Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| conformation of cobrotoxin in aqueous solution as studied by nuclear magnetic resonance. | the 270-mhz proton nmr spectra of cobrotoxin from naja naja atra were observed in 2h2o solution. the pka value (5.93) of his-32 is slightly lower than the pka value (6.65) of the reference model of n-acetylhistidine methylamide, because of the electrostatic interaction with arg-33 and asp-31. the pka value (5.3--5.4) of his-4 is appreciably low, because of the interaction with the positively charged guanidino group possibly of arg-59. the hydrogen-deuterium exchange rates in 2h2o solution were m ... | 1979 | 43248 |
| immunochemical studies on cardiotoxin from taiwan cobra venom. | 1976 | 61249 | |
| renaturation of a reduced taiwan cobra cardiotoxin. | refolding of a denatured protein obtained by reducing cardiotoxin from the taiwan cobra with mercaptoethanol has been carried out in aqueous and non-aqueous solutions. oxidation of the reduced protein in 0.05 m phosphate buffer (ph 7.2) resulted in isolating an active protein which showed, as compared to native cardiotoxin, identical conformation and biological activities such as lethality, antigenicity and muscle contracture inducing activity. on the other hand, the reduced protein was undergoi ... | 1978 | 76481 |
| preparation of highly potent naja naja atra (formosan cobra) antivenin. | as the preparation of high titer antiserum against naja naja atra venom is a time-consuming process, attempts were made to develop a immunization procedure for producing highly potent antiserums within a short period. rabbits were immunized for 12 weeks with (1) whole venom as used routinely in our institute, (ii) whole venom adsorbed on carboxymethyl-cellulose (cmc) and mixed with freund's complete adjuvant and (iii) neurotoxin adsorbed on cmc and adjuvant mixture followed by cmc-whole venom-ad ... | 1978 | 115651 |
| production of potent antivenin against cobra venom with conjugated-cobrotoxin. | cobra venom (naja naja atra) and its fractions obtained by ammonium sulfate precipitation were subjected to chromatography on cm-cellulose colum. a highly purified cobrotoxin obtained by the repeated chromatography on preparative cm-cellulose column was 6.7 times more toxic than the original cobra venom. the toxin was detoxified by a bifunctional reagent, glutaraldehyde, to about 99.8% and utilized for immunization in animals. mice received 4 weekly immunization with detoxified cobrotoxin and ch ... | 1979 | 121068 |
| the chemistry and biological effects of cardiotoxin from the chinese cobra (n. naja linn.) on hormonal responses in isolated cell systems. | 1975 | 170713 | |
| purification and characterization of nerve growth factor from the venom of bungarus multicinctus. | the nerve growth factor from bungarus multicinctus venom was purified by means of successive chromatography on sephadex g-50, carboxymethyl-cellulose, carboxymethyl-sephadex c-50 and sephadex g-50. the purified nerve growth factor was homogeneous by polyacrylamide disc gel electrophoresis. the molecular weight was estimated to be about 21 000 by gel filtration. compared with the nerve growth factors from the venoms of other elapidae, namely naja naja and naja naja atra, this protein showed high ... | 1978 | 417735 |
| [purification by affinity chromatography and properties of the acetylcholinesterase of formosan cobra (naja naja atra) venom (author's transl)]. | the acetylcholinesterase was purified by cm-sephadex chromatography and affinity chromatography on sepharose bound m-[6-(6-aminocaproylamino)caproylamino]phenyltrimethylammonium bromide. the purified enzyme was obtained with a specific activity of 5470 u/mg (1160-fold purification) and a 89% yield. the molecular weight of the native enzyme was estimated to be 144,000. the enzyme is split into two subunits of approximately equal molecular weight (mr 69,000) by sds treatment. it is a glycoprotein ... | 1979 | 536451 |
| conformational prediction for snake venom toxins and laser raman scattering of a cardiotoxin from taiwan cobra (naja naja atra) venom. | secondary structure regions in snake venom toxins were predicted using the prediction method of chou and fasman (chou, p. y., and fasman, g. d. (1974), biochemistry 13,222) and an averaging scheme assuming structural homology in each type of toxins. the results indicate that, in general, snake toxins contain only some beta-sheet regions and beta bends. the content of secondary structures thus predicted does vary to some extent. the predicted results correlate well with conclusions from physicoch ... | 1977 | 560203 |
| conformational stability of a snake cardiotoxin. | a snake cardiotoxin from the venom of the formosan cobra, naja naja atra, is a basic polypeptide. the protein can be denatured in 6.0 m guanidine hydrochloride or at elevated temperatures. its conformation remains virtually the same in solvents of lower polarity than water such as 1, 2-ethanediol or 1-propanol and 1, 2-ethanediol (1:1 v/v). the circular dichroism spectrum is atypical in water in that the peptide chromophores show a small negative cd band at 214 nm and a large positive one at 195 ... | 1977 | 591177 |
| location of disulfide bridges in cardiotoxin from the venom of formosan cobra (naja naja atra). | the location of the four disulfide bridges in cardiotoxin from the venom of the formosan cobra, naja naja atra, was determined by isolating cystine-containing peptides from the enzymic and partial acid hydrolyzates of the intact toxin. the results indicate that the disulfide bridges are formed by half cystine residues 3--21, 14--38, 42--53, and 54--59. the amino acid sequence at the position 48--49 was revised to -leu-val- instead of val-leu- as reported previously. | 1978 | 649257 |
| primary structures of cardiotoxin analogues ii and iv from the venom of naja jaja atra. | cardiotoxin analogues ii and iv were isolated from the venom of naja naja atra by gel filtration on sephadex g-50 followed by cm-cellulose chromatography. the venom contains at least four cardiotoxin analogues that account for about 54% of the weight of the lyophilized crude venom. these four cardiotoxin analogues, named cardiotoxin analogues i, ii, iii, and iv, show strong cytotoxicity to yoshida sarcoma cells but the lethal toxicity is one-order less. these toxins contain 60 amino acid residue ... | 1977 | 849468 |
| optical activity and conformation of cobra neurotoxin. | cobra neurotoxin from formosan cobra (naja naja atra) venom is a compact globular protein having an intrinsic viscosity of 4.5 ml/g. the protein is stable in 7.5 m urea but can be denatured in 4.1 m guanidine hydrochloride or at elevated temperature (above 70 degrees c). its conformation remains virtually the same in solvents of lower polarity than water such as 1,2-ethanediol or a mixed solvent of 1-propanol-1,2-ethanediol-water (5:1:1 by volume). the circular dichroism spectrum is "atypical" i ... | 1977 | 870027 |
| neuromuscular blocking actions of neurotoxins isolated from laticauda semifasciata, naja naja and naja naja atra--a comparative assay--. | 1977 | 916390 | |
| amino acid sequences of neurotoxins i and iii of the elapidae snake naja mossambica massambica. | the amino acid sequences of two neurotoxins of the african cobra naja mossambica mossambica have been determined using almost uniquely phenylisothiocyanate degradation in a liquid protein sequencer programmed alternatively with 'protein' and 'peptide' programs. when compared to known sequences of so-called 'short' neurotoxins belonging to other elapidae snakes, neurotoxins i and iii of naja mossambica mossambica are very similar to the cobrotoxin, a neurotoxin isolated from the formosan cobra na ... | 1977 | 923577 |
| amino acid sequence of cardiotoxin from the venom of naja naja atra. | 1976 | 955081 | |
| the amino acid sequence of cardiotoxin-analogue iv from the venom of naja naja atra. | 1976 | 992063 | |
| amino acid sequence of cardiotoxin-analogue ii from the venom of naja naja atra. | 1976 | 999683 | |
| isolation and characterization of nerve growth factor from the venom of naja naja atra. | nerve growth factor was isolated from the venom of naja naja atra by ion exchange and gel permeation chromatography and was found to be homogeneous by disc gel electrophoresis. the molecular weight was estimated to be approximately 20,000 by gel filtration and 22,000 by ultracentrifugation. this protein, which showed an isoelectric point of ph 7.02, probably consists of two subunits of equal molecular weight which are held together or interact with each other noncovalently. the biological activi ... | 1976 | 1002678 |
| the chemical synthesis of taiwan cobra venom toxins [proceedings]. | 1976 | 1014028 | |
| blockade of acetylcholine receptors: a model of myasthenia gravis. | in order to block acetylcholine receptors of muscle, the alpha toxin of the formosan cobra (naja naja atra) was given intravenously to rats. electrophysiological and pharmacological changes typical of myasthenia gravis were recorded, including decremental responses to repetitive stimuli, curare sensitivity, neostigmine reversal, and posttetanic phenomena. this model supports the concept that a reduction of available acetylcholine receptors may play an important role in myasthenia gravis. | 1975 | 1145181 |
| amino acid sequence of cardiotoxin-analogue i from the venom of naja naja atra. | 1975 | 1147930 | |
| [pharmacokinetics of cytotoxin 14 from naja naja atra venom]. | the pharmacokinetics of cytotoxin 14 (ct 14) from naja naja atra venom was studied with biotin-avidin enzyme-linked immunosorbent assay. the plasma concentration-time curve of ct 14 after bolus i.v. 0.2 mg.kg-1 into rabbits was found to fit a two-compartment open model. t1/2 alpha was 5.8 +/- 0.6 min and t1/2 beta was 3.5 +/- 0.2 h. a rapid absorption was seen after im injection (0.5 mg.kg-1) to rabbits. the peak level was 260 +/- 90 ng.ml-1 and tpeak was 13.6 +/- 2.4 min. the absolute bioavaila ... | 1992 | 1302445 |
| inhibition of sendai virus by various snake venom. | viperid, elapid and crotalid snake venoms were screened in vitro for antiviral activity against sendai virus. the hemolysis of 10(8) human erythrocytes in 1 ml, caused by 70 hau of sendai virus, was abolished when the virions were pretreated with 10 ug of the viperid venom of echis coloratus, and was considerably diminished when pretreated with 10 ug of the venom of echis carinatus sochureki, the cobra venoms of naja atra and naja nigricollis nigricollis. these venoms did not affect the erythroc ... | 1992 | 1328790 |
| immunochemical properties of naja naja atra (taiwan cobra) phospholipase a2 using polyclonal and monoclonal antibodies. | the immuno-chemical properties of naja naja atra phospholipase a2 (nna-pla2) were studied by using the chemically modified pla2 derivatives and the pla2 homologues toward anti-nna-pla2 polyclonal and monoclonal antibodies. anti-nna-pla2 polyclonal antibodies inhibited the enzymatic activity of nna-pla2 and hemachatus haemachatus de-i by 87% and 68%, respectively. however, the enzymatic activities of naja nigricollis cms-9 and notexin were not significantly affected by the polyclonal antibodies. ... | 1992 | 1373010 |
| [specific killing of human leukemic t-cells by a monoclonal antibody coupled to the cytotoxin from chinese cobra]. | the immunotoxin (it) was prepared by conjugating cytotoxin from chinese cobra (naja naja atra) venom with monoclonal antibody (mcab) wu71 directed to human t-cells. first, calcium ions were used to suppress the cytolytic reaction while cell antigen was allowed to react with mcab. then magnesium ions and the chelating agent egta were used to abolish the calcium inhibition. with this treatment, the it showed high cytotoxicity for the leukemic cell line cem, which was antigen positive (82.4% of the ... | 1992 | 1394735 |
| effects of snake venom phospholipase a2 toxins (beta-bungarotoxin, notexin) and enzymes (naja naja atra, naja nigricollis) on aminophospholipid asymmetry in rat cerebrocortical synaptosomes. | the effects of snake venom phospholipase a2 (pla2) toxins (beta-bungarotoxin, notexin) and pla2 enzymes (naja nigricollis, naja naja atra) on aminophospholipid asymmetry in rat cerebrocortical synaptic plasma membranes (spm) were examined. incubation of intact synaptosomes with 2 mm 2,4,6-trinitrobenzene sulfonic acid (tnbs) for 40 min, under non-penetrating conditions, followed by spm isolation, allowed us to calculate the percentage of phosphatidylethanolamine (pe) and phosphatidylserine (ps) ... | 1992 | 1417932 |
| inhibition of phosphorylation of synapsin i and other synaptosomal proteins by beta-bungarotoxin, a phospholipase a2 neurotoxin. | some snake venom neurotoxins, such as beta-bungarotoxin (beta-butx), which possess relatively low phospholipase a2 (pla2) activity, act presynaptically to alter acetylcholine (ach) release both in the periphery and in the cns. in investigating the mechanism of this action, we found that beta-butx (5 and 15 nm) inhibited phosphorylation, in both resting and depolarized synaptosomes, of a wide range of proteins, including synapsin i. naja naja atra pla2, which has higher pla2 activity, also inhibi ... | 1992 | 1431893 |
| mojave toxin affects fusion of myoblasts and viability of myotubes in cell cultures. | mojave toxin is a neurotoxic, heterodimeric phospholipase isolated from the venom of crotalus scutulatus scutulatus. responses of primary rat muscle cell cultures and clonal muscle cell lines to treatment with mojave toxin and its constituent subunits were examined. continuous exposure of cells to 0.5 microm or 1.0 microm mojave toxin or the basic subunit, added 24 hr after plating, prevented fusion of primary myoblasts and c2 myoblasts to multinucleate myotubes. under the same experimental cond ... | 1992 | 1509491 |
| kinetics of the hydrolysis of micellar substrates catalyzed by snake venom phospholipases a2. | effects of ca2+ on the kinetic parameters for the hydrolysis of mixed micelles of 1,2-dipalmitoyl-sn-glycero-3-phosphorylcholine (dic16pc) with triton x-100, catalyzed by a cobra (naja naja atra) (group i) and a habu (trimeresurus flavoviridis) (group ii) pla2s, were studied and compared with the results reported for other group i and ii enzymes. the substrate bindings to group i enzymes were independent of the ca2+ binding, whereas the substrate bindings to group ii enzymes were facilitated mor ... | 1992 | 1569045 |
| [biotin-avidin-elisa for cytotoxin purified from cobra venom]. | a technique combining the biotin-avidin amplifying system with sandwich enzyme-linked immunosorbent assay (b-a-elisa) was developed for the microassay of the cytotoxin from naja naja atra venom. the horse-peroxidase was used as the marker and polystyrene microhemagglutination plates as solid carrier. the sensitivity was 0.5 ng.ml-1. the assay range was 1.25-320 ngml-1 with coefficient of variation of 4.9% (intragroup) and 8.1% (intergroups), respectively. | 1992 | 1598840 |
| structural analysis and comparison of cobrotoxin and cardiotoxins by near-ir fourier transform raman spectroscopy. | venom toxins were isolated from formosan cobra (naja naja atra) by cation-exchange chromatography. the near-ir ft-raman analytical method has been applied to the characterization and classification of the toxin components in their lyophilized forms. structural analysis and comparison of various purified toxin fractions were made with respect to their amino acid compositions and near-ir fourier-transform raman spectra. the results indicate that the major secondary structure of cobra toxins includ ... | 1992 | 1610379 |
| comparative effects of phospholipase a2 neurotoxins and enzymes on membrane potential and na+/k+ atpase activity in rat brain synaptosomes. | beta-bungarotoxin (beta-butx) and notexin are phospholipase a2 (pla2) neurotoxins which cause an irreversible blockade of neurotransmitter release through specific and potent effects at the presynaptic nerve terminal; however, their mechanism of action is uncertain. we examined the effects of beta-butx and notexin on na+/k+ atpase activity using sprague-dawley rat brain synaptosomes in order to determine if alterations in activity might modulate neurotoxin-induced depolarization. treatment of sy ... | 1991 | 1648801 |
| effects of anti-inflammatory drugs on rat hind-paw swelling caused by phospholipase a2 from naja naja atra venom. | rat hind-paw swelling was induced dose-dependently by subplantar injection of acidic phospholipase a2 (nnavpla2) from naja naja atra venom. diphenhydramine and methysergide pretreatment greatly reduced the swelling effect caused by nnavpla2. several doses of compound 48/80 given to deplete the histamine content of rat hind paw, also greatly suppressed nnavpla2-induced paw swelling. the paw swelling caused by nnavpla2 was reduced following pretreatment with bw 755c, a dual inhibitor of cyclooxyge ... | 1991 | 1683689 |
| comparison of the enzymatic and edema-producing activities of two venom phospholipase a2 enzymes. | the edema-producing activity of nnavpla2, an acidic phospholipase a2 (pla2) enzyme from naja naja atra venom (nnav), was less potent than that of tmvpla2 ii, a basic pla2 from trimeresurus mucrosquamatus venom (tmv). these edema-forming effects were greatly suppressed by pretreatment of rats with diphenhydramine/methysergide or compound 48/80, which reduced the tissue content of histamine and serotonin. heparin abolished and suppressed the paw edema caused by protamine and tmvpla2 ii, respective ... | 1990 | 1703083 |
| production and characterization of monoclonal antibodies against naja naja atra cobrotoxin. | twelve monoclonal antibodies against cobrotoxin from naja naja atra venom were tested for cross-reactivity with eight different snake toxins, binding to linear epitopes, prevention of cobrotoxin binding to acetylcholine receptor (achr) in vitro, and protection in mice concomitantly given a lethal dose of cobrotoxin. the antibodies were highly specific, as evidenced by little reactivity with other snake toxins. none of the monoclonal antibodies bound to reduced cobrotoxin or synthesized 8-mer reg ... | 1991 | 1724806 |
| structural analysis of phospholipase a2 by near-ir fourier transform raman spectroscopy. | venom toxins were isolated from formosan cobra (naja naja atra) by cation-exchange chromatography. most toxin components could be obtained in relatively pure forms by single-step ion-exchange chromatography whereas an extra step of gel permeation was needed for the separation of phospholipase a2 (pla2) from the major neurotoxic component, i.e. cobrotoxin. the newer near-ir ft-raman analytical method has been applied to the characterization of pla2 in their lyophilized forms. structural analysis ... | 1991 | 1789801 |
| characterization and immunological comparison of isoenzymes of phospholipases a2 from snake venoms of different genera and families. | phospholipases a2 (pla2) were isolated and purified from the taiwan cobra (naja naja atra) and several snake species of the same or different genera by semipreparative cation-exchange and reversed-phase hplc. they were shown to possess different enzymatic activity toward the synthetic substrate l-alpha-lecithin by the fatty-acid titration method. the immunological cross-reactivity of these structurally similar isotoxins was investigated using immunodiffusion, precipitin reaction and enzyme-linke ... | 1991 | 1810246 |
| a non-radioactive receptor assay for snake venom postsynaptic neurotoxins. | a non-radioactive assay was developed for detecting the binding of postsynaptic neurotoxins to acetylcholine receptor (achr) from torpedo californica. enzyme linked immunosorbent assay (elisa) wells coated with long or short chain neurotoxins specifically bound to purified achr while crotamine or two different cardiotoxins did not. bound receptor was detected by antibody against achr. specificity was determined by dose-response experiments and competition studies using carbamylcholine chloride, ... | 1991 | 1862522 |
| a convenient method to differentiate the monoclonal antibodies with differing immunochemical properties. | three monoclonal antibodies (mabs) against naja naja atra phospholipase a2 (pla2) were prepared by hybridoma technique. of which two mabs, 1e531 and 5f92 inhibited the enzymatic activity of pla2, but 5f6f10 did not. 1e531 and 5f92 nearly exhibited the same binding patterns which was different from that observed with 5f6f10 toward the chemically modified derivatives and homologous variants of pla2 as revealed by enzyme immunoassay. this suggests that, based on the results of comparative analysis ... | 1991 | 1953802 |
| effect of anti-inflammatory drugs on the cardiotoxin-induced hind-paw oedema in rats. | cardiotoxin, isolated from naja naja atra venom, induced rat hind-paw oedema. this effect was suppressed by the pretreatment with dexamethasone or bw 755c, or subplantar co-injection with fpl 55712. pretreatment with aspirin alone did not affect this response, while a significant reduction of cardiotoxin-induced paw oedema was achieved with aspirin in combination with diphenhydramine and methysergide. subplantar co-injection of paf antagonist, bn 52021 or l 652731, with cardiotoxin had no effect ... | 1990 | 1983146 |
| fusion of sphingomyelin vesicles induced by proteins from taiwan cobra (naja naja atra) venom. interactions of zwitterionic phospholipids with cardiotoxin analogues. | egg sphingomyelin vesicles were used to assay aggregation/fusion activities of proteins from taiwan (naja naja atra) venom to avoid the problem of phospholipase a2 contamination during protein purification. it led to the identification of a new cardiotoxin (ctx) analogue protein (ctx v) with major aggregation/fusion, but few hemolysis, activities. on the contrary, cardiotoxin (ctx iii) induced significant hemolysis of human red blood cells but exhibited few aggregation/fusion activities. to stud ... | 1991 | 1993698 |
| amino acid sequences of nerve growth factors derived from cobra venoms. | amino acid sequences of nerve growth factors (ngfs), purified from the venoms of indian cobra (naja naja) and thailand cobra (naja naja siamensis) were determined. the sequence of n. naja ngf differed from that reported previously by hogue-angeletti et al. [(1976) biochemistry 15, 26-34]. the sequence of n. naja siamensis ngf was identical to that of formosan cobra naja naja atra ngf, determined previously by oda et al. [(1989) biochem. int. 19, 909-917] and to that deduced from the nucleotide s ... | 1991 | 1995338 |
| snake venom cardiotoxins and bee venom melittin activate phospholipase c activity in primary cultures of skeletal muscle. | the effects of cardiotoxin fractions from naja naja kaouthia and naja naja atra snake venoms and synthetic melittin peptide were examined on lipolytic activity in red blood cells and primary skeletal muscle cultures. both native cardiotoxin fractions caused considerable production of free fatty acids in red blood cells. this production was abolished when the fractions were first treated with p-bromophenacyl bromide to reduce the venom phospholipase a2 activity contamination. in equine and human ... | 1991 | 2054159 |
| preliminary crystallographic analysis of cardiotoxin v with major fusion activity from taiwan cobra (naja naja atra) venom. | crystals of a cardiotoxin from taiwan cobra venom have been obtained by the vapor diffusion method using methyl pentanediol as precipitant. the crystals belong to the hexagonal space group p6(1)22 (or p6(5)22), with cell dimensions a = b = 47.5 a, c = 111.3 a, alpha = beta = 90 degrees and gamma = 120 degrees and diffract to a resolution of 2.2 a. there is one molecule per asymmetric unit and the solvent content is estimated to be 53%. | 1991 | 2056526 |
| phospholipid hydrolysis and loss of membrane integrity following treatment of rat brain synaptosomes with beta-bungarotoxin, notexin, and naja naja atra and naja nigricollis phospholipase a2. | the effects of the phospholipase a2 (pla2) toxins, beta-bungarotoxin and notexin, and the pla2 enzymes from naja naja atra and naja nigricollis snake venoms on the plasma membrane integrity of synaptosomes were examined. synaptosomes were isolated from rat brain cerebral cortex, corpus striatum and hippocampus. osmotic activity, lactate dehydrogenase leakage, and leakage of 2-deoxy-d-(1-3h)-glucose-6-phosphate were monitored (37 degrees c, 10-120 min) following incubation with 0.5, 5 and 50 nm c ... | 1990 | 2080518 |
| inhibition of phosphorylation of rat synaptosomal proteins by snake venom phospholipase a2 neurotoxins (beta-bungarotoxin, notexin) and enzymes (naja naja atra, naja nigricollis). | some snake venom neurotoxins, such as beta-bungarotoxin (beta-butx) and notexin, which inhibit the release of neurotransmitter at both peripheral and central presynaptic terminals possess phospholipase a2 activity. in contrast, most snake venom phospholipase a2 enzymes such as those isolated from naja naja atra and naja nigricollis are structurally homologous to these neutrotoxins but do not have any specific or potent presynaptic action although they have higher enzymatic activities than the ne ... | 1990 | 2089738 |
| inhibitory effect of edta.ca2+ on the hydrolysis of synaptosomal phospholipids by phospholipase a2 toxins and enzymes. | phospholipases a2 (pla2) are ca2(+)-dependent enzymes that are inhibited by edta; this inhibition would be expected to be reversed by restoring the ca2+ concentration. by examining the hydrolysis of synaptosomal phospholipids by pla2 enzymes, naja naja atra and naja nigricollis, and by toxins with pla2 activity, beta-bungarotoxin (beta-butx) and notexin, we demonstrated a novel inhibitory action of edta manifested in the presence of excess ca2+. we postulate the formation of an edta.ca2+ complex ... | 1990 | 2123106 |
| lack of the blocking effect of cobrotoxin from naja naja atra venom on neuromuscular transmission in isolated nerve muscle preparations from poisonous and non-poisonous snakes. | neuromuscular transmission in the chinese cobra naja naja atra was not affected by its own toxin (cobrotoxin) at a concentration of as high as 100 microm, while in the frog a concentration of less than 0.1 microm cobrotoxin depressed the amplitude of the end-plate potential to less than 10% of its original value within 30 min or directly blocked the nerve-evoked muscle action potential. the lack of effect of cobrotoxin was also observed in the nerve-muscle preparations from a pit viper (agkistro ... | 1990 | 2175458 |
| [preparation of toxoid from taiwan cobra (naja naja atra) venom]. | potency of sixty antitoxic unit was reached after two immunizations in 2-week intervals of rabbits and horses with 10-25 mg taiwan cobra (naja naja atra) venom which was detoxified by 0.125% glutaraldehyde. now this procedure has become a routine antivenine-producing method by which snake bivalent neurotropic antivenine is produced. the stability test showed that taiwan cobra toxoid kept at 37 degrees c for 40 days, the antigenicity increased by 24% and toxicity decreased by 10% as compared to t ... | 1990 | 2176918 |
| two-dimensional nmr studies and secondary structure of cobrotoxin in aqueous solution. | the 1h-nmr spectra of cobrotoxin, a neurotoxic protein isolated from formosan cobra naja naja atra, have been studied by two-dimensional nmr techniques. of 62 amino acid residues in cobrotoxin, the complete assignments of 58 residues have been made. the resonances from several of the remaining residues have been identified but not yet specifically assigned. the secondary structure of an antiparallel triple- and double-stranded beta-sheet has also been determined by observing the noe. | 1990 | 2249693 |
| the effect of cholinergic manipulations on the analgesic response to cobrotoxin in mice. | intracerebroventricular (i.c.v.) injection of cobrotoxin (ct), a neurotoxin isolated from the venom of naja naja atra, produced an antinociceptive response in mice as measured by the tail-flick test. this effect of ct was blocked by systemic administration of atropine, but not by methylatropine or naloxone. depletion of central acetylcholine (ach) by hemicholinium-3 (hc-3) blocked the antinociceptive action of cobrotoxin. these results suggest that central cholinergic neurons are important for t ... | 1990 | 2266778 |
| interfacial catalysis: the mechanism of phospholipase a2. | a chemical description of the action of phospholipase a2 (pla2) can now be inferred with confidence from three high-resolution x-ray crystal structures. the first is the structure of the pla2 from the venom of the chinese cobra (naja naja atra) in a complex with a phosphonate transition-state analogue. this enzyme is typical of a large, well-studied homologous family of pla2s. the second is a similar complex with the evolutionarily distant bee-venom pla2. the third structure is the uninhibited p ... | 1990 | 2274785 |
| crystal structure of cobra-venom phospholipase a2 in a complex with a transition-state analogue. | the crystal structure of a complex between a phosphonate transition-state analogue and the phospholipase a2 (pla2) from naja naja atra venom has been solved and refined to a resolution of 2.0 angstroms. the identical stereochemistry of the two complexes that comprise the crystal's asymmetric unit indicates both the manner in which the transition state is stabilized and how the hydrophobic fatty acyl chains of the substrate are accommodated by the enzyme during interfacial catalysis. the critical ... | 1990 | 2274787 |
| bites by the white-lipped pit viper (trimeresurus albolabris) and other species in hong kong. a survey of 4 years' experience at the prince of wales hospital. | the case records of 242 snake bite victims admitted to the prince of wales hospital in hong kong between september 1984 and october 1988 were studied retrospectively. when the snake was identified, the white-lipped pit viper (trimeresurus albolabris) was by far the commonest species involved. in addition to local oedema and inflammation, evidence of a significant blood clotting disturbance was present in at least 10% of cases, defibrination and thrombocytopenia being the commonest findings. sinc ... | 1990 | 2325197 |
| leukotriene and prostaglandin production in rat brain synaptosomes treated with phospholipase a2 neurotoxins and enzymes. | beta-bungarotoxin (beta-butx) and notexin cause an irreversible blockade of neurotransmitter release through specific and potent effects at the presynaptic nerve terminal, however, the mechanism of action is uncertain. we examined the effects of beta-butx and notexin on lt and pg production in rat cerebrocortical synaptosomes in order to determine if eicosanoid production might mediate or regulate the pharmacological actions of these phospholipase a2 (pla2) neurotoxins. the effects of the pla2 e ... | 1990 | 2343144 |
| kinetic and inhibition studies of phospholipase a2 with short-chain substrates and inhibitors. | the action of the phospholipases a2 (pla2s) from naja naja naja, naja naja atra, and crotalus atrox venoms as well as the enzyme from porcine pancreas on a number of short-chain, water-soluble substrates was studied. the inhibition of these enzymes by short-chain phosphonate- and thiophosphonate-containing phospholipid analogues was also examined. the kinetic patterns observed for the action of the venom pla2s on substrates containing phosphocholine head groups all deviated from a classical mich ... | 1990 | 2383571 |
| interactions in red blood cells between fatty acids and either snake venom cardiotoxin or halothane. | phospholipase a2 (pla2) activity enhances snake venom cardiotoxin (ctx)-induced and general anesthetic (halothane)-induced hemolysis of red blood cells. in the case of halothane-induced hemolysis, this effect appears to be related primarily to free fatty acids. in the present study, the interaction between ctxs and halothane and the effects of different free fatty acids on cardiotoxin and halothane-induced hemolysis were examined. the hemolytic actions of halothane and a ctx from naja naja kaout ... | 1990 | 2402762 |
| monoclonal antibodies against vipera lebetina venom nerve growth factor cross-react with other snake venom nerve growth factors. | nerve growth factor (ngf) was isolated from the venom of vipera lebetina and was purified to homogeneity as judged by sds gel electrophoresis. the biologically active ngf was used to immunize balb/c mouse, and the spleen cells from immunized mouse were fused with mouse pai myeloma cells. forty-seven hybrid cell lines, secreting monoclonal antibodies to v. lebetina ngf, were isolated and nine of them purified from ascitic fluids. the isolated antibodies define two partially overlapping epitopes o ... | 1987 | 2448608 |
| assessment of the role of tryptophan residues in phospholipase a2 by fluorescence quenching. | tryptophan (trp) fluorescence of two phospholipases a2 (pla2) from naja naja atra and naja nigricollis snake venoms was quenched by acrylamide and iodide. trp residues in n. naja atra pla2 were equally accessible to acrylamide and iodide. iodide quenching studies indicate that there are two classes of trp fluorophores in n. nigricollis cms-9. the accessible class consists of trp-18 and trp-19. removal of the n-terminal octapeptide caused a perturbation of the micro-environment of the trp residue ... | 1989 | 2489051 |
| studies on the status of lysine residues in phospholipase a2 from naja naja atra (taiwan cobra) snake venom. | phospholipase a2 (pla2) from naja naja atra (taiwan cobra) snake venom was subjected to lysine modification with trinitrobenzene sulphonic acid (tnbs), and two major trinitrophenylated (tnp) derivatives, tnp-1 and tnp-2, were separated by h.p.l.c. tnp-1 contained only one tnp group on lys-6 and showed a marked decrease in enzymic activity, but still retained 45% of the lethal toxicity. both lys-6 and lys-65 were modified in tnp-2, and modification of lys-65 caused a further reduction of the leth ... | 1989 | 2511834 |
| factors in snake venoms that increase capillary permeability. | capillary permeability increasing (cpi) activity is a phenomenon of the microvasculature caused by many agents such as snake venoms, histamine, 5-hydroxytryptamine (5-ht), prostaglandins and leukotrienes. since no systematic study has been done to determine what components of snake venom cause cpi activity, a cpi factor from naja naja atra (taiwan cobra) venom was isolated using intravenous injections of evan's blue dye as the indicator of increased permeability and the factor's properties were ... | 1989 | 2576052 |
| amino acid sequences of cytotoxin-like basic proteins derived from cobra venoms. | amino acid sequences of cytotoxin-like basic proteins (clbps), purified from the venoms of formosan cobra (naja naja atra) and indian cobra (naja naja), were reinvestigated. the determined sequences differed from those reported previously by takechi et al. [(1985) biochem. int. 11, 795-802; (1987) biochem. int. 14, 145-152]. the sequence of clbps at residues 25-30 was found to be hydrophilic as compared with those of cytotoxins. the difference in the hydrophobicity of this region might be respon ... | 1989 | 2583280 |
| role of ca2+ in the substrate binding and catalytic functions of snake venom phospholipases a2. | phospholipases a2 are classified into two groups, i and ii, according to differences in the polypeptide-chain length and the intramolecular-disulfide bondings. the effects of ca2+ on the kinetic parameters for the hydrolysis of monodispersed and micellar phosphatidylcholines, catalyzed by a cobra (naja naja atra) enzyme (group i) and by mamushi (agkistrodon halys blomhoffii) and habu (trimeresurus flavoviridis) enzymes (group ii), were studied by the ph-statassay method at 25 degrees c, ph 8.0-8 ... | 1989 | 2606904 |
| amino acid sequence of nerve growth factor purified from the venom of the formosan cobra naja naja atra. | nerve growth factor (ngf) was isolated from the venom of the formosan cobra (naja naja atra). the amino acid sequence was determined by a combination of conventional methods. the total number of amino acid residues was 116, giving a molecular mass of 13,057 da. the sequence was identical with that deduced from the nucleotide sequence of an ngf cdna from the venom gland of naja naja siamensis, reported by selby et al. [j. neurosci. res., 18, 293-298 (1987)]. | 1989 | 2619756 |
| do chemical modifications dissociate between the enzymatic and pharmacological activities of beta bungarotoxin and notexin? | we have measured enzymatic, hemolytic and anticoagulant activities, lethal potencies and effects on contractions of the phrenic nerve-diaphragm preparation, by chemically modified derivatives of beta bungarotoxin (beta butx) and notexin, two presynaptically acting toxins which have pla2 activity. the following chemical modifications of beta butx were tested: alkylation and methylation of histidine 48, alkylation of tryptophan 19, sulfonylation of tyrosine 68, oxidation of methionines 6 and 8, se ... | 1989 | 2718187 |
| factors influencing the hemolysis of human erythrocytes by cardiotoxins from naja naja kaouthia and naja naja atra venoms and a phospholipase a2 with cardiotoxin-like activities from bungarus fasciatus venom. | the effects of red blood cell age and incubation conditions (temperature, divalent cation type and concentration, ph and glucose) on hemolysis induced by cardiotoxin fractions from naja naja atra and naja naja kaouthia venoms, a phospholipase a2 with cardiotoxin-like activities from bungarus fasciatus venom and bee venom phospholipase a2 were examined. hemolysis by the snake venom toxins was dependent on red blood cell age (aged more susceptible than fresh) and the temperature of incubation (37 ... | 1989 | 2718193 |
| roles of mast cells and pmn leukocytes in cardiotoxin-induced rat paw edema. | cardiotoxin, isolated from the venom of naja naja atra, was found to cause rat hind-paw edema in a dose-dependent manner. this edematous response was significantly suppressed by pretreatment with diphenhydramine, methysergide or compound 48/80, which reduced the tissue histamine content. polymorphonuclear (pmn) leukocyte infiltration appeared within 1 h and had accumulated markedly in the rat paw 3-6 h after subplantar injection of cardiotoxin. methotrexate pretreatment significantly reduced not ... | 1989 | 2721549 |
| hemolytic activity of thionin from pyrularia pubera nuts and snake venom toxins of naja naja species: pyrularia thionin and snake venom cardiotoxin compete for the same membrane site. | pyrularia thionin (p. thionin) is a strongly basic peptide of 47 amino acids which is hemolytic, cytotoxic and neurotoxic. it shows the greatest hemolytic activity toward human erythrocytes. rabbit, guinea pig and pig erythrocytes show decreasing activity in that order, and little or no activity is shown with sheep, horse, cow or mouse erythrocytes. crotalus venoms are inactive, but the venoms from naja naja atra, naja naja ceylonicus and naja naja melanoleuca and, more specifically, cardiotoxin ... | 1989 | 2749751 |
| immunological relationships of phospholipase a2 neurotoxins from snake venoms. | polyclonal rabbit antisera were raised against ten snake phospholipase a2 neurotoxins and one snake phospholipase a2 cytotoxin. immunological cross-reactivities between these toxins, two other snake phospholipase a2 enzymes and pancreatic phospholipase a2 were studied using elisa technology. all snake phospholipase a2 neurotoxins fell into two main antigenic classes. one antigenic class was composed of all the elapid toxins tested (textilotoxin, taipoxin, notexin, pseudexin and beta-bungarotoxin ... | 1989 | 2799839 |
| step-wise thermal denaturation of cobrotoxin, a snake venom neurotoxin from naja naja atra: a proton nuclear magnetic resonance study. | temperature dependence of proton nuclear magnetic resonance spectra has been followed for cobrotoxin, a postsynaptic neurotoxin from naja naja atra venom. several aromatic amino-acid residues, including the functionally essential trp-29 located at the tip of the central loop of the molecule, have been found to undergo a thermal structural transition above the global thermal denaturation temperature. it is suggested that a local structure around these residues behaves somehow independently of the ... | 1989 | 2803517 |
| sequence characterization of venom toxins from thailand cobra. | several toxins with distinct pharmacological properties were isolated from the venom of thailand cobra (naja naja siamensis) by cation-exchange chromatography. two neurotoxins and one basic toxin with cardiotoxic activity were further purified and sequenced. the neurotoxins characterized were closely similar to the previously reported long- and short-chain neutrotoxins. the complete sequences of one minor neurotoxin and one cardiotoxin analogue were determined with the automatic protein sequence ... | 1989 | 2807733 |
| comparison of enzymatic and pharmacological activities of lysine-49 and aspartate-49 phospholipases a2 from agkistrodon piscivorus piscivorus snake venom. | the basic lys-49 phospholipase a2 (pla2) from agkistrodon piscivorus piscivorus venom is homologous to the basic asp-49 pla2 from the same venom as well as other snake venom pla2 enzymes. it differs, however, in several respects, most important being replacement of the previously invariant asp-49 at the calcium binding site by lys, resulting in a reversed order of addition of calcium and phospholipid, phospholipid binding first. although the preferences for phospholipid substrates of the two enz ... | 1987 | 3109429 |
| role of the n-terminal region in phospholipases a2 from naja naja atra (taiwan cobra) and naja nigricollis (spitting cobra) venoms. | the n-terminal alpha-amino groups of two phospholipases a2 (pla2) from naja naja atra and naja nigricollis venoms were selectively modified with trinitrobenzene sulfonic acid, and the modified derivatives were separated by high performance liquid chromatography (hplc). trinitrophenylated (tnp) derivatives contained only one tnp group in the alpha-amino group of asn-1 and showed a marked decrease in enzymatic activity. pla2 enzymes were cleaved with cnbr, and the n-terminal octapeptide was separa ... | 1988 | 3188062 |
| purification and characterization of a lethal protein with phospholipase a1 activity from the hornet (vespa basalis) venom. | the hornet, vespa basalis, is one of the most dangerous species of wasps found in taiwan. the insect is aggressive and its venom is highly toxic. by gel filtration on a fractogel tsk hw 50 column followed by cation-exchange chromatography on cm-trisacryl m, a lethal protein was purified from the venom. it has a molecular mass of about 32 kda and an i.v. ld50 value of 0.32 micrograms/g mouse. the toxin is capable of catalyzing the hydrolysis of emulsified phospholipids but not sphingomyelin. anal ... | 1988 | 3196744 |
| lipid-induced changes in the secondary structure of snake venom cardiotoxins. | the secondary structures of three snake venom cardiotoxins (from hemachatus hemachatus, naja naja atra, and naja naja naja), in aqueous solution and in a lipid-bound form, were investigated by fourier-transform infrared spectroscopy. the conformation-sensitive protein infrared bands in the amide i region were analyzed using deconvolution and band-fitting procedures. the spectra of the three cardiotoxins in aqueous buffer are very similar; they indicate a high content of both antiparallel beta-sh ... | 1988 | 3335526 |
| tryptophan residue essential for activity of naja naja atra phospholipase a2. | when naja naja atra phospholipase a2, which contains three tryptophan residues at the 18th, 19th, and 61st positions, was oxidized with n-bromosuccinimide at ph 4.0, its activity decreased in a convex manner with increase in the extent of oxidation of tryptophan residues. the curve shape showed that the tryptophan residue oxidized last is most responsible for the activity. the order of accessibilities of the three tryptophan residues, which was analyzed according to the method reported previousl ... | 1988 | 3360757 |
| amino acid sequence of a less-cytotoxic basic polypeptide (lcbp) isolated from the venom of the indian cobra (naja naja). | a less-cytotoxic polypeptide, designated as lcbp, was isolated from the venom of naja naja by gel filtration on sephadex g-50 followed by cm-cellulose chromatography. the cytotoxicity toward yoshida sarcoma cells and lethal toxicity toward mice of lcbp were both one order of magnitude lower than that of cytotoxins and that of toxin a, respectively. lcbp is a single polypeptide consisting of 61 amino acid residues with four intramolecular disulfide linkages, and the amino acid sequence is the sam ... | 1987 | 3566773 |
| characterization of the anticoagulants from taiwan cobra (naja naja atra) snake venom. | taiwan cobra (naja naja atra) snake venom was separated into 19 fractions by means of cm-sephadex c-50 column chromatography. anticoagulant fractions v-vii were refractionated by gel filtration on sephadex g-50 and the purified component possessed phospholipase a2 activity and an inhibitory effect on collagen-induced platelet aggregation. the anticoagulant action could be antagonized by phospholipid or platelet factor 3. anticoagulant fraction xvii was also further refractionated by gel filtrati ... | 1987 | 3576637 |
| different susceptibilities of platelet phospholipids to various phospholipases and modifications induced by thrombin. possible evidence of rearrangement of lipid domains. | on the membrane surface of the human platelet, phosphatidylcholine (pc) and phosphatidylethanolamine (pe) were hydrolyzed to different extents by the snake venom phospholipases a2 of varying pi values. the susceptibility of platelet phospholipids to basic phospholipase a2 of naja nigricollis (pi 10.6) has been reported (wang et al. (1986) biochim. biophys. acta 856, 244-258). the susceptibilities of platelet phospholipids to acidic phospholipase a2 of naja naja atra (pi 5.2) and to neutral phosp ... | 1987 | 3580366 |
| electrophysiologic observation of the effects of matrine co against arrhythmia induced by chinese cobra venom on isolated rat sinus node and papillary muscles. | 1987 | 3613639 | |
| monoclonal antibody immunoaffinity chromatography of the nerve growth factor from snake venoms. | 1. pure monoclonal antibodies to vipera lebetina venom nerve growth factor have been isolated by affinity chromatography using cnbr-agarose bound antigen. 2. nerve growth factors from ten snake venoms (vipera lebetina, vipera russellii, vipera berus berus, vipera ursini, echis carinatus, agkistrodon halys, bungarus caeruleus, naja naja oxiana, naja naja, naja naja atra) were purified using monoclonal antibodies against ngf linked to brcn-activated agarose. | 2013 | 3621902 |
| depolarization of skeletal muscle cells in culture by a cardiotoxin-like basic polypeptide from the venom of the taiwan cobra (naja naja atra). | a cardiotoxin-like basic polypeptide from the venom of naja naja atra is homologous to cardiotoxins from the same venom, but much less toxic. to determine if it acts like the cardiotoxins its depolarizing ability was measured. it was about 10 times less potent than the cardiotoxins. five amino acids are conserved in the sequences studied, on the exposed second and third loops of the toxin backbone. they may be part of the toxins' interactive site. | 1987 | 3629619 |
| multiple effects of alpha-toxins on the nicotinic acetylcholine receptor. | very low concentrations (5 nm) of alpha-toxin from the venom of naja naja atra produced a characteristic fade in muscle compound action potential and tetanus induced by repetitive nerve stimulation which was identical to the effects of curare. high concentrations of alpha-toxin and all concentrations of alpha-bungarotoxin reduced the response but produced very little fade in comparison to curare. these results suggest that alpha-toxins have more than one effect at the neuromuscular junction. | 1987 | 3691793 |
| actions of cardiotoxins from the southern chinese cobra (naja naja atra) on rat cardiac tissue. | the cardiotoxic actions of southern chinese cobra (naja naja atra) venom have been investigated. cardiotoxicity accounted for lethality of crude venom in anaesthetized rats and cardiotoxic polypeptides constituted the bulk of the venom when it was fractionated by cm-sephadex chromatography. the cardiotoxic actions of these polypeptides were investigated in isolated cardiac tissue. actions of cardiotoxins on rate, force and intracellular potentials occurred more readily in ventricular tissue and ... | 1986 | 3715895 |
| effects of modification of tyrosines 3 and 62 (63) on enzymatic and toxicological properties of phospholipases a2 from naja nigricollis and naja naja atra snake venoms. | previously we selectively modified his (48), arg, lys, asp, glu and trp residues in the basic phospholipase a2 from naja nigricollis and the acidic phospholipase a2 from n. n. atra snake venoms. evidence was obtained for the existence of separate but perhaps overlapping sites responsible, respectively, for their enzymatic and pharmacological properties. we have now modified one or two (tyr 3, tyr 62 [63], tyr 3 + 62 [63]) out of the nine tyrosine residues in these enzymes using p-nitrobenzenesul ... | 1986 | 3775785 |
| effect of alkylation of tryptophan residues on the enzymatic and pharmacological properties of snake venom phospholipase a2. | snake venom phospholipases a2 show a remarkable degree of amino acid sequence homology yet differ markedly in enzymatic and pharmacological activities. the basic phospholipase a2 from naja nigricollis venom has much greater lethal potency, cardiotoxicity, hemolytic and anticoagulant activity than the acidic or neutral enzymes from naja naja atra or hemachatus haemachatus venoms, respectively, even though it has lower enzymatic activity than the latter two enzymes. previous studies in which we se ... | 1985 | 3924381 |
| [the detoxification of naja naja atra venom and preparation of potent antivenin]. | the 99.2% toxicity of naja naja atra venom can be detoxified by treatment with 0.25% ga (glutaraldehyde) solution at ph 6.8 and still remains its antigenicity. using the ga treated venom incorporated with freund's complete adjuvant as immunogen, the titer of immune horse sera can be enhanced rapidly. the modified immunization method not only shortened the period of immunization (from 180 to 60 days), but also increased the potency of immune sera (from 75 to 170 units). the method also diminished ... | 1985 | 3933920 |
| effects of beta-bungarotoxin and naja naja atra snake venom phospholipase a2 on acetylcholine release and choline uptake in synaptosomes. | beta-bungarotoxin is a potent presynaptically acting snake venom toxin that exhibits phospholipase a2 activity. we compared the effects of beta-bungarotoxin and a less toxic snake venom phospholipase a2 on synaptosomal 3h-acetylcholine release and 3h-choline uptake. the purpose of these experiments was to study the mode by which beta-bungarotoxin inhibits 3h-acetylcholine release in this preparation. under non-depolarizing conditions, both beta-bungarotoxin and naja naja atra phospholipase a2 st ... | 1986 | 3952766 |
| the relationship between high-affinity noncatalytic binding of snake venom phospholipases a2 to brain synaptic plasma membranes and their central lethal potencies. | the basic phospholipase a2 from naja nigricollis (african spitting cobra) snake venom is enzymatically less active but more toxic than the acidic phospholipase a2 from naja naja atra (taiwan cobra) snake venom, following injection into the right lateral ventricle of the brain of rats. when radiolabeled with 125i, these phospholipases a2 retained enzymatic activities and lethal potencies. both enzymes bound with high affinity and specificity to brain synaptic plasma membrane preparations in vitro ... | 1986 | 3964691 |
| circular dichroism study of the unfolding-refolding of a cardiotoxin from taiwan cobra (naja naja atra) venom. | circular dichroism spectroscopy has been used to study the unfolding-refolding process of a cardiotoxin from taiwan cobra (naja naja atra) venom upon addition of fluoroalcohols or sodium dodecyl sulfate (sds) to its aqueous solution. in these experiments, the disulfide bridges remained intact. the unfolding process has been found to be reversible both for fluoroalcohols and for sds unfolding. the reversibility of the unfolding-refolding process of cardiotoxin in aqueous mixtures of fluoroalcohol ... | 2014 | 4074722 |
| amino acid sequence of a cardiotoxin-like basic polypeptide (clbp) with low cytotoxic activity isolated from the venom of the formosan cobra (naja naja atra). | a cardiotoxin-like basic polypeptide, designated as clbp, was isolated from the venom of naja naja atra by gel filtration on sephadex g-50 followed by cm-cellulose chromatography. the cytotoxicity toward yoshida sarcoma cells and lethal toxicity toward mice of clbp were both one-order lower than those of cardiotoxins and cobrotoxin, respectively. clbp is a single polypeptide consisting of 61 amino acid residues with four intramolecular disulfide linkages. the amino acid sequence of clbp shows a ... | 1985 | 4091854 |
| kinetics of the hydrolysis of monodispersed dihexanoyllecithin catalyzed by a cobra (naja naja atra) venom phospholipase a2. | the hydrolysis of 1,2-dihexanoyl-sn-glycero-3-phosphorylcholine (dic6pc), catalyzed by a cobra (naja naja atra) venom phospholipase a2, was studied at 25 degrees c ionic strength 0.1 in the presence of 3-10 mm ca2+, which can saturate the ca2+-binding site of the enzyme. the initial velocity data, obtained at various concentrations of the substrate below the critical micellar concentration (cmc), were analyzed according to the michaelis-menten equation. the km value was practically independent o ... | 2013 | 4093439 |
| effect of naja naja atra venom on cytochrome c oxidase, l-ascorbic acid oxidase, peroxidase, and catalase. | 1965 | 4287255 | |
| chemical studies on phospholipase a from formosan cobra (naja naja atra) venom. | 1972 | 4512906 | |
| local necrosis induced by cobra (naja naja atra) venom. | 1972 | 4539445 | |
| comparison of naja naja siamensis and naja naja atra venoms. | 1968 | 4966517 | |
| [a study of the fractions obtained by chromatography of the venom of naja naja atra on sulphoethyl-sephadex]. | 1968 | 4971838 | |
| role of cardiotoxin and phospholipase a in the blockade of nerve conduction and depolarization of skeletal muscle induced by cobra venom. | 1. the effects of phospholipase a (pha), cardiotoxin (ctx) and neurotoxin (cobrotoxin) isolated from formosan cobra (naja naja atra) venom on conduction of the rat phrenic nerve and membrane potential of the rat diaphragm were studied.2. phospholipase a, lysolecithin and cobrotoxin were without effect on the axonal conduction. cardiotoxin was the only active agent in cobra venom, but it was less potent than the crude venom.3. the blocking action of cardiotoxin was markedly accelerated by the sim ... | 1972 | 5041453 |
| chemical modification of cobratoxin from the venom of formosan cobra (naja naja atra). | 1970 | 5313270 |