Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
|---|
| kinetic characterization of phospholipase a2 modified by manoalogue. | manoalogue, a synthetic analogue of the sea sponge-derived manoalide, has been previously shown to partially inactivate the phospholipase a2 from cobra venom (reynolds, l. j., morgan, b. p., hite, e. d., mihelich, e. d., & dennis, e. a. (1988) j. am. chem. soc. 110, 5172) by reacting with enzyme lysine residues. in the present study, the inactivation of the phospholipases a2 from pig pancreas, bee venom, and cobra (naja naja naja) venom by manoalogue was studied in detail. manoalogue-treated enz ... | 1991 | 1911741 |
| acute lung injury induced by phospholipase a2. structural and functional changes. | on the basis of the observation that serum levels of phospholipase a2 (pla2) are elevated in pancreatitis and systemic sepsis, and the association of these conditions with the subsequent development of acute lung injury, the present investigation examined the structural and physiologic consequences of intratracheal administration of pla2 to adult male rats. rats received direct intratracheal instillation of either control vehicle or 40,000 units/kg of pla2 repurified from naja naja venom. animal ... | 1991 | 1902636 |
| comparison of the catalytic properties of phospholipase a2 from pancreas and venom using a continuous fluorescence displacement assay. | phospholipases a2 from pig pancreas and the venoms from bee, naja naja and crotalus atrox have been studied by using a new continuous fluorescence displacement assay that utilizes normal phospholipid substrates [wilton (1990) biochem. j. 266, 435-439]. with limiting amounts of substrate, the assay demonstrated stoichiometric conversion into products with both pancreatic and venom enzymes, and thus would allow phospholipid determination at concentrations down to about 0.1 microm. the substrate sp ... | 1991 | 1898370 |
| [1-14c]oleate-labeled autoclaved yeast: a membranous substrate for measuring phospholipase a2 activity in vitro. | radiolabeled, autoclaved yeast were tested as a substrate for mammalian phospholipase a2 activity because the only other membranous substrate used for this purpose, autoclaved escherichia coli, totally lacks a major mammalian phospholipid, phosphatidylcholine. candida albicans were grown in the presence of [1-14c]oleate and then autoclaved. sixty three percent of the incorporated label was in yeast phospholipid, and more than 95% of that was in the 2-acyl position. the distribution of label in t ... | 1991 | 1872466 |
| 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 |
| interfacial catalysis by phospholipase a2: substrate specificity in vesicles. | the binding equilibrium of phospholipase a2 (pla2) to the substrate interface influences many aspects of the overall kinetics of interfacial catalysis by this enzyme. for example, the interpretation of kinetic data on substrate specificity was difficult when there was a significant kinetic contribution from the interfacial binding step to the steady-state catalytic turnover. this problem was commonly encountered with vesicles of zwitterionic phospholipids, where the binding of pla2 to the interf ... | 1991 | 1854740 |
| synthesis and characterization of a heterobifunctional mercurial cross-linking agent: incorporation into cobratoxin and interaction with the nicotinic acetylcholine receptor. | the heterobifunctional organomercurial reagents 3-(acetoxymercurio)- and 3-(chloromercurio)-5-nitrosalicylaldehyde were prepared, characterized in model studies, and used to probe the interaction between cobratoxin, purified from the venom of the thailand cobra (naja naja siamensis), and the affinity-purified nicotinic acetylcholine receptor (acchr) from torpedo california electroplax. these reagents may also be useful in introducing chemically well-defined heavy metal atoms into proteins contai ... | 1991 | 1854732 |
| procoagulant activities in venoms from central asian snakes. | the venoms from central asian snakes (echis carinatus, echis multisquamatus, vipera ursini, vipera lebetina, agkistrodon halys halys and naja naja oxiana) contain several enzymes with amidolytic- and procoagulant activity. we have characterized the activities and the mol. wts of the venom enzymes that are able to convert a number of commercially available chromogenic substrates for activated coagulation factors. the chromogenic substrate cleavage patterns obtained for the crude venoms may be hel ... | 1991 | 1830705 |
| purification and characterization of a neurotoxic phospholipase a2 from indian cobra (naja naja naja) venom. | snake venoms contain multimolecular forms of phospholipase a2 which are diverse with respect to their pharmacological properties. a neurotoxic pla2 from naja naja naja venom has been purified in two steps. (1) the whole venom was fractionated on cm-sephadex c-25 column; 4.6% of the total pla2 activity recovered was found in the nn-v fraction. (2) the nn-vb-pla2 fraction was purified to homogeneity by gel filtration of fraction nn-v on sephadex g-50. it is a basic protein with a mol. wt between 1 ... | 1991 | 1814010 |
| isolation and characterization of a lethal phospholipase a2 (nn-ivb1-pla2) from the indian cobra (naja naja naja) venom. | indian cobra (naja naja naja) venom is reported to contain multiple forms of phospholipase a2. only a couple of them have been isolated and characterized. a lethal phospholipase a2 (nn-ivb1-pla2) from naja naja naja venom has been purified in three steps involving cm-sephadex c-25, sephadex g-50 and rechromatography on cm-sephadex c-25 columns. it is a basic protein with pl value between 7-7.5 and has molecular weight between 11,000-11,500. the ld50 of nn-ivb1-pla2 is 1.2 mg/k g body weight. it ... | 1991 | 1810247 |
| 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 |
| effects of chemical modification on enzymatic and toxicological properties of phospholipases a2 from naja naja naja and vipera russelli snake venoms. | the effects of chemical modification with 4-nn-dimethyl amino azo benzene-4'-isothiocyanate on various biological activities of phospholipases a2, nn-xiii-pla2 from naja naja naja and vrv-pl-viiia from vipera russelli snake venoms were investigated. modification of the enzymes resulted in significant reduction of lethal, hemolytic, anticoagulant and enzymatic activities. the km value of the modified enzymes was increased. the modified enzymes failed to induce edema in the foot pads of mice and w ... | 1991 | 1801318 |
| 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 |
| the involvement of polymorphonuclear leukocytes in the pathogenesis of bronchopneumonia in calves. ii. granulocyte-induced changes in erythrocyte membrane phospholipid topology. | phospholipid topology in erythrocyte membranes of bronchopneumonic calves and changes in phospholipid asymmetry induced by incubation of erythrocytes with neutrophils of diseased calves were examined. using aminophospholipid tracing by non-penetrating probe, trinitrobenzenesulfonic acid, and phospholipid hydrolysis by specific phospholipase a2 from naja naja venom and sphingomyelinase from staphylococcus aureus it was stated that in erythrocytes from diseased calves phosphatidylserine and, to so ... | 1991 | 1785438 |
| interleukin-1 alpha stimulates the release of prostaglandin e2 and phospholipase a2 from fetal rat calvarial cells in vitro: relationship to bone nodule formation. | we have shown previously that interleukin-1 (il-1) has biphasic effects on the formation of bone nodules in long-term cultures of fetal rat calvarial (rc) cells (ellies and aubin, cytokine 2:430-437, 1990). to determine the role of arachidonic acid metabolism in this process, we have examined the release of prostaglandin e2 (pge2) and phospholipase a2 (pla2) from rc cells under conditions that allowed concomitant analysis of the formation of bone nodules. recombinant human il-1 alpha (rhil-1 alp ... | 1991 | 1785374 |
| isolation and fundamental characteristics of a phospholipase b inhibitor from autolyzed torulaspora delbrueckii. | phospholipase b inhibitor was found in the autolyzate of yeast cells, torulaspora delbrueckii. the inhibitor was purified to homogeneity by ethanol precipitation, gel filtration with sephadex g-10, ion-exchange chromatography with deae-sephacel, and gel filtration with asahipak gs-320. on thin-layer chromatography the purified inhibitor was detected with the hanes-isherwood reagent, which is used to detect phosphorus. the activity of the inhibitor was not affected by heat treatment at 100 degree ... | 1991 | 1760134 |
| comparative chromatography of brazilian coral snake (micrurus) venoms. | 1. elution profiles of 11 coral snake venoms, including those of micrurus albicinctus, m. corallinus, m. frontalis altirostris, m. f. brasiliensis, m. f. frontalis, m. fulvius fulvius, m. ibiboboca, m. lemniscatus ssp., m. rondonianus, m. spixii spixii and m. surinamensis surinamensis, were compared using high performance gel filtration and reverse phase media. 2. micrurus venom profiles were compared with those of "outgroup" taxa bothrops moojeni, naja naja kaouthia and bungarus multicinctus. 3 ... | 1991 | 1756614 |
| absence of lung reactions after complement depletion during dialysis: an experimental study in pigs. | sequestration of 111in-labeled neutrophils (polymorphonuclear leukocytes--pmns) in the lungs during sham dialysis was studied dynamically using a gamma camera. five animals were pretreated with cobra venom factor, naja naja (cvf), to achieve depletion of the complement system, mainly c5a. seven animals were studied without pretreatment with cvf. central hemodynamics and gas exchange were studied as well as neutrophil function using luminescence and aggregation. in the control group there was a s ... | 1991 | 1741685 |
| structural features of carbohydrate moieties in snake venom glycoproteins. | the structures of the carbohydrate moieties of glycoproteins in snake venoms are largely unknown. in the present study, we have analyzed venoms of several species of snakes as well as plasma and tissue glycoproteins from one species of cobra (naja naja kaouthia) by lectin affinity staining of western blots. the data demonstrate that glycoproteins in cobra venom invariably contain terminal alpha-galactosyl residues with negligible proportions of sialic acids. interestingly, however, terminal alph ... | 1992 | 1731789 |
| renaturation of cobra venom phospholipase a2 expressed from a synthetic gene in escherichia coli. | cobra venom (naja naja naja) phospholipase a2 (pla2) contains 14 cysteines in the form of 7 disulfide bonds amongst its 119 amino acids. a gene encoding the pla2 was synthesized and inserted into a bacterial expression vector containing the phage lambda pl promoter. in order to obtain protein without the initiating methionine at the n-terminus, a factor xa site was engineered upstream from the pla2 gene. upon heat-induction of the cells transformed with the expression plasmid, the protein is pro ... | 1992 | 1730025 |
| extracellular phospholipase a2 and histamine release from rat peritoneal mast cells. | phospholipase a2 (pla2) from cobra (naja naja) venom and pla2 from porcine pancreas accelerated ige antibody-mediated histamine release from rat peritoneal mast cells. these enhancements were clearly abrogated by heating the enzymes and pretreatment with parabromophenacyl bromide, mepacrine and antiflammin. indomethacin (cyclooxygenase inhibitor) and aa-861 (lipoxygenase inhibitor) did not affect the enhancement by pla2. these results indicate that extracellular pla2 enhances the ige antibody-me ... | 1991 | 1725674 |
| 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 |
| intracellular mechanisms involved in short-term regulation of net protein synthesis in pancreatic acini. | the mechanisms regulating the net synthesis of digestive enzymes during short-term stimulation by agonists were examined in pancreatic acini isolated from the rat. dispersed pancreatic acini were stimulated for up to 60 min with various concentrations of cholecystokinin octapeptide (cck-op), carbachol, a23187, 4 beta-phorbol 12-myristate 13-acetate (pma). the effects of these agonists on net protein synthesis was determined by measuring the incorporation of [3h]leucine or [35s]methionine into pr ... | 1991 | 1708286 |
| 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 |
| primary structure and functional properties of cobra (naja naja naja) venom kunitz-type trypsin inhibitor. | a trypsin inhibitor from the venom of the cobra naja naja naja has been isolated by a single step of reverse-phase high-performance liquid chromatography. the protein strongly inhibits trypsin (ki = 3.5 pm). the primary structure was determined by peptide analysis of the [14c]carboxymethylated inhibitor. the 57-residue polypeptide chain belongs to the family of kunitz-type inhibitors, and exhibits 42% residue identity with bovine pancreatic trypsin inhibitor. the structure shows only 70% identit ... | 1990 | 1702708 |
| antiallergic and anti-inflammatory action of tioxamast in rats. i. antiallergic activity in vivo and in vitro. | tioxamast (f 1865) is an antiallergic drug that, administered systemically, reduces anaphylaxis in various models in rats. this action is due mainly to the inhibition of the synthesis and release of certain mediators. orally or intraduodenally administered tioxamast inhibits ige-dependent passive cutaneous anaphylaxis (ed50 = 0.8 mg/kg), ige-dependent passive pulmonary anaphylaxis (ed50 = 0.5 mg/kg), and igg-dependent passive cutaneous anaphylaxis (ed50 = 0.6 mg/kg). it has little or not effect ... | 1990 | 1700967 |
| 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 |
| effects of a cardiotoxin from naja naja kaouthia venom on skeletal muscle: involvement of calcium-induced calcium release, sodium ion currents and phospholipases a2 and c. | snake venom cardiotoxin (ctx) fractions induce contractures of skeletal muscle and hemolysis of red blood cells. the fractions also contain trace amounts of venom-derived phospholipase a2 (pla2) contamination and activate tissue phospholipase c (plc) activity. the present study examines the mechanisms of action of a ctx fraction from naja naja kaouthia venom in skeletal muscle. sphingosine competitively antagonized ctx-induced red blood cell hemolysis, but not skeletal muscle contractures. ctx r ... | 1991 | 1666202 |
| comparative enzymatic composition of brazilian coral snake (micrurus) venoms. | 1. venoms of 11 coral snake taxa, including micrurus albicinctus, m. corallinus, m. frontalis altirostris, m. f. brasiliensis, m. f. frontalis, m. fulvius fulvius, m. ibiboboca, m. lemniscatus ssp., m. randonianus, m. spixii spixii, and m. surinamensis surinamensis, were examined for 13 enzymatic activities. 2. these were compared with venoms of three outgroup taxa: naja naja kaouthia, bungarus multicinctus, and bothrops moojeni. 3. enzyme activity levels in micrurus venoms were highly variable ... | 1991 | 1662592 |
| comparison of group i and ii soluble phospholipases a2 activities on phagocytic functions of human polymorphonuclear and mononuclear phagocytes. | soluble phospholipase a2 (pla2) purified from rheumatoid synovial fluid (group ii) and repurified naja naja venom pla2 (group i) were compared for their influence on phagocytic activity of human polymorphonuclear (pmn) and mononuclear (mo) phagocytes. group ii pla2 reduced chemotaxis, adhesiveness, and intracellular bactericidal activity (icba) and induced release of muramidase from pmns. group i pla2 suppressed chemotaxis, and enhanced icba but had no influence on other phagocytic functions. gr ... | 1991 | 1649131 |
| 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 |
| reversibility of the activation of soluble phospholipase a2 on lipid bilayers: implications for the activation mechanism. | the time-courses of hydrolysis of large vesicles of dipalmitoylphosphatidylcholine were compared using four species of phospholipase a2 (agkistrodon piscivorus piscivorus, crotalus adamanteus and naja naja venoms and porcine pancreatic). in all four cases, the hydrolysis rate suddenly increases 10 to 100-fold at the time (tau) when a specific mole fraction of reaction products has accumulated. the intrinsic fluorescence emission of the three venom enzymes also increases suddenly at time tau. bot ... | 1992 | 1643108 |
| purification and properties of the l-amino acid oxidase from monocellate cobra (naja naja kaouthia) venom. | 1. the l-amino acid oxidase of the monocellate cobra (naja naja kaouthia) venom was purified to electrophoretic homogeneity. the molecular weight of the enzyme was 112,200 as determined by sephadex g-200 gel filtration chromatography, and 57,400 as determined by sds-polyacrylamide gel electrophoresis. 2. the enzyme had an isoelectric point of 8.12 and a ph optimum of 8.5. it showed remarkable thermal stability, and, unlike many venom l-amino acid oxidase, was also stable in alkaline medium. the ... | 1992 | 1612186 |
| 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 |
| [pharmacological study on naja naja kaouthia lesson. iii. effects of 50% ethanolic extracts from liver and gall bladder on phagocytic activity of mouse reticuloendothelial system]. | effects of 50% ethanolic extracts from the liver and the gall bladder of naja naja kaouthia lesson (cob-l or cob-g) were studied on the phagocytic activity of a mouse reticuloendothelial system. the clearance-rate of carbon was shortened by the oral administration of cob-l or cob-g (50 or 200 mg/kg). cob-l or cob-g promoted the phagocytosis of latex by peritoneal macrophages (m phi). furthermore, effects of these extracts on the peritoneal m phi were biochemically investigated using in vitro exp ... | 1992 | 1608042 |
| [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 |
| direct effects and augmentation of airway smooth muscle contraction caused by phospholipase a2. | we examined the effect of phospholipase a2 (pla2; naja naja) on isometric tracheal smooth muscle force generation in guinea pig trachealis in situ. direct application of pla2 to the surface of the trachea caused dose-related contraction of tracheal smooth muscle. in seven guinea pigs, a dose/density of 100 micrograms/cm2 pla2 caused active tension (at) that began immediately and was maximum (1.32 +/- 0.13 g/cm) at 5 min (p less than 0.01 versus baseline tension). pla2 also augmented the contract ... | 1992 | 1596019 |
| use of hplc to demonstrate variation of venom toxin composition in the thailand cobra venoms naja naja kaouthia and naja naja siamensis. | the composition of the venoms of naja naja kaouthia and naja naja siamensis from different commercial sources has been investigated using both ion-exchange and reverse-phase high-pressure liquid chromatography (rp-hplc) in order to investigate variation in toxin contents. the venoms contained identical major toxin components, although in different relative concentrations. the venom collected separately from the left and right glands of individual snakes were virtually the same as judged by rp-hp ... | 1992 | 1595079 |
| differential hydrolysis of 1-alkyl-2-acyl and diacylglycerophosphocholines by human and non-human phospholipases a2. | the activity of two human phospholipases a2, purified from synovial fluid and lumbar disc herniations, was tested using alkylacyl- and diacylglycerophosphocholines and the influence of the chemical link at the sn-1 position of glycerol was investigated. both enzymes exhibited 2.5-3-fold selectivity for 1-ester-linked compared to 1-ether-linked phosphatidylcholine. no significant selectivity was observed with pancreatic phospholipase a2 while naja naja naja venom enzyme was more efficient against ... | 1992 | 1576169 |
| 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 |
| preparation, characterization and immunogenicity of various polymers and conjugates of elapid postsynaptic neurotoxins. | seven polymeric forms and conjugates of purified principal postsynaptic neurotoxins of naja naja siamensis (nns), ophiophagus hannah (oh) and bangarus fasciatus (bf) have been synthesized by controlled polymerization in which only 29-60% of the toxins were allowed to react. a carbodiimide (ecdi) and glutaraldehyde (ga) were used as coupling agents while bsa and tetanus toxoid (tt) were used as carriers. the antigenic mosaic of these immunogens was: nns-ecdi, nns-bf-oh-ecdi, nns-bsa-ecdi, nns-tt- ... | 1992 | 1565098 |
| implications of a consensus recognition site for phosphatidylcholine separate from the active site in cobra venom phospholipases a2. | a model structure of naja naja kaouthia cobra venom phospholipase a2 has been constructed by utilizing molecular modeling techniques. analysis of the model and available biochemical data reveal the presence in this enzyme of a putative recognition site for choline derivatives in loop 57-70 made up of residues trp-61, tyr-63, phe-64, and lys-65, together with glu-55. the magnitude and shape of the electrostatic potential in this binding site are approximately 80% similar to that in the mcpc603 an ... | 1992 | 1550815 |
| cinatrins, a novel family of phospholipase a2 inhibitors. ii. biological activities. | cinatrins a, b and c3 inhibited phospholipase a2 purified from rat platelets in a dose-dependent manner. cinatrin c3, the most potent component (ic50 70 microm), was noncompetitive with a ki value of 36 microm. cinatrins b and c3 also inhibited both porcine pancreas and naja naja venom phospholipase a2. inhibition of rat platelet phospholipase a2 by cinatrin c3 was independent of ca2+ and substrate concentration. comparison with duramycin, another phospholipase a2 inhibitor, displayed inhibition ... | 1992 | 1548189 |
| investigation of ligand-binding sites of the acetylcholine receptor using photoactivatable derivatives of neurotoxin ii from naja naja oxiana. | several photoaffinity derivatives of neurotoxin ii from the venom of the central asian cobra naja naja oxiana have been prepared. after reaction of the 125i-labeled derivatives with the nicotinic acetylcholine receptor from electric organ, the alpha-subunit of the nachr is almost exclusively labeled by the derivative carrying the photoactivatable group in position lys46. in contrast to this, a reactive group at lys26 predominantly labels the gamma- and delta-subunits, while the alpha- and beta-s ... | 2006 | 1525162 |
| a novel type of phospholipase a2 inhibitor, thielocin a1 beta, and mechanism of action. | thielocin a1 beta, a novel phospholipase a2 inhibitor, was isolated from thielavia terricola rf-143. it inhibited various phospholipase a2s in a dose-dependent manner. among these, group ii phospholipase a2 from rat was most sensitive to thielocin a1 beta (ic50 = 0.0033 microm). the inhibition of phospholipase a2 by thielocin a1 beta was independent of ca2+ and substrate concentration. in addition, the inhibition of rat group ii phospholipase a2 was noncompetitive (ki = 0.0068 microm) and revers ... | 1992 | 1517154 |
| 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 |
| binding properties of pyrularia thionin and naja naja kaouthia cardiotoxin to human and animal erythrocytes and to murine p388 cells. | pyrularia thionin and snake venom cardiotoxin are strongly basic peptides which induce hemolysis, depolarization of muscle cells and activation of endogenous phospholipase a2. an earlier study of the hemolysis reaction indicated that the two peptides bind to and compete for the same site on human erythrocytes. a recent study examined the hemolysis induced by both peptides as the phosphate and ca2+ content of the reaction mixture was varied. the results of the recent study (vernon, l. p. and roge ... | 1992 | 1509490 |
| effect of calcium and phosphate ions on hemolysis induced by pyrularia thionin and naja naja kaouthia cardiotoxin. | pyrularia thionin is a strongly basic bioactive peptide of 47 amino acids isolated from nuts of pyrularia pubera. it is hemolytic, cytotoxic and activates an endogenous phospholipase a2 in 3t3 cells. earlier studies have shown that the cardiotoxin from naja naja kaouthia has similar activities and binds to the same site as pyrularia thionin. since the peptides appear to bind to the phospholipids of cell membranes to elicit their cellular responses, the effect of modifying the electrostatic envir ... | 1992 | 1509489 |
| sphingolipid metabolism and signal transduction: inhibition of in vitro phospholipase activity by sphingosine. | sphingosine inhibits protein kinase c activity in vitro and has been used to implicate this enzyme in signal transduction and cell function. we report that sphingosine directly inhibits phospholipases a2 and d. sphingosine inhibits ca(2+)-dependent phospholipases a2 from naja naja, porcine pancreas, crotalus adamanteus, human disc and neutrophil in a dose-dependent manner with ic50 values ranging from 5-40 microm using [1-14c]oleate-labelled autoclaved e. coli (20 microm) as substrate. inhibitio ... | 1992 | 1504102 |
| activation of bovine factor v by an activator purified from the venom of naja naja oxiana. | the crude venom of many elapid snakes appeared to contain proteins that activated blood coagulation factor v. the factor v activator present in the venom of naja naja oxiana was purified to homogeneity by chromatography on a mono-s column. the activator was a single chain protein with an apparent mol. wt of 48,000, as judged by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate and by gel permeation chromatography on sephacryl s200. activation of bovine factor v by the ... | 1992 | 1440644 |
| 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 |
| 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 |
| lipopolysaccharide-induced stimulation of alveolar macrophage opsonin-independent phagocytosis. | alveolar macrophage (am) opsonin-independent phagocytosis may be an important process by which bacteria are cleared from the airspaces. although it has been shown that clearance of bacteria from the lung is altered in association with endotoxemia, the effect of endotoxemia on opsonin-independent phagocytosis is unknown. because alterations in am opsonin-independent phagocytosis could potentially influence bacterial clearance in the lung, we studied the effects of the intravenous injection of esc ... | 1992 | 1405605 |
| [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 |
| antiflammins. anti-inflammatory activity and effect on human phospholipase a2. | two anti-inflammatory peptides (antiflammins) corresponding to a high amino acid similarity region between lipocortin i and uteroglobin were tested for their ability to inhibit purified human synovial fluid phospholipase a2 (hsf-pla2). no inhibitory activity was observed, even at such high concentrations of peptides as 50 microm. when antiflammins were preincubated with the enzyme and/or the substrate, no hsf-pla2 inhibition was detected. in vivo anti-inflammatory activity of these peptides was ... | 1992 | 1387313 |
| 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 |
| calcium ion independent membrane leakage induced by phospholipase-like myotoxins. | the two snake venom myotoxins ammodytin l and myotoxin ii, purified respectively from vipera ammodytes ammodytes and bothrops asper, have phospholipase-like structures but lack an asp-49 in the active site and are without normal phospholipase activity. the interaction of these proteins with different types of liposomes indicated that the myotoxins were able to provoke rapid and extensive release of the aqueous content of liposomes. leakage was measured by two different methods: fluorescence dequ ... | 1992 | 1334427 |
| alpha-cobratoxin: proton nmr assignments and solution structure. | the solution structure of alpha-cobratoxin, a neurotoxin purified from the venom of the snake naja naja siamensis, at ph 3.2 is reported. sequence-specific assignments of the nmr resonances was attained by a combination of a generalized main-chain-directed strategy and of the sequential method. the nmr data show the presence of a triple-stranded beta-sheet (residues 19-25, 36-41, and 52-57), a short helix, and turns. an extensive number of noe cross peaks were identified in the noesy nmr maps. t ... | 1992 | 1317211 |
| [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 |
| mapping the functional topography of a receptor. | photoactivatable derivatives of the alpha-neurotoxin ii from naja naja oxiana are useful tools for investigating the three dimensional architecture of the extra-membrane part of the nicotinic acetylcholine receptor from the electric tissue of torpedo californica. three derivatives, carrying an azidobenzoyl group in position lys-15, lys-26, and lys-46, respectively, are shown to react differently within the receptor's quaternary structure. especially the lys-26 and lys-46 derivatives can be used ... | 2007 | 1299215 |
| toxicities, ld50 prediction and in vivo neutralisation of some elapid and viperid venoms. | toxicity levels of elapid (naja naja and naja oxiana) viperid (vipera lebetina and vipera russelli) venoms for mice and rat for intraperitoneal intravenous and intramuscular routes have been determined. the data have been analysed using a mathematical expression to calculate lethal venom concentrations in human snake bite cases. further, in vivo neutralisation of snake venom potency (after experimental injection) using high voltage-low current electric shock treatment has been attempted. this tr ... | 1992 | 1294479 |
| comparative characterization of two toxic phospholipases a2 from indian cobra (naja naja naja) venom. | indian cobra venom contains many phospholipase a2 (pla2) toxins. in the present study two toxic pla2s have been purified from the indian cobra (naja naja naja) venom by column chromatography. the nn-xia-and nn-xib-pla2s have mol. wts between 10,700 and 15,000. the nn-xia-pla2 induces myotoxic effects, oedema and neurotoxicity in mice and has an i.p. ld50 of 8.5 mg/kg body weight. the nn-xia-pla2 is also cytotoxic to ehrlich ascites tumour cells. the other pla2, nn-xib, in contrast has an i.p. ld ... | 1992 | 1279838 |
| possible relationship between membrane proteins and phospholipid asymmetry in the human erythrocyte membrane. | after incubation of human erythrocytes at 37 degrees c in the absence of glucose (a) for 24 h, (b) for 4 h with 8 mm hexanol or (c) for 3 h with sh reagents, phosphatidylethanolamine becomes partly susceptible to hydrolysis by phospholipase a2 from naja naja. the presence of glucose during the pretreatments suppresses this effect, except in the case of sh reagents that inhibit glycolysis. after incubation with tetrathionate, up to 45% of the phosphatidylethanolamine is degraded by the enzyme, an ... | 1976 | 1276220 |
| hydrolysis of phosphatidylcholine liposomes by phospholipases a2. effects of the local anesthetic dibucaine. | (1) dibucaine evokes a downward shift in the phase transition temperature of saturated phosphatidylcholines, while it also affects the pretransition. (2) the binding of dibucaine to phosphatidylcholine liposomes increases sharply when the lipid is transformed from the gel phase to the liquid-crystalline phase. (3) the activity of naja naja phospholipase a2 towards dimyristoyl phosphatidylcholine liposomes is either stimulated or inhibited by dibucaine, depending on whether the substrate is in th ... | 1976 | 1260059 |
| purification, characterization, and partial amino acid sequence of nerve growth factor from cobra venom. | the nerve growth factor (ngf) from naja naja (cobra) venom has been purified and its structure compared to the ngf from mouse submaxillary gland. a two-step purification procedure has been devised, consisting of a gel filtration step in 1 m acetic acid followed by chromatography of the active pool on carboxymethylcellulose at ph 5. the molecular weight of the native protein was found to be 28000, and this value was reduced by approximately one-half under denaturing conditions. these values are c ... | 1976 | 1247508 |
| topological asymmetry of phospholipid metabolism in rat erythrocyte membranes. evidence for flip-flop of lecithin. | 1. the distribution of phospholipids between inside and outside of rat erythrocyte membranes was studied by incubating the cells with phospholipase a2 from naja naja venom and sphingomyelinase from staphylococcus aureus. 2. choline-containing phospholipids were found to comprise the majority of the outer layer of the membrane. 3. the incorporation of radioactive fatty acids into phospholipids occurred predominantly at the inside of the membrane. 4. exchange of phospholipids between red cell memb ... | 1976 | 1245188 |
| sensitivity of cultured embryonic heart cells to cardiotoxin obtained from naja naja siamensis venom. | 1975 | 1239834 | |
| the reaction of choline dehydrogenase with some electron acceptors. | 1. the choline dehydrogenase (ec 1.1.99.1) was solubilized from acetone-dried powders of rat liver mitochondria by treatment with naja naja venom. 2. the kinetics of the reaction of enzyme with phenazine methosulphate and ubiquinone-2 as electron acceptors were investigated. 3. with both electron acceptors the reaction mechanism appears to involve a free, modified-enzyme intermediate. 4. with some electron acceptors the maximum velocity of the reaction is independent of the nature of the accepto ... | 1975 | 1218095 |
| kinetic analysis of phospholipase a2 activity toward mixed micelles and its implications for the study of lipolytic enzymes. | a detailed kinetic scheme is proposed for the action of phospholipase a2 on mixed micelles of phospholipid and surfactant: see article. where e is the enzyme, a is the mixed micelle, and b is the phospholipid substrate in the mixed micelle. this scheme takes into account quantitatively the involvement of the lipid-water interface in the action of this enzyme toward substrate in macromolecular lipid complexes. the kinetic equation for this scheme is derived and four simplifying assumptions which ... | 1975 | 1194274 |
| characterization and physical properties of the major form of phospholipase a2 from cobra venom (naja naja naja) that has a molecular weight of 11,000. | the major form of phospholipase a2 from cobra venom (naja naja naja) was prepared in 30% yield and was homogeneous on polyacrylamide gel electrophoresis with and without sodium dodecyl sulfate and on sephadex g-100 chromatography. the monomer molecular weight is about 11,000 according to sodium dodecyl sulfate-polyacrylamide gel electrophoresis. ultracentrifugation and molecular sieve techniques were employed to confirm the molecular weight and to demonstrate a concentration-dependent aggregatio ... | 1975 | 1194273 |
| further studies on the binding properties of cobra neurotoxin to cholinergic receptors in mouse skeletal muscle. | preparations of 3h-monoacetylated derivatives of naja naja siamensis neurotoxin siamensis 3 were found to be resistant to degradation and deacetylation during in vitro muscle incubation. a low rate of free 3h-acetate (less than 0.4%) was present in the preparations, but should not interfere with the binding of toxin to cholinergic receptors in mouse extensor digitorum longus muscles in vitro. the binding of toxin to cholinergic receptors in mouse extensor digitorum longus muscle was essentially ... | 1975 | 1185161 |
| amino-acid sequence of toxin iii of naja haje. | the complete amino acid sequence of toxin iii of naja haje (72 residues) has been established mainly by use of a protein sequenator (identification of 70 residues). the two c-terminal residues have been determined by digestion with carboxypeptidases a and b. addition of succinylated protein or peptide greatly improved the performance of the sequenator for the edman degradation of peptides: on one peptide (39 residues) degradation went to step 34 with a protein program and on two peptides (10 and ... | 1975 | 1183429 |
| relation between various phospholipase actions on human red cell membranes and the interfacial phospholipid pressure in monolayers. | the action of purified phospholipases on monomolecular films of various interfacial pressures is compared with the action on erythrocyte membranes. the phospholipases which cannot hyorolyse phospholipids of the intact erythrocyte membrane, phospholipase c from bacillus cereus, phospholipase a2 from pig pancreas and crotalus adamanteus and phospholipase d from cabbage, can hydrolyse phospholipid monolayers at pressure below 31 dynes/cm only. the phospholipases which can hydrolyse phospholipids of ... | 1975 | 1174576 |
| the cytotoxins of cobra venoms. isolation and partial characterization. | eight basic proteins which lyse virus-transformed mouse fibroblasts in culture have been isolated from the venoms of six asian naja naja subspecies. these cytotoxins appear to represent an homologous series of proteins, all within the molecular weight range of 7000-8000. they have been divided into three arbitrary types on the basis of amino acid composition, electrophoretic mobilities and elution order upon ion-exchange chromatography. the rate at which the toxins effect cell lysis: (1) appears ... | 1975 | 1170892 |
| evidence for endocytotic uptake of cobra neurotoxin in mouse skeletal muscle. | an isolated 3h-labelled neurotoxin from naja naja siamensis binds irreversibly to the extensor digitorum longus muscle of the mouse in vitro. the binding consists of an adsorption to cholinergic receptors and of a slower temperature sensitive binding mechanism. the slow binding is markedly stimulated by the presence of cationic proteins (protamine, histone and polylysine) and is blocked at low temperature (+4 degrees c). vinblastine and colchicine inhibit the stimulatory effect of protamine on t ... | 1975 | 1159415 |
| effect of atropine in reducing plasma protein shedding by the canine oxyntic glandular mucosa induced by topical irrigation with histamine or cobra venom. | the shedding of plasma protein by the canine oxyntic glandular mucosa induced by topical irrigation of the mucosa with a solution of histamine after the gastric mucosal barrier is broken is reduced by intravenous administration of atropine. plasma shedding induced by repeated irrigation of the normal mucosa with solutions of naja naja venom is likwise reduced by intravenous atropine. the nature of atropine-sensitive component of plasma shedding is unknown. | 1975 | 1150023 |
| the complete amino acid sequence of a cardiotoxin from the venom of naja naja (cambodian cobra). | the complete amino acid sequence of a small, basic protein with cardiotoxic activity is described. this toxin, designated naja naja f8, was isolated from the venom of naja naja, of cambodian origin, by gel filtration on sephadex g-75 followed by gradient ion exchange chromatography on bio-rex 70. the cardiotoxin f8, molecular weight 6727 from amino acid composition, consists of 60 amino acids in a single peptide chain cross-linked by four disulfide bridges and is devoid of histidine, tryptophan, ... | 1987 | 1148180 |
| amino acid sequence of cardiotoxin-analogue i from the venom of naja naja atra. | 1975 | 1147930 | |
| 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 |
| [the blocking action of snake venom polypeptides on the cholinergic mechanisms of leech dorsal muscle]. | the blocking action of alpha-polypeptides from the venoms of elapid snakes (bungarus multicinctus and naja naja siamensis) was studied on leech dorsal muscle. it was shown that these neurotoxins failed to inhibit the responses to mononitrogen cholinomimetics (acetylcholine, nicotine, carbamylcholine, etc.). the capacity of neurotoxins to inhibit the responses to the bisquaternary cholinommimetics depended upon the length of the molecule. the neurotoxins were active against the "shorter" cholinom ... | 1975 | 1111642 |
| comparative studies on cytotoxin from the indian cobra venom and cardiotoxin from the formosan cobra venom, with special reference to the effect on the growth of ehrlich ascites tumor cells in mice. | 1976 | 1068210 | |
| photoaffinity labeling and quaternary structure of the acetylcholine receptor from torpedo californica. | membrane fragments from electric tissue of torpedo californica containing nicotinic acetylcholine receptor are composed of four different polypeptide chains with molecular weights of 40,000 (alpha), 48,000 (beta), 62,000 (gamma), and 66,000 (delta). the alpha and beta chains are still present in all and gamma and delta in some of the receptor preparations after triton x-100 extraction and purification by affinity chromatography. all components of the receptor react covalently with the photoaffin ... | 1976 | 1066671 |
| prevention and suppression by azathioprine of venom-induced protein-losing gastropathy in dogs. | irrigation of the dog's oxyntic glandular mucosa contained in a chronically prepared, vagally denervated, separated pouch of the dog's stomach with a solution (0.5 mg ml-1) of lyophilized venom of the hooded cobra (naja naja) increases the permeability of the mucosa. if irrigation with venom solution is repeated at weekly intervals, the mucosa responds with increasing plasma-shedding which reaches a peak of 1-2 ml min-1 from roughly 60 cm2 of mucosa in 4-6 weeks. plasma shedding in response to i ... | 1976 | 1062810 |
| [acetylcholinesterase of cobra venom. determination of concentration of active sites]. | o-nitrophenyl dimethylcarbamate and organophosphorus inhibitors o-n-propyl-p-nitrophenyl methylphosphonate, o-n-butyl-p-nitrophenyl methylphosphonate, o,o-diethyl-p-nitrophenyl phosphate, o-n-butyl-s-(beta-ethylmercaptoethyl) methylthiophosphonate, methysulphate of o,o-diethyl-s-(beta-phenyldimethylammoniumethly) thiophosphate were used in the titration of acetylcholinesterase active site concentratration in naja naja oxiana venom. no side reactions with the acetylcholinesterase molecule as well ... | 1976 | 1030638 |
| [effect of central asian cobra (naja naja oxiana) venom on the biosynthesis of nucleic acids and protein in animal cells]. | cobra poison at a dose of 4 microng/kg of body weight intensified the 3h-thimidine incorporation into dna of mice liver tissue; 20-40 microng/kg of the poison inhibited the incorporation. single intraperitoneal administration of high doses of cobra poison (50-150 microng/kg) decreased the incorporation of 14c-thimidine into dna 1.2-1.9-fold. little doses of the poison increased the incorporation of 14c-hydrolysate of chlorella protein into proteins of liver cells and the high doses inhibited thi ... | 2013 | 1027229 |
| 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 |
| amino acid sequence of cardiotoxin-analogue ii from the venom of naja naja atra. | 1976 | 999683 | |
| the primary structure of toxin b from the venom of the indian cobra naja naja. | 1976 | 992083 | |
| the amino acid sequence of cardiotoxin-analogue iv from the venom of naja naja atra. | 1976 | 992063 | |
| morphological observations on motor end-plates in rabbits with experimental myasthenia. | the morphology of motor end-plates in rabbits immunized with torpedo nicotinic acetylcholine receptor (nachr) has been studied by light and electron microscopy. rabbits were studied either after one period of paralysis, some in parallel with electrophysiological recordings of mepps and epps and of naja naja alpha-neurotoxin binding properties or after recovery followed by a second paralysis. changes in the sub-neural apparatus were noted after cholinesterase staining only in the latter group. ul ... | 1976 | 978217 |
| nicotinic acetylcholine receptor from rat brain. solubilization, partial purification, and characterization. | nicotinic acetylcholine receptor protein (nachr) has been solubilized from rat cerebral cortices by extracting a crude membrane fraction with the nonionic detergent triton x-100 (polyoxyethylene-p-t-octylphenol). the solubilized nachr was partially purified by affinity chromatography (naja naja siamensis alpha-toxin affinity arm, linked to sepharose 4b) and characterized by binding of 125i-labeled alpha-bungarotoxin. the reaction of labeled toxin and nachr appears to be second order with a rate ... | 1976 | 977572 |
| amino acid sequence of cardiotoxin from the venom of naja naja atra. | 1976 | 955081 | |
| effects of local anaesthetics on phospholipases. | 1. the effects of six local anaesthetics have been studied on the activities of soluble phospholipases a2 (ec 3.1.1.4) and lysophospholipase (ec 3.1.1.5). 2. phospholipase a2 activity in human seminal plasma towards sonicated radioactively-labelled phosphatidylethanolamine was slightly stimulated a low and inhibited at high concentrations of all anaesthetic compounds employed. the order of decreasing potency was chlorpromazine, dibucaine, tetracaine, lidocaine, cocaine and procaine. in line with ... | 1976 | 952985 |
| neuromuscular blocking actions of neurotoxins isolated from laticauda semifasciata, naja naja and naja naja atra--a comparative assay--. | 1977 | 916390 | |
| effects of aliphatic dicarboxylic acids on neuromuscular inhibition produced by naja naja siamensis toxin 3 and d-tubocurarine. | 1977 | 906030 | |
| discrimination between nicotinic receptors in vertebrate ganglia and skeletal muscle by alpha-bungarotoxin and cobra venoms. | 1. we have used snake neurotoxins, alpha-bungarotoxin and venoms from naja naja siamensis and naja nivea, to distinguish the nicotinic receptors of ganglia from those of skeletal neuromuscular junctions. 2. these neurotoxins failed to block responses of isolated guinea-pig longitudinal muscle with adherent myenteric plexus to the nicotinic agonists, nicotine or dimethylphenylpiperazinium, to acetylcholine (ach), or to electrical field stimulation. 3. the toxins failed to affect responses of the ... | 1977 | 894538 |
| nicotinic cholinergic receptors in rat brain identified by [125i]naja naja siamensis alpha-toxin binding. | 1977 | 890462 | |
| [effect of diacid analogs of phosphatidylcholines on phospholipase a2 activity from naja naja venom]. | 1977 | 889937 | |
| interrelation between two anticomplement cobra venom factors isolated from crude naja naja cobra venom. | two moieties occurring in crude naja naja cobra venom were found to possess anticomplement activity. both materials possessed similar molecular weights and specific activities but dissimilar elution profiles upon ion-exchange chromatography. the anticomplement activities of these materials were maintained upon digestion with neuraminidase, and their elution profiles from cation-exchange chromatography became identical after this treatment. it was concluded that the differences between the two an ... | 1977 | 886456 |
| studies of nicotinic acetylcholine receptor protein from rat brain. ii. partial purification. | the pharmacological specificity of the binding of 125i-labeled alpha-bungarotoxin to a 1% emulphogene bc-720 extract of a rat brain particulate fraction has been investigated. the extract contains a component which possesses the binding characteristics of a nicotinic acetylcholine receptor protein. the crude soluble acetylcholine receptor protein was purified by affinity chromatography utilizing the alpha-neurotoxin of naja naja siamensis as ligand and 1.0 m carbamylcholine chloride as eluant. a ... | 1977 | 884157 |