine-binding protein from lymnae ... | 2017 | 28864897 |
| a novel in vitro potency assay of antisera against thai naja kaouthia based on nicotinic acetylcholine receptor binding. | snake envenomation is an important medical problem. one of the hurdles in antivenom development is the in vivo assay of antivenom potency which is expensive, gives variable results and kills many animals. we report a novel in vitro assay involving the specific binding of the postsynaptic neurotoxins (psnts) of elapid snakes with purified torpedo californica nicotinic acetylcholine receptor (nachr). the potency of an antivenom is determined by its antibody ability to bind and neutralize the psnt, ... | 2017 | 28819275 |
| protection against osteoarthritis in experimental animals by nanogold conjugated snake venom protein toxin gold nanoparticle-naja kaouthiacytotoxin 1. | increased severity of osteoarthritis (oa) and adverse side effects of its treatment led to the search for alternative therapies. it was previously reported that snake venom protein toxin naja kaouthia cytotoxin 1 (nkct1) and gold nanoparticle (gnp) individually have potential against excremental arthritis. in this study, we analyzed the protective activity of gnp conjugated protein toxin nkct1 (gnp-nkct1) against experimental oa. | 2016 | 28474628 |
| [bitten by an exotic venomous snake]. | patients who have been bitten by an exotic venomous snake are at risk of severe morbidity and a fatal outcome following an incorrect risk-assessment. treatment with an antivenom can be necessary and can turn out to be lifesaving. in the netherlands there are only a few cases of bites from exotic venomous snakes each year. | 2017 | 28421973 |
| two acidic, anticoagulant pla2 isoenzymes purified from the venom of monocled cobra naja kaouthia exhibit different potency to inhibit thrombin and factor xa via phospholipids independent, non-enzymatic mechanism. | the monocled cobra (naja kaouthia) is responsible for snakebite fatality in indian subcontinent and in south-western china. phospholipase a2 (pla2; ec 3.1.1.4) is one of the toxic components of snake venom. the present study explores the mechanism and rationale(s) for the differences in anticoagulant potency of two acidic pla2 isoenzymes, nk-pla2α (13463.91 da) and nk-pla2β (13282.38 da) purified from the venom of n. kaouthia. | 2014 | 25118676 |
| comparative venom gland transcriptomics ofnaja kaouthia(monocled cobra) from malaysia and thailand: elucidating geographical venom variation and insights into sequence novelty. | the monocled cobra (naja kaouthia) is a medically important venomous snake in southeast asia. its venom has been shown to vary geographically in relation to venom composition and neurotoxic activity, indicating vast diversity of the toxin genes within the species. to investigate the polygenic trait of the venom and its locale-specific variation, we profiled and compared the venom gland transcriptomes ofn. kaouthiafrom malaysia (nk-m) and thailand (nk-t) applying next-generation sequencing (ngs) ... | 2017 | 28392982 |
| envenoming by chinese krait (bungarus multicinctus) and banded krait (b. fasciatus) in myanmar. | a retrospective study of 8 cases of envenoming by chinese krait (bungarus multicinctus) and one banded krait (b. fasciatus) in southern myanmar is reported. chinese krait bite produced minimal local reactions, except in one person bitten on the lip which resulted in local swelling. onset of neurotoxic symptoms occurred 2.5-6 h after the bite, and the interval between bite and death ranged from 12-30 h. three deaths were due to respiratory failure. four mildly envenomed cases recovered spontaneou ... | 2004 | 9509180 |
| muscarinic toxin-like proteins from cobra venom. | three new polypeptides were isolated from the venom of the thailand cobra naja kaouthia and their amino-acid sequences determined. they consist of 65-amino-acid residues and have four disulfide bridges. a comparison of the amino-acid sequences of the new polypeptides with those of snake toxins shows that two of them (mtlp-1 and mtlp-2) share a high degree of similarity (55-74% sequence identity) with muscarinic toxins from the mamba. the third polypeptide (mtlp-3) is similar to muscarinic toxins ... | 2000 | 11082188 |
| purification of the nicotinic acetylcholine receptor protein by affinity chromatography using a regioselectively modified and reversibly immobilized alpha-toxin from naja nigricollis. | a new method of affinity chromatography purification of the detergent-solubilized nicotinic acetylcholine receptor protein (nachr) is presented, based on the reversible coupling of a chemically monomodified alpha-toxin from naja nigricollis to a resin. the alpha-toxin was monothiolated on the epsilon-amino group of its lysine-15 by reaction with n-succinimidly-3-(2-pyridyldithio)propionate and was covalently linked in a reversible manner to a thiopropyl-activated agarose resin by thiol-disulfide ... | 1997 | 9059496 |
| inhibition of nicotinic acetylcholine receptors, a novel facet in the pleiotropic activities of snake venom phospholipases a2. | phospholipases a2 represent the most abundant family of snake venom proteins. they manifest an array of biological activities, which is constantly expanding. we have recently shown that a protein bitanarin, isolated from the venom of the puff adder bitis arietans and possessing high phospholipolytic activity, interacts with different types of nicotinic acetylcholine receptors and with the acetylcholine-binding protein. to check if this property is characteristic to all venom phospholipases a2, w ... | 2014 | 25522251 |
| molecular modeling of nk-ct1, from indian monocellate cobra (naja kaouthia) and its docking interaction with human dna topoisomerase ii alpha. | a 6.76 kda molecular weight cardio and cytotoxic protein of 60 amino acids in length called nk-ct1, was purified from the venom of indian monocellate cobra (naja kaouthia) by ion-exchange chromatography and hplc as described in our earlier report. therefore it is of interest to utlize the sequence of nk-ct1 for further functional inference using molecular modeling and docking. thus homology model of nk-ct1 is described in this report. the anti-proliferative activity of the protein, binding with ... | 2016 | 28149043 |
| bites by the monocled cobra,naja kaouthia, in chittagong division, bangladesh: epidemiology, clinical features of envenoming and management of 70 identified cases. | abstractwe describe 70 cases of monocled cobra (naja kaouthia) bite admitted to chittagong medical college hospital, bangladesh. the biting snakes were identified by examining the dead snake and/or detectingn. kaouthiavenom antigens in patients' serum. bites were most common in the early morning and evening during the monsoon (may-july). ligatures were routinely applied to the bitten limb before admission. thirty-seven patients consulted traditional healers, most of whom made incisions around th ... | 2017 | 28138054 |
| evaluation of cytotoxicity of a purified venom protein from naja kaouthia (nkct1) using gold nanoparticles for targeted delivery to cancer cell. | in our earlier report, gold nanoparticle (gnp) and snake venom protein toxin nkct1 were conjugated and primary characteristics were done. in this communication, further characteristics of gnp-nkct1 were done with tga, bet, zeta potential, icp-ms, ftir, xps, and in vitro release kinetics for its physicochemical, molecular nature and bonding. tga and icp-ms showed that the number of conjugation was 40 ± 5 to 90 ± 8 nkct1 per gold nanoparticles. ftir and xps corresponding to (co), (nh), (ss) reform ... | 2017 | 27836789 |
| cross-neutralisation of in vitro neurotoxicity of asian and australian snake neurotoxins and venoms by different antivenoms. | there is limited information on the cross-neutralisation of neurotoxic venoms with antivenoms. cross-neutralisation of the in vitro neurotoxicity of four asian and four australian snake venoms, four post-synaptic neurotoxins (α-bungarotoxin, α-elapitoxin-nk2a, α-elapitoxin-ppr1 and α-scutoxin; 100 nm) and one pre-synaptic neurotoxin (taipoxin; 100 nm) was studied with five antivenoms: thai cobra antivenom (tcav), death adder antivenom (daav), thai neuro polyvalent antivenom (tnpav), indian polyv ... | 2016 | 27763543 |
| nkct1 (purified naja kaouthia protein toxin) conjugated gold nanoparticles induced akt/mtor inactivation mediated autophagic and caspase 3 activated apoptotic cell death in leukemic cell. | gold nanoparticle (gnp) and snake venom protein toxin nkct1 was conjugated as stated earlier (bhowmik et al., 2013). the aim of this study was to explore the caspase dependent apoptotic pathway and autophagy inducing ability of gold nanoparticles tagged snake venom protein toxin nkct1 (gnp-nkct1) in human leukemic u937 and k562 cell line. | 2016 | 27527270 |
| attempted suicide by snake bite: a case study. | snake bite is an important public health issue in india and is almost always accidental in manner. suicide by snake bite or injection of snake venom is extremely rare. suicidal ideation and behavior is known to be influenced by various socio-economic and psychological factors. the method employed for suicide is also influenced by the occupation of the victim. we report a case where a snake charmer had attempted suicide by inflicting a bite by a monocled cobra. | 2016 | 27417152 |
| central loop of non-conventional toxin wtx from naja kaouthia is important for interaction with nicotinic acetylcholine receptors. | 'three-finger' toxin wtx from naja kaouthia interacts with nicotinic and muscarinic acetylcholine receptors (nachrs and machrs). mutagenesis and competition experiments with (125)i-α-bungarotoxin revealed that arg31 and arg32 residues from the wtx loop ii are important for binding to torpedo californica and human α7 nachrs. computer modeling suggested that loop ii occupies the orthosteric binding site at α7 nachr. the similar toxin interface was previously described as a major determinant of all ... | 2016 | 27343701 |
| an analysis of venom ontogeny and prey-specific toxicity in the monocled cobra (naja kaouthia). | venoms of snakes of the family elapidae (cobras, kraits, mambas, and relatives) are predominantly composed of numerous phospholipases a2 (pla2s) and three-finger toxins (3ftxs), some of which are lethal while others are not significantly toxic. currently, the only identified prey-specific toxins are several nonconventional 3ftxs, and given the large diversity of 3ftxs within monocled cobra (naja kaouthia) venom, it was hypothesized that several 3ftxs, previously found to be non-toxic or weakly t ... | 2016 | 27163885 |
| venom and purified toxins of the spectacled cobra (naja naja) from pakistan: insights into toxicity and antivenom neutralization. | geographical variations of snake venoms can result in suboptimal effectiveness of indian antivenoms that are currently used in most south asian countries. this study investigated the toxicity and neutralization profile of the venom and toxins from pakistani spectacled cobra, naja naja, using vins polyvalent antivenom (vpav, india), naja kaouthia monovalent antivenom (nkmav, thailand), and neuro bivalent antivenom (nbav, taiwan). cation-exchange and reverse-phase high-performance liquid chromatog ... | 2016 | 27022154 |
| geographical venom variations of the southeast asian monocled cobra (naja kaouthia): venom-induced neuromuscular depression and antivenom neutralization. | the southeast asian monocled cobras (naja kaouthia) exhibit geographical variations in their venom proteomes, especially on the composition of neurotoxins. this study compared the neuromuscular depressant activity of the venoms of n. kaouthia from malaysia (nk-m), thailand (nk-t) and vietnam (nk-v), and the neutralization of neurotoxicity by a monospecific antivenom. on chick biventer cervicis nerve-muscle preparation, all venoms abolished the indirect twitches, with nk-t venom being the most po ... | 2017 | 26972756 |
| quantifying demyelination in nk venom treated nerve using its electric circuit model. | reduction of myelin in peripheral nerve causes critical demyelinating diseases such as chronic inflammatory demyelinating polyneuropathy, guillain-barre syndrome, etc. clinical monitoring of these diseases requires rapid and non-invasive quantification of demyelination. here we have developed formulation of nerve conduction velocity (ncv) in terms of demyelination considering electric circuit model of a nerve having bundle of axons for its quantification from ncv measurements. this approach has ... | 2016 | 26932543 |
| naturally occurring disulfide-bound dimers of three-fingered toxins: a paradigm for biological activity diversification. | disulfide-bound dimers of three-fingered toxins have been discovered in the naja kaouthia cobra venom; that is, the homodimer of alpha-cobratoxin (a long-chain alpha-neurotoxin) and heterodimers formed by alpha-cobratoxin with different cytotoxins. according to circular dichroism measurements, toxins in dimers retain in general their three-fingered folding. the functionally important disulfide 26-30 in polypeptide loop ii of alpha-cobratoxin moiety remains intact in both types of dimers. biologi ... | 2008 | 18381281 |
| post-ovipositional development of the monocled cobra, naja kaouthia (serpentes: elapidae). | external morphological development between oviposition and hatching of the monocled cobra, naja kaouthia, is described. ten developmental stages are diagnosed according to nine features. these include fusion of the body wall musculature along the ventral midline, appearance of the endolymphatic ducts, formation of the eyelid, and the appearance of scales on the head and body. additional observations of the developing skull are made at four of these ten stages, based on cleared and stained heads. | 2002 | 16351869 |
| thrombin-induced reactive oxygen species generation in platelets: a novel role for protease-activated receptor 4 and gpibα. | platelets are essential for maintaining haemostasis and play a key role in the pathogenesis of cardiovascular disease. upon ligation of platelet receptors through subendothelial matrix proteins, intracellular reactive oxygen species (ros) are generated, further amplifying the platelet activation response. thrombin, a potent platelet activator, can signal through gpibα and protease-activated receptor (par) 1 and par4 on human platelets, and recently has been implicated in the generation of ros. w ... | 2015 | 26569550 |
| purification and characterization of nk-3ftx: a three finger toxin from the venom of north east indian monocled cobra. | snake venom three finger toxins (3ftxs) are a non-enzymatic family of venom proteins abundantly found in elapids. we have purified a 7579.5 ± 0.591 da 3ftx named as nk-3ftx from the venom of naja kaouthia of north east india origin. the primary structure was determined by a combination of n-terminal sequencing and electrospray ionization liquid chromatography-mass spectrometry/mass spectrometry. biochemical and biological characterization reveal that it is nontoxic to human cell lines and exhibi ... | 2016 | 26293154 |
| affinity adsorbent based on combinatorial phage display peptides that bind alpha-cobratoxin. | combinatorial phage display was used to discover peptides that selectively bind to the alpha-cobratoxin (neurotoxin) component of the multi-component venom of the thai cobra, naja kaouthia. peptide sequences determined in this way were synthesized chemically and were covalently attached to agarose through the alpha-amino terminus. such affinity chromatography supports selectively bound the alpha-cobratoxin component from crude venom, while passage of the crude venom over the support selectively ... | 2004 | 15135114 |
| differential hydrolysis of erythrocyte and mitochondrial membrane phospholipids by two phospholipase a2 isoenzymes (nk-pla2-i and nk-pla2-ii) from the venom of the indian monocled cobra naja kaouthia. | we previously demonstrated that venom from the indian monocled cobra naja kaouthia is a rich source of phospholipase a2 enzymes, and we purified and characterized a major pla2 isoenzyme (nk-pla2-i) from n. kaouthia venom. in the present study, we report the purification and biochemical characterization of a second pla2 isoenzyme (nk-pla2-ii) from the same venom. a comparison of the membrane phospholipid hydrolysis patterns by these two pla2s has revealed that they cause significantly more damage ... | 2004 | 15081888 |
| structural insight into specificity of interactions between nonconventional three-finger weak toxin from naja kaouthia (wtx) and muscarinic acetylcholine receptors. | weak toxin from naja kaouthia (wtx) belongs to the group of nonconventional "three-finger" snake neurotoxins. it irreversibly inhibits nicotinic acetylcholine receptors and allosterically interacts with muscarinic acetylcholine receptors (machrs). using site-directed mutagenesis, nmr spectroscopy, and computer modeling, we investigated the recombinant mutant wtx analogue (rwtx) which, compared with the native toxin, has an additional n-terminal methionine residue. in comparison with the wild-typ ... | 2015 | 26242733 |
| snake venomics of monocled cobra (naja kaouthia) and investigation of human igg response against venom toxins. | the venom proteome of the monocled cobra, naja kaouthia, from thailand, was characterized by rp-hplc, sds-page, and maldi-tof-tof analyses, yielding 38 different proteins that were either identified or assigned to families. estimation of relative protein abundances revealed that venom is dominated by three-finger toxins (77.5%; including 24.3% cytotoxins and 53.2% neurotoxins) and phospholipases a2 (13.5%). it also contains lower proportions of components belonging to nerve growth factor, ohanin ... | 2015 | 25771242 |
| preliminary crystallographic analysis of phospholipase a(2) from naja naja kaouthia lesson venom. | an acidic phospholipase a(2) isolated from the venom of naja naja kaouthia lesson in guangxi exhibits anticoagulative and hemolytic activities. in this work, the enzyme was crystallized by the method of hanging drop vapor diffusion. two crystal forms were obtained and characterized by x-ray diffraction. one of them belonged to space group p 4 ( 3 ) 2 ( 1 )2 or p4(1)2(1)2 with unit cell parameters a b 8.797 nm, c 10.831 nm and there were three molecules per asymmetric unit the other belonged to s ... | 2001 | 12040404 |
| venomics, lethality and neutralization of naja kaouthia (monocled cobra) venoms from three different geographical regions of southeast asia. | previous studies showed that venoms of the monocled cobra, naja kaouthia from thailand and malaysia are substantially different in their median lethal doses. the intraspecific venom variations of n. kaouthia, however, have not been fully elucidated. here we investigated the venom proteomes of n. kaouthia from malaysia (nk-m), thailand (nk-t) and vietnam (nk-v) through reverse-phase hplc, sds-page and tandem mass spectrometry. the venom proteins comprise 13 toxin families, with three-finger toxin ... | 2015 | 25748141 |
| nicotinic acetylcholine receptor α7 subunit is involved in the cobratoxin-induced antinociception in an animal model of neuropathic pain. | in this study we report that cobratoxin (cbtx), a long-chain postsynaptic α-neurotoxin isolated from the thailand cobra, naja naja kaouthia, has antinociceptive effect in rats with neuropathic pain. the neuropathic pain model was established in rats with partial sciatic nerve ligature (psnl) method. the pain response was examined behaviorally with mechanical paw withdrawal and thermal paw withdrawal method. different doses (0.56, 1.12 and 4.50 μg/kg) of cbtx were injected intrathecally. injectio ... | 2015 | 25447771 |
| nano gold conjugation, anti-arthritic potential and toxicity studies of snake naja kaouthia (lesson, 1831) venom protein toxin nkct1 in male albino rats and mice. | nanoscience and nanotechnology have found their way in the fields of pharmacology and medicine. the conjugation of drug to nanoparticles combines the properties of both. in this study, gold nanoparticle (gnp) was conjugated with nkct1, a cytotoxic protein toxin from indian cobra venom for evaluation of anti-arthritic activity and toxicity in experimental animal models. gnp conjugated nkct1 (gnp-nkct1) synthesized by nabh4 reduction method was stable at room temperature (25 +/- 2 degrees c), ph 7 ... | 2014 | 25141538 |
| ophiophagus hannah venom: proteome, components bound by naja kaouthia antivenin and neutralization by n. kaouthia neurotoxin-specific human scfv. | venomous snakebites are an important health problem in tropical and subtropical countries. king cobra (ophiophagus hannah) is the largest venomous snake found in south and southeast asia. in this study, the o. hannah venom proteome and the venom components cross-reactive to n. kaouthia monospecific antivenin were studied. o. hannah venom consisted of 14 different protein families, including three finger toxins, phospholipases, cysteine-rich secretory proteins, cobra venom factor, muscarinic toxi ... | 2014 | 24828754 |
| in vivoandin vitrotoxicity of nanogold conjugated snake venom protein toxin gnp-nkct1. | research on nanoparticles has created interest among the biomedical scientists. nanoparticle conjugation aims to target drug delivery, increase drug efficacy and imaging for better diagnosis. toxicity profile of the nanoconjugated molecules has not been studied well. in this communication, the toxicity profile of snake venom cytotoxin (nkct1), an antileukemic protein toxin, was evaluated after its conjugation with gold nanoparticle (gnp-nkct1). gold nanoparticle conjugation with nkct1 was done w ... | 2014 | 28962228 |
| three cases of severe neurotoxicity after cobra bite (naja kaouthia). | | 2001 | 11400547 |
| [structure and conformational heterogeneity of the weak toxin from the cobra naja kaouthia venom]. | resonances in the two-dimensional 1h nmr spectra of a weak toxin (wtx) from the venom of cobra naja kaouthia for all 65 amino acid residues were assigned. the amino acid sequence of wtx, determined by the sequentional assignment of spin systems, was found to be similar to that of the cm-9a toxin from the n. kaouthia venom. unlike cm-9a, wtx contains an additional trp36 residue; lys50 and tyr52 are interchanged; and there is a thr residue in place of arg2. for some residues of wtx, the presence o ... | 2017 | 11357403 |
| venomics of naja sputatrix, the javan spitting cobra: a short neurotoxin-driven venom needing improved antivenom neutralization. | the venom proteome of naja sputatrix (javan spitting cobra) was elucidated through reverse-phase hplc, nano-esi-lcms/ms and data mining. a total of 97 distinct protein forms belonging to 14 families were identified. the most abundant proteins are the three-finger toxins (3ftxs, 64.22%) and phospholipase a2(pla2, 31.24%), followed by nerve growth factors (1.82%), snake venom metalloproteinase (1.33%) and several proteins of lower abundance (<1%) including a variety of venom enzymes. at subproteom ... | 2017 | 28159706 |
| design of a truncated cardiotoxin-i analogue with potent insulinotropic activity. | insulin secretion by pancreatic β-cells in response to glucose or other secretagogues is tightly coupled to membrane potential. various studies have highlighted the prospect of enhancing insulin secretion in a glucose-dependent manner by blocking voltage-gated potassium channels (k(v)) and calcium-activated potassium channels (k(ca)). such strategy is expected to present a lower risk for hypoglycemic events compared to katp channel blockers. our group recently reported the discovery of a new ins ... | 2014 | 24552570 |
| [a case of favourable outcome of severe acute intoxication with an animal poison after a bite by the monocled cobra]. | this paper reports a case of severe acute intoxication with an animal poison after a bite by the monocled cobra. combined treatment including artificial lung ventilation, infusion-detoxication and desensitizing (hormonal) therapy, hemosorption, correction of metabolic disorders with cytoflavin, antibacterial therapy had positive effect on the patient's condition and ensured the favourable outcome ofpotentially lethal poisoning without the use ofa specific anti-snake venom serum. | 2014 | 25790716 |
| biochemical and biological characterization of naja kaouthia venom from north-east india and its neutralization by polyvalent antivenom. | this study describes biochemical and biological properties of naja kaouthia (indian monocled cobra) venom of north-east india. the ld50 of the crude venom was found to be 0.148mg/kg and neurotoxicitic symptoms like paralysis of lower limbs and heavy difficulty in breathing at sub-lethal dose in mice was observed. the venom exhibited pla2, indirect hemolytic and myotoxic activities but showed weak proteolytic and low direct hemolytic activities. it did not exhibit any hemorrhage when injected int ... | 2013 | 24349704 |
| in vivo neutralization of α-cobratoxin with high-affinity llama single-domain antibodies (vhhs) and a vhh-fc antibody. | small recombinant antibody fragments (e.g. scfvs and vhhs), which are highly tissue permeable, are being investigated for antivenom production as conventional antivenoms consisting of igg or f(ab')2 antibody fragments do not effectively neutralize venom toxins located in deep tissues. however, antivenoms composed entirely of small antibody fragments may have poor therapeutic efficacy due to their short serum half-lives. to increase serum persistence and maintain tissue penetration, we prepared l ... | 2013 | 23894495 |
| factors in snake venoms that increase capillary permeability. | capillary permeability increasing (cpi) activity is a phenomenon of the microvasculature caused by many agents such as snake venoms, histamine, 5-hydroxytryptamine (5-ht), prostaglandins and leukotrienes. since no systematic study has been done to determine what components of snake venom cause cpi activity, a cpi factor from naja naja atra (taiwan cobra) venom was isolated using intravenous injections of evan's blue dye as the indicator of increased permeability and the factor's properties were ... | 1989 | 2576052 |
| a highly active anticomplement factor from the venom of naja kaouthia. | a highly active anticomplement factor (cobra venom factor) from the venom of naja kaouthia in south yunnan, china was isolated by sequential column chromatography (sp-sephadex-c-25, q sepharose hp and sephadex g-150). it displays strong anticomplement activities in vitro and in vivo, and has anticomplement activity of 1 515 u per mg. the purified anticomplement factor was homogeneous on sds-page with a molecular weight of 149 kd. it is composed of three polypeptide chains which are connected by ... | 2001 | 12040387 |
| antisnake venom activity of ethanolic seed extract of strychnos nux vomica linn. | the whole seed extract of s. nux vomica (in low doses) effectively neutralized daboia russelii venom induced lethal, haemorrhage, defibrinogenating, pla2 enzyme activity and naja kaouthia venom induced lethal, cardiotoxic, neurotoxic, pla2 enzyme activity. the seed extract potentiated polyvalent snake venom antiserum action in experimental animals. an active compound (snvnf) was isolated and purified by thin layer chromatography and silica gel column chromatography, which effectively antagonised ... | 2004 | 15233470 |
| cross-neutralization of thai cobra (naja kaouthia) and spitting cobra (naja siamensis) venoms by thai cobra antivenom. | the neutralizing capacity of antivenom prepared against thai cobra (naja kaouthia) venom was compared in mice using the homologous venom and that of spitting cobra (naja siamensis). the amounts of antivenoms neutralizing a dose of 4 ld50 of the test venom were determined. four antivenom preparations were used: three purified antivenoms and a crude antivenom, which were made using n. kaouthia venom only. almost the same neutralizing capacity was obtained with the purified antivenoms, whereas a sl ... | 1997 | 9428112 |
| neostigmine for the treatment of neurotoxicity following envenomation by the asiatic cobra. | envenomation by the monocellate cobra (naja kaouthia) is usually manifested clinically as neurotoxicity and local tissue necrosis. treatment often requires administration of large quantities of antivenin, resulting in a high incidence of serum reactions. in cases where antivenin administration may be delayed for several hours or administration is contraindicated, the use of the anticholinesterase drug neostigmine may temporarily reverse the potentially lethal neurological effects of the venom. d ... | 1996 | 8669746 |
| identification of α-cobratoxin in equine plasma by lc-ms/ms for doping control. | cobra venom (naja kaouthia) contains a toxin called α-cobratoxin (α-cbtx). this toxin is a natural protein containing 71 amino acids (mw 7821 da) with a reported analgesic potency greater than morphine. in 2007, in usa, this substance was found in the barns of a thoroughbred trainer and since then till date, the lack of a detection of this molecule has remained a recurring problem for the horseracing industry worldwide. to solve this problem, the first method for the detection of α-cobratoxin in ... | 2013 | 23581651 |
| antileukemic potential of pegylated gold nanoparticle conjugated with protein toxin (nkct1) isolated from indian cobra (naja kaouthia) venom. | limited efficacy of current first-line treatment for leukemia calls attention for further development of efficient strategies. recently, much attention has been given to nanoparticle-based drug delivery systems loaded with dual drugs to improve current disease therapies by overcoming toxicity. in the present study, we document to explore an approach to conjugate gold nanoparticles (gnps) with protein toxin (nkct1), a protein toxin from the indian cobra (naja kaouthia) venom, and to establish its ... | 2017 | 26069500 |
| cardiotoxin-i: an unexpectedly potent insulinotropic agent. | insulin secretion from pancreatic β-cells is a complex process, involving the integration and interaction of multiple external and internal stimuli, in which glucose plays a major role. understanding the physiology leading to insulin release is a crucial step toward the identification of new targets. in this study, we evaluated the presence of insulinotropic metabolites in naja kaouthia snake venom. only one fraction, identified as cardiotoxin-i (ctx-i) was able to induce insulin secretion from ... | 2012 | 22807058 |
| influence of chemistry in immobilization of cobra venom phospholipase a2: implications as to mechanism. | phospholipase a2 from naja naja kaouthia venom was covalently coupled onto agarose beads using two different chemistries. the effect of micellar competitive inhibitors in the coupling media was evaluated. enzyme bound to n-hydroxysuccinimide-activated agarose, which is reactive primarily toward epsilon-amino groups, had 20% activity retention against micellar diheptanoylphosphatidylcholine (dic7-pc). enzyme bound through carboxylic groups, using a modification of the carbodiimide method, had 50% ... | 1993 | 8347610 |
| ventricular bigeminy following a cobra envenomation. | envenoming by some species of cobras (naja species) may include cardiotoxic effects including various dysrhythmias. however, dysrhythmias leading specifically to ventricular bigeminy have not been previously documented. we report a case of cardiotoxicity and the development of ventricular bigeminy following a cobra envenomation. | 2012 | 22702902 |
| evaluation of the mechanism of skin enhancing surfactants on the biomembrane of shed snake skin. | the aim of the present work was to investigate the effects of different surfactants at various concentrations as a skin penetration enhancer through the biomembrane of the shed skin of naja kaouthia. additionally, the enhancer mechanism(s) of each class of surfactants were evaluated using physical characterization techniques, such as scanning electron microscopy (sem), attenuated total reflectance-fourier transform infrared (atr-ftir) spectroscopy, and small and wide angle x-ray scattering (swax ... | 2012 | 22466556 |
| dimeric α-cobratoxin x-ray structure: localization of intermolecular disulfides and possible mode of binding to nicotinic acetylcholine receptors. | in naja kaouthia cobra venom, we have earlier discovered a covalent dimeric form of α-cobratoxin (αct-αct) with two intermolecular disulfides, but we could not determine their positions. here, we report the αct-αct crystal structure at 1.94 å where intermolecular disulfides are identified between cys(3) in one protomer and cys(20) of the second, and vice versa. all remaining intramolecular disulfides, including the additional bridge between cys(26) and cys(30) in the central loops ii, have the s ... | 2012 | 22223648 |
| anionic lipids: determinants of binding cytotoxins from snake venom on the surface of cell membranes. | the cytotoxic properties of cytotoxins (cts) from snake venom are mediated by their interaction with the cell membrane. the hydrophobic pattern containing the tips of loops i-iii and flanked by polar residues is known to be a membrane-binding motif of cts. however, this is not enough to explain the difference in activity among various cts which are similar in sequence and in 3d structure. the mechanism of further ct-membrane interaction leading to pore formation and cell death still remains unkn ... | 2010 | 22649646 |
| use of hplc to demonstrate variation of venom toxin composition in the thailand cobra venoms naja naja kaouthia and naja naja siamensis. | the composition of the venoms of naja naja kaouthia and naja naja siamensis from different commercial sources has been investigated using both ion-exchange and reverse-phase high-pressure liquid chromatography (rp-hplc) in order to investigate variation in toxin contents. the venoms contained identical major toxin components, although in different relative concentrations. the venom collected separately from the left and right glands of individual snakes were virtually the same as judged by rp-hp ... | 1992 | 1595079 |
| structural divergence of cysteine-rich secretory proteins in snake venoms. | cysteine-rich secretory proteins (crisps) are expressed in spermatocytes and granules of neutrophils in mammals, and are associated with sperm maturation and host defense. related proteins have recently been recovered in snake venoms, and some of the snake venom-derived crisps exhibit ion channel blocking activity. here we isolated and identified two novel crisps (kaouthin-1 and kaouthin-2) from the venom of naja kaouthia (elapidae), and cloned the encoding cdnas. kaouthin-1 and kaouthin-2 were ... | 2009 | 19106157 |
| phospholipase a2-interacting weak neurotoxins from venom of monocled cobra naja kaouthia display cell-specific cytotoxicity. | the molecular weights of two phospholipase a(2) (pla(2))-interacting polypeptides (kaouthiotoxins (ktxs)-ktx-a and ktx-b) purified from the venom of monocled cobra naja kaouthia, were estimated by mass spectrometry as 7722 and 7627da, respectively. binary sequence alignment showed that both ktxs share substantial sequence homology with weak neurotoxins from cobra venom and they were devoid of any enzymatic activity. their pi was determined at ph 8.1 showing basic nature of these proteins. ktxs d ... | 2008 | 18456298 |
| snake venoms. the amino acid sequences of two melanoleuca-type toxins. | toxins cm-10 from naja nivea and cm-9a from naja naja kaouthia venoms were purified by gel filtration followed by ion-exchange chromatography. whereas toxin cm-10 contains 65 amino acids, toxin cm-9a contains only 64 but they each include ten half-cystine residues. the complete primary structures of the toxins have been established. the sequences and the invariant amino acids of toxins cm-10 from n. nivea and cm-9a from n.n. kaouthia venoms resemble those of the melanoleuca-type toxins. in the t ... | 1980 | 7380387 |
| the complete primary structures of three cytotoxins (cm-6, cm-7 and cm-7a) from naja naja kaouthia (siamese cobra) snake venom. | | 1980 | 7210030 |
| naja kaouthia envenomation in the midwest. | exotic pet ownership and distribution continues to grow in popularity in the united states. in light of this dangerous hobby and trade, emergency physicians may be confronted with caring for a patient injured by animals not indigenous to our country. we report a patient with significant neurotoxicity resulting from being envenomated by his pet suphan cobra. | 2004 | 15303386 |
| analysis of lectin-bound glycoproteins in snake venom from the elapidae and viperidae families. | this paper describes an efficient method of studying the glycoproteins found in snake venom. the glycosylation profiles of the elapidae and viperidae snake families were analyzed using fitc-labeled lectin glycoconjugates. the con a-agarose affinity enrichment technique was used to fractionate glycoproteins from the n. naja kaouthia venom. the results revealed a large number of con a binding glycoproteins, most of which have moderate to high molecular weights. to identify the proteins, the isolat ... | 2013 | 15253418 |
| purification and characterization of an anticoagulant phospholipase a(2) from indian monocled cobra (naja kaouthia) venom. | an anticoagulant, non-toxic phospholipase a(2) was isolated from the venom of indian monocled cobra (naja kaouthia) by a combination of ion-exchange chromatography on cm-sephadex c-50 and gel filtration on sephadex g-50. this purified protein named nk-pla(2)-i, had a subunit molecular mass of 13.6 kda and migrated as a dimer under non-reduced condition in sds-page. nk-pla(2)-i was a highly thermostable protein requiring basic ph optima for its catalytic activity and showed preferential hydrolysi ... | 2003 | 12467665 |
| crystal structures of an acidic phospholipase a(2) from the venom of naja kaouthia. | a phospholipase a(2) purified from the venom of naja kaouthia (guangxi cobra) exhibits anticoagulant activities. the structures of two crystal forms were determined by x-ray crystallography at 2.8a resolution with the naja naja (india cobra) pla(2) as an initial model. the enzyme exhibits a trimer structure, which is similar to that of india cobra pla(2). this reinforces the physiological relevance of the oligomer. the trimer has a wide cavity, which allows the substrate to enter and interact wi ... | 2002 | 12076645 |
| a novel short neurotoxin, cobrotoxin c, from monocellate cobra (naja kaouthia) venom: isolation and purification, primary and secondary structure determination, and tertiary structure modeling. | a novel short neurotoxin, cobrotoxin c (cbt c) was isolated from the venom of monocellate cobra (naja kaouthia) using a combination of ion-exchange chromatography and fplc. its primary structure was determined by edman degradation. cbt c is composed of 61 amino acid residues. it differs from cobrotoxin b (cbt b) by only two amino acid substitutions, thr/ala11 and arg/thr56, which are not located on the functionally important regions by sequence similarity. however, the ld50 is 0.08 mg/g to mice, ... | 2002 | 12039691 |
| restoration of nerve growth factor in organs of mice injected with cobra venom followed by specific treatment and reversal period. | research from this laboratory reported the decreased levels of endogenously present nerve growth factor (ngf) in organs of mice as a consequence of sub-lethal injection of naja kaouthia venom. this research reports that the decreased levels of ngf in organs of mice were prevented by (1) specific treatment and (2) restored to normal by a prolonged period. adult female balb/c mice were injected intramuscularly (im) with a sub-lethal dose of cobra venom. the injected mice were divided into five gro ... | 2002 | 12009116 |
| biochemical composition, lethality and pathophysiology of venom from two cobras-- naja naja and n. kaouthia. | the cobras naja naja and n. kaouthia are abundant in eastern and north-eastern india, accounting for maximum snakebite deaths. here we report on variation in the composition of naja kaouthia and n. naja venom from eastern india on corresponding differences in the severity of pathogenesis. these two venoms differ in chromatographic elution profile through sephadex g-50 and enzyme activity, protein and carbohydrate contents associated with each fraction. the presence of greater amounts of basic ph ... | 2002 | 11818235 |
| decreased levels of nerve growth factor in organs of mice as a consequence of sub-lethal injection of cobra venom. | nerve growth factor (ngf) is endogenously present in salivary glands of mice and sex organs of various animals. this research reports the presence of ngf in almost all major organs of mice at varying concentrations. the research further reports that intramuscular injection of a sub-lethal dose of naja kaouthia venom lowered the levels of ngf in the organs of mice. adult balb/c male mice were injected with a half lethal dose of cobra venom. the mice were sacrificed for organs at 2, 8, and 24 hour ... | 2001 | 11695817 |
| [cobra venom contains a protein belongs to the crisp family]. | amino acid sequences of several fragments of the 25 k protein (molecular mass 24,953 da) previously isolated from cobra naja kaouthia (kukhtina et al. bioorg. khim., 2000, vol. 26, pp. 803-807) were determined. their comparison with the primary structures of known proteins showed that the 25 k protein belongs to the crisp family and is the first protein of this type identified in cobra venoms. | 2017 | 11443947 |
| first tryptophan-containing weak neurotoxin from cobra venom. | with the purpose of studying structure-function relationships among weak neurotoxins (called so because of their low toxicity), we have isolated a toxin (wtx) from the venom of cobra naja kaouthia using a combination of gel-filtration and ion-exchange chromatography. the amino acid sequence of the isolated toxin was determined by means of edman degradation and maldi mass spectrometry, the primary structure obtained being confirmed by 1h-nmr in the course of spatial structure analysis. the wtx se ... | 2001 | 11223079 |
| regional and accelerated molecular evolution in group i snake venom gland phospholipase a2 isozymes. | in accordance with detection of a few phospholipase a2 (pla2) isozyme genes by southern blot analysis, only two cdnas, named nnkpla-i , and nnkpla-ii, encoding group i pla2s, nnkpla-i and nnkpla-ii, respectively, were isolated from the venom gland cdna library of elapinae naja naja kaouthia of malaysia. nnkpla-i and nnkpla-ii showed four amino acid substitutions, all of which were brought about by single nucleotide substitution. no existence of clones encoding cm-ii and cm-iii, pla2 isozymes whi ... | 2000 | 10669032 |
| anti-platelet activity of a three-finger toxin (3ftx) from indian monocled cobra (naja kaouthia) venom. | a low molecular weight anti-platelet peptide (6.9 kda) has been purified from naja kaouthia venom and was named kt-6.9. maldi-tof/tof mass spectrometry analysis revealed the homology of kt-6.9 peptide sequence with many three finger toxin family members. kt-6.9 inhibited human platelet aggregation process in a dose dependent manner. it has inhibited adp, thrombin and arachidonic acid induced platelet aggregation process in dose dependent manner, but did not inhibit collagen and ristocetin induce ... | 2013 | 24183721 |
| diversity of pbi-ddei satellite dna in snakes correlates with rapid independent evolution and different functional roles. | to better understand pbi-ddei satellite dna located in the centromeric region of python, molecular evolution analysis was conducted on 40 snake species. a ladder-like pattern of dna bands with repetition of the 194-210 bp monomer was observed in 15 species using pcr. molecular cloning was performed to obtain 97 at-rich monomer sequences. phylogenetic and network analyses showed three pbi-ddei subfamilies with sequences grouped in species-specific clusters, suggesting rapid evolution. slow evolut ... | 2019 | 31664097 |
| development of alpha-neurotoxin antibodies in patients envenomed by the monocellate thai cobra (naja kaouthia). | serum samples from 50 patients envenomed by the thai cobra (naja kaouthia) were tested by enzyme immune assay for the presence of antibodies against the principal neurotoxin. samples were taken between 1 month and 19 years after the bite. only 16% (8/50) of the samples were positive for antibodies against neurotoxin, while 76% (38/50) were positive for antibodies against whole venom. there was no clear correlation between the presence of antibodies against neurotoxin and clinical features. | 1994 | 7725334 |
| the two subunits of a phospholipase a2 inhibitor from the plasma of thailand cobra having structural similarity to urokinase-type plasminogen activator receptor and ly-6 related proteins. | amino acid sequences of the two subunits (31-kda and 25-kda subunits) of a phospholipase a2 (pla2) inhibitory protein, purified from the blood plasma of thailand cobra naja naja kaouthia, were determined by alignment of peptides obtained by lysyl endopeptidase, staphylococcal v8 protease and endoproteinase asp-n digestions. the respective subunits were composed of 188 and 185 amino acid residues, and the former contained one asparagine-linked sugar chain at the position 157. there was 29% identi ... | 1994 | 7980598 |
| isolation and characterization of a phospholipase a2 inhibitor from the blood plasma of the thailand cobra naja naja kaouthia. | a phospholipase a2 (pla2) inhibitory protein was purified from the blood plasma of the thailand cobra naja naja kaouthia by sequential chromatography on sephadex g-200, deae affi-gel blue, and protein-pak g-butyl columns. the purified inhibitor was a glycoprotein with an apparent molecular mass of about 90 kda and contained 25- and 31-kda subunits with a molar ratio of 1:2. the 31-kda subunit contained a glycosidic chain and the molecular mass was reduced to 28 kda by n-glycosidase f treatment. ... | 1994 | 8179612 |
| effect of calcium and phosphate ions on hemolysis induced by pyrularia thionin and naja naja kaouthia cardiotoxin. | pyrularia thionin is a strongly basic bioactive peptide of 47 amino acids isolated from nuts of pyrularia pubera. it is hemolytic, cytotoxic and activates an endogenous phospholipase a2 in 3t3 cells. earlier studies have shown that the cardiotoxin from naja naja kaouthia has similar activities and binds to the same site as pyrularia thionin. since the peptides appear to bind to the phospholipids of cell membranes to elicit their cellular responses, the effect of modifying the electrostatic envir ... | 1992 | 1509489 |
| purification and properties of the l-amino acid oxidase from monocellate cobra (naja naja kaouthia) venom. | 1. the l-amino acid oxidase of the monocellate cobra (naja naja kaouthia) venom was purified to electrophoretic homogeneity. the molecular weight of the enzyme was 112,200 as determined by sephadex g-200 gel filtration chromatography, and 57,400 as determined by sds-polyacrylamide gel electrophoresis. 2. the enzyme had an isoelectric point of 8.12 and a ph optimum of 8.5. it showed remarkable thermal stability, and, unlike many venom l-amino acid oxidase, was also stable in alkaline medium. the ... | 1992 | 1612186 |
| implications of a consensus recognition site for phosphatidylcholine separate from the active site in cobra venom phospholipases a2. | a model structure of naja naja kaouthia cobra venom phospholipase a2 has been constructed by utilizing molecular modeling techniques. analysis of the model and available biochemical data reveal the presence in this enzyme of a putative recognition site for choline derivatives in loop 57-70 made up of residues trp-61, tyr-63, phe-64, and lys-65, together with glu-55. the magnitude and shape of the electrostatic potential in this binding site are approximately 80% similar to that in the mcpc603 an ... | 1992 | 1550815 |
| structural features of carbohydrate moieties in snake venom glycoproteins. | the structures of the carbohydrate moieties of glycoproteins in snake venoms are largely unknown. in the present study, we have analyzed venoms of several species of snakes as well as plasma and tissue glycoproteins from one species of cobra (naja naja kaouthia) by lectin affinity staining of western blots. the data demonstrate that glycoproteins in cobra venom invariably contain terminal alpha-galactosyl residues with negligible proportions of sialic acids. interestingly, however, terminal alph ... | 1992 | 1731789 |