Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| phospholipase a of snake venoms. ii. catalytic properties of the enzyme from naja naja. | 1971 | 5542004 | |
| seasonal changes in the histology of the adrenal gland of the cobra, naja naja. | 1971 | 5542988 | |
| the n-terminal amino acid sequences of two basic cytotoxic proteins from the venom of the indian cobra. | 1971 | 5564473 | |
| isolation of the principal neurotoxins of two naja naja subspecies. | 1971 | 5568672 | |
| isolation of phospholipase a isoenzymes from naja naja venom and their action on membrane-bound enzymes. | 1968 | 5705754 | |
| central neurotoxic effects of the venoms of naja naja and vipera palestinae. | 1968 | 5710997 | |
| seasonal variations in histology and corticosteroid synthesis in vitro in the adrenal of the cobra (naja naja). | 1969 | 5775360 | |
| seasonal changes in the thyroid gland in the male cobra, naja naja l. | 1969 | 5798451 | |
| seasonal changes in the in vitro production of testicular androgens by the cobra (naja naja linn). | 1969 | 5817028 | |
| 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 | |
| sphaerechinorhynchus serpenticola sp. n. (acanthocephala: sphaerechinorhynchinae), a parasite of the asian cobra, naja naja (cantor), in borneo (malaysia). | 1966 | 5927219 | |
| lipid monolayers: action of phospholipase a of crotalus atrox and naja naja venoms on phosphatidyl choline and phosphatidal choline. | the activity of phospholipase a on phosphatidyl choline and phosphatidal choline spread as monolayers on phosphate buffers containing snake venom (crotalus atrox or naja naja) was studied by measuring the fall of surface potential as a function of time, ph, film pressure, temperature, and concentrations of phosphate and venom. at 25 degrees c, ph 7.0, and 0.2 micrograms of venom per ml, optimal activity was observed with both venoms on both substrates at 12 dynes/cm film pressure on 0.04 m phosp ... | 1966 | 5947040 |
| [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 | |
| seasonal changes in the testis of the cobra, naja naja (linn). | 1966 | 6007029 | |
| the neurohypophysial hormones of a reptile species, the cobra (naja naja). | 1967 | 6057829 | |
| the effects of whole cobra venom (naja naja) and its fractions on the heart. | 1967 | 6080378 | |
| [preparation and esr study of spin-labeled derivatives of naja naja oxiana neurotoxin ii]. | after neurotoxin ii naja naja oxiana reaction with n-hydroxysuccinimidyl 2,2,6,6-tetramethyl-4-carboxymethylpiperidine-1-oxyl, six derivatives were isolated, each containing one spin label. their analysis (reduction, carboxymethylation, tryptic hydrolysis, isolation and identification of the spin labeled peptide) allowed to localize the label position: the epsilon-amino groups of lys15, lys25, lys26, lys44, lys48, and alpha-amino group of leu1. the neurotoxin ii reaction with n-hydroxysuccinimid ... | 1983 | 6091692 |
| 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 |
| a comparison of eel electroplax and snake venom acetylcholinesterase. | the effects of some cholinergic ligands, harmala alkaloids and local anesthetics on the activity of eel electroplax and naja naja siamensis venom acetylcholinesterase have been studied. in most cases, eel electroplax was found to be more susceptible towards inhibition than the venom acetylcholinesterase. no major difference was observed with respect to the type of inhibition in both enzymes. the activation of the two enzyme preparations by inorganic cations (ca2+, mg2+ and na+) showed a similar ... | 1984 | 6146473 |
| inhibition of biological activity of mouse beta-nerve growth factor by monoclonal antibody. | a continuous hybrid cell line was derived that secretes monoclonal antibody capable of inhibiting the biological activity of mouse beta-nerve growth factor (beta-ngf). results obtained with monovalent fragments indicate that the monoclonal antibody inhibits activity by interfering with the direct interaction between beta-ngf and the cell membrane receptor rather than by precipitating the dimeric form of beta-ngf. this monoclonal antibody binds to an antigenic determinant common to mouse beta-ngf ... | 1980 | 6159686 |
| cytoarchitectonic pattern of the hypothalamus in the cobra, naja naja. | the distribution and cytoarchitectonic pattern of the magno- and parvocellular hypothalamic nuclei of the cobra. naja naja, are described at the light-microscopic level. with respect to their tinctorial affinity to paraldehyde fuchsin (af) as a representative of the gomori-type of stains, the magnocellular neurons belong to the "af-positive" and the parvocellular neurons to the "af-negative" elements. in addition to the supraoptic and paraventricular nuclei proper, two accessory aggregations of ... | 1981 | 6166381 |
| purification and characterization of anticomplement factor (cobra venom factor) from the naja naja atra venom. | anticomplement factor (cobra venom factor) from the venom of naja naja atra was purified by means of successive chromatography on deae-cellulose, sephadex g-200 and sepharose cl-6b. the purified anticomplement factor was homogeneous as judged by polyacrylamide discontinuous gel electrophoresis at ph 9.4. the yield from 3.0 g of the crude venom was approx. 28 mg. the molecular weight was estimated to be about 156 000 by sds-polyacrylamide gel electrophoresis. the isoelectric point was about 5.2. ... | 1982 | 6173071 |
| 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 |
| studies on snake venom enzymes: part i. purification of atpase, a toxic component of naja naja venom & its inhibition by potassium gymnemate. | 1982 | 6215333 | |
| 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 |
| [fluorescence characteristics of lysine and arginine residues in venom of naja naja atra]. | 1984 | 6239506 | |
| 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 | |
| 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 |
| 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 |
| individual assignments of the amide proton resonances involved in the triple-stranded antiparallel pleated beta-sheet structure of a long neurotoxin, laticauda semifasciata iii from laticauda semifasciata. | the characteristic feature of the crystal structure of erabutoxin b, a short neurotoxin from laticauda semifasciata, and alpha-cobratoxin, a long neurotoxin from naja naja siamensis, is the presence of a triple-stranded antiparallel pleated beta-sheet structure formed by the central and the third peptide loops. in the present study, we have studied the assignment of slowly exchangeable amide protons of laticauda semifasciata iii from l. semifasciata, using nuclear overhauser effects (noe) and sp ... | 1982 | 6279398 |
| fractionation of protein components of plasma membranes from the electric organ of torpedo marmorata. | a procedure has been developed for the separation of intrinsic proteins of plasma membranes from the electric organ of torpedo marmorata. (na+ + k+)-atpase, nicotinic acetylcholine receptor and acetylcholinesterase remained active after solubilization with the nonionic detergent dodecyl octaethylene glycol monoether (c12e8). these components could be separated by ion exchange chromatography on deae-sephadex a-25. fractions enriched in ouabain-sensitive k+-phosphatase or (na+ + k+)-atpase activit ... | 1982 | 6297554 |
| induction of ornithine decarboxylase by treatment of guinea pig lymphocytes with phospholipase c. | treatment of guinea pig lymphocytes with clostridium perfringens phospholipase c but not with naja naja snake venom phospholipase a2 increased ornithine decarboxylase activity. the increase in ornithine decarboxylase activity was suppressed by actinomycin d or cycloheximide, suggesting that de novo syntheses of rna and protein are necessary for the increase in the enzyme activity. these results suggest that the activation of phospholipase c rather than that of phospholipase a2 is responsible for ... | 1983 | 6299785 |
| [specificity of the nuclease from the venom of the middle asia cobra (naja naja oxiana) to the macrostructure of polyribonucleotides]. | 2017 | 6312288 | |
| on the interaction of cobra venom protein cardiotoxins with erythrocytes. | the principally active hemolytic toxin (cardiotoxin) previously purified from the venom of the thailand cobra, naja naja siamensis, was shown to produce spontaneous twitching, contractures and membrane depolarization in sartorius muscles from the frog, rana pipiens. spontaneous twitching, observed at concentrations greater than 0.1 um was completely abolished by addition of tetrodotoxin and not affected by d-tubocurarine. dose and time dependent membrane depolarization of muscle fibers was obser ... | 1984 | 6333874 |
| proteolytic-independent cobra neurotoxin inhibiting activity of curcuma sp. (zingiberaceae). | the 1: 1 (w/v) aqueous extract of curcuma sp. (zingiberaceae) was shown to antagonize the toxic action of naja naja siamensis neurotoxin possibly via direct inactivation of the toxin. the plant extract possessed proteolytic activity which could be separated from the neurotoxin inhibiting activity. the mechanism of antagonism between the plant extract and the neurotoxin was shown not to be involved with the existence of proteolytic activity in the plant extract. | 1983 | 6356379 |
| 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 |
| [nmr study of the spatial structure of the naja naja siamensis toxin 3]. | the 300 and 500 mhz 1h nmr spectra of a long-chain neurotoxin, toxin 3 naja naja siamensis (s-t3), its derivatives and close homolog, toxin 3 naja naja naja (n-t3), have been analyzed. a combination of double resonance, difference spectroscopy and usage of a series of toxin s-t3 derivatives acetylated or trifluoroacetylated at lysine residues allowed to assign the signals from all aromatic protons and a number of signals in the aliphatic region, and to elucidate the microenvironment of certain f ... | 1984 | 6437411 |
| 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 |
| variation in yield and lethality of venoms from iranian snakes. | the dangerous venomous terrestrial snakes of iran belong to three groups: the elapidae (cobras); the viperinae (true vipers); the crotalinae (pit vipers). geographical distribution of each species was determined. studies on the venoms extracted from the following iranian snakes, oxus cobra, naja naja oxiana, levantine viper (afyi), vipera lebetina, carpet viper, echis carinatus, persian horned viper, pseudocerastes persicus, latifii viper, vipera latifii, mountain viper, vipera xanthina and cauc ... | 1984 | 6474490 |
| 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 |
| 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 |
| inactivation of toxin b from the indian cobra by cleavage of a specific bond during limited hydrolysis with trypsin. | two neurotoxins, "toxin b", a long neurotoxin from naja naja, and "cobrotoxin", a short neurotoxin from naja naja atra, were compared with respect to their limited hydrolysis by trypsin and chymotrypsin and its effect on their neurotoxicity. limited hydrolysis of toxin b with trypsin cleaves peptide bonds at arg68-lys69 and arg33-gly34 in the toxin molecule and causes complete loss of the neurotoxicity yielding des-carboxyl terminal toxin b(1-68) nicked at arg33-gly34 in the molecule. on the oth ... | 1984 | 6487344 |
| [relative localization of the bound acetylcholine receptor subunits and neurotoxin]. | a series of neurotoxin ii (naja naja oxiana) derivatives, each containing one p-azido-[14c]benzoyl group, have been prepared. those labeled at leu1, lys15, lys25, lys26, or lys46 associate specifically with the acetylcholine receptor from the torpedo marmorata electric organs and form the crosslinks with it as a result of irradiation. electrophoresis in polyacrylamide gel and gel chromatography revealed the contacts between the neurotoxins and alpha, beta, gamma and delta subunits of the recepto ... | 1984 | 6487390 |
| joint action of membrane-active components from central asian cobra (naja naja oxiana eichwald) venom on rat liver mitochondrial functions. | 1984 | 6490077 | |
| effect of central asian cobra (naja naja oxiana eichwald) venom cytotoxin on enzymatic hydrolysis of phospholipids. | 1984 | 6490078 | |
| cobra venom factor: improved method for purification and biochemical characterization. | a method to purify cobra venom factor (cvf) from cobra venom by sequential column chromatography is described which yields a product virtually free of phospholipase a2, a common contaminant of cvf preparations. the separation of phospholipase a2 from cvf was achieved by chromatography on cibacron blue-agarose, a resin that tightly binds cobra venom phospholipase a2. a rapid and simple hemolytic assay for the qualitative and quantitative determination of cvf based on its ability to induce bystand ... | 1984 | 6491300 |
| photochemically induced nuclear polarization study of exposed tyrosines, tryptophans, and histidines in postsynaptic neurotoxins and in membranotoxins of elapid and hydrophid snake venoms. | the accessibility of surface tyrosines, histidines, and tryptophans in snake venom neurotoxins (short and long) and in membranotoxins to excited triplet 10-(carboxyethyl)-flavin was studied by photochemically induced dynamic nuclear polarization at 270 mhz. trp-29 is accessible in the short neurotoxins--erabutoxins a, b, and c and cobrotoxin--and also in the long neurotoxins--alpha-cobratoxin and alpha-bungarotoxin. tyr-25 is practically inaccessible in all neurotoxins. tyr-39 in cobrotoxin and ... | 1984 | 6498168 |
| reoxidation and renaturation studies on the main toxin of naja naja samarensis. | the main toxin of naja naja samarensis is a very small and rigid protein (mr 6850, 8 cysteines). when fully reduced, it regains its native conformation by a mechanism involving a rapid cysteine oxidation and a slower, less temperature-dependent disulfide exchange. in a native-like form of the protein we observed a population whose cysteines were incompletely reoxidized. when intermediates with blocked cysteines were incubated with oxidized and reduced glutathione, the percentage of native-like m ... | 1984 | 6500055 |
| 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 |
| 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 |
| [complement and noncomplement hemolysis of blood cells in patients with various blood diseases after the administration of the crude toxins of agkistrodon piscivorus, naja naja, naja oxiana]. | 1984 | 6515308 | |
| 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 |
| amino acid sequence of cytotoxin iia isolated from the venom of the indian cobra (naja naja). | a cytotoxic basic polypeptide, designated as cytotoxin iia, was purified to homogeneous state from the venom of the indian cobra (naja naja) by a combination of gel filtration on sephadex g-50, cm-cellulose chromatography, and fast protein liquid chromatography. cytotoxin iia is a single polypeptide consisting of 60 amino acid residues with four intramolecular disulfide linkages. the toxin showed high cytotoxicity toward yoshida sarcoma and ascites hepatoma cells as did cytotoxins i and ii isola ... | 1984 | 6525197 |
| effect of ca2+ on the action of cobra (naja naja oxiana eichwald) venom components on mitochondrial enzyme systems. | 1984 | 6526419 | |
| [2-d-nmr study of the conformation characteristics of toxin 3 from naja naja siamensis venom]. | the spatial structure of "long" toxin 3 naja naja siamensis in solution has been studied by methods of two-dimensional (2d) 1h nmr spectroscopy. the individual signal assignments for 67 out of 71 residues and analysis of nuclear overhauser effects between distinct protons of the molecule allowed the comparison of the toxin 3 conformations at different ph values and temperatures. it was shown that the deprotonated imidazole ring of his22 residue (at ph greater than or equal to 7,5) is surrounded ... | 1984 | 6529443 |
| bindings of ca2+ and substrate analogs to a cobra venom phospholipase a2 in which the alpha-amino group is modified to an alpha-keto group. | the ph dependence of the chemical reaction rate of p-bromophenacyl bromide (bpb) with his 48 of cobra (naja naja atra) venom phospholipase a2, in which the alpha-nh2 group had been selectively modified to an alpha-keto group, was studied at 25 degrees c and ionic strength 0.1 in the absence of ca2+. the ph-dependence curve was monophasic with a midpoint at ph 7.9, which corresponds to the pk value of his 48 of the alpha-nh2-modified enzyme, whereas the curve for the intact enzyme was biphasic, i ... | 1984 | 6530402 |
| [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 |
| chiral synthesis of a dithiolester analog of phosphatidylcholine as a substrate for the assay of phospholipase a2. | the synthesis of a dithiolester analog of phosphatidylcholine, 1,2-bis(heptanoylthio)-1,2-dideoxy-sn-glycerol-3-phosphocholine (thio pc), is described. starting with 1-trityl-sn-glycerol (prepared from d-mannitol), tosylation followed by displacement with potassium methyl xanthate gave a trithiocarbonate. reductive cleavage of the latter gave a 1,2-dithiol which was then acylated, detritylated, and esterified with choline phosphate. hydrolysis of thio pc by phospholipase a2 (naja naja) indicated ... | 1983 | 6655369 |
| 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 |
| hypotensive actions of snake parathyroid glands. | parathyroid gland extracts from four different snake species, ptyas korros, ptyas mucosa, elaphe radiata, and naja naja, were prepared and their hypotensive actions were assayed in anesthetized p. korros. all extracts were hypotensive and the responses, except that of n. naja, were dose related. their potencies were, however, different in different species. these data suggest that the hypotensive property of the parathyroid hormone is probably widely distributed in submammalian vertebrates. | 1983 | 6667839 |
| separation of cardiotoxins (cytotoxins) from the venoms of naja naja and naja naja atra by reversed-phase high-performance liquid chromatography. | 1983 | 6668340 | |
| purification of acidic phospholipases from indian cobra (naja naja naja) venom. | 1983 | 6668341 | |
| inhibitory activity of cardiotoxin ii of the indian cobra & certain antibiotics on lysis of bacteria promoted by lysozyme. | 1983 | 6671671 | |
| effect of membrane active components from the venom of central asian cobra (naja naja oxiana eichwald) on some functional parameters of mitochondria. | 1983 | 6671676 | |
| [high-performance exclusion liquid chromatography of protected peptides on soft and semi-solid gels]. | fractionated soft gels sephadex lh-20, sephadex lh-60, enzakryl k-2 and semirigid gels - spheron p-40, spheron p-300 and spheron p-1000 were tested for separation of protected synthetic fragments of neurotoxin ii from the central asian cobra (naja naja oxiana) venom. applicability of the above gels for size exclusion hplc of protected peptides in organic media is discussed. | 1983 | 6679779 |
| [study of long-chain neurotoxins from naja naja siamensis and naja naja oxiana venoms by circular dichroism and fluorescence]. | cd and fluorescence spectroscopy were used to study the conformational mobility of long-chain neurotoxins from the venom of cobra naja naja siamensis and naja naja oxiana (stx and nt-i, respectively). microenvironment of tryptophan residues in these neurotoxins and their lysine-modified derivatives was also analyzed. ionization of his22 (pk 5,4-5,6) in stx influences the invariant trp29 microenvironment. no conformational change was observed on titration of single his residue situated in the c-t ... | 1983 | 6679782 |
| [1h-nmr study of the naja naja oxiana neurotoxin ii and its spin-labeled derivatives. conformation of "short" neurotoxins]. | in 1h nmr spectra of neurotoxin ii n. n. oxiana the chemical shift ph-dependences in h2o and 2h2o solutions were studied, and also the deuterium exchange rates and chemical shift temperature gradients were measured for the amide protons. the spin probe method was applied to assess the degree of exposure into solvent of the amide and side chain protons. with the purpose of establishing mutual disposition of certain neurotoxin ii groupings, nuclear overhauser effect was studied in the 1h nmr spect ... | 1983 | 6679788 |
| the interaction of dialkyl ether lecithins with phospholipase a2 (naja naja naja). | dialkyl lecithins are nonhydrolyzable substrate analogues for phospholipase a2 (naja naja naja). short chain dialkyl lecithins (which form monomers and micelles), and long chain ether-linked lecithins (which form bilayers or can be solubilized in detergent micelles) have been used to study phospholipase a2/phospholipid interactions. the results of gel filtration, 1h and 31p nmr spectroscopy, kinetic assays and uv difference spectroscopy show that binding of the ether-linked lecithins is independ ... | 1983 | 6687887 |
| 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 |
| fluorescence energy transfer between cobra alpha-toxin molecules bound to the acetylcholine receptor. | an approach was developed with steady state fluorescence energy transfer measurements to examine the spatial relationship between the two alpha-toxins bound to the acetylcholine receptor. by taking advantage of the slow dissociation rates of alpha-toxins (naja naja siamensis 3) from the receptor and of the equal probability with which alpha-toxins bind to the two alpha-toxin-binding sites, we derived an equation which allows prediction of a "true" efficiency of transfer based on the relationship ... | 1984 | 6715368 |
| 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 |
| [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 | |
| 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 |
| molecular characterization of the complement activating protein in the venom of the indian cobra (naja n. siamensis). | 1981 | 6790937 | |
| chemical modification of lysine and histidine residues in phospholipase a2 from the venom of naja naja atra (taiwan cobra). | 1981 | 6795761 | |
| 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 | |
| site-specific fluorescein-labeled cobra alpha-toxin. biochemical and spectroscopic characterization. | cobra alpha-toxin purified from naja naja siamensis venom was labeled with near stoichiometric quantities of fluorescein isothiocyanate. a monofluorescein alpha-toxin was separated in 50-60% yield from unconjugated alpha-toxin and other reaction products by ion exchange chromatography. the isolated mono-conjugated alpha-toxin electrofocuses largely as a single entity with 92% appearing with a pi of 9.6. the unmodified toxin has a pi of 10.7. thermolysin digestion and subsequent high pressure liq ... | 1982 | 6802819 |
| 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 |
| 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 |
| an attempt to identify amino groups of naja naja siamensis neurotoxin that interact with acetylcholine receptor by a comparison of their reactivities in free and receptor-bound neurotoxin. | an attempt to identify amino groups of naja naja siamensis neurotoxin that interact with acetylcholine receptor by a comparison of their reactivities in free and receptor bound neurotoxin. toxicon 21, 219-229, 1983--free naja naja siamensis neurotoxin was acetylated with non-radioactive and acetylcholine receptor-bound neurotoxin with radioactive acetic anhydride. the toxins from the two experiments were combined and the monoacetyl derivatives isolated by chromatography on bio-rex 70. the yields ... | 1983 | 6857707 |