Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
|---|
| arbovirus infections in reptiles: immunological evidence for a high incidence of japanese encephalitis virus in the cobra naja naja. | 1974 | 4460310 | |
| convulsant activity of naja naja venom and its phospholipase a component. | 1974 | 4458108 | |
| effect of cobra (naja naja) venom on succinic dehydrogenase and cholinesterase of rat tissue. | 1974 | 4442994 | |
| the isolation and sequence determination of a cytotoxin from the venom of the middle-asian cobra naja naja oxiana. | 1974 | 4435217 | |
| investigation of the naja naja siamensis toxin binding site of the cholinergic receptor protein from torpedo electric tissue. | 1974 | 4430347 | |
| the major lethal neurotoxin of the venom of naja naja philippinensis. purification, physical and chemical properties, partial amino acid sequence. | 1974 | 4426734 | |
| amino acid sequence of neurotoxin i from naja naja oxiana venom. | 1974 | 4411932 | |
| possible implication of glutathione reductase in haemolysis by the direct lytic factor of cobra venom (naja naja). | 1972 | 4404949 | |
| the amino acid sequence of cytotoxin ii from the venom of the indian cobra (naja naja). | 1972 | 4340873 | |
| amino acid sequence of cytotoxin i from the venom of the indian cobra (naja naja). | 1971 | 4332596 | |
| the hydrolysis of unimolecular films of p32-labelled lecithin, phosphatidylethanolamine and phosphatidylinositol with phospholipase a (naja naja venom). | 1966 | 4287839 | |
| effect of naja naja atra venom on cytochrome c oxidase, l-ascorbic acid oxidase, peroxidase, and catalase. | 1965 | 4287255 | |
| glycoproteins as components of the lethal factors in cobra venom (naja naja). | 1965 | 4285392 | |
| chemical modifications of the postsynaptic naja naja neurotoxins. | 1972 | 4267235 | |
| inhibition of na + - and k + -activated atpase by the direct lytic factor of cobra venom (naja naja). | 1972 | 4261171 | |
| modification of amino groups in naja naja neurotoxins and the preparation of radioactive derivatives. | 1972 | 4259996 | |
| steroid synthesis by the seminiferous tubules of the snake naja naja. | 2014 | 4256856 | |
| [comparative hemolysis experiments on guinea pig and rat erythrocytes in vitro with phospholipase a and direct lytic factor from cobra (naja naja) venom]. | 1971 | 4250101 | |
| immunochemical characterization of naja naja siamensis toxin and of a chemically modified toxin. | 1974 | 4214148 | |
| chemical modification of the tryptophan residue in toxin b from the venom of the indian cobra. | 1974 | 4208572 | |
| chemical modification of tyrosine residue in "toxin b" from the venom of the indian cobra, naja naja. | 1974 | 4207860 | |
| phospholipase isoenzymes from naja naja venom. i. purification and partial characterization. | 1973 | 4202693 | |
| immunization studies with naja naja venom detoxified by photooxidation. | 1968 | 4170737 | |
| studies on purified eel acetylcholine receptor and anti-acetylcholine receptor antibody. | rabbit antiserum against purified electrophorus electricus acetylcholine receptor is studied using an immunoprecipitin assay to measure either antibody titer or concentration of toxin-binding sites in solubilized receptor preparations. this antiserum, unlike control serum, blocks the electrophysiological response of the electroplax to carbamylcholine. toxin (alpha-neurotoxin, naja naja) and several cholinergic ligands produce partial inhibition of the reaction of antiserum with purified acetylch ... | 1973 | 4128544 |
| positional distribution of fatty acids in cardiolipin of mitochondria from 21-day-old rats. | pure cardiolipins (1,3-diphosphatidylglycerol) were prepared from mitochondria of heart, liver and kidney from 21-day-old male wistar rats and submitted to naja naja venom phospholipase a2 (ec 3.1.1.4) action. incubation conditions were controlled carefully, and a complete hydrolysis of cardiolipin to lysocardiolipin (di [1 (1'') acyl sn-glycero-3-phosphoryl] 1',3'-sn-glycerol) and fatty acids from positions 2(2'') was obtained in less than two hr practically without side reactions. cardiolipins ... | 1985 | 4094521 |
| kinetics of the hydrolysis of monodispersed dihexanoyllecithin catalyzed by a cobra (naja naja atra) venom phospholipase a2. | the hydrolysis of 1,2-dihexanoyl-sn-glycero-3-phosphorylcholine (dic6pc), catalyzed by a cobra (naja naja atra) venom phospholipase a2, was studied at 25 degrees c ionic strength 0.1 in the presence of 3-10 mm ca2+, which can saturate the ca2+-binding site of the enzyme. the initial velocity data, obtained at various concentrations of the substrate below the critical micellar concentration (cmc), were analyzed according to the michaelis-menten equation. the km value was practically independent o ... | 2013 | 4093439 |
| amino acid sequence of a cardiotoxin-like basic polypeptide (clbp) with low cytotoxic activity isolated from the venom of the formosan cobra (naja naja atra). | a cardiotoxin-like basic polypeptide, designated as clbp, was isolated from the venom of naja naja atra by gel filtration on sephadex g-50 followed by cm-cellulose chromatography. the cytotoxicity toward yoshida sarcoma cells and lethal toxicity toward mice of clbp were both one-order lower than those of cardiotoxins and cobrotoxin, respectively. clbp is a single polypeptide consisting of 61 amino acid residues with four intramolecular disulfide linkages. the amino acid sequence of clbp shows a ... | 1985 | 4091854 |
| [central action of snake venoms on body temperature in rats]. | experiments on rats were made to study the effect on the body temperature of the rat of intracerebroventricular injection of venoms of indian cobra, north american rattle snake, and central asian shchitomordnik. it was established that the rise of rectal temperature by 1.5-2.0 degrees c after 90 min was evoked by cobra venom alone. that increase in the body temperature was not prevented by pretreatment with the protein synthesis inhibitors anisomycin or cycloheximide, but was completely abolishe ... | 1985 | 4085638 |
| effect of pure venom phospholipase a2 from the central asian cobra (naja naja oxiana eichwald) on oxidative functions of rat liver mitochondria. | 1985 | 4077115 | |
| circular dichroism study of the unfolding-refolding of a cardiotoxin from taiwan cobra (naja naja atra) venom. | circular dichroism spectroscopy has been used to study the unfolding-refolding process of a cardiotoxin from taiwan cobra (naja naja atra) venom upon addition of fluoroalcohols or sodium dodecyl sulfate (sds) to its aqueous solution. in these experiments, the disulfide bridges remained intact. the unfolding process has been found to be reversible both for fluoroalcohols and for sds unfolding. the reversibility of the unfolding-refolding process of cardiotoxin in aqueous mixtures of fluoroalcohol ... | 2014 | 4074722 |
| [synthesis of tritium-labeled n,n-dimethyl-2-phenylaziridinium and its reaction with acetylcholinesterase]. | the synthesis of tritium-labeled n,n-demethyl-2-phenylaziridinium has been described. the specific radioactivity of the product obtained was 1,06 tbq/mmole. kinetics of incorporation of this radioactive label into acetylcholinesterase of cobra venom (naja naja oxiana) has been studied at 1,05 mm ligand concentration (25 degrees c, ph 7,50. 0,15 m phosphate buffer). under these conditions two molecules of the radioactive label have been found to react with the enzyme. one molecule incorporates fa ... | 1985 | 4074397 |
| contractile response of the isolated dorsal aorta of the snake to angiotensin ii and norepinephrine. | vasopressor action is a phylogenetically old function of angiotensin (ang) ii. the action can be ascribed to both direct activation of vascular ang ii receptors and through catecholamine release. in the rat snake, ptyas korros, the possible presence of common adrenergic-ang receptors and their involvement in this action have been proposed. in order to elucidate the vasopressor mechanism of ang ii in the snake, and to test the presence of common adrenergic-ang receptors, the contractile response ... | 1985 | 4065534 |
| biochemical characterization of two nicotinic receptors from the optic lobe of the chick. | we have studied putative nicotinic acetylcholine receptors in the optic lobe of the newborn chick, using 125i-labeled alpha-bungarotoxin, a specific blocker of acetylcholine receptors in the neuromuscular junction, and [3h]acetylcholine, a ligand which in the presence of atropine selectively labels binding sites of nicotinic character in rat brain cortex (schwartz et al., 1982). [3h]acetylcholine binds reversibly to a single class of high affinity binding sites (kd = 2.2 x 10(-8) m) which occur ... | 1985 | 4055785 |
| activation, aggregation, and product inhibition of cobra venom phospholipase a2 and comparison with other phospholipases. | the kinetics of phospholipid hydrolysis by cobra venom phospholipase a2 were examined and compared to those of phospholipase a2 from porcine pancreas, crotalus adamanteus (rattlesnake) venom, and bee venom. only the enzyme from naja naja naja (cobra) venom was found to be activated significantly by phosphorylcholine-containing compounds when hydrolyzing phosphatidylethanolamine. the cobra venom enzyme was also the only one in which these activators induced protein aggregation. the parallel speci ... | 1985 | 4030786 |
| cytolytic activity of cytotoxin isolated from indian cobra venom against experimental tumor cells. | cytolytic activity of cytotoxin isolated from the venom of the indian cobra (naja naja) on experimental tumor cells was far stronger than that on normal cells such as peritoneal exudate cells, spleen cells, and erythrocytes of the rat. the effect on yoshida sarcoma cells was temperature-dependent, being stronger at 37 degrees c than at 0 degrees c. intramolecular disulfide linkages and free amino groups in the cytotoxin molecule were shown to be essential for the lytic action on the cell membran ... | 1985 | 4015662 |
| [biospecific adsorption chromatography of phospholipase a2 from different sources]. | methods of biospecific adsorption chromatography of phospholipase a2 obtained from porcine pancreas and naja naja oxiana, vipera ursini renardi, vespa orientalis venoms were developed. granulated polyamide with covalently linked phosphatidylethanolamine were used as an affinity adsorbent. chemical inertness of linked phosphatidylethanolamine to the hydrolytic action of phospholipase a2 and its high affinity for biospecific complexes are shown. forms of phospholipase a2 different in their affinit ... | 1985 | 3991479 |
| methyl branching in short-chain lecithins: are both chains important for effective phospholipase a2 activity? | several seven-carbon fatty acyl lecithins with varied acyl chain branching have been synthesized and characterized as potential phospholipase a2 substrates. micellar bis(4,4-dimethylpentanoyl) phosphatidylcholine, bis(5-methylhexanoyl)phosphatidylcholine, bis(3-methylhexanoyl)phosphatidylcholine, and bis(2-methylhexanoyl)phosphatidylcholine are poor substrates for phospholipase a2 (naja naja naja). these branched lecithins also inhibit the hydrolysis of diheptanoylphosphatidylcholine by the enzy ... | 1985 | 3986178 |
| the relationship between high-affinity noncatalytic binding of snake venom phospholipases a2 to brain synaptic plasma membranes and their central lethal potencies. | the basic phospholipase a2 from naja nigricollis (african spitting cobra) snake venom is enzymatically less active but more toxic than the acidic phospholipase a2 from naja naja atra (taiwan cobra) snake venom, following injection into the right lateral ventricle of the brain of rats. when radiolabeled with 125i, these phospholipases a2 retained enzymatic activities and lethal potencies. both enzymes bound with high affinity and specificity to brain synaptic plasma membrane preparations in vitro ... | 1986 | 3964691 |
| effects of beta-bungarotoxin and naja naja atra snake venom phospholipase a2 on acetylcholine release and choline uptake in synaptosomes. | beta-bungarotoxin is a potent presynaptically acting snake venom toxin that exhibits phospholipase a2 activity. we compared the effects of beta-bungarotoxin and a less toxic snake venom phospholipase a2 on synaptosomal 3h-acetylcholine release and 3h-choline uptake. the purpose of these experiments was to study the mode by which beta-bungarotoxin inhibits 3h-acetylcholine release in this preparation. under non-depolarizing conditions, both beta-bungarotoxin and naja naja atra phospholipase a2 st ... | 1986 | 3952766 |
| comparative study on the cardiac actions of bovine parathyroid hormone (1-34). | the cardiac stimulatory effects of bovine parathyroid hormone (1-34) [bpth-(1-34)] were studied on isolated atria and ventricular strips from cobra snakes (naja naja), ducklings (anas platyrhynchos), pigeons (columba livia), japanese quails (coturnix coturnix japonica), laboratory rats (rattus norvegicus), and dogs (canis familiaris). in all atrial preparations, bpth-(1-34) caused positive chronotropism. this suggests that the chronotropic effect of pth is ubiquitous among the terrestrial verteb ... | 1986 | 3940926 |
| aggregation studies on fluorescein-coupled cobra venom phospholipase a2. | phospholipase a2 from naja naja naja venom (indian cobra) undergoes a concentration-dependent aggregation, and at an assay concentration of 1 microgram ml-1, it exists as a monomer. however, there is some evidence that the enzyme is actually active as a dimer or higher order aggregate. previous attempts to determine the aggregation state of the enzyme under actual assay conditions were thwarted by experimental difficulties due in part to the low enzyme concentrations required. this aggregation h ... | 1985 | 3936540 |
| [the detoxification of naja naja atra venom and preparation of potent antivenin]. | the 99.2% toxicity of naja naja atra venom can be detoxified by treatment with 0.25% ga (glutaraldehyde) solution at ph 6.8 and still remains its antigenicity. using the ga treated venom incorporated with freund's complete adjuvant as immunogen, the titer of immune horse sera can be enhanced rapidly. the modified immunization method not only shortened the period of immunization (from 180 to 60 days), but also increased the potency of immune sera (from 75 to 170 units). the method also diminished ... | 1985 | 3933920 |
| affinity chromatography of phospholipase a2 from naja naja naja (indian cobra) venom. | a rapid and improved purification procedure is described for phospholipase a2 from the indian cobra, naja naja naja. the procedure is based on affinity chromatography of the venom through affi-gel blue to obtain a 9-fold purification in one step. however, as there are multiple forms of the enzyme in the venom and other proteins do bind to affi-gel blue, further purification is achieved by de-11 cellulose. finally, a minor contaminant is removed by sulfopropyl sephadex c-25 chromatography. the re ... | 1985 | 3927524 |
| real-time fluorescence polarization measurements: interaction of phospholipase a2 with a fluorescent lecithin derivative. | we have modified an slm 4800 fluorometer to allow continuous measurement of fluorescence polarization. the modifications included construction of simple mechanical and electronic accessories which allowed polarizer position to be program-controlled by an hp 9815 calculator. with these modifications we were able to follow the interaction of the fluorescent lipid analog 1-acyl-2-(n-4-nitrobenzo-2-oxa-1,3-diazole)-aminododecanoyl phosphatidylcholine (i) with naja-naja venom phospholipase a2 (pla2) ... | 2013 | 3924989 |
| effect of alkylation of tryptophan residues on the enzymatic and pharmacological properties of snake venom phospholipase a2. | snake venom phospholipases a2 show a remarkable degree of amino acid sequence homology yet differ markedly in enzymatic and pharmacological activities. the basic phospholipase a2 from naja nigricollis venom has much greater lethal potency, cardiotoxicity, hemolytic and anticoagulant activity than the acidic or neutral enzymes from naja naja atra or hemachatus haemachatus venoms, respectively, even though it has lower enzymatic activity than the latter two enzymes. previous studies in which we se ... | 1985 | 3924381 |
| two new inhibitors of phospholipase a2 produced by penicillium chermesinum. taxonomy, fermentation, isolation, structure determination and biological properties. | plastatin and the known fungal metabolite, luteosporin, have been isolated from fermentations of penicillium chermesinum as inhibitors of porcine pancreatic phospholipase a2 (pla2). structure 1 for plastatin was deduced from its spectroscopic properties. plastatin and luteosporin inhibited pancreatic pla2 competitively with ki values of 0.89 microm and 12.8 microm, respectively. pla2 preparations from naja naja and crotalus adamanteus were not significantly inhibited by plastatin and luteosporin ... | 1985 | 3839502 |
| action of cobra venom phospholipase a2 on large unilamellar vesicles: comparison with small unilamellar vesicles and multibilayers. | phospholipase a2 (naja naja naja) catalyzes the hydrolysis of dipalmitoyl phosphatidylcholine in small unilamellar vesicles (suvs) with a faster initial rate than in large unilamellar vesicles (luvs) and multilamellar vesicles (mlvs). for the suvs, the hydrolysis was initially faster for gel phase than liquid crystalline phase phospholipid. for both luvs and mlvs, hydrolysis was low except in a small temperature range around the thermotropic phase transition of the phospholipid. in this temperat ... | 1985 | 3838567 |
| a one-step isolation procedure for phospholipase a2-free cobra venom factor by fast protein liquid chromatography. | a very rapid and efficient procedure for isolation of cobra venom factor (cof) from naja naja venom is presented. the method is based on mono q anion exchange chromatography on a system for fast protein liquid chromatography (fplc). cof was eluted by a buffer of ph 7.4 at 280 mm salt. a purification of 33.7 x was reached with a yield of at least 27%. contamination with phospholipase was under the detection limit of a sensitive radiometric assay (less than 25 ppm), while the starting material con ... | 1987 | 3819435 |
| 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 ... | 1986 | 3801457 |
| effects of modification of tyrosines 3 and 62 (63) on enzymatic and toxicological properties of phospholipases a2 from naja nigricollis and naja naja atra snake venoms. | previously we selectively modified his (48), arg, lys, asp, glu and trp residues in the basic phospholipase a2 from naja nigricollis and the acidic phospholipase a2 from n. n. atra snake venoms. evidence was obtained for the existence of separate but perhaps overlapping sites responsible, respectively, for their enzymatic and pharmacological properties. we have now modified one or two (tyr 3, tyr 62 [63], tyr 3 + 62 [63]) out of the nine tyrosine residues in these enzymes using p-nitrobenzenesul ... | 1986 | 3775785 |
| 1-stearyl,2-stearoylaminodeoxy phosphatidylcholine, a potent reversible inhibitor of phospholipase a2. | 1-stearyl, 2-stearoylaminodeoxy phosphatidylcholine, a structurally modified phospholipid substrate analog exhibits potent and reversible inhibition of phospholipase a2 from cobra venom (n. naja naja). the apparent ki values determined in two different assay systems employing phosphatidylcholine-surfactant mixed micelles are in reasonable agreement (40 microm and 16 microm) and indicate that the inhibitor binds to the enzyme as much as two orders of magnitude more tightly than does dipalmitoyl p ... | 1986 | 3755338 |
| selectivity and regulation in the phospholipase a2-mediated attack on cholinergic synaptic vesicles by beta-bungarotoxin. | the total fatty acid composition of purified torpedo californica electric organ synaptic vesicles was determined by glc analysis of methyl esters. limit amounts of fatty acids released by high concentrations of either beta-bungarotoxin (beta-butx) or naja naja venom phospholipase a2 (pla2) acting in deoxycholate are reported. the time and enzyme concentration dependence for beta-butx- and pla2-induced release of fatty acids from intact synaptic vesicles indicate that pla2 is 100- to 1,000-fold m ... | 1986 | 3746303 |
| rate-determining step in phospholipase a2 mechanism. 18o isotope exchange determined by 13c nmr. | h2(18)o isotope exchange into specifically 13c-labeled substrate was used to obtain information on the rate-limiting step in the action of the phospholipase a2 from the venom of the indian cobra (naja naja naja). incorporation of 18o was detected by the effect of 18o on 13c chemical shifts in 13c nmr. the enzymatic hydrolysis of a micellar phosphatidylcholine analogue of platelet-activating factor 1-alkyl-2-[1-13c]lauroyl-sn-glycero-3-phosphorylcholine proceeds by an o-acyl cleavage of the sn-2 ... | 1986 | 3745162 |
| conformation of cardiotoxins isolated from naja naja siamensis. | 2013 | 3733141 | |
| hypotensive compounds isolated from the dried body of naja naja kaouthia lesson. i. isolation of inosine as a hypotensive principle and structure-activity study of related compounds. | 1986 | 3719873 | |
| [effect of modification of naja naja oxiana neurotoxin ii on the stoichiometry of its complexes with acetylcholine receptor]. | it was discovered that illumination of the complex formed by the solubilized acetylcholine receptor from torpedo marmorata and lys25-p-azidobenzoyl derivative of neurotoxin ii results in the appearance on the receptor of up to 4 additional binding sites. acetylcholine and neurotoxin ii, but not the long-chain neurotoxins bind specifically to these sites. the additional binding sites could be also detected after illuminating the receptor complex with other photoactivable derivatives, provided the ... | 1986 | 3718547 |
| [reversible inhibition of acetylcholinesterases of different origins by quaternary phosphonium compounds]. | studies have been made on the reversible inhibition of acetylcholinesterase activity from the erythrocytes of man, horse and camel, the electric organ of the skate torpedo marmorata and eel electrophorus electricus, the venom of the snakes naja naja and vipera lebetina, the brain of the pigeon columba livia by tetraphenyl-, triphenylalkyl- and tributyrylalkyl-phosphonium salts. the investigated phosphonium inhibitors exhibit an evident specificity in their action: they were more effective in inh ... | 1986 | 3716682 |
| actions of cardiotoxins from the southern chinese cobra (naja naja atra) on rat cardiac tissue. | the cardiotoxic actions of southern chinese cobra (naja naja atra) venom have been investigated. cardiotoxicity accounted for lethality of crude venom in anaesthetized rats and cardiotoxic polypeptides constituted the bulk of the venom when it was fractionated by cm-sephadex chromatography. the cardiotoxic actions of these polypeptides were investigated in isolated cardiac tissue. actions of cardiotoxins on rate, force and intracellular potentials occurred more readily in ventricular tissue and ... | 1986 | 3715895 |
| analysis of folding intermediates from the main toxin of naja naja samarensis containing two blocked cysteines. | the formation of folding intermediates blocked by iodoacetate from the main toxin of naja naja samarensis was monitored by fplc and the populations were identified by amino acid analyses. we have determined conditions allowing for the highest yield in the populations with two blocked cysteines. the free cysteines remaining under these conditions were labeled with iodo[14c]acetate and localized by peptide mapping in one of the products isolated by ion-exchange chromatography (nt3iii). we have als ... | 1986 | 3699158 |
| the binding site for alpha-bungarotoxin resides in the sequence 188-201 of the alpha-subunit of acetylcholine receptor: structure, conformation and binding characteristics of peptide [lys] 188-201. | in order to study where the binding site of cholinergic agents is in the sequence of the alpha-subunit of nicotinic acetylcholine receptor (achr), we have synthetized 3 peptides with an amino acid sequence corresponding to the following sequences of the alpha-subunit of torpedo californica achr: 125-143, 158-167, [lys] 188-201. for binding studies the peptides were immobilized on sepharose 4b. only the peptide [lys] 188-201 binds 125i-alpha-bungarotoxin (alpha-bgtx) with kd of 1.03 microm. the b ... | 1987 | 3696481 |
| multiple effects of alpha-toxins on the nicotinic acetylcholine receptor. | very low concentrations (5 nm) of alpha-toxin from the venom of naja naja atra produced a characteristic fade in muscle compound action potential and tetanus induced by repetitive nerve stimulation which was identical to the effects of curare. high concentrations of alpha-toxin and all concentrations of alpha-bungarotoxin reduced the response but produced very little fade in comparison to curare. these results suggest that alpha-toxins have more than one effect at the neuromuscular junction. | 1987 | 3691793 |
| bites by the philippine cobra (naja naja philippinensis): an important cause of death among rice farmers. | we investigated mortality from cobra (naja naja philippinensis) bite among filipino rice farmers. village records in one area were examined and we conducted a careful survey in this and two additional areas among inhabitants at varying risk for snakebite. the death rate from cobra bite was estimated to be as high as 107.1 deaths per 100,000 population per year at one site. most victims were young (median age 17) and 98% were males. only 8% of the victims studied reached a hospital. the confirmed ... | 1987 | 3688317 |
| synthesis of prodan-phosphatidylcholine, a new fluorescent probe, and its interactions with pancreatic and snake venom phospholipases a2. | a new fluorescent probe, prodan-pc, was synthesized by incubating thio-pc, a thiol ester analogue of phosphatidylcholine [1,2-bis(decanoylthio)-1,2-dideoxy-sn-glycero-3-phosphocholine], with acrylodan, a fluorescent thiol-reactive reagent [6-acryloyl-2-(dimethylamino)naphthalene], in the presence of phospholipase a2, which served to generate lysothio-pc in situ. prodan-pc (ppc) showed maximum absorption in ethanol at 370 nm. the fluorescence emission spectrum showed maximum emission at 530 nm in ... | 1987 | 3651404 |
| depolarization of skeletal muscle cells in culture by a cardiotoxin-like basic polypeptide from the venom of the taiwan cobra (naja naja atra). | a cardiotoxin-like basic polypeptide from the venom of naja naja atra is homologous to cardiotoxins from the same venom, but much less toxic. to determine if it acts like the cardiotoxins its depolarizing ability was measured. it was about 10 times less potent than the cardiotoxins. five amino acids are conserved in the sequences studied, on the exposed second and third loops of the toxin backbone. they may be part of the toxins' interactive site. | 1987 | 3629619 |
| monoclonal antibody immunoaffinity chromatography of the nerve growth factor from snake venoms. | 1. pure monoclonal antibodies to vipera lebetina venom nerve growth factor have been isolated by affinity chromatography using cnbr-agarose bound antigen. 2. nerve growth factors from ten snake venoms (vipera lebetina, vipera russellii, vipera berus berus, vipera ursini, echis carinatus, agkistrodon halys, bungarus caeruleus, naja naja oxiana, naja naja, naja naja atra) were purified using monoclonal antibodies against ngf linked to brcn-activated agarose. | 2013 | 3621902 |
| amino acid sequence of a cytotoxin-like basic protein with low cytotoxic activity from the venom of the thailand cobra naja naja siamensis. | a cytotoxin-like basic protein (clbp) was isolated from the venom of the thailand cobra (naja naja siamensis). the cytotoxicity of clbp toward fl cells was one order of magnitude lower than those of cytotoxins. the amino acid sequence was determined by a combination of conventional methods. the total number of amino acid residues was 62, giving a molecular mass of 6977 da. the sequence at residues 25-30 in the clbp molecule was found to be significantly different from those of cytotoxins. this r ... | 1987 | 3595859 |
| a new ribonuclease from cobra venom (naja naja) showing specificity towards cytidylic acid. | a ribonuclease was isolated and purified to homogeneity from cobra venom. the enzyme was found to be homogeneous on sds and non-sds polyacrylamide gel electrophoreses, and high performance liquid chromatography. the purified enzyme hydrolysed poly(rc), but not poly(ra), poly(ru), poly(rg), poly(ri), or poly(ri).poly(rc). the presence of magnesium was found to be an essential requirement for the nucleolytic activity of this enzyme. | 1987 | 3593367 |
| different susceptibilities of platelet phospholipids to various phospholipases and modifications induced by thrombin. possible evidence of rearrangement of lipid domains. | on the membrane surface of the human platelet, phosphatidylcholine (pc) and phosphatidylethanolamine (pe) were hydrolyzed to different extents by the snake venom phospholipases a2 of varying pi values. the susceptibility of platelet phospholipids to basic phospholipase a2 of naja nigricollis (pi 10.6) has been reported (wang et al. (1986) biochim. biophys. acta 856, 244-258). the susceptibilities of platelet phospholipids to acidic phospholipase a2 of naja naja atra (pi 5.2) and to neutral phosp ... | 1987 | 3580366 |
| characterization of the anticoagulants from taiwan cobra (naja naja atra) snake venom. | taiwan cobra (naja naja atra) snake venom was separated into 19 fractions by means of cm-sephadex c-50 column chromatography. anticoagulant fractions v-vii were refractionated by gel filtration on sephadex g-50 and the purified component possessed phospholipase a2 activity and an inhibitory effect on collagen-induced platelet aggregation. the anticoagulant action could be antagonized by phospholipid or platelet factor 3. anticoagulant fraction xvii was also further refractionated by gel filtrati ... | 1987 | 3576637 |
| amino acid sequence of a less-cytotoxic basic polypeptide (lcbp) isolated from the venom of the indian cobra (naja naja). | a less-cytotoxic polypeptide, designated as lcbp, was isolated from the venom of naja naja by gel filtration on sephadex g-50 followed by cm-cellulose chromatography. the cytotoxicity toward yoshida sarcoma cells and lethal toxicity toward mice of lcbp were both one order of magnitude lower than that of cytotoxins and that of toxin a, respectively. lcbp is a single polypeptide consisting of 61 amino acid residues with four intramolecular disulfide linkages, and the amino acid sequence is the sam ... | 1987 | 3566773 |
| effects of naja haje (egyptian cobra), naja naja (hooded cobra), naja nigricollis (spitting cobra) and naja mossambica mossambica (mozambique spitting cobra) venoms on the isolated guinea-pig tracheal muscle. | venoms from n. haje, n. naja, n. nigricollis and n. mossambica were tested on the isolated guinea-pig trachea. the four venoms (1-30 micrograms/ml) contracted the tracheal smooth muscle after a delay of 40-60 sec. a second challenge with the venoms caused either no or a much reduced contraction or a relaxant effect. the contraction could be prevented by pretreatment with antihistaminics, but not by atropine, methysergide or indomethacin, indicating that it is due to histamine release by the veno ... | 1986 | 3564065 |
| the action of various venoms on escherichia coli. | the antibacterial activity of honeybee venom (apis mellifera), three snake venoms (naja naja sputatrix, vipera russellii and crotalus adamanteus) and the polypeptide melittin was investigated against escherichia coli. minimum inhibitory concentration values, cell lysis and alterations in cell permeability were determined and action against e. coli was in the order: a. mellifera venom greater than melittin greater than n. naja sputatrix venom much greater than v. russellii venom greater than c. a ... | 1986 | 3542922 |
| positive response to edrophonium in patients with neurotoxic envenoming by cobras (naja naja philippinensis). a placebo-controlled study. | to study the ability of anticholinesterase drugs to reverse the potentially fatal paralytic effects of cobra venom, we conducted a placebo-controlled, double-blind crossover trial of intravenous edrophonium (tensilon) in 10 adults with neurotoxic envenoming caused by bites of the philippine cobra (naja naja philippinensis). there was significantly more improvement in ptosis and endurance of upward gaze after edrophonium than after placebo. five minutes after injection, the mean difference (+/- s ... | 1986 | 3537783 |
| analysis of ligand binding to the synthetic dodecapeptide 185-196 of the acetylcholine receptor alpha subunit. | a synthetic dodecapeptide corresponding to residues 185-196 of the torpedo acetylcholine receptor alpha subunit, which contains the adjacent cysteine residues at positions 192 and 193, was recently shown by us to contain the essential elements for alpha-bungarotoxin binding. in the present study, we have used sepharose-linked peptides for quantitative analysis of the cholinergic binding properties of this and other synthetic peptides. sepharose-linked peptides corresponding to residues 1-20, 126 ... | 1986 | 3466185 |
| 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 ... | 1986 | 3462717 |
| partial sequence of hemoglobin from cobra (naja naja naja). | hemoglobin from the cobra snake, naja naja naja, was isolated and its chains separated on a cm-cellulose column. the separation profile revealed an alpha and two beta chains having the molar proportions of [alpha]2[beta 1]1[beta 2]1. the n-terminal amino acid sequence of the intact chains and of the cnbr peptides were carried out. the beta 2 chain was found to be heterogeneous comprising a minor component amounting to 11%. this later showed changes at two positions 9 and 14 in the first 30 resid ... | 1987 | 3447643 |
| effects of cardiotoxin d from naja naja siamensis snake venom upon murine splenic lymphocytes. | cardiotoxin d from naja naja siamensis is cytotoxic to t-lymphocytes above 150 femtomoles/10(6) cells. equivalent lysis of macrophages or b-lymphocytes requires at least 1000 times more toxin. reduction and carboxamidomethylation of cardiotoxin d does not effect t cell lysis. at higher toxin concentrations, 50% t-cell lysis occurs within 10 min. splenocytes cultured with mitogens are up to five times more susceptible to toxin than unstimulated cells. cardiotoxin d may directly disrupt the plasma ... | 1987 | 3433298 |
| contracture induction by snake venom cardiotoxin in skeletal muscle from humans and rats. | contracture responses to cardiotoxin (ctx) from naja naja kaouthia venom were investigated in rat and human skeletal muscle of similar fiber type distribution to determine species differences in mechanism of action. rat diaphragm strips and human vastus lateralis preparations were directly stimulated in a tissue bath. the calcium dependence of toxin action, synergism between ctx and phospholipase a2 (pla2) activity and roles of na+ + k+-atpase activity and the sarcoplasmic reticulum ca2+ stores ... | 1987 | 3433297 |
| enzymatic activities of malayan cobra (naja naja sputatrix) venoms. | the enzymatic activities of four samples of malayan cobra venom were investigated. there was significant variation in the contents of l-amino acid oxidase, alkaline phosphomonoesterase, acetylcholinesterase, phospholipase a, 5'-nucleotidase and hyaluronidase. the phosphodiesterase content was, however, constant. storage of the lyophilized venom powder at 25 degrees c for 1 month did not affect the enzymatic activities. the venom enzymatic activities were generally also stable at 4 degrees c in 0 ... | 1987 | 3433296 |
| probing the role of substrate conformation in phospholipase a2 action on aggregated phospholipids using constrained phosphatidylcholine analogues. | phospholipase a2s hydrolyze aggregated phospholipid substrates much more rapidly than dispersed monomeric ones. whether this is a consequence of interface-associated conformational changes of the enzyme or of the substrate, or of both, remains a key question in lipid enzymology. this problem is addressed herein using a rationally designed probe of substrate conformation. (1,3/2)-1-o-(phosphorylcholine)-2,3-o-dihexanoylcyclopentane-1,2,3 -triol is a novel short chain phosphatidylcholine analogue ... | 2012 | 3417646 |
| toxicity of central asian cobra (naja naja eichwald) venom and its components to the larvae of blowfly parasarcophaga ruficornis fabr. | 1988 | 3397115 | |
| lipid-induced aggregation of phospholipase a2: sucrose density gradient ultracentrifugation and crosslinking studies. | the aggregation behavior of cobra venom (naja naja naja) phospholipase a2 in the presence of lipids and ca2+ was examined using ultracentrifugation and crosslinking techniques. velocity sedimentation experiments were performed in sucrose gradients. the sedimentation coefficients of the cobra phospholipase a2 and various controls, including bovine serum albumin (bsa), malate dehydrogenase, carbonic anhydrase and pancreatic phospholipase a2, were calculated both in the presence and absence of liga ... | 1988 | 3382690 |
| a role for acetylcholine receptors in the fusion of chick myoblasts. | the role of acetylcholine receptors in the control of chick myoblast fusion in culture has been explored. spontaneous fusion of myoblasts was inhibited by the nicotinic acetylcholine receptor antagonists alpha-bungarotoxin, naja naja toxin and monoclonal antibody mcab 5.5. the muscarinic antagonists qnb and n-methyl scopolamine were without effect. atropine had no effect below 1 microm, where it blocks muscarinic receptors; at higher concentrations, when it blocks nicotinic receptors also, atrop ... | 1988 | 3372592 |
| amino-acid sequences of four cytotoxins (cytotoxins i, ii, iii and iv) purified from the venom of the thailand cobra, naja naja siamensis. | four cytotoxins, designated as cytotoxins i, ii, iii and iv, were isolated from the venom of the thailand cobra (naja naja siamensis) by gel filtration on sephadex g-75 followed by cm-cellulose chromatography. the amino-acid sequences were determined by a combination of conventional methods. cytotoxins i, ii, iii and iv were each composed of 60 amino-acid residues and their molecular weights were calculated to be 6693, 6646, 6709 and 6739, respectively. the amino-acid sequences were compared wit ... | 1988 | 3365434 |
| tryptophan residue essential for activity of naja naja atra phospholipase a2. | when naja naja atra phospholipase a2, which contains three tryptophan residues at the 18th, 19th, and 61st positions, was oxidized with n-bromosuccinimide at ph 4.0, its activity decreased in a convex manner with increase in the extent of oxidation of tryptophan residues. the curve shape showed that the tryptophan residue oxidized last is most responsible for the activity. the order of accessibilities of the three tryptophan residues, which was analyzed according to the method reported previousl ... | 1988 | 3360757 |
| effect of phospholipids on fluorescence polarization and lifetimes of fluorescein-labeled phospholipase a2. | phospholipids and divalent metal ions induce changes in the fluorescence polarization of fluorescein-labeled phospholipase a2 from the indian cobra (hazlett, t.l. and dennis, e.a. (1985) biochemistry 24, 6152-6158) which may be indicative of enzyme aggregation. lifetimes and rotational correlation times of the conjugate in the presence of these and other ligands are now reported. the correlation times of monomeric phospholipase a2 were shorter than expected for a hydrated, 13,000 molecular weigh ... | 1988 | 3337833 |
| lipid-induced changes in the secondary structure of snake venom cardiotoxins. | the secondary structures of three snake venom cardiotoxins (from hemachatus hemachatus, naja naja atra, and naja naja naja), in aqueous solution and in a lipid-bound form, were investigated by fourier-transform infrared spectroscopy. the conformation-sensitive protein infrared bands in the amide i region were analyzed using deconvolution and band-fitting procedures. the spectra of the three cardiotoxins in aqueous buffer are very similar; they indicate a high content of both antiparallel beta-sh ... | 1988 | 3335526 |
| tourniquet application after cobra bite: delay in the onset of neurotoxicity and the dangers of sudden release. | the effects of tourniquet application were prospectively studied in 36 hospitalized patients who developed neurotoxic symptoms after bites by the philippine cobra (naja naja philippinensis). tourniquets had been applied in 94% of cases and delayed the onset of symptoms. four patients were asymptomatic prior to the release of their tourniquet and in 11 patients symptoms worsened precipitously. most importantly, 4 patients developed complete respiratory paralysis requiring artificial ventilation o ... | 1988 | 3275141 |
| oral toxicity of central asian cobra (naja naja oxiana eichwald) venom and its fractions to adult blowflies parasarcophaga ruficornis fabricius. | 1988 | 3248836 | |
| edema-inducing activity of phospholipase a2 purified from human synovial fluid and inhibition by aristolochic acid. | a neutral-active, ca2+-dependent phospholipase a2 (pla2) purified 11,000-fold from human synovial fluid (hsf) induced edema when injected into the mouse foot pad. the edema produced by hsf-pla2 was dose-dependent and was positively correlated with the dose-dependent in vitro expression of pla2 activity. maximum edema was achieved within 45 min after the injection and persisted for at least 6 h. aristolochic acid [8-methoxy-6-nitrophenanthro(3,4-d)-1,3-dioxole-5-carboxylic acid], a major chemical ... | 1988 | 3220517 |
| [studies of complex lipids. synthesis of ionophore derivatives of diphosphatidylglycerol (cardiolipin)]. | synthesis of cardiolipin analogues containing an ionophore residue in the fatty acid moiety is described. the ionophore, dibenzo-18-crown-6, has been incorporated into second position of the glycerol residue by acylating mono- and dilysocardiolipin with a modified fatty acid anhydride. lyso-derivatives of cardiolipin have been prepared by enzymatic hydrolysis of beef heart cardiolipin by snake venom phospholipase a2 (naja naja oxiana). | 2011 | 3219123 |
| antigenic relationships and relative immunogenicities of venom proteins from six poisonous snakes of thailand. | venoms from naja naja siamensis, ophiophagus hannah, bungarus fasciatus, vipera russelli, calloselasma rhodostoma and trimeresurus albolabris have been studied by means of sodium dodecyl sulfate polyacrylamide gel electrophoresis and immunoblotting. the immunoblots were stained with rabbit homologous and heterologous antibodies. in general, the higher the mol. wt the protein the higher the immunogenicity although two proteins with mol. wts of 23,000 and 25,000 from o. hannah venom are extraordin ... | 1988 | 3201490 |
| purification and characterization of a lethal protein with phospholipase a1 activity from the hornet (vespa basalis) venom. | the hornet, vespa basalis, is one of the most dangerous species of wasps found in taiwan. the insect is aggressive and its venom is highly toxic. by gel filtration on a fractogel tsk hw 50 column followed by cation-exchange chromatography on cm-trisacryl m, a lethal protein was purified from the venom. it has a molecular mass of about 32 kda and an i.v. ld50 value of 0.32 micrograms/g mouse. the toxin is capable of catalyzing the hydrolysis of emulsified phospholipids but not sphingomyelin. anal ... | 1988 | 3196744 |
| role of the n-terminal region in phospholipases a2 from naja naja atra (taiwan cobra) and naja nigricollis (spitting cobra) venoms. | the n-terminal alpha-amino groups of two phospholipases a2 (pla2) from naja naja atra and naja nigricollis venoms were selectively modified with trinitrobenzene sulfonic acid, and the modified derivatives were separated by high performance liquid chromatography (hplc). trinitrophenylated (tnp) derivatives contained only one tnp group in the alpha-amino group of asn-1 and showed a marked decrease in enzymatic activity. pla2 enzymes were cleaved with cnbr, and the n-terminal octapeptide was separa ... | 1988 | 3188062 |
| 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 ... | 1988 | 3188052 |
| [modulation of the m-cholinergic reaction by the venom of the central asian cobra (naja naja oxiana)]. | the effect of the central asian cobra's (naja naja oxiana) poison upon cholinergic response of isolated small intestine was studied in the wistar rats. the effect involved a significant activation by 30-70 per cent of m-cholinergic response in the type of "noncompetitive" interaction. the modulating effect of the poison is supposed to occur due to changes in cytoplasmatic membrane. | 1988 | 3181518 |
| bites by the philippine cobra (naja naja philippinensis): prominent neurotoxicity with minimal local signs. | we studied 39 patients envenomed by the philippine cobra (naja naja philippinensis). neurotoxicity occurred in 38 cases and was the predominant clinical feature. respiratory paralysis developed in 19 patients, and was often rapid in onset--in 3 cases apnea occurred within 30 min of the bite. there were 2 deaths, both in patients who were moribund upon arrival at the hospital. three patients developed necrosis, and 14 individuals with systemic symptoms had no local swelling. both cardiotoxicity a ... | 1988 | 3177741 |
| higher order structure of chloroplastic 5s ribosomal rna from spinach. | the secondary and tertiary structure of chloroplastic 5s ribosomal rna from spinach was investigated by the use of several chemical and enzymatic structure probes. the four bases were monitored at one of their watson-crick base-pairing positions with dimethyl sulfate [at a(n1) and c(n3)] and with 1-cyclohexyl-3-(2-morpholinoethyl)carbodiimide metho-p-toluenesulfonate [at g(n1) and u(n3)]. position n7 of purines was probed with diethyl pyrocarbonate (adenines) and with dimethyl sulfate (guanines) ... | 1988 | 3167011 |
| binding of a curarimimetic toxin from cobra venom to the nicotinic acetylcholine receptor. interactions of six biotinyltoxin derivatives with receptor and avidin. | we have reacted n-hydroxysuccinimidyl biotin with the principal curarimimetic toxin in naja naja siamensis venom, biotinylating each of the five lysine residues and the n-terminal isoleucine. the six monobiotinyl-toxins were isolated by ion-exchange chromatography, and the residue modified in each was identified by peptide mapping and amino acid analysis. we evaluated the role of each lysine in the binding of toxin to the acetylcholine receptor by measuring the affinity of each biotinyltoxin for ... | 1985 | 3161881 |
| site-specific epsilon-nh2 monoacylation of pancreatic phospholipase a2. 2. transformation of soluble phospholipase a2 into a highly penetrating "membrane-bound" form. | long-chain lecithins present in bilayer structures like vesicles or membranes are only very poor substrates for pancreatic phospholipases a2. this is probably due to the fact that pancreatic phospholipases a2 cannot penetrate into the densely packed bilayer structures. to improve the weak penetrating properties of pancreatic phospholipases a2, we prepared and characterized a number of pancreatic phospholipase a2 mutants that have various long acyl chains linked covalently to lys116 in porcine an ... | 1988 | 3130102 |