| neurotoxin from venom of the cobra, naja naja siamensis. purification and radioactive labeling. | | 1972 | 5027738 |
| [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 |
| 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 |
| 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 |
| [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 |
| [venom of the cobra (naja naja) and neuromuscular paralyzing agents]. | | 1966 | 5952128 |
| pharmacological properties of cardiotoxin isolated from the venom of naja naja atra. | | 1966 | 6002954 |
| the neurohypophysial hormones of a reptile species, the cobra (naja naja). | | 1967 | 6057829 |
| snake alpha-toxin effects on cholinergic and noncholinergic responses of aplysia californica neurons. | the effects of alpha-toxins from bungarus multicinctus (alpha butx) and naja naja siamensis (alpha ntx) were studied on synaptic responses and on extrasynaptic responses to focally applied acetylcholine (ach), histamine (hm), gamma-aminobutyric acid (gaba), and glutamate (glu) in neurons of the marine mollusc, aplysia californica. binding of 125i-alpha butx to aplysia ganglia homogenates was pharmacologically characterized and compared with the pharmacological sensitivity of 125i-alpha butx bind ... | 1981 | 6114995 |
| effects of beta-bungarotoxin and phospholipase a2 from naja naja atra snake venom on atpase activities of synaptic membranes from rat cerebral cortex. | non-neurotoxic phospholipase a2 of formosan cobra venom possessed higher hydrolytic activity on phosphatidylcholine vesicles and also had higher inhibitory action on na+-k+-atpase and mg2+-atpase of the rat synaptic membrane than neurotoxic beta-bungarotoxin of formosan krait venom. na+-k+-atpase was more susceptible than mg2+-atpase to the inhibitory action of toxins, especially in the presence of triton x-100. the inhibition of atpases by toxins followed the michaelis-menton equation. it is in ... | 1982 | 6123164 |
| antigenic relationships between human and cobra complement factors c3 and cobra venom factor (cvf) from the indian cobra (naja naja). | the presence of a factor immunologically related to cobra venom factor (cvf) was demonstrated in serum and plasma from the indian cobra (naja naja kaoutia). the factor was purified from cobra plasma by affinity chromatography on an anti-cvf gel and was found to consist of a protein composed of two polypeptide chains similar in size to those of human c3. with use of immunoblotting technique, common antigenic determinants were found in the smaller chain of the prepared material and the beta-chain ... | 1983 | 6194220 |
| higher order structure in the 3'-minor domain of small subunit ribosomal rnas from a gram negative bacterium, a gram positive bacterium and a eukaryote. | an experimental approach was used to determine and compare the highest order structure within the 150 to 200 nucleotides at the 3'-ends of the rnas from the small ribosomal subunits of escherichia coli, bacillus stearothermophilus and saccharomyces cerevisiae. chemical reagents were employed to establish the degree of stacking and/or accessibility of each adenosine, guanosine and cytidine. the double helices were probed with a cobra venom ribonuclease from naja naja oxiana, and the relatively un ... | 1983 | 6194304 |
| proteolytic activities of cobra venoms based on inactivation of alpha 2-macroglobulin. | the venoms of various cobra species showed a wide range of abilities to cleave hide powder azure, with naja naja kaouthia and ophiophagus hannah venoms showing the lowest activities and naja nivea venom showing the greatest activity on this dye-linked substrate. the activities of the venoms on hide powder did not completely correlate with their ability to inactivate the alpha 2-macroglobulin of human serum. incubation of 4-5 micrograms of naja nigricollis venom per microliter of serum for 30 min ... | 1984 | 6197999 |
| higher-order structure in the 3'-terminal domain vi of the 23 s ribosomal rnas from escherichia coli and bacillus stearothermophilus. | an experimental approach was used to determine, and compare, the higher-order structure within domain vi of the 23 s ribosomal rnas from escherichia coli and bacillus stearothermophilus. this domain, which encompasses approximately 300 nucleotides at the 3' end of the rnas, consists of two large subdomains. the 5' subdomain has been conserved during evolution and appears to be functionally important for the binding of the ef-1 x gtp x aminoacyl-trna complex in eukaryotes. the 3' subdomain has di ... | 1984 | 6209406 |
| anaerobic metabolism of carbon tetrachloride and formation of catabolically resistant phospholipids. | anaerobic incubation of microsomes with 14c-carbon tetrachloride leads to trichloromethyl radicals which, apart from other detrimental reactions, bind covalently to phospholipids. these labelled lipids are extracted, phosphatidylcholine is isolated and incubated with phospholipase a2 from naja naja snake venom and from porcine pancreas. half of the covalently modified phosphatidylcholine is resistant toward phospholipase a2. distribution of such catabolically resistant phospholipids from the end ... | 1984 | 6231931 |
| properties of curaremimetic neurotoxin binding sites in the rat central nervous system. | properties of mammalian central nervous system binding sites for curaremimetic neurotoxins are investigated with the simonsen-albino rat and 125i-labeled alpha-bungarotoxin or the principal neurotoxin from naja naja siamensis. evidence is presented that high-affinity toxin binding sites are distributed as expected for a synaptic neurotransmitter receptor, display distinct nicotinic cholinergic pharmacology, and are sensitive to preincubation with nicotinic agonists. affinity of toxin sites for a ... | 1984 | 6231955 |
| the deacetylation of n-hydroxy-2-acetylaminofluorene by rat liver microsomes and carboxyl esterase. | we have demonstrated that incubation of rat liver microsomes with n-hydroxy-2-acetylaminofluorene (n-oh-aaf) leads to formation of a 2-nitrosofluorene-membrane lipid adduct. this adduct exists as a nitroxyl free radical, termed n-o-laf, in its oxidized state. when microsomes were incubated with the sulfhydryl binding agent, rho-hydroxymercuribenzoate, a larger amount of n-ol-laf formed. we interpret this as a slowdown in the rate of endogenous chemical reduction of carcinogen-membrane lipid addu ... | 1980 | 6260332 |
| the effects of alpha- and beta-neurotoxins from the venoms of various snakes on transmission in autonomic ganglia. | we have previously shown that certain commercially available lots of alpha-bungarotoxin block transmission in ciliary and choroid neurons of both pigeon and chicken ciliary ganglia at a concentration of 10 microgram/ml (1.2 microm). the blockade is antagonized by pre-incubation with 100 microm tubocurarine. further evidence that this blockade is produced by a postsynaptic action, as one would expect of an alpha-neurotoxin, are our findings that: (a) exposure to the toxin prevents the depolarizat ... | 1981 | 6261879 |
| biochemical characterization of a toxin from indian cobra (naja naja naja) venom. | | 1981 | 6267739 |
| phospholipids chiral at phosphorus. preparation and spectral properties of chiral thiophospholipids. | the thiophospholipid 1,2-dipalmitoyl-sn-glycero-3-thiophosphocholine (dppsc) was shown to be a mixture of two diastereomers by 31p nuclear magnetic resonance. the isomer that resonates at the lower field in cdcl3 (56.12 ppm) was designated as isomer a and the other (resonates at 56.07 ppm) as isomer b. phospholipase a2 from four different sources (bee venom, naja naja venom, crotalus adamanteus venom, and porcine pancreas) was shown to hydrolyze the isomer b of dppsc specifically, whereas phosph ... | 1983 | 6688028 |
| location of single-stranded and double-stranded regions in rat liver ribosomal 5s rna and 5.8s rna. | rat liver 5s rrna and 5.8s rrna were end-labelled with 32p at 5'-end or 3'-end of the polynucleotide chain and partially digested with single-strand specific s1 nuclease and double-strand specific endonuclease from the cobra naja naja oxiana venom. the parallel use of these two structure-specific enzymes in combination with rapid sequencing technique allowed the exact localization of single-stranded and double-stranded regions in 5s rna and 5.8 s rna. the most accessible regions to s1 nuclease i ... | 1981 | 6272219 |
| [a case of bite by naja naja naja in india. problems posed by the treatment of snake bites]. | the author reports a case of poisonous snake bite by naja naja naja, in india. the patient recovered rapidly after treatment by antivenom serum. he emphasizes the importance of prompt intravenous injection of serum. serum is less active for viper bites, and should be injected even more rapidly. however, in france, some authors prefer heparin for treating french viper bites. further studies are needed to clarify this therapeutic problem. | 1984 | 6722971 |
| the inhibitory effect of purified cobra venom factor, isolated from the venom of naja naja atra, on the in vivo immune response in galleria mellonella. | | 1981 | 6786928 |
| central neurotoxic effects of the venoms of naja naja and vipera palestinae. | | 1968 | 5710997 |
| inactivation and solubilization of opiate receptors by phospholipases a2. | (1) as previously shown, stereospecific binding of opiates to membrane bound receptors is inhibited by treatment with small amounts of phospholipase a2 from vipera russelli. this effect is quantified and compared with the enzymes from the venoms of naja naja siamensis, apis mellifica and from porcine pancreas. all enzymes are equally effective. the inhibition is due to partial phospholipid hydrolysis leading to inactivation of membrane-bound receptor. (2) bee venom phospholipase a2 together with ... | 1982 | 6279149 |
| study of hemolysis in the lethal effect of naja naja venom in the mouse and guinea pig. | | 1969 | 5823352 |
| isolation of three different neurotoxins from indian cobra (naja naja) venom and the relation of their action to phospholipase a. | | 1965 | 5880536 |
| changes in membrane phospholipid distribution during platelet activation. | exposure of phospholipids at the outer surface of activated and control platelets was studied by incubation with a mixture of phospholipase a2 from naja naja and bee venom, solely or in combination with sphingomyelinase from staphylococcus aureus, using conditions under which cell lysis remained below 10%. incubation with phospholipase a2 alone revealed a markedly increased susceptibility of the phospholipids in platelets activated by a mixture of collagen plus thrombin, by the sh-oxidizing comp ... | 1983 | 6418205 |
| effects of chicken and mammalian gonadotropin-releasing hormones (gnrh) on in vivo pituitary gonadotropin release in amphibians and reptiles. | the ability of mammalian and chicken gonadotropin-releasing hormones (gnrh) and their agonistic analogs to stimulate in vivo gonadotropin release were tested in a frog (rana catesbeiana), snake (naja naja), and turtle (sternotherus odoratus). in the frog, chicken and mammalian gnrh were equipotent in stimulating the release of fsh and lh. attendant increases in plasma androgen and the occurrence of spermiation confirmed the release of biologically active gonadotropin. neither of the gnrh prepara ... | 1984 | 6427062 |
| effect of the purified phospholipases a2 from snake and bee venoms on rabbit platelet function. | effects of seven purified phospholipases a2 from the venoms of snakes (naja naja atra, trimeresurus mucrosquamatus and t. gramineus) and honey bee (apis mellifera) on rabbit washed platelet suspension in the absence of bovine serum albumin have been studied. only phospholipases a2 from n. n. atra, t. mucrosquamatus and a. mellifera venoms induced platelet aggregation with small amounts of 14c-serotonin release. they showed tachyphylaxis and also cross-tachyphylaxis in inducing platelet aggregati ... | 1984 | 6441310 |
| cardiotoxin from naja naja atra snake venom: a potentiator of platelet aggregation. | cardiotoxin, isolated from naja naja atra snake venom, potentiates platelet aggregation induced by adp, thrombin, collagen and venom phospholipase a2. the malondialdehyde formation caused by adp, thrombin and venom phospholipase a2 were also increased in the presence of cardiotoxin. both potentiation of aggregation and increase in malondialdehyde were blocked by indomethacin or ca2+ (5 mm or 0.05 mm). cardiotoxin did not potentiate thrombin-induced aggregation of p-bromophenacyl bromide-modified ... | 1984 | 6474495 |
| clinical features of neurotoxic snake bite and response to antivenom in 47 children. | among 47 children admitted to the chulalongkorn medical school hospital for neurotoxic snake bite, the attackers were identified in 15; the cobra (naja naja) was the snake involved in all cases. clinical manifestations in all 47 children appeared to follow a similar pattern. drowsiness heralded the systemic effects in most of the patients. the characteristic systemic signs were those resulting from the neuromuscular effects of the venom and included ptosis, frothy saliva, slurred speech, respira ... | 1984 | 6507733 |
| cholesterol solubilization by short-chain lecithins: characterization of mixed micelles and cholesterol oxidase activity. | the synthetic short-chain lecithins diheptanoylphosphatidylcholine and dioctanoylphosphatidylcholine solubilize cholesterol up to 10 and 18 mol %, respectively. the half-time for diheptanoylphosphatidylcholine solubilization of solid cholesterol is 80 (+/- 30) min. this is much faster than triton x-100 micelle or egg lecithin vesicle solubilization of solid cholesterol. both the broadening of lecithin and [4-13c]cholesterol carbon resonances by mn2+ and the observation of surface dilution kineti ... | 1981 | 6947824 |
| evidence for a highly asymmetric arrangement of ether- and diacyl-phospholipid subclasses in the plasma membrane of krebs ii ascites cells. | (1) krebs ii ascites cells were taken as a model of the neoplastic cells to investigate the transverse distribution of phospholipids in the plasma membrane. the experimental procedure was based on non-lytic degradation of phospholipids in the intact cell by naja naja phospholipase a2 and staphylococcus aureus sphingomyelinase c and on phospholipid analysis of purified plasma membranes. it was shown that the three major phospholipids, i.e., phosphatidylcholine, phosphatidylethanolamine and sphing ... | 1984 | 6509047 |
| effect of carboxylate group modification on enzymatic and cardiotoxic properties of snake venom phospholipases a2. | by treating naja nigricollis and naja naja atra phospholipase a2 with carbodiimide and semicarbazide, we obtained derivatives having varied numbers of modified carboxylate groups. when tested on artificial and natural substrates, derivatives of both enzymes with a modified carboxylate group at the active site (asp-49) retained little enzymatic activity (1/41 to 10%). however, the derivatives of n. nigricollis also lost most of their lethal potency (5% of native), while those of n. n. atra retain ... | 1984 | 6523504 |
| effect of ca2+ on the action of cobra (naja naja oxiana eichwald) venom components on mitochondrial enzyme systems. | | 1984 | 6526419 |
| some parameters of affinity chromatography in the purification of antibody against naja naja siamensis toxin 3. | some parameters in the purification of antibodies against naja naja siamensis toxin 3 by affinity chromatography were studied on toxin sepharose, toxin-succinylaminoethyl sepharose, toxin-albumin sepharose and toxin succinylaminoethyl biogel adsorbents. immunologically pure antibody with 10-12-fold increase in potency was obtained by chromatography of horse refined globulin on all these adsorbents. the maximum antibody binding capacities were higher for adsorbents containing linear spacers but r ... | 1982 | 7061874 |
| [a new low molecular-weight protein effector of human complement from the venom of the central asian cobra naja naja oxiana]. | six protein effectors of human complement were isolated from the whole venom of the central asian cobra naja naja oxiana. three of them have acidic properties and molecular weights of 61 000, 5000 and 3000, and the rest are basic proteins with molecular weights of 54 000, 9000 and 7000. two low molecular weight basic proteins cfb-ii and cfb-iii are isolated in as high amounts as 115 and 85 mg per g of dry venom. all the effectors inhibit the classical pathway of complement activation and, with t ... | 1984 | 6567467 |
| stimulation of prostaglandin e2 synthesis by exogenous phospholipase a2 and c in rabbit kidney medulla slices. | we have investigated the effects of phospholipase a2 and c on the synthesis of prostaglandin e2 in rabbit kidney medulla and the release of fatty acids from the medulla slices. exogenous phospholipase a2 [from naja naja (indian cobra) venom] and phospholipase c (from clostridium welchii) stimulated prostaglandin e2 production in a dose-dependent manner. at the maximal effective concentrations (0.5 unit of phospholipase a2/ml, 2 units of phospholipase c/ml), phospholipase c increased prostaglandi ... | 1984 | 6585201 |
| complement in the serum and venom of brazilian snakes (crotalidae). | proteins antigenically related to cof, the anticomplementary protein of the venom of the indian hooded cobra (naja naja), were found in a variety of elapid and viper venoms but not in the venom of brazilian crotalids . in keeping with this finding was the weak ability of brazilian snake venom to convert c3 in human serum. all snake serums tested, including brazilian crotalids , contained a beta-globulin antigenically related to cof. this serum protein in brazilian snake serum had a number of cha ... | 1984 | 6587747 |
| development of simple standard assay procedures for the characterization of snake venom. | in accordance with the recommendations of the report of a who coordination meeting on venoms and antivenoms, methods have been developed for the assessment of lethal, defibrinogenating, procoagulant, haemorrhagic, and necrotizing properties of venoms, and used to study 53 venoms from 30 different species of snakes of medical importance throughout the world. the venoms studied included echis carinatus (iran), naja naja kaouthia (thailand), notechis scutatus (australia), trimeresurus flavoviridis ... | 1983 | 6609011 |
| phospholipid hydrolysis in serum lipoproteins by a basic phospholipase a2 from naja nigricollis snake venom and an acidic phospholipase a2 from naja naja atra snake venom. | apparent km and vmax values for pc and pe hydrolysis were determined following exposure of hdl, ldl, and vldl to a basic phospholipase a2 from n. nigricollis snake venom and an acidic phospholipase a2 from n. nigricollis snake venom and an acidic phospholipase a2 from n. n. atra snake venom. both enzymes hydrolyzed the lipoprotein phospholipids approximately as fast as they hydrolyzed pure phospholipids in mixed micelles, however, the n. nigricollis enzyme, which has a much stronger anticoagulan ... | 1983 | 6623492 |
| dissociation of pharmacological and enzymatic activities of snake venom phospholipases a2 by modification of carboxylate groups. | the carboxylate groups in an acidic and in a basic phospholipase a2 (pla2) enzyme, purified, respectively, from naja naja atra and naja nigricollis snake venoms, were modified with carbodiimide and semicarbazide. the derivatives modified at ph 3.5 and ph 5.5 had less than 1% (n. nigricollis) or 2% (n. n. atra) residual enzymatic activity, whereas 12-16% enzymatic activity remained following modification at ph 5.5 in the presence of ca2+. in marked contrast, these derivatives retained variable, b ... | 1983 | 6651873 |
| a double antibody sandwich micro-elisa kit for the rapid diagnosis of snake bite. | a micro elisa assay was established to diagnose systemic poisoning for the rapid administration of specific antivenom. rabbit anti venom igg was bound to the solid phase to enable detection of venom from both the malayan pit viper (agkistrodon rhodostoma) and the common cobra (naja naja). this assay is read visually and takes 35 to 45 minutes to perform. it can detect 15.6 ng/ml of viper venom in 75 minutes and 7.8 ng/ml of cobra venom in 55 minutes. tests on sera from snake bite patients showed ... | 1983 | 6658505 |
| inhibitory activity of cardiotoxin ii of the indian cobra & certain antibiotics on lysis of bacteria promoted by lysozyme. | | 1983 | 6671671 |
| action of naja naja venom on erythrocytes of laboratory animals. | | 1982 | 7169244 |
| effect of membrane active components from the venom of central asian cobra (naja naja oxiana eichwald) on some functional parameters of mitochondria. | | 1983 | 6671676 |
| phospholipid asymmetry in the membranes of intact human erythrocytes and in spectrin-free microvesicles derived from them. | phospholipase a2 from bee venom and naja naja has been used to study the orientation of phospholipids present in the membrane of intact human erythrocytes and in spectrin-free microvesicles derived from the cells by treatment with ca2+ and a23187. little difference between the cells and microvesicles was observed in the apparent accessibility of phospholipids to the enzyme, suggesting that the original lipid asymmetry was maintained in the absence of spectrin. however, incubation of the microves ... | 1984 | 6722143 |
| delayed hypersensitivity reactions to listeria monocytogenes in rats decomplemented with cobra factor and in c5-deficient mice. | the in vivo effect of cobra factor (cof), the complement-activating protein of cobra (naja naja) venom, was investigated, using quantifiable assays for localization of labelled donor lymphoblasts and of host macrophages in intraperitoneal and subcutaneous sites of injection of antigens from listeria monocytogenes. both commercially available (cordis) and highly purified cof impaired these inflammatory responses, suggesting that the complement-activating protein was itself responsible rather than ... | 1981 | 6788681 |
| dissociation of enzymatic activity from lethality and pharmacological properties by carbamylation of lysines in naja nigricollis and naja naja atra snake venom phospholipases a2. | | 1981 | 6795762 |
| effects of intraventricular curarimimetics on hippocampal electrical activity. | the effects on the hippocampal electroencephalogram (eeg) of intraventricular injections of the nicotinic ligand alpha-naja naja toxin, and of d-tubocurarine, were studied in rats immobilized with gallamine or anesthetized with urethane. the eeg recordings were taped and processed off-line to calculate power spectra, autocorrelation functions, and averages. in addition, the times at which spike-and-wave complexes appeared were identified and autocorrelation histograms and cross correlations (wit ... | 1983 | 6822252 |
| ultracytochemical observations on intracytoplasmic lipids by enzymic digestive methods: histochemical trials. | the penetration of rhizopus arrhizus lipase into ethionine fatty livers was examined histochemically. a free-floating, 30 microns thick vibratome section of the livers perfused with aldehydes was shown to be suitable for ultracytochemical analysis by the lipase digestive method. accessibility of phospholipids in the outer membrane of erythrocytes to naja naja phospholipase a2 was observed under a light microscope, and intact red cells were used for the ultracytochemical analysis by the phospholi ... | 1983 | 6827071 |
| effect of phospholipase a on actions of cobra venom cardiotoxins on erythrocytes and skeletal muscle. | the actions of two phospholipase-free cardiotoxins from the venom of the cobra naja naja siamensis were compared to phospholipase-contaminated cardiotoxins in terms of their ability to lyse human erythrocytes and to depolarize and contract skeletal muscle. the presence of 3-5% (w/w) phospholipase caused a 20-30-fold increase in the haemolytic activity of the two cardiotoxins, the pure cardiotoxins being virtually without haemolytic activity at 10(-7)-10(-6) m. phospholipase contamination did not ... | 1983 | 6830777 |
| effect of methylation of histidine-48 on some enzymatic and pharmacological activities of snake venom phospholipases a2. | the effects on some pharmacological and enzymatic properties were determined following methylation of histidine at the enzymatic active site of the basic relatively toxic naja nigricollis and the acidic relatively non-toxic naja naja atra phospholipases a2. following methylation a very low residual enzymatic activity (0.4-1% of control) was accompanied by a parallel loss in intraventricular lethality, anticoagulant potency, direct hemolytic action and ability to block directly and indirectly evo ... | 1983 | 6834999 |
| catabolism of phospholipids by chicken seminal components after storage. | the possibility of an activation of chicken spermatozoal phospholipase a2 during in vitro storage of undiluted semen was investigated. after storage for periods up to 24 hr at 5 c, the ability of semen to catabolize added phosphatidylcholine labeled on the 2nd carbon of glycerol with 14c oleic acid was assessed. neither spermatozoa nor plasma from undiluted chicken semen was found to be capable of catabolizing added 14c labeled phosphatidylcholine, regardless of the storage period. no enzyme act ... | 1984 | 6483728 |
| further characterization and n-terminal sequence of cobra venom phospholipase a2. | n-terminal amino acid sequence data on cobra venom phospholipase a2 (naja naja naja) demonstrate the absence of histidine at positions 10 and 20, in contrast to most other naja enzymes. the presence of three tryptophans was demonstrated by p-toluenesulfonic acid hydrolysis, and the location of two of these at positions 18 and 19 parallels other naja phospholipase a2 sequences. based on the amino acid composition of the enzyme, the theoretical e278 0.1% should be 2.2, which is consistent with dry ... | 1980 | 7459378 |
| joint action of membrane-active components from central asian cobra (naja naja oxiana eichwald) venom on rat liver mitochondrial functions. | | 1984 | 6490077 |
| complement-independence of the acute-phase production of serum amyloijd p-component (sap) in mice. | mice depleted of circulating c3 by injection of cobra factor (cof), the c3-activating protein of cobra (naja naja) venom, mounted the same acute-phase responses of serum amyloid p-component (sap) to subsequent injection of casein, bacterial lipopolysaccharide or croton oil as did normal control mice. there was also evidence for accelerated synthesis of c3 itself in response to injection of these acute-phase stimulants in cof-treated mice. on the other hand complement activation produced by injec ... | 1980 | 7000131 |
| mapping trna structure in solution using double-strand-specific ribonuclease v1 from cobra venom. | a method for mapping all base-paired stems in both elongation and initiator trnas is described using double-stranded-specific ribonuclease v1 from the venom of the cobra naja naja oxiana. 32p-end-labeled rna is first partially digested with double-strand-specific v1 nuclease under near physiological conditions, and the resultant fragments are than electrophoretically fractionated by size in adjacent lanes of a polyacrylamide gel run in 90% formamide. after autoradiography, the base-paired nucleo ... | 1981 | 7031604 |
| purification and partial characterization of a bacterial phospholipid: cholesterol acyltransferase. | a glycerophospholipid:cholesterol acyltransferase has been purified to near homogeneity from cell-free culture supernatants of aeromonas salmonicida. the characteristics of the enzyme distinguish it from bacterial phospholipases; however, it shares several properties with the lecithin:cholesterol acyltransferase of mammalian plasma. thus, the enzyme inhibits 2-positional specificity as an acyltransferase and it will act as a phospholipase a2 in the absence of cholesterol. furthermore, it has no ... | 1982 | 7061477 |
| the trna-like structure at the 3' terminus of turnip yellow mosaic virus rna. differences and similarities with canonical trna. | the 3' terminus of tymv rna, which possesses trna-like properties, has been studied. a 3' terminal fragment of 112 nucleotides was obtained by cleavage with rnase h after hybridization of a synthetic oligodeoxynucleotide to the viral rna. the accessibility of cytidine and adenosine residues was probed with chemical modification. enzymatic digestion studies were performed with rnase t1, nuclease s1 and the double-strand specific rnase from the venom of the cobra naja naja oxiana. a model is propo ... | 1982 | 7079175 |
| biochemical and pharmacological properties of cardiotoxins isolated from cobra venom. | it has been established that cardiotoxins isolated from elapidae snakes tend to be contaminated with phospholipase. after a thorough comparison of the methods available for the separation of these two components, both hydrophobic and immunoaffinity chromatography have been found to be convenient and effective methods. with cardiotoxins isolated from naja naja siamensis we observed that as the contaminating phospholipase was removed, the cardiotoxins were converted from relatively powerful haemol ... | 1982 | 7080031 |
| effects of purified cardiotoxins from the thailand cobra (naja naja siamensis) on isolated skeletal and cardiac muscle preparations. | four polypeptides were isolated by non-exchange chromatography from the crude cardiotoxin fraction of thailand cobra (naja naja siamensis) venom. fraction i and 71 amino acid residues including 1 tryptophan, while fractions, ii, iii and iv had 60 amino acids and no tryptophan. when tested on isolated skeletal muscle (chick biventer cervicis, chick embryo muscle in culture, guinea pig hemidiaphragm) and cardiac muscle (guinea pig and cat left atria, cat papillary muscle) preparations, fractions i ... | 1982 | 7080050 |
| use of erythrocyte hemolysis kinetics in the purification of complex cardiotoxin mixtures. | a human erythrocyte hemolysis kinetic method provides a useful way to follow the purification of cobra venom cardiotoxins or other hemolytic factors. initial rates of hemolysis, measured as hemoglobin released with time for the separated cardiotoxins from the venom of the thailand cobra naja naja siamensis, vary over a greater range than do other commonly used measures of their biological activity. recovery of the hemolytic activity of the gross cardiotoxin fraction in the subsequently separated ... | 1982 | 7080058 |
| mammalian muscle acetylcholine receptor purification and characterization. | nicotinic acetylcholine receptor (acchr) was purified from fetal calf muscle by an affinity chromatographic method utilizing alpha-neurotoxin from naja naja siamensis as an immobilized ligand. preparations of acchr with an average specific activity of 5 nmol of alpha-toxin bound/mg of protein were obtained, i.e., 75% of the theoretical specific activity assuming identity with torpedo acchr. sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the purified acchr consistently showed the pr ... | 1982 | 7104316 |
| partial characterization of four toxins from venom of the indian cobra (naja naja). | | 1982 | 7106818 |
| cardiotoxins from the venom of malayan cobra (naja naja sputatrix). | | 1982 | 7149742 |
| effects on muscle of a toxin from indian cobra (naja naja naja) venom. | the mode of action of a purified toxin from naja naja naja (indian cobra) venom was investigated in frog rectus abdominis muscle, chick biventer cervicis muscle, cat tibialis anterior muscle (close-arterial) and in both innervated and denervated rat diaphragm muscle preparations. the toxin inhibited the acetylcholine responses of rectus abdominis muscle. the inhibition was antagonized by neostigmine and increasing concentrations of acetylcholine, suggesting a competitive binding of the toxin to ... | 1982 | 7164106 |
| subunit composition of bovine muscle acetylcholine receptor. | acetylcholine receptors from fetal calf muscle were purified to homogeneity (specific activity up to 7500 nmol/g of protein), in reasonable yields (20-50%), and near-milligram quantity. purification was by affinity chromatography on naja naja siamensis toxin coupled to agarose by using methods similar to those for receptors from fish electric organs, but with modifications to account for the low concentration of receptor in muscle and the high probability of proteolysis. immunochemical methods a ... | 1982 | 7171558 |
| comparative study of three basic polypeptides from snake venoms in relation to their effects on the cell membrane of normal and tumor cells. | basic polypeptides producing a variety of effects on animals and cells have been isolated from snake venoms. many possess common structural features and also produce similar pharmacological effects. this has led to doubt as to the specificity of each polypeptide. study of toxin gamma (cardiotoxin from naja nigricollis), cytotoxin p6 (from naja naja, preferentially cytotoxic to certain cells) and neurotoxin alpha (naja nigricollis) under identical conditions shows that they are separate entities ... | 1980 | 7214315 |
| peripheral versus central action of a toxin from indian cobra (naja naja naja) venom. | | 1981 | 7268800 |
| [effect of phospholipase a2 from the venoms of bee and middle asian cobra on choline uptake by synaptosomes]. | the effect of purified phospholipase a2 from venom of the bee apis mellifica and from venom of the cobra naja naja oxiana on the na+-dependent high affinity choline transport into the synaptosomes of rabbit corpus striatum (active uptake) was studied. both phospholipases a2 were shown to inhibit the active choline uptake by the synaptosomes. the bee venom phospholipase at a concentration of 10(-8) m and the cobra venom phospholipase at a concentration of 10(-6) m produced a 50% inhibition of cho ... | 1981 | 7295818 |
| effects of arginine modification of naja nigricollis and naja naja atra snake venom phospholipases a2 on enzymatic activity, lethality and anticoagulant action. | | 1981 | 7302958 |
| improvement of malayan cobra (naja naja sputatrix) antivenin. | a low molecular weight toxic fraction was isolated from venom of the malayan cobra (naja naja sputatrix) by sephadex g-50 gel filtration chromatography. the fraction accounted for almost 100% of the venom lethality. antisera were prepared by immunizing rabbits with the low molecular weight toxic fraction, the glutaraldehyde-treated low molecular weight toxic fraction and the glutaraldehyde-treated, sea snake neurotoxin-enriched low molecular weight toxic fraction, respectively. only the serum of ... | 1983 | 6845388 |
| isolation and characterization of two toxins from the venom of the malayan cobra (naja naja sputatrix). | two principal toxins of the malayan cobra (naja naja sputatrix) venom have been purified to electrophoretic homogeneity by successive sp-sephadex c-25 ion exchange chromatography and sephadex g-50 gel filtration chromatography. they are designated as sputa-neurotoxin 1 (sn1) and sputa-neurotoxin 2 (sn2), respectively. both toxins belong to the group of short neurotoxins which are composed of approximately 60 amino acid residues. the ld50 values following i.p. injection of the purified toxins are ... | 1983 | 6857705 |
| effects of iodipamide on human c3 and factor b in vitro. | the effects of iodipamide on c3 and factor b in normal human serum and in purified form have been examined by immunoelectrophoresis and sodium dodecyl sulfate polyacrylamide gel electrophoresis (sds-page). temperature-dependent changes in immunoelectrophoretic profiles have been observed; however, these are not the same as those obtained after treatment of normal human serum (nhs) with cobra venom factor naja naja. analyses of iodipamide-treated nhs and purified c3 and factor b by reducing sds-p ... | 1982 | 6922882 |
| inhibition of protein kinase c by snake venom toxins: comparison of enzyme inhibition, lethality and hemolysis among different cardiotoxin isoforms. | cardiotoxins, neurotoxins and phospholipase a2 (pla2) are three major classes of toxic components present in the taiwan cobra, naja naja atra of the elapidae family. cardiotoxins (or called cytotoxins), a group of major polypeptides of around 60 amino-acid residues present abundantly in the elapid family of snakes, comprise about 45-55% of the crude venom of taiwan cobra. in contrast to another prominent group of structurally similar neurotoxins with well-established acetylcholine receptors and ... | 1995 | 7549929 |
| primary structure of a cytotoxin-like basic protein from naja naja naja (indian cobra) venom. | the complete amino acid sequence of a cytotoxin-like basic protein (clbp) from the venom of naja naja naja (indian cobra) was determined by manual degradation using a 4-dimethylaminoazobenzene-4'-isothiocyanate double-coupling method. peptide fragments obtained by chemical cleavage with cyanogen bromide and enzymic cleavages with trypsin and staphylococcus aureus proteases for sequence analysis were purified by reversed-phase chromatography. the total number of amino acid residues was 61, with l ... | 1995 | 7558599 |
| highly efficient immobilization of phospholipase a2 and its biomedical applications. | a new method for the immobilization of phospholipase a2 (pla2) has been developed to enhance the activity retention of immobilized pla2. when pla2 from the venom of agkistrodon piscivorus piscivorus was pretreated with 4-nitro-3-octanoyl-oxybenzoic acid to acylate epsilon-amino groups of two lysines (lys-7 and lys-10) and the resulting acylated enzyme was covalently coupled onto carbonyldiimidazole-activated cross-linked agarose beads, the immobilized acylated enzyme showed high retention of act ... | 1995 | 7658163 |
| beta-bungarotoxin blocks phorbol ester-stimulated phosphorylation of marcks, gap-43 and synapsin i in rat brain synaptosomes. | the phospholipase a2 neurotoxin, beta-bungarotoxin, presynaptically blocks acetylcholine release. its mechanism of action is unknown; however, our previous studies suggest that it inhibits phosphorylation of synaptosomal proteins, which might be expected to decrease neurotransmitter release. in our present study, we found that 1 nm beta-butx blocked phorbol ester-stimulated phosphorylation of gap-43, marcks and synapsin i without affecting their basal phosphorylation. in contrast, a 1 nm concent ... | 1995 | 7676466 |
| monoclonal antibody epitope mapping of plasmodium falciparum rhoptry proteins. | plasmodium falciparum rhoptry proteins of the 140/130/110-kda high molecular weight complex (hmwc) are secreted into the erythrocyte membrane during merozoite invasion. epitopes of membrane-associated hmwc proteins can be detected using rhoptry-specific antibodies by immunofluorescence assays. phospholipase treatment of ring-infected intact human erythrocytes, membrane ghosts, and inside-out vesicles results in the release of the hmwc as demonstrated by immunoblotting. we characterized the membr ... | 1993 | 7682186 |
| primary structure of hemoglobin from cobra naja naja naja. | cobra snake naja naja naja hemoglobin shows four bands on triton electrophoresis. we present the primary structure of one alpha and one beta chain. the separation of polypeptide chains was achieved by ion exchange chromatography on carboxymethyl cellulose column. the amino acid sequence was established by automatic edman degradation of the native chains and tryptic and hydrolytic peptides in a gas-phase sequencer. the structural data are compared with those of human and other reptile hemoglobins ... | 1994 | 7710658 |
| effects of inorganic phosphorus compounds on the hydrolysis of phosphatidylcholine liposomes by phospholipid-deacylating enzymes. | structural requirements of inorganic phosphorus compounds as specific activators or inhibitors for phospholipase a2 and phospholipase b were investigated using orthophosphate, pyrophosphate and polyphosphate. it was observed that orthophosphate and pyrophosphate stimulated the activities of phospholipase a2 from bee venom, snake (naja naja) venom and pig pancreas, and also phospholipase b from the yeast torulaspora delbrueckii. however, polyphosphate was found to act as an inhibitor for phosphol ... | 1995 | 7710702 |
| expression of glutathione s-transferase-cardiotoxin fusion protein in escherichia coli. | we report here the construction of cardiotoxin v gene, from cobra snake venom (naja naja atra), by chemically synthesized oligonucleotides and its expression as a glutathione s-transferase-cardiotoxin fusion protein in the inclusion bodies of escherichia coli. the expression of cardiotoxin fusion protein in protein with a yield of about 35 mg/liter culture was confirmed by highly specific anti-peptide antibodies generated against the unique amino acid residues located at the tip of loop ii of ca ... | 1994 | 7725337 |
| chemical modification and inactivation of phospholipases a2 by a manoalide analogue. | chemical modification and inactivation of bovine pancreatic, porcine pancreatic, naja naja atra and pseudechis australis phospholipases a2 (pla2s), belonging to group i, and of trimeresurus flavoviridis, vipera russelli russelli and agkistrodon halys blomhoffii pla2s, belonging to group ii, were investigated by the use of a manoalide (mld)-analogue, 1-(2,5-dihydro-hydroxy-5-oxo-3-furanyl)-8,12-dimethyl-4-formyl-3,7, 11-tridecatrienol. at appropriate time intervals, residual pla2 activities towar ... | 1995 | 7755577 |
| phospholipase a2 domain formation in hydrolyzed asymmetric phospholipid monolayers at the air/water interface. | phospholipase a2 (pla2) catalyzed hydrolysis of asymmetric 1-caproyl-2-palmitoyl-phosphatidylcholine (6,16-pc) and 1-palmitoyl-2-caproyl-phosphatidylcholine (16,6-pc) lipid monolayers at the air/water interface was investigated. surface pressure isotherms, surface potential and fluorescence microscopy at the air/water interface were used to characterize the asymmetric monolayer systems. cobra (n. naja naja) and bee venom pla2 exhibit hydrolytic activity towards 16,6-pc monolayers at all surface ... | 1995 | 7756350 |
| binding mode of phospholipase a2 with a new type of phospholipid analog having an oxazolidinone ring. | inhibition of phospholipases a2 (pla2s) by a new type of monodispersed phospholipid analog, 3-dodecanoyl-4-phosphatidylcholinohydroxymethyl-2-oxazolidinone (oxazolidinone-pc), was investigated by the ph stat assay method using monodispersed 1,2-dihexanoyl-sn-glycero-3-phosphorylcholine (dic6pc) as the substrate. the pla2s used were those from bovine pancreas and cobra (naja naja atra) venom (group i) and from japanese mamushi (agkistrodon halys blomhoffii) venom (group ii). this new-type substra ... | 1995 | 7775386 |
| the use of fluoresceinphosphatidylethanolamine (fpe) as a real-time probe for peptide-membrane interactions. | the characterization of fluoresceinphosphatidylethanolamine (fpe) as a real-time indicator of the electrostatic nature of a membrane surface is described. the conditions appropriate for the labelling of membranes and the implementation of fpe as a tool to monitor the interactions of various peptides with model membranes are outlined. it is shown that of the membrane-active peptides studied, naja naja kaouthia cardiotoxin and pyrularia thionin bind to certain model membranes without insertion. wh ... | 1995 | 7795709 |
| chemical modification of lys-6 in taiwan cobra phospholipase a2 with 4-chloro-3,5-dinitrobenzoate. | phospholipase a2 (pla2) from naja naja atra snake venom was modified with 4-chloro-3,5-dinitrobenzoate, and one major carboxydinitrophenylated (cdnp) pla2 was separated by high performance liquid chromato-graphy. cdnp-pla2 contained only one cdnp group on lys-6 and showed a 93% drop in enzymatic activity. however, carboxydinitrophenylation did not significantly affect the secondary structure of the enzyme molecule as revealed by the cd spectra, and ca2+ binding and antigenicity of cdnp-pla2 were ... | 1994 | 7804147 |
| micellar bolaform and omega-carboxylate phosphatidylcholines as substrates for phospholipases. | a series of mixed-chain diacyl-pcs which contain an omega-cooh on the sn-2 chain [1-cx-2-cy-(cooh)-pc] and bolaform (1-cx-2,2'-cy-1'-cx-pc) phosphatidylcholines were synthesized and examined as substrates for phospholipase a2 (naja naja naja) and c (bacillus cereus). there is very little detectable phospholipase a2 activity toward pure micellar 1-acyl-2-acyl-(omega-cooh) species. in addition, when these same omega-cooh species are present at concentrations above their cmcs, they are potent inhib ... | 1994 | 8172875 |
| a passive hemagglutination test for antibody to naja naja siamensis toxin 3. | | 1981 | 7336448 |
| binding of naja naja siamensis alpha-toxin to the chick ciliary ganglion: a light-microscopy autoradiographic study. | | 1980 | 7374944 |
| cytotoxicity of cobra (naja naja kaouthia) venom on rabbit red blood cells and s-180 tumor cells in the presence of tetracaine, lidocaine and procaine. | the cytocidal action of naja naja kaouthia venom on rabbit red blood cells and s-180 tumor cells treated with local anesthetics (tetracaine, lidocaine and procaine) were studied. the s-180 cells were more sensitive to the venom than the red blood cells which required albumin for efficient hemolysis in the 10 minute assay. all three local anesthetics at lower concentrations protected both cell types against venom hemolysis. at higher concentrations the local anesthetics enhanced the cell lysis to ... | 1980 | 7385945 |
| [reactions between 3h-monoacetylcobratoxin and membrane preparations from denervated muscles and caudate nuclei]. | 3h-monoacetyl derivative of the major neurotoxin of venom obtained from naja naja oxiana was used as a marker of the nicotinic cholinoreceptor (n-chr). it was shown that binding of neurotoxin with the membranes of bovine caudate nuclei unlike binding with the membranes of the rabbit gastrocnemius muscles is less strong and cannot be blocked completely with high concentrations of neurotoxin and d-tubocurarine. serum of the rabbits immmunized with the protein preparation isolated from the membrane ... | 1980 | 7397340 |
| immunochemical cross-reactivity of neurotoxic phospholipase a2 enzymes from indian cobra (naja naja naja) venom using polyclonal antibodies. | rabbit antibodies were prepared against purified phospholipase a2 (nn-xia-pla2) from indian cobra (naja naja naja) venom. the pla2 has haemolytic, neurotoxic, myotoxic, cytotoxic and oedema-inducing activities apart from the catalytic activity. the immunological cross-reactivity of structurally similar neurotoxic pla2s was investigated using enzyme-linked immunosorbent assay (elisa) and immunodiffusion. anti-nn-xia-pla2 igg cross-reacted with other purified neurotoxic pla2s from the same venom. ... | 1993 | 7505490 |
| differential effects of mandevilla velutina compounds on paw oedema induced by phospholipase a2 and phospholipase c. | this study compares the effect of mandevilla velutina compounds with some anti-inflammatory drugs against phospholipase a2- and phospholipase c-induced rat hindpaw oedema. injection of phospholipase a2 (naja naja, 2.5-20 u/paw) and phospholipase c (clostridium perfringens, 0.03-0.05 u/paw) caused a dose-and-time-related increase in paw oedema. compounds mv 8608 (55 mumol/kg) and mv 8612 (32 mumol/kg, i.p.) inhibited phospholipase a2-induced paw oedema without interfering with phospholipase c-ind ... | 1993 | 8276072 |
| effect of nonapeptide fragments of uteroglobin and lipocortin i on oedema and mast cell degranulation. | the anti-inflammatory action of nonapeptide fragments of uteroglobin or lipocortin i known as antiflammins, was tested in the carrageenan or phospholipase a2 rat paw oedema model. the development of carrageenan-induced oedema in rats was significantly inhibited during the early and late phases of the oedema by the local administration of antiflammins 1 and 2. however, the peptides were not able to inhibit phospholipase a2-induced oedema. the time course of the anti-oedematous activity of nonapep ... | 1994 | 7535228 |
| a study on the functional subunits of phospholipases a2 by enzyme immobilization. | pancreatic and venom phospholipases a2 have complex and distinct oligomerization behaviour. pancreatic enzymes are monomeric in solution, but their quaternary structure at interfaces is unknown. on the other hand, certain crotalid venom phospholipases a2 are dimeric in solution, and different reports have proposed either the monomer or the dimer as the catalytically functional subunit. in this study, enzyme immobilization was used as a tool for determining the functional subunits of these enzyme ... | 1994 | 7980413 |
| effects of direct lytic factors from southern chinese cobra venom on ca2+ movement in rabbit aorta strip. | the purified direct lytic factors (dlf) from southern chinese cobra (naja naja atra) venom induced a contractile response in ca(2+)-free krebs' solution and a further increase in the tension following a subsequent addition of ca2+ into bath. after depletion of intracellular ca2+ pool by phenylephrine, dlf failed to induce any contractile response. in 45ca2+ experiments, dlf increased both 45ca2+ release and 45ca2+ influx. procaine 2 mmol.l-1 decreased the dlf induced 45ca2+ release and 45ca2+ in ... | 1993 | 8010046 |
| [distribution of 131i-cytotoxin 14 from naja naja atra venom in rats]. | cytotoxin 14 (ct14) from naja naja atra venom was labelled with 131i by chloramine-t method and its tissue distribution was studied in rats. the highest concentration of the cytotoxin was found in kidney, 5979 dpm per mg weight, 14 times more than that of the control animals, at 0.5 h after i.v. injection and high concentrations were found in liver, spleen, pancreas, and adrenal. ct14 was also found in brain at 2 h after injection, 50 dpm per mg weight, 3 times more than that of the control. | 1994 | 8010097 |