Publications

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
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
annual cycles in levels of pituitary and plasma gonadotropin, gonadal steroids, and thyroid activity in the chinese cobra (naja naja).		1980	7461439
purification and characterization of anti-cholinesterase factor from the venom of naja naja atra.	the anti-cholinesterase factor from naja naja atra venom was purified by means of successive column chromatography on sephadex g-75, carboxymethyl-cellulose and hydroxyapatite. the purified anti-cholinesterase factor was homogeneous by sodium dodecyl sulfate polyacrylamide gel electrophoresis. the molecular weight was estimated to be approx. 50 000. the isoelectric point was determined to be 6.8. this factor was found to be the first cholinesterase inhibitor protein. we have called this anti-cho ...	1980	7397218
purification, some properties and amino-acid sequences of two phospholipases a (cm-ii and cm-iii) from naja naja kaouthia venom.	two phospholipases a, cm-ii and cm-iii, were purified from the siamese cobra (naja naja kaouthia) venom, from thailand, by gel filtration on sephadex g-50 followed by ion-exchange chromatography on cm-cellulose. they each comprise 119 amino acid residues including 14 half-cystine residues. the complete primary structures of the two phospholipases a have been elucidated and their sequences are 96% identical. the sequences, the invariant amino acid residues and the sequences around the active cent ...	1980	7460933
snake venoms. the amino acid sequences of two melanoleuca-type toxins.	toxins cm-10 from naja nivea and cm-9a from naja naja kaouthia venoms were purified by gel filtration followed by ion-exchange chromatography. whereas toxin cm-10 contains 65 amino acids, toxin cm-9a contains only 64 but they each include ten half-cystine residues. the complete primary structures of the toxins have been established. the sequences and the invariant amino acids of toxins cm-10 from n. nivea and cm-9a from n.n. kaouthia venoms resemble those of the melanoleuca-type toxins. in the t ...	1980	7380387
the complete primary structures of three cytotoxins (cm-6, cm-7 and cm-7a) from naja naja kaouthia (siamese cobra) snake venom.		1980	7210030
[observations on cytolysis by cobra venom. effect of sucrose loading].	ls cells cultivated for 4 days in sucrose-containing medium (su) are more fragile than cells cultivated in medium devoid of this sugar (tn) when they are incubated with naja-naja venom; in fact the 51cr radioactivity released into the medium by previously labelled cells is increased for the sucrose ones. phospholipase does not seem to contribute to the lytic activity of the venom, which is dependent on the direct lytic factor: neither varying the temperature of incubation nor adding edta to the ...	1980	7459127
transverse distribution of phospholipids in organelle membranes from ricinus communis l. var. hale endosperm: mitochondria and glyoxysomes.	phospholipase a(2) (naja naja), the nonpenetrating dye trinitrobenzene sulfonate, and the penetrating dye dinitrofluorobenzene, were used to determine the transmembrane distributions of phospholipids of mitochondria and glyoxysomes isolated from endosperm tissue of castor bean (ricinus communis l. var. hale). these studies indicated that the phospholipid distributions were distinctly asymmetric in the accessible (reacted with the probes without total membrane disruption by detergents) pools of t ...	1980	16661334
a single-step separation procedure for several protein constituents of venom of the indian cobra (naja naja).		1980	7450809
three-dimensional structure of the "long" neurotoxin from cobra venom.	the three-dimensional structure of alpha-cobra-toxin, the "long" neurotoxin from the venom of naja naja siamensis, has been determined at 2.8-a resolution. crystals grown as hexagonal needles have space group p6522 with unit cell parameters a = b = 74.59 a, c = 42.89 a; one molecule per asymmetric unit. phases were determined with a single isomorphous derivative with hgi2 by using the anomalous scattering of the single-site hgi2 molecule to resolve the phase ambiguity. the polypeptide chain fold ...	1980	6930640
interaction of spin-labeled naja naja siamensis alpha-neurotoxin with acetylcholine receptor from torpedo californica.		1980	7371834
purification of two phospholipase a isoenzymes with anticoagulant activity from the venom of the cobra naja naja siamensis.		1980	7210026
the amino acid sequence of toxin d isolated from the venom of indian cobra (naja naja).	a neurotoxin, designated toxin d, was isolated from the venom of naja naja by gel-filtration on sephadex g-50 followed by cm-cellulose chromatography. the amino acid sequence of toxin d was determined by analyzing tryptic and chymotryptic peptides of the reduced and s-carboxymethyl derivative. the venom contains at least four long (toxins a, b, c and d) and two short neurotoxins (toxins i and ii) that account for about 16% of the lyophilized crude venom by weight. toxin d consists of 71 amino ac ...	1981	7326259
19f nmr determination of intramolecular distances in spin- and fluorine-labelled proteins: neurotoxin ii naja naja oxiana.		1981	7327263
six polymorphic crystal forms of alpha-cobratoxin.	six different crystal forms of the long neurotoxin alpha-cobratoxin isolated from the venom of naja naja siamensis have been obtained and the conditions for their crystallisation are described. heavy atom derivatives for two of these forms have been prepared and have proven suitable for high-resolution x-ray studies and, with one of them, a 0.28-nm resolution structure has been determined. all but one of the crystal forms were grown between ph 2 and ph 3. two novel suggestions are made which may ...	1981	7308208
cobra venom phospholipase a2: a review of its action toward lipid/water interfaces.	this review focuses on the mechanism of action of phospholipase a2 from cobra venom (naja naja naja) toward the lipid/water interface. particular points of interest include dramatic changes in the enzyme activity if the physical state of its substrate is altered and the activation of the enzyme by phosphorylcholine containing lipids. the experimental findings include the following: micellar substrates are hydrolyzed faster by the enzyme than various bilayer forms of substrate aggregation. the ac ...	1981	7242529
first aid for cobra (naja naja) bites.		1981	7239610
molecular characterization of the complement activating protein in the venom of the indian cobra (naja n. siamensis).		1981	6790937
phospholipase a2 from cobra venom (naja naja naja).		1981	7278679
source of carbohydrate in a toxic protein from indian cobra (naja naja naja) venom.		1981	7245223
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
the 1h nuclear-magnetic-resonance spectra and spatial structure of the naja mossambica mossambica neurotoxin iii.	the proton nmr spectra at 300 mhz of neurotoxin iii from venom of naja mossambica mossambica are reported. by the use of double resonance techniques, ph dependence chemical shifts, isotope labeling technique, and comparison with homologous neurotoxins all proton signals in the aromatic and methyl regions as well as epsilon-ch2 proton signals of some lysine residues have been assigned to individual amino acid residues and their spatial microenvironment has been determined. the results deduced on ...	1981	7297555
complete amino acid sequence of a phospholipase a2 from the venom of naja naja atra (taiwan cobra).		1981	7222082
chemical modification of lysine and histidine residues in phospholipase a2 from the venom of naja naja atra (taiwan cobra).		1981	6795761
a proton-magnetic-resonance study on the molecular conformation and structure-function relationship of a long neurotoxin, laticauda semifasciata iii from laticauda semifasciata.	the 300-mhz and 500-mhz nmr spectra of a long neurotoxin laticauda semifasciata iii (ls iii) from laticauda semifasciata have ben analysed. comparison with the nmr spectra of alpha-cobratoxin from naja naja siamensis, a homologous long neurotoxin to laticauda semifasciata iii, allowed the assignment of all the aromatic protein resonances to specific amino acid residues. all the methyl proton resonances have been assigned to specific types of amino acid residues. the ph dependences of the aromati ...	1981	7318828
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
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
a passive hemagglutination test for antibody to naja naja siamensis toxin 3.		1981	7336448
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
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
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
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
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
proton-nuclear-magnetic-resonance study on molecular conformations of long neurotoxins. alpha-bungarotoxin from bungarus multicinctus and toxin b from naja naja.	the 270-mhz proton nmr spectra were analyzed of the long neurotoxins alpha-bungarotoxin from bungarus multicinctus and toxin b from naja naja. the aromatic proton resonances were completely assigned to individual nuclei for alpha-bungarotoxin and in part for toxin b. the ph dependences of proton chemical shifts were analyzed by the nonlinear least-square method, for obtaining pka values and protonation shifts. the pka values of tyr-25, an invariant residue of neurotoxins, are 12.1 for alpha-bung ...	1981	7308209
contamination of commercially obtained agkistrodon contortrix mokasen snake venom with bungarus multicinctus and naja naja atra snake venoms.		1981	7268802
isolation and preliminary characterisation of two toxic phospholipases a2 from the venom of the malayan cobra (naja naja sputatrix).	two toxic phospholipases a have been isolated from the venom of the malayan cobra (naja naja sputatrix). the phospholipases a were purified by successive ion-exchange chromatography on sp-sephadex c-25, sephadex g-75 gel filtration chromatography and successive bio-rex 70 ion-exchange chromatography. the purified toxic phospholipases a were homogeneous electrophoretically. they were designated as sputatrix phospholipase a-i and sputatrix phospholipase a-ii. positional specificity studies showed ...	1982	7150663
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
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
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
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
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
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
action of naja naja venom on erythrocytes of laboratory animals.		1982	7169244
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
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
enhancement of naja naja atra antivenin production in horses.	as the conventional hyperimmunization schedule in horses introduced by tanaka could not produce enough neutralizing antibody against naja naja atra venom, the mixture of carboxymethyl cellulose (cmc)-cobra venom incorporated with adjuvant was used for immunization. the neutralizing antibody produced (30 ld50) seemed to be increased but still not to reach the satisfactory level. by using cmc-cobratoxin adjuvant mixture as an immunizing agent, highly potent antivenin (220 ld50) was obtained.	1982	7183425
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
chain structure of cobra venom factor from naja naja and naja haje venom.	the chain structure of cobra venom factor, whether isolated from naja naja venom (cvfn) or from naja haje (cvfh) is similar. both homologous proteins are composed of three disulphide-linked chains (a, b, and c) with apparent molecular weights of 72,000, 54,000, and 27,000-35,000 for cvfn and 68,000, 51,000 and 30,000-32,000 cvfh. that all three polypeptides are integral parts of cvf was demonstrated by investigation of the chain pattern after partial reduction. reduction with 1-2 mm dithiothreit ...	1982	7100817
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
hemolytic properties of membrane-active polypeptides from the venom of central asian cobra (naja naja oxiana eichwald).		1982	7184846
cobra venom acetylcholinesterase: nature of charge isoforms.	charge isoforms of cobra (naja naja oxiana) venom acetylcholinesterase, separated by isoelectric focusing, differ only by the number of free carboxyl groups of glutamic and/or aspartic acid side-chains in the enzyme molecule. the isoforms appear to be produced by a post-translational deamidation of accessible glutamin and/or asparagine residues. the isoforms have identical catalytic specificities towards characteristic acetylcholinesterase substrates.	1982	7173192
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
role of monomeric activators in cobra venom phospholipase a2 action.	phospholipase a2 from cobra venom (naja naja naja), which acts poorly on phosphatidylethanolamine (pe) in mixed micelles, is activated toward pe by the monomeric phospholipid dibutyrylphosphatidylcholine (dibutyryl-pc) which is an, even poorer substrate. phosphorus-31 nuclear magnetic resonance spectroscopy was employed to show that only pe is hydrolyzed in mixtures of pe and dibutyryl-pc of various concentrations. the activation shows saturation behavior, and the fully activated enzyme hydrolyz ...	1982	7082644
studies on snake venom enzymes: part i. purification of atpase, a toxic component of naja naja venom & its inhibition by potassium gymnemate.		1982	6215333
specific binding to isolated acetylcholine receptor of a synthetic peptide duplicating the sequence of the presumed active center of a lethal toxin from snake venom.	to verify the existence of a lethal "active center" in snake venom neurotoxins and to assess its delineation within their polypeptide sequences, a tritriacontapeptide matching residues 16-48 of the natural "major" toxin of naja naja philippinensis (hauert, j., maire, m., sussmann, a., and bargetzi, j. p. (1974) int. j. pept. protein research 6, 201-222) has been synthesized by solid-phase technology (juillerat, m. a., and bargetzi, j. p. (1980), results presented at the 16th european peptide sym ...	1982	7061455
local conformational transition of toxin b from naja naja as studied by nuclear magnetic resonance and circular dichroism.	the 270-mhz proton nmr spectra of toxin b, a long neurotoxin from naja naja, in 2h2o solution were analyzed. from the analysis of the discontinuous ph dependence of his-21 c-2 proton chemical shift a 23 degrees c, toxin b is found to exhibit a slow-exchange conformational transition between the states a and b with the transition midpoint at ph 5.75. separate peaks due to the states a and b were also observed for his-21 c-4 proton, tyr-25 ring protons, phenylalanine ring protons and two c-alpha p ...	1982	7060589
interaction surfaces of neurotoxins and acetylcholine receptor.	binding of neurotoxin ii naja naja oxiana derivatives containing one spin label at various positions (leu 1, glu 2, lys 15, lys 25, lys 26, his 31, lys 44 and lys 46) to purified solubilized acetylcholine receptor protein (achr) from torpedo marmorata was studied by epr techniques. achr interaction with several dansylated neurotoxin ii derivatives was followed by difference fluorescence spectroscopy. a series of neurotoxin ii p-azidobenzoyl derivatives were prepared and in three of them modified ...	1982	7080049
electron microscopy of complexes of isolated acetylcholine receptor, biotinyl-toxin, and avidin.	the principal curarimimetic toxin of naja naja siamensis derivatized with biotinyl groups binds specifically both to acetylcholine receptor, isolated from torpedo californica electric tissue, and to avidin. isolated complexes of receptor monomer or dimer, biotinyl-toxin, and avidin were negatively stained and examined in the scanning transmission electron microscope. we measured the angle made by the radius of each avidin bound at the periphery of a monomeric unit in dimer to the axis connecting ...	1982	6952187
purification of acidic phospholipases from indian cobra (naja naja naja) venom.		1983	6668341
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
[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
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
[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
[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
ultracytochemical observations on intracytoplasmic lipids by enzymic digestive methods: histochemical trials1.	the penetration of rbizopus arrhizus lipase into ethioine fatty livers was examined histochemically. a free-floating, 30 μm 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 a2was observed under a light microscope, and intact red cells were used for the ultracytochemical analysis by the phospholipase di ...	1983	28054839
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
separation of cardiotoxins (cytotoxins) from the venoms of naja naja and naja naja atra by reversed-phase high-performance liquid chromatography.		1983	6668340
unfolding processes of small globular proteins: the two-state vs multi-state model.	1. the alcohol-induced unfolding of two homologous proteins, neurotoxin and cardiotoxin from taiwan cobra (naja naja atra) venom has been analysed. 2. it is postulated that the unfolding process for both proteins is a multi-state conformational transition. 3. it has been hypothesized that between the compact native state of the protein and its fully unfolded state there exists a quasi-continuous spectrum of conformational metastates of protein species. 4. the population distribution of these met ...	1983	6862085
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
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
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 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
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
effect of membrane active components from the venom of central asian cobra (naja naja oxiana eichwald) on some functional parameters of mitochondria.		1983	6671676
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
[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