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phospholipase a2 as a mechanosensor.osmotic swelling of large unilamellar vesicles (luvs) causes membrane stretching and thus reduces the lateral packing of lipids. this is demonstrated to modulate strongly the catalytic activity of phospholipase a2 (pla2) toward a fluorescent phospholipid, 1-palmitoyl-2-[(6-pyren-1-yl)]decanoyl-sn-glycero-3-phosphocholine (ppdpc) residing in luvs composed of different unsaturated and saturated phosphatidylcholines. the magnitude of the osmotic pressure gradient delta omega required for maximal pl ...19957612831
interactions of n-terminal fragments of groups i and ii phospholipases a2 with phospholipid bilayers and their surface recognition properties.in order to elucidate the roles of the n-terminal segments of groups i and ii phospholipases a2 (pla2s) which have been known to have alpha-helical structure and have been assumed to be involved in the water/lipid interface recognition site, the peptides corresponding to the n-terminal moieties of group i pla2 (naja naja atra) and group ii pla2s (trimeresurus flavoviridis and crotalus atrox) were synthesized and their interactions with model membranes were studied. circular dichroism spectra sho ...19948117749
classification of myonecrosis induced by snake venoms: venoms from the prairie rattlesnake (crotalus viridis viridis), western diamondback rattlesnake (crotalus atrox) and the indian cobra (naja naja naja).the pathogenesis of myonecrosis induced by three different snake venoms was studied by light microscopic examination of skeletal muscle tissue taken at time periods ranging from 0.25 hr to 4 weeks after an intramuscular injection of the venom into mice. it was possible to identify different types of myonecrosis based on the abnormal morphologic states of the damaged cells. the types of myonecrosis observed correlated with the types of components present in the venom injected. venoms containing d ...19883188052
self-association and active enzyme forms of naja naja naja and crotalus atrox phospholipase a2 studied by analytical ultracentrifugation.the dimerization of phospholipase a2 (plpa2) from naja naja naja (pakistani cobra) and crotalus atrox (western diamondback rattlesnake) has been studied from ph 2.5 to 11 at 20 degrees c in 1 mm cacl2, 0.21 m ionic strength. for the c. atrox enzyme, it was found necessary to use a combination of sedimentation equilibrium and fluorescence yield data to analyze the association. sedimentation equilibrium in the analytical ultracentrifuge sufficed for the study of the n. naja plpa2. in the region of ...19863801457
lipid monolayers: action of phospholipase a of crotalus atrox and naja naja venoms on phosphatidyl choline and phosphatidal choline.the activity of phospholipase a on phosphatidyl choline and phosphatidal choline spread as monolayers on phosphate buffers containing snake venom (crotalus atrox or naja naja) was studied by measuring the fall of surface potential as a function of time, ph, film pressure, temperature, and concentrations of phosphate and venom. at 25 degrees c, ph 7.0, and 0.2 micrograms of venom per ml, optimal activity was observed with both venoms on both substrates at 12 dynes/cm film pressure on 0.04 m phosp ...19665947040
development of dot-elisa for the detection of venoms of major indian venomous snakes.india remained an epicenter for the snakebite-related mortality and morbidities due to widespread agricultural activities across the country and a considerable number of snakebites offended by indian cobra (naja naja), common krait (bungarus caeruleus), russell's viper (daboia russelii), and saw-scaled viper (echis carinatus). presently, there is no selective test available for the detection of snake envenomation in india before the administration of snake antivenin. therefore, the present study ...201729024771
neutralization of inflammation by inhibitingin vitroandin vivosecretory phospholipase a2by ethanol extract ofboerhaavia diffusal.inflammation is a normal and necessary prerequisite to healing of the injured tissues. inflammation contributes to all disease process including immunity, vascular pathology, trauma, sepsis, chemical, and metabolic injuries. the secretory phospholipase a2(spla2) is a key enzyme in the production of pro-inflammatory mediators in chronic inflammatory disorders such as rheumatoid arthritis, coronary heart disease, diabetes, and asthma. the spla2also contribute to neuroinflammatory disorders such as ...201728539742
development of a new polyspecific antivenom for snakebite envenoming in sri lanka: analysis of its preclinical efficacy as compared to a currently available antivenom.a new whole igg, freeze-dried, polyspecific antivenom was prepared from the plasma of horses immunized with the venoms of the snakes daboia russelii, echis carinatus, hypnale hypnale, and naja naja from sri lanka. the preclinical neutralizing ability of this antivenom against several toxic and enzymatic activities of these four venoms was analyzed, and compared with that of a batch of vins antivenom (india) being currently used in sri lanka. the activities tested were: lethality, hemorrhagic, in ...201627720977
rapid and selective detection of experimental snake envenomation - use of gold nanoparticle based lateral flow assay.in this study, we have developed a gold nanoparticle based simple, rapid lateral flow assay (lfa) for detection of indian cobra venom (cv) and russell's viper venom (rv). presently, there is no rapid, reliable, and field diagnostic test available in india, where snake bite cases are rampant. therefore, this test has an immense potential from the public health point of view. the test is based on the principle of the paper immunochromatography assay for detection of two snake venom species using p ...201627377230
snakebite by the shore pit viper (trimeresurus purpureomaculatus) treated with polyvalent antivenom.although snakebites are uncommon, there are several species of medically important venomous snakes native to singapore. we present a case of envenoming by the shore pit viper (trimeresurus purpureomaculatus) that showed clinical improvement when treated with the indian (haffkine) polyvalent antivenom. a 40-year-old man was bitten on his right hand by a snake, which was identified through photos and his description to be a shore pit viper, which is native to the local mangrove area. severe swelli ...201627061038
differential action of medically important indian big four snake venoms on rodent blood coagulation.snakebite is a global health problem affecting millions of people. according to who, india has the highest mortality and/or morbidity due to snakebite. in spite of commendable research on indian big four venomous species; naja naja and bungarus caeruleus (elapid); daboia russelii and echis carinatus (viperid), no significant progress has been achieved in terms of diagnosis and management of biting species with appropriate anti-snake venom. major hurdle is identification of offending species. pre ...201626592458
rare cardiac sequelae of a hump-nosed viper bite.the hump-nosed pit viper (hypnale hypnale) is the commonest cause for venomous snakebites in sri lanka. previously, it was thought to cause only local envenomation. however recently, several systemic effects and even mortality has been reported. along with other snakes, such as the indian cobra (naja naja), the common krait (bungarus caeruleus), the russell's viper (daboia russelii) and the saw-scaled viper (echis carinatus), the hump-nosed viper is now also considered capable of causing lethal ...201526369415
a study of snake bite among children presenting to a paediatric ward in the main teaching hospital of north central province of sri lanka.snake bite is a common problem in the north central province of sri lanka. common krait (bungarus careuleus), ceylon krait (bungarus ceylonicus), cobra (naja naja), russell's viper (daboia russelii), saw-scaled viper (echis carinatus) and hump-nosed pit viper (hypnale hypnale) are the six species of venomous land snakes in sri lanka. a significant number of adults and children are bitten by snakes every year. however, the majority of research studies done in sri lanka and other countries show ad ...201425073710
identification of novel inhibitors of daboia russelli phospholipase a2 using the combined pharmacophore modeling approach.crystal structures available for daboia russelli venom pla(2) confirm that it undergoes dimerization with asymmetry and hence difference in the conformation of active site of the two subunits. the active site of subunit a is open and that of subunit b is closed. pharmacophore models were generated based on the interaction of different types of inhibitors with their preferred subsites in the active site of subunit a. particularly, the features responsible for recognizing subsites 1-3 and those of ...201424703201
in vitro and in vivo evaluation of polyherbal formulation against russell's viper and cobra venom and screening of bioactive components by docking studies.the present study emphasizes to reveal the antivenom activity of aristolochia bracteolata lam., tylophora indica (burm.f.) merrill, and leucas aspera s. which were evaluated against venoms of daboia russelli russelli (russell's viper) and naja naja (indian cobra). the aqueous extracts of leaves and roots of the above-mentioned plants and their polyherbal (1 : 1 : 1) formulation at a dose of 200 mg/kg showed protection against envenomed mice with ld50 doses of 0.44 mg/kg and 0.28 mg/kg against ru ...201323533518
comparison of proteomic profiles of the venoms of two of the 'big four' snakes of india, the indian cobra (naja naja) and the common krait (bungarus caeruleus), and analyses of their toxins.snake venoms are mixtures of biologically-active proteins and peptides, and several studies have described the characteristics of some of these toxins. however, complete proteomic profiling of the venoms of many snake species has not yet been done. the indian cobra (naja naja) and common krait (bungarus caeruleus) are elapid snake species that are among the 'big four' responsible for the majority of human snake envenomation cases in india. as understanding the composition and complexity of venom ...201728602829
isolation and preliminary characterisation of two toxic phospholipases a2 from the venom of the malayan cobra (naja naja sputatrix).two toxic phospholipases a have been isolated from the venom of the malayan cobra (naja naja sputatrix). the phospholipases a were purified by successive ion-exchange chromatography on sp-sephadex c-25, sephadex g-75 gel filtration chromatography and successive bio-rex 70 ion-exchange chromatography. the purified toxic phospholipases a were homogeneous electrophoretically. they were designated as sputatrix phospholipase a-i and sputatrix phospholipase a-ii. positional specificity studies showed ...19827150663
use of immunoturbidimetry to detect venom-antivenom binding using snake venoms.immunoturbidimetry studies the phenomenon of immunoprecipitation of antigens and antibodies in solution, where there is the formation of large, polymeric insoluble immunocomplexes that increase the turbidity of the solution. we used immunoturbidimetry to investigate the interaction between commercial snake antivenoms and snake venoms, as well as cross-reactivity between different snake venoms.201323416032
hemostatic interference of indian king cobra (ophiophagus hannah) venom. comparison with three other snake venoms of the subcontinent.unlike naja naja, bungarus caeruleus, echis carinatus, and daboia/vipera russellii venoms, ophiophagus hannah venom is medically ignored in the indian subcontinent. being the biggest poisonous snake, o. hannah has been presumed to inject several lethal doses of venom in a single bite. lack of therapeutic antivenom to o. hannah bite in india makes any attempt to save the victim a difficult exercise. this study was initiated to compare o. hannah venom with the above said venoms for possible interf ...201222817464
evidence for existence of venom 5' nucleotidase in multiple forms through inhibition of concanavalin a.pharmacologically active 5' nucleotidase is a ubiquitously distributed enzyme in snake venoms. in this study the effect of concanavalin a (con-a) on different snake venoms 5' nucleotidase activity is tested in order to know the protein nature which will ultimately help in purification of the enzyme with high yield. con-a inhibited naja naja, naja kauthia, naja melanoleuca, naja naja sputatrix, agistrodon halys blomhoffii, bothrops asper and oxyranus scutellas venom 5' nucleotidase activity at di ...201020941753
molecular diversity in venom proteins of the russell's viper (daboia russellii russellii) and the indian cobra (naja naja) in sri lanka.to examine the molecular diversity of the venom proteins of the russell's viper (daboia russellii russellii) and the indian cobra (naja naja) in sri lanka, we isolated 38 venom proteins through a combination of anion exchange chromatography followed by reversed-phase high performance liquid chromatography. from the venom of d. r. russellii we isolated 15 proteins: 5 isozymes of phospholipase a(2) (pla(2)), 4 serine proteases, 2 c-type lectin-like proteins, 2 l-amino acid oxidases, 1 cysteine-ric ...201020203422
vanillic acid as a novel specific inhibitor of snake venom 5'-nucleotidase: a pharmacological tool in evaluating the role of the enzyme in snake envenomation.vanillic acid has been investigated for its inhibitory effect on naja naja, daboia russellii, and trimeresurus malabaricus venom 5'-nucleotidase activity. trimeresurus malabaricus venom 5'-nucleotidase activity was 1.3- and 8.0-fold higher than that of n. naja and d. russellii venoms, respectively. substrate specificity studies showed that for all the venoms tested, 5'-amp was the preferred substrate for 5'-nucleotidase. this indicates the central role of adenosine in snake envenomation. vanilli ...200919961411
syndromic approach to treatment of snake bite in sri lanka based on results of a prospective national hospital-based survey of patients envenomed by identified snakes.of 860 snakes brought to 10 hospitals in sri lanka with the patients they had bitten, 762 (89%) were venomous. russell's vipers (daboia russelii) and hump-nosed pit vipers (hypnale hypnale) were the most numerous and h. hypnale was the most widely distributed. fifty-one (6%) were misidentified by hospital staff, causing inappropriate antivenom treatment of 13 patients. distinctive clinical syndromes were identified to aid species diagnosis in most cases of snake bite in sri lanka where the bitin ...200919815895
a glycoprotein from a folk medicinal plant, withania somnifera, inhibits hyaluronidase activity of snake venoms.venom hyaluronidases help in rapid spreading of the toxins by destroying the integrity of the extra-cellular matrix of the tissues in the victims. a hyaluronidase inhibitor (wsg) is purified from a folk medicinal plant, withania somnifera. the glycoprotein inhibited the hyaluronidase activity of cobra (naja naja) and viper (daboia russelii) venoms, which was demonstrated by zymogram assay and staining of the skin tissues for differential activity. wsg completely inhibited the activity of the enz ...200616513428
crystal structure of the complex of group i pla2 with a group ii-specific peptide leu-ala-ile-tyr-ser (laiys) at 2.6 a resolution.phospholipases a(2)s (pla(2)s) are widely distributed in mammals and snake venoms. they catalyze the production of arachidonic acid from membrane phospholipids leading to the bioynthesis of pro-inflammatory eicosanoids. a peptide leu-ala-ile-tyr-ser (laiys) was designed and synthesized as a specific inhibitor of pla(2). it was shown earlier that the peptide bound to group ii pla(2) specifically and had a dissociation constant (k(d)) of 8.8 x 10(-9) m. in the present studies for the binding of la ...200516278156
enzymatic activities of some snake venoms from families elapidae and viperidae.alkaline phosphomonoesterase, phosphodiesterase, l-amino acid oxidase, hyaluronidase, 5'-nucleotidase, arginine ester hydrolase, phospholipase a2 and proteinase activities were determined in eight snake venoms, including three from sea snake, of families elapidae and viperidae from pakistan. the species includes three sea snakes hydrophis cyanocinctus, enhydrina schsitosa, microcephalophis gracilis gracilis and two land snakes naja naja naja, bungarus caeruleus of family elapidae while three lan ...199616414774
a sensitive fluorogenic enzyme linked immunosorbent assay for the detection of vipera russelli venom.a highly sensitive fluorogenic enzyme-linked immunosorbent assay (felisa) has been adapted for the detection of vipera russelli venom. the assay sensitivity was observed to be 0.1 pg/ml (1 x 10(-13) g/ml). venoms from snakes of the vipera group exhibited a high degree of cross-reactivity when tested with the antibody raised against v. russelli venom. with the exception of venom from naja naja, all the tested venoms from unrelated families also showed cross-reactivity. this procedure is useful fo ...19938167946
effects of chemical modification on enzymatic and toxicological properties of phospholipases a2 from naja naja naja and vipera russelli snake venoms.the effects of chemical modification with 4-nn-dimethyl amino azo benzene-4'-isothiocyanate on various biological activities of phospholipases a2, nn-xiii-pla2 from naja naja naja and vrv-pl-viiia from vipera russelli snake venoms were investigated. modification of the enzymes resulted in significant reduction of lethal, hemolytic, anticoagulant and enzymatic activities. the km value of the modified enzymes was increased. the modified enzymes failed to induce edema in the foot pads of mice and w ...19911801318
phospholipase a of snake venoms. i. isolation and molecular properties of isoenzymes from naja naja and vipera russellii venoms. 19715542003
identification of enzymes and toxins in venoms of indian cobra and russell's viper after starch gel electrophoresis. 196113767976
comparison of three classes of snake neurotoxins by homology modeling and computer simulation graphics.we present a systematic structure comparison of three major classes of postsynaptic snake toxins, which include short and long chain alpha-type neurotoxins plus one angusticeps-type toxin of black mamba snake family. two novel alpha-type neurotoxins isolated from taiwan cobra (naja naja atra) possessing distinct primary sequences and different postsynaptic neurotoxicities were taken as exemplars for short and long chain neurotoxins and compared with the major lethal short-chain neurotoxin in the ...199910198241
nicotinic acetylcholine receptor contains multiple binding sites: evidence from binding of alpha-dendrotoxin.we have studied the stoichiometry of the binding of the long alpha-neurotoxins from the venom of dendroaspis viridis (alpha-dendrotoxin) and naja naja siamensis (alpha-cobratoxin) to the membrane-bound acetylcholine receptor (acchor) from torpedo californica electric organ. the number of toxin molecules bound to one acchor molecule was determined by simultaneous-quantitative gas-phase microsequencing of all the amino acid sequences present in acchor-alpha-neurotoxin complexes. this method permit ...19863462717
purification and characterization of an anti-hemorrhagic protein from naja naja (indian cobra) venom.snake venom kunitz-type proteins are well known to inhibit serine proteases but a few studies have also shown matrix metalloproteases (mmps) inhibition. in view of the fact that mmps and snake venom metalloproteases (svmps) have similar catalytic site, inhibition of svmp activity by kunitz-type proteins remains to be studied. recent proteomic studies of naja naja (n. naja) venom revealed the abundance of kunitz-type proteins. in this regard, present study aimed at purification of a protease inhi ...201729107082
ten years of snakebites in iran.many species of venomous snakes are found in iran. the most medically important species which are responsible for the most snakebite incidents in iran belong to the viperidae family, including vipera lebetina, echis carinatus, pseudocerastes persicus, vipera albicornuta and the elapidae family, especially naja naja oxiana. at least one kind of venomous snake is found in each of the 31 provinces, and many provinces have more than one venomous species. as a result, snakebite is a considerable heal ...201425193748
cross neutralization of dangerous snake venoms from africa and the middle east using the vacsera polyvalent antivenom. egyptian organization for biological products & vaccines.this study was performed to assess the ability of polyvalent snake venom anti-serum, produced by the egyptian organization for biological products & vaccines (vacsera), to neutralize several toxic activities of snake venoms, not only of those included in the antivenom mixture, but also some additional venoms of snakes from egyptian, african, and middle eastern habitats. in general, the results revealed that polyvalent snake venom anti-serum from vacsera is highly effective in neutralizing egypti ...200212503876
procoagulant activities in venoms from central asian snakes.the venoms from central asian snakes (echis carinatus, echis multisquamatus, vipera ursini, vipera lebetina, agkistrodon halys halys and naja naja oxiana) contain several enzymes with amidolytic- and procoagulant activity. we have characterized the activities and the mol. wts of the venom enzymes that are able to convert a number of commercially available chromogenic substrates for activated coagulation factors. the chromogenic substrate cleavage patterns obtained for the crude venoms may be hel ...19911830705
lack of the blocking effect of cobrotoxin from naja naja atra venom on neuromuscular transmission in isolated nerve muscle preparations from poisonous and non-poisonous snakes.neuromuscular transmission in the chinese cobra naja naja atra was not affected by its own toxin (cobrotoxin) at a concentration of as high as 100 microm, while in the frog a concentration of less than 0.1 microm cobrotoxin depressed the amplitude of the end-plate potential to less than 10% of its original value within 30 min or directly blocked the nerve-evoked muscle action potential. the lack of effect of cobrotoxin was also observed in the nerve-muscle preparations from a pit viper (agkistro ...19902175458
role of ca2+ in the substrate binding and catalytic functions of snake venom phospholipases a2.phospholipases a2 are classified into two groups, i and ii, according to differences in the polypeptide-chain length and the intramolecular-disulfide bondings. the effects of ca2+ on the kinetic parameters for the hydrolysis of monodispersed and micellar phosphatidylcholines, catalyzed by a cobra (naja naja atra) enzyme (group i) and by mamushi (agkistrodon halys blomhoffii) and habu (trimeresurus flavoviridis) enzymes (group ii), were studied by the ph-statassay method at 25 degrees c, ph 8.0-8 ...19892606904
proteomic characterization of two snake venoms: naja naja atra and agkistrodon halys.snake venom is a complex mixture of proteins and peptides, and a number of studies have described the biological properties of several venomous proteins. nevertheless, a complete proteomic profile of venom from any of the many species of snake is not available. proteomics now makes it possible to globally identify proteins from a complex mixture. to assess the venom proteomic profiles from naja naja atra and agkistrodon halys, snakes common to southern china, we used a combination strategy, whic ...200415285721
structural determinants of the intrinsic fluorescence emission in notexin and phospholipase a2 enzymes.fluorescence measurements of the homologous proteins, notexin and pla2 enzymes from naja naja atra, naja nigricollis, and hemachatus haemachatus venoms, showed that the wave-length of maximum emission and the quantum yield of their intrinsic fluorescence emission spectra were different. to verify the factors which affected their fluorescence characteristics, the dynamics of tryptophan residues in those homologous proteins were studied by quenching with acrylamide, iodide, and cesium. the degrees ...19938142000
immunochemical properties of naja naja atra (taiwan cobra) phospholipase a2 using polyclonal and monoclonal antibodies.the immuno-chemical properties of naja naja atra phospholipase a2 (nna-pla2) were studied by using the chemically modified pla2 derivatives and the pla2 homologues toward anti-nna-pla2 polyclonal and monoclonal antibodies. anti-nna-pla2 polyclonal antibodies inhibited the enzymatic activity of nna-pla2 and hemachatus haemachatus de-i by 87% and 68%, respectively. however, the enzymatic activities of naja nigricollis cms-9 and notexin were not significantly affected by the polyclonal antibodies. ...19921373010
a comparative in silico characterization of functional and physicochemical properties of 3ftx (three finger toxin) proteins from four venomous snakes.snake venom is an abundant resource of diverse pharmacologically bioactive proteins and peptides and a good natural source of drug lead compounds and used as important research tools in the field of toxicology, pharmacology and neuroscience. three finger toxins (3ftx) is an important super-family of snake venom proteins which has a conserved three finger like appearance in three dimensional structures. members of 3ftx family show a wide array of pharmacological effects by targeting different rec ...201424966535
actions of snake neurotoxins on an insect nicotinic cholinergic synapse.here we examine the actions of six snake neurotoxins (alpha-cobratoxin from naja naja siamensis, erabutoxin-a and b from laticauda semifasciata; cm12 from n. haje annulifera, toxin iii 4 from notechis scutatus and a long toxin from n. haje) on nicotinic acetylcholine receptors in the cercal afferent, giant interneuron 2 synapse of the cockroach, periplaneta americana. all toxins tested reduced responses to directly-applied ach as well as epsps evoked by electrical stimulation of nerve xi with si ...200717710455
genomic structures of cardiotoxin 4 and cobrotoxin from naja naja atra (taiwan cobra).two genomic dnas with the size of 2.3 kb and 2.4 kb, which were isolated from the liver of naja naja atra (taiwan cobra), encoded the precursors of cardiotoxin 4 and cobrotoxin, respectively. both genes shared virtually identical overall organization with three exons separated by two introns, which were inserted in the similar positions of the gene's coding regions. moreover, their nucleotide sequences shared approximately 84.2% identity. this result reveals the evolutionary relationship between ...19979367842
identification of a locality in snake venom alpha-neurotoxins with a significant compositional similarity to marine snail alpha-conotoxins: implications for evolution and structure/activity.alpha-neurotoxins from elapid snake venoms and alpha-conotoxins from marine snails bind specifically and with high affinity to nicotinic cholinoceptors. although both types of toxin are polypeptides, there is more than a fourfold difference in size between the two and no clear sequence homology is evident. a systematic computer search of the three-dimensional structure of erabutoxin b (an alpha-neurotoxin from the false sea snake laticauda semifasciata) was performed to identify the locality tha ...19892514275
[1h-nmr study of the naja naja oxiana neurotoxin ii and its spin-labeled derivatives. conformation of "short" neurotoxins].in 1h nmr spectra of neurotoxin ii n. n. oxiana the chemical shift ph-dependences in h2o and 2h2o solutions were studied, and also the deuterium exchange rates and chemical shift temperature gradients were measured for the amide protons. the spin probe method was applied to assess the degree of exposure into solvent of the amide and side chain protons. with the purpose of establishing mutual disposition of certain neurotoxin ii groupings, nuclear overhauser effect was studied in the 1h nmr spect ...19836679788
individual assignments of the amide proton resonances involved in the triple-stranded antiparallel pleated beta-sheet structure of a long neurotoxin, laticauda semifasciata iii from laticauda semifasciata.the characteristic feature of the crystal structure of erabutoxin b, a short neurotoxin from laticauda semifasciata, and alpha-cobratoxin, a long neurotoxin from naja naja siamensis, is the presence of a triple-stranded antiparallel pleated beta-sheet structure formed by the central and the third peptide loops. in the present study, we have studied the assignment of slowly exchangeable amide protons of laticauda semifasciata iii from l. semifasciata, using nuclear overhauser effects (noe) and sp ...19826279398
a proton-magnetic-resonance study on the molecular conformation and structure-function relationship of a long neurotoxin, laticauda semifasciata iii from laticauda semifasciata.the 300-mhz and 500-mhz nmr spectra of a long neurotoxin laticauda semifasciata iii (ls iii) from laticauda semifasciata have ben analysed. comparison with the nmr spectra of alpha-cobratoxin from naja naja siamensis, a homologous long neurotoxin to laticauda semifasciata iii, allowed the assignment of all the aromatic protein resonances to specific amino acid residues. all the methyl proton resonances have been assigned to specific types of amino acid residues. the ph dependences of the aromati ...19817318828
the 1h nuclear-magnetic-resonance spectra of neurotoxin i and cardiotoxin vii4 from naja mossambica mossambica.two toxins from the venom of naja mossambica mossambica, neurotoxin i and cardiotoxin vii4, were investigated in aqueous solution by high-resolution 1h nuclear magnetic resonance (nmr) techniques at 360 mhz. the spectral characterization of the proteins included determination of the number of slowly exchanging amide protons which can be observed in 2h2o solution, measurement of the amide proton chemical shifts and exchange rates, characterization of the aromatic spin systems and the internal mob ...197833043
prevalence ofamblyomma gervaisiticks on captive snakes in tamil nadu.ticks are the important ectoparasites that occur on snakes and transmit rickettsiosis, anaplasmosis and ehrlichiosis. a total of 62 snakes (reticulated python, indian rock python, rat snakes and spectacled cobra) were examined for tick infestation at chennai snake park trust (guindy), arignar anna zoological park (vandalur) and rescue centre (velachery) in tamil nadu from september, 2015 to june, 2016. ticks from infested snakes were collected and were identified asamblyomma gervaisi(previously ...201729114125
a novel prothrombin activator from the venom of micropechis ikaheka: isolation and characterization.a novel prothrombin activator, mikarin, has been isolated from micropechis ikaheka venom. it is a single polypeptide chain metalloproteinase with the apparent molecular weight of 47kda. mikarin exhibits ca(2+)-independent prothrombin activation, but no effects on other blood coagulation factors, such as factor x and fibrinogen. mikarin is the first member of group i prothrombin activators from elapid venom. like other high-molecular-weight snake venom proteinases, it has three structural domains ...200212485606
cobra neurotoxin produces central analgesic and hyperalgesic actions via adenosine a1and a2areceptors.cobra neurotoxin, a short-chain peptide isolated from snake venom of naja naja atra, showed both a central analgesic effect and a hyperalgesic effect in mice tests. in order to explore mechanisms, a hypothesis is put forward that cobra neurotoxin takes effect through adenosine receptor pathway. the central effects of cobra neurotoxin were evaluated using the hot plate test (a model of acute pain) and the spinal cord injury (a model of central pain) in mice and using a1receptor antagonist (dpcpx) ...201728758541
photoresponsive nanocapsulation of cobra neurotoxin and enhancement of its central analgesic effects under red light.cobra neurotoxin (cnt), a peptide isolated from snake venom ofnaja naja atra, shows central analgesic effects in our previous research. in order to help cnt pass through blood-brain barrier (bbb) and improve its central analgesic effects, a new kind of cnt nanocapsules were prepared by double emulsification with soybean lecithin and cholesterol as the shell, and pheophorbide as the photosensitizer added to make it photoresponsive. the analgesic effects were evaluated by hot plate test and acetic ...201728496322
contributing factors for complications and outcomes in patients with snakebite: experience in a medical center in southern taiwan.snakebite usually results in various complications, such as significant soft tissue damage, infection, hematological, and neurological deficit. surgical intervention, usually, is indicated in patients with tissue necrosis, infection, and compartment syndrome. to identify the contributing factors for complications and outcomes in different patients with snakebite so that outcomes can be evaluated and treatment of such patients can be initiated at the earliest.201728195896
putative membrane lytic sites of p-type and s-type cardiotoxins from snake venoms as probed by all-atom molecular dynamics simulations.cardiotoxins (ctxs) belonging to the three-finger toxin superfamily of snake venoms are one of principal toxic components and the protein toxins exhibit membrane lytic activities when the venoms are injected into victims. in the present study, complex formations between ctx vi (a p-type ctx from naja atra) and ctx1 (an s-type ctx from naja naja) on zwitterionic popc bilayers (a major lipid component of cell membranes) have been studied in near physiological conditions for a total dynamic time sc ...201627628673
a single-label fluorescent derivatization method for quantitative determination of neurotoxin in vivo by capillary electrophoresis coupled with laser-induced fluorescence detection.neurotoxin (nt), a short-chain α-neurotoxin, is the main neurotoxic protein identified from the venom of naja naja atra. as an effective drug for the analgesis of advanced cancer patients, nt lasts longer than morphine and does not cause addiction. however, achieving a sensitive and high-resolution measurement of nt is difficult because of the extra-low content of nt in vivo. therefore, developing a novel method to quantify nt is essential to study its pharmacokinetics in vivo. although nt conta ...201627175860
taiwan cobra cardiotoxin iii suppresses egf/egfr-mediated epithelial-to-mesenchymal transition and invasion of human breast cancer mda-mb-231 cells.breast cancer is a highly malignant carcinoma and most deaths of breast cancer are caused by metastasis. the epithelial-to-mesenchymal transition (emt) has emerged as a pivotal event in the development of the invasive and metastatic potentials of cancer progression. epidermal growth factor (egf) and its receptor, egfr, play roles in cancer metastasis. ctx iii, a basic polypeptide isolated from naja naja atra venom, has been shown to exhibit anticancer activity; however, the effect of ctx iii on ...201626774845
cobrotoxin from naja naja atra venom ameliorates adriamycin nephropathy in rats.chronic kidney disease (ckd) becomes a global health problem with high morbidity and mortality. adriamycin- (adr-) induced rodent chronic nephropathy is a classic experimental model of human minimal lesion nephrotic syndrome. the present study investigated the effect of cobrotoxin (ctx) on adr-induced nephropathy. rats were given 6 mg/kg adr once through the tail vein to replicate adr nephropathy model. ctx was administered to rats daily by placing a fast dissolving ctx membrane strip under the ...201526640497
antinociceptive effect of najanalgesin from naja naja atra in a neuropathic pain model via inhibition of c-jun nh2-terminal kinase.najanalgesin, a toxin isolated from the venom of naja naja atra, has been shown to exert significant analgesic effects in a neuropathic pain model in rats. however, the molecular mechanism underlying this protective effect of najanalgesin is poorly understood. the present study sought to evaluate the intracellular signaling pathways that are involved in the antinociceptive effect of najanalgesin on neuropathic pain.201526315082
neurotoxin from naja naja atra venom inhibits skin allograft rejection in rats.recent studies reported that naja naja atra venom (nnav) regulated immune function and had a therapeutic effect on adjunctive arthritis and nephropathy. we hypothesized that nnav and its active component, neurotoxin (ntx), might inhibit skin allograft rejection.201526071222
erratum to "ameliorating adriamycin-induced chronic kidney disease in rats by orally administrated cardiotoxin from naja naja atra venom".[this corrects the article doi: 10.1155/2014/621756.].201525852765
naja naja atra venom ameliorates pulmonary fibrosis by inhibiting inflammatory response and oxidative stress.naja naja atra venom (nnav) displays diverse pharmacological actions including analgesia, anti-inflammation and immune regulation.in this study, we investigated the effects of nnav on pulmonary fibrosis and its mechanisms of action.201425465226
modulated mechanism of phosphatidylserine on the catalytic activity of naja naja atra phospholipase a2 and notechis scutatus scutatus notexin.phosphatidylserine (ps) externalization is a hallmark for apoptotic death of cells. previous studies showed that naja naja atra phospholipase a2 (nnapla2) and notechis scutatus scutatus notexin induced apoptosis of human cancer cells. however, nnapla2 and notexin did not markedly disrupt the integrity of cellular membrane as evidenced by membrane permeability of propidium iodide. these findings reflected that the ability of nnapla2 and notexin to hydrolyze membrane phospholipids may be affected ...201425449100
naja naja atra venom protects against manifestations of systemic lupus erythematosus in mrl/lpr mice.systemic lupus erythematosus (sle) is an autoimmune disease and effective therapy for this pathology is currently unavailable. we previously reported that oral administration of naja naja atra venom (nnav) had anti-inflammatory and immune regulatory actions. we speculated that nnav may have therapeutic effects in mrl/lpr sle mice. twelve-week-old mrl/lpr mice received oral administration of nnav (20, 40, and 80 μg/kg) or tripterygium wilfordii polyglycosidium (10 mg/kg) daily for 16 weeks. the e ...201425093033
differential effects of naja naja atra venom on immune activity.previous studies reported that naja naja atra venom (nnav) inhibited inflammation and adjuvant arthritis. here we investigated the role of nnav in regulation of immune responses in mice. oral administration of nnav to normal mice showed significant increase in natural killer cell activity, b lymphocyte proliferation stimulated by lipopolysaccharides, and antibody production in response to sheep red blood cells. meanwhile, nnav markedly decreased t lymphocyte proliferation stimulated by concanava ...201425024726
cardiotoxin iii suppresses hepatocyte growth factor-stimulated migration and invasion of mda-mb-231 cells.the hepatocyte growth factor (hgf)/c-met signalling pathway is deregulated in most cancers and associated with a poor prognosis in breast cancer. cardiotoxin iii (ctx iii), a basic polypeptide isolated from naja naja atra venom, has been shown to exhibit anticancer activity. in this study, we use hgf as an invasive inducer to investigate the effect of ctx iii on mda-mb-231 cells. when cells were treated with non-toxic doses of ctx iii, ctx iii inhibited the hgf-promoted cell migration and invasi ...201424964901
ameliorating adriamycin-induced chronic kidney disease in rats by orally administrated cardiotoxin from naja naja atra venom.previous studies reported the oral administration of naja naja atra venom (nnav) reduced adriamycin-induced chronic kidney damage. this study investigated the effects of intragastric administrated cardiotoxin from naja naja atra venom on chronic kidney disease in rats. wistar rats were injected with adriamycin (adr; 6 mg/kg body weight) via the tail vein to induce chronic kidney disease. the cardiotoxin was administrated daily by intragastric injection at doses of 45, 90, and 180  μ g/kg body we ...201424876873
brain pharmacokinetics of neurotoxin-loaded pla nanoparticles modified with chitosan after intranasal administration in awake rats.neurotoxin (nt), an analgesic peptide which was separated from the venom of naja naja atra, is endowed an exceptional specificity of action that blocks transmission of the nerve impulse by binding to the acetylcholine receptor in the membrane. however, it has limited permeability across the blood-brain barrier (bbb).201324087853
the protective effects of cobra venom from naja naja atra on acute and chronic nephropathy.this study investigated the effects of naja naja atra venom (nnav) on acute and chronic nephropathy in rats. rats received 6 mg/kg adriamycin (adr) once to evoke the chronic nephropathy or 8 ml/kg 50% v/v glycerol to produce acute renal failure (arf). the nnav was given orally once a day starting five days prior to adr or glycerol injection and continued to the end of experiments. the animals were placed in metabolic cages for 24 h for urine collection for urinary protein determination. the kidn ...201323983784
inhibition of src activation with cardiotoxin iii blocks migration and invasion of mda-mb-231 cells.cardiotoxin iii (ctx iii), a basic polypeptide isolated from naja naja atra venom, has been demonstrated to display anticancer activity. breast cancer is a highly malignant carcinoma and most deaths of breast cancer are caused by metastasis. in this study, we show that ctx iii blocks migration and invasion of mda-mb-231 breast cancer cells without affecting apoptosis or cell cycle arrest. ctx iii caused significant block of src kinase activity in mda-mb-231 cells. moreover, ctx iii treatment was ...201323933586
cardiotoxin iii inhibits proliferation and migration of oral cancer cells through mapk and mmp signaling.cardiotoxin iii (ctxiii), isolated from the snake venom of formosan cobra naja naja atra, has previously been found to induce apoptosis in many types of cancer. early metastasis is typical for the progression of oral cancer. to modulate the cell migration behavior of oral cancer is one of the oral cancer therapies. in this study, the possible modulating effect of ctxiii on oral cancer migration is addressed. in the example of oral squamous carcinoma ca9-22 cells, the cell viability was decreased ...201323710144
fusogenicity of naja naja atra cardiotoxin-like basic protein on sphingomyelin vesicles containing oxidized phosphatidylcholine and cholesterol.this study investigated the effect of oxidized phosphatidylcholine (oxpc) and cholesterol (chol) on naja naja atra cardiotoxin-like basic protein (clbp)-induced fusion and leakage in sphingomyelin (sm) vesicles. compared with those on pc/sm/chol vesicles, clbp showed a lower activity to induce membrane permeability but a higher fusogenicity on oxpc/sm/chol vesicles. a reduction in inner-leaflet fusion elucidated that clbp fusogenicity was not in parallel to its membrane-leakage activity on oxpc/ ...201323426438
therapeutic potential of naja naja atra venom in a rat model of diabetic nephropathy.to study the protective effects of naja naja atra venom (nnav) in a rat model of diabetic nephropathy (dn).201223228832
behavioral and morphological evidence for the involvement of glial cells in the antinociceptive effect of najanalgesin in a rat neuropathic pain model.neuropathic pain is a devastating neurological disease that seriously affects patients' quality of life. despite a high level of incidence, the underlying mechanisms of neuropathic pain are still poorly understood. however, recent evidence supports the prominent role of spinal glial cells in neuropathic pain states. in our laboratory, we observed that najanalgesin, a novel peptide isolated from the venom of naja naja atra, exerts significant analgesic effects on acute pain in mice and neuropathi ...201222687474
cardiotoxin iii suppresses mda-mb-231 cell metastasis through the inhibition of egf/egfr-mediated signaling pathway.cardiotoxin iii (ctx iii), a basic polypeptide isolated from naja naja atra venom, has been shown to exhibit anticancer activity. epidermal growth factor (egf) and its receptor, egfr, play roles in cancer metastasis in various tumors. we use egf as a metastatic inducer of mda-mb-231 cells to investigate the effect of ctx iii on cell migration. ctx iii inhibited the egf-induced activation of matrix metalloproteinase-9 (mmp-9), and further suppressed cell invasion and migration without obvious cel ...201222683533
structural and functional insights into lipid-bound nerve growth factors.nerve growth factor (ngf) is a dimeric molecule that modulates the survival, proliferation, and differentiation of nervous cells and is also known to act on cells of the immune system and endocrine system. ngfs extracted from mouse submaxillary gland and cobra venom have different immunological behaviors, yet the underlying mechanism remains unclear. here we report the crystal structure of the ngf purified from chinese cobra naja naja atra (cngf), which unexpectedly reveals a 2-tailed lipid mole ...201222649032
quercetin modulates activities of taiwan cobra phospholipase a2 via its effects on membrane structure and membrane-bound mode of phospholipase a2.the goal of the present study is to elucidate the mechanism of quercetin on modulating naja naja atra phospholipase a2 (pla2) activities. sphingomyelin inhibited pla2 enzymatic activity and membrane-damaging activity against egg yolk phosphatidylcholine (eypc), while cholesterol and quercetin abrogated the sphingomeyelin inhibitory effect. quercetin incorporation led to a reduction in pla2 enzymatic activity and membrane-damaging activity toward eypc/sphingomyelin/cholesterol vesicles. both chol ...201222581333
nanoparticle-mediated delivery of neurotoxin-ii to the brain with intranasal administration: an effective strategy to improve antinociceptive activity of neurotoxin.neurotoxin-ii (nt-ii), an analgesic peptide which was separated from the venom of naja naja atra, is endowed an exceptional specificity of action that block transmission of the nerve impulse by binding to the acetylcholine receptor in the membrane. however, it has limited permeability across the blood-brain barrier (bbb) after intravenously (i.v.) injection.201221721852
lipid domain formation modulates activities of snake venom phospholipase a(2) enzymes.the goal of the present study is to elucidate the effect of lipid domain formation on activities of naja naja atra and bungarus multicinctus phospholipase a(2) (pla(2)) enzymes. sphingomyelin inhibited enzymatic activity and membrane-damaging activity of pla(2) against egg yolk phosphatidylcholine (eypc), while cholesterol and cholesterol sulfate abrogated the inhibitory effect of sphingomyelin. the ability of cholesterol and cholesterol sulfate to abolish the inhibitory effect of sphingomyelin ...201020705082
interaction of naja naja atra cardiotoxin 3 with h-trisaccharide modulates its hemolytic activity and membrane-damaging activity.to address whether saccharide moieties of blood groups a, b and o antigens modulate hemolytic activity of naja naja atra cardiotoxins (ctxs), the present study was carried out. unlike other ctx isotoxins, hemolytic activity of ctx3 toward blood group o cholesterol-depleted red blood cells (rbcs) was notably lower than that of blood groups a and b cholesterol-depleted rbcs. conversion of blood group b rbcs into blood group o rbcs by alpha-galactosidase treatment attenuated the susceptibility for ...201020193704
inactivation of epidermal growth factor receptor and downstream pathways in oral squamous cell carcinoma ca9-22 cells by cardiotoxin iii from naja naja atra.cardiotoxin iii (1), a basic polypeptide with 60 amino acid residues isolated from naja naja atra venom, has potential therapeutic activity in cancer. treatment with 1 reduced phosphorylation of egfr and akt, as well as erk in ca9-22 cells. moreover, 1-treatment inhibited constitutive activation of stat3 and stat5 in a time-dependent manner. up-regulation of bax and down-regulation of anti-apoptotic proteins including bcl-2, bcl-x(l), and myeloid cell leukemia-1(mcl-1) were also found in cells t ...200919754129
roles of lysine residues and n-terminal alpha-amino group in membrane-damaging activity of taiwan cobra cardiotoxin 3 toward anionic and zwitterionic phospholipid vesicles.in contrast to a slight increase in activity toward phosphatidylcholine (eypc)/dimyristoyl phosphatidic acid (dmpa) vesicles, guanidination of naja naja atra cardiotoxin 3 (ctx3) and selective trinitrophenylation of n-terminal alpha-amino group enhanced notably membrane-damaging activity on eypc/egg yolk sphingomyelin (eysm) vesicles. chemically modified ctx3 showed a reduction in its hemolytic activity and cytotoxicity. these reflected that membrane-damaging activity of ctx3 was affected by pho ...201719647762
consensus sequence l/pkssll mimics crucial epitope on loop iii of taiwan cobra cardiotoxin.phage display is effective in screening peptides that mimic venom's neutralizing epitopes. a phage display cyclized heptapeptide library (c7c library) was panned with purified divalent antivenin igg, which neutralizes naja naja atra venom (nav) and bungarus multicinctus venom (bmv). the selected heptapeptide sequences were aligned with known protein sequences of nav and bmv in genbank. one of the four consensus sequences, l/pkssll, mimicked the crucial epitope on loop iii of taiwan cobra cardiot ...200919632196
differential binding to phospholipid bilayers modulates membrane-damaging activity of naja naja atra cardiotoxins.to address the events that modulate membrane-damaging activity of naja naja atra cardiotoxins (ctxs), the present study was carried out. it was found that ctx isotoxins showed different activities in inducing leakage of vesicles made of egg yolk phosphatidylcholine (eypc)/dimyristoyl phosphatidic acid (dmpa) or eypc/egg yolk sphingomyelin (eysm). although ctxs had different gross conformations, the toxins showed similar binding affinity for phospholipid vesicles. topographical contact between to ...200919450618
purification and characterization of a novel antinociceptive toxin from cobra venom (naja naja atra).snake venoms have demonstrated antinociceptive activity, and certain isolated neurotoxins have demonstrated significant analgesia in animal models. here we report a novel analgesic toxin which was isolated from naja naja atra and was given the name 'najanalgesin'. the ld(50) of the crude venom and najanalgesin were 0.89mg/kg and 2.69mg/kg, respectively. we used the writhing test and hot plate test to evaluate the antinociceptive properties of the crude venom and najanalgesin after intraperitonea ...200818765245
the mechanism of cytotoxicity by naja naja atra cardiotoxin 3 is physically distant from its membrane-damaging effect.in order to dissect out whether multiple activities of cardiotoxins (ctxs) are connected, to some extent, with each other, studies on reduced and s-carboxyamidomethylated (rcam) naja naja atra ctx3 were carried out in the present study. although both ctx3 and rcam-ctx3 induced apoptotic death of pc-3 cells as evidenced by propodium iodide/annexin v double staining, degradation of procaspases and dna fragmentation, the cytotoxicity of rcam-ctx3 was mostly 100-fold lower than that noted with nativ ...200717714752
structural and functional analysis of natrin, a venom protein that targets various ion channels.cysteine-rich secretory proteins (crisps) are secreted single-chain proteins found in different sources. natrin is a member of the crisp family purified from the snake venom of naja naja atra, which has been reported as a bkca channel blocker. in our study, crystals of natrin were obtained in two different crystal forms and the structure of one of them was solved at a resolution of 1.68a. our electrophysiological experiments indicated that natrin can block the ion channel currents of the voltage ...200617070778
purification and characterization of ophiophagus hannah cytotoxin-like proteins.three cytotoxin-like proteins from the venom of ophiophagus hannah were isolated by a combination of ion exchange chromatography and reverse phase hplc. amino acid sequence analysis revealed that these proteins all consisted of 63 amino acids and shared approximate 50% and 56% sequence identity with naja naja atra cardiotoxins and cardiotoxin-like basic proteins (clbps), respectively. cd spectra revealed that their secondary structure was dominated with beta-sheet as those noted with cardiotoxin ...200616899267
molecular cloning and evolution of the genes encoding the precursors of taiwan cobra cardiotoxin and cardiotoxin-like basic protein.genomic dnas encoding the precursors of eight cardiotoxins and two cardiotoxin-like basic proteins (clbp) were isolated from the liver of naja naja atra (taiwan cobra). the cardiotoxin and clbp genes have three exons like alpha-neurotoxin precursors. the promoter regions of these genes are highly conserved and contain the consensus transcriptional factor-binding sites for tbp, nf-1, caccc-binding site, spl and efii, suggesting that these genes are regulated using similar transcriptional mechanis ...200415587986
purification, n-terminal sequencing, crystallization and preliminary x-ray diffraction analysis of atratoxin, a new short-chain alpha-neurotoxin from the venom of naja naja atra.atratoxin, a new alpha-neurotoxin purified to homogeneity by a series of liquid chromatographies from the venom of naja naja atra (mainland chinese cobra), is a small single-polypeptide alkaline protein with a pi of about 9.5 and molecular weight of 6952 da estimated by mass spectrometry. although the sequencing of the n-terminal 15 residues (lechnqqttqqpegg) shows that this neurotoxic protein contains most of the residues, especially at the conserved positions, of the consensus sequence of shor ...200211976497
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 ...200211904231
glutaraldehyde cross-linking alters the environment around trp(29) of cobrotoxin and the pathway for regaining its fine structure during refolding.cobrotoxin, purified from the venom of naja naja atra (taiwan cobra), was subjected to modification with glutaraldehyde in order to prepare intra- and intermolecule cross-linked derivatives. monomeric and dimeric derivatives were separated from polymeric derivatives by gel filtration. the results of amino acid analysis and sequence determination revealed that only lys residues were selectively modified by glutaraldehyde. glutaraldehyde cross-linking was accompanied by a change in the gross confo ...200111532076
refolding of taiwan cobra neurotoxin: intramolecular cross-link affects its refolding reaction.in order to explore the effect of intramolecular cross-linking in the folding reaction of cobrotoxin from naja naja atra (taiwan cobra) venom, the toxin molecule was modified with glutaraldehyde (ga). the monomeric ga-modified cobrotoxin (mga-cobrotoxin) was separated from the dimeric and trimeric derivatives using gel filtration. the results of electrophoretic and chromatographic analyses revealed that mga-cobrotoxin comprised two modified derivatives, which contained modified lys residues at p ...200111370853
[expression and characterization of two kinds of recombinant snake neurotoxins].the cdna encoding the precursor of cobrotoxin was cloned from the venom gland of the chinese continental cobra (naja naja atra) by rt-pcr. its deduced amino acid sequence analysis showed that the mature protein was identical to that identified from the taiwan cobra (naja naja atra) by protein sequencing technique. the cdna encoding the mature protein was then subcloned into the expression vector pmal-p2. the gene of cm11, which was formed by ligation of the fragments of the synthetic oligonucleo ...200011059270
structure-function studies on taiwan cobra long neurotoxin homolog.a novel long neurotoxin homolog was purified from naja naja atra (taiwan cobra) venom using the combination of ion exchange chromatography and reverse phase high performance liquid chromatography. the determined protein sequence was essentially the same as that deduced from the cdna amplified by reverse transcriptase-polymerase chain reaction. the long neurotoxin homolog exhibited an activity that inhibited acetylcholine-induced muscle contractions, as with n. naja atra cobrotoxin. the degree of ...200011004569
sequencing and model structure of a naja naja atra protein fragment.we report the amino acid sequence of a basic protein isolated from the snake venom of naja naja atra. an automated edman sequencer was used to determine the 65-residue sequence, aided by electrospray ionization/mass spectrometry. online reduction and pyridylethylation of the peptide was performed to identify the cysteine residues. trypsin, chymotrypsin and aspartic digestions were carried out to derive peptide fragments for further sequencing. fragmented peptides were overlapped to obtain the co ...200010917453
comparison of the structural stability of two homologous toxins isolated from the taiwan cobra (naja naja atra) venom.cardiotoxin analogue iii (ctx iii) and cobrotoxin (cbtx) isolated from the taiwan cobra venom (naja naja atra) are structurally homologous, small molecular weight, all-beta-sheet proteins, cross-linked by four disulfide bonds at identical positions. the conformational stabilities of these toxins are compared based on temperature-dependent chemical shifts and amide proton exchange kinetics using two-dimensional nmr spectroscopy. the structure of ctx iii is found to be significantly more stable th ...200010913281
elucidation of the solution structure of cardiotoxin analogue v from the taiwan cobra (naja naja atra)--identification of structural features important for the lethal action of snake venom cardiotoxins.the aim of the present study is to understand the structural features responsible for the lethal activity of snake venom cardiotoxins. comparison of the lethal potency of the five cardiotoxin isoforms isolated from the venom of taiwan cobra (naja naja atra) reveals that the lethal potency of ctx i and ctx v are about twice of that exhibited by ctx ii, ctx iii, and ctx iv. in the present study, the solution structure of ctx v has been determined at high resolution using multidimensional proton nm ...200010794406
activation of phospholipase a(2) by long chain fatty acyl groups involves a novel unstable linkage.the acidic isoform of phospholipase a(2) from naja mossambica mossambica was activated by treatment with a molar equivalent of oleoyl imidazolide. modification of the protein was accompanied by 50% quenching of tryptophan fluorescence and a significant red shift. the (3)h(9,10) labeled oleoyl residue was co-eluted with the enzyme during gel filtration in the presence of 20% 1-propanol or excess albumin, both of which remove free oleic acid from the enzyme. in contrast, the adduct was labile as t ...200010788797
roles of aromatic residues in high interfacial activity of naja naja atra phospholipase a(2) 200010747813
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