Publications

the mechanism of 2,2,2-trichloroacetic acid-induced protein precipitation.	the mechanism of 2,2,2-trichloroacetic acid (tca)-induced precipitation of proteins is studied. the tca-induced protein precipitation curves are observed to be u-shaped. it is bound that the protein-precipitate-inducing effects of tca are due to the three chloro groups in the molecule. using cardiotoxin iii (ctx iii) isolated from the taiwan cobra (naja naja atra), as a model protein, we attempt to understand the molecular basis for the tca-induced effects. employing circular dichroism, proton-d ...	1997	9188068
cdna sequence analysis of cardiotoxin variants from taiwan cobra.	five cdnas encoding cardiotoxin variants were constructed from the cellular rna isolated from the venom glands of naja naja atra by reverse transcription-polymerase chain reaction. a high degree of nucleotide sequence homology was observed between these variants and other determined ones. among them, a novel cardiotoxin 6 had 61 amino acid residues rather than 60 ones that usually observed with naja naja atra cardiotoxins. the other cardiotoxin variants were the homologues of cardiotoxins 1, v o ...	1997	9192088
variabilin: a dual inhibitor of human secretory and cytosolic phospholipase a2 with anti-inflammatory activity.	the marine product variabilin was identified as a novel inhibitor of phospholipase a2 (pla2), which exhibited ic50 values of 6.9 microm and 7.9 microm for human synovial secretory pla2 and u937 cells cytosolic pla2 activities, respectively. this compound was less potent on bee venom or zymosan-injected rat air pouch enzymes and failed to affect naja naja venom pla2. the production of leukotriene b4 by human neutrophils stimulated with calcium ionophore a23187 was also inhibited by variabilin, wh ...	1997	9223548
novel snornas from naja naja atra (taiwan cobra) and bungarus multicinctus (taiwan banded krait), form extended sequence complementarity to 5s rrna.	during the mapping and sequencing of naja naja atra cobrotoxin and cardiotoxin 4 genes, we have found that novel small nucleolar rnas (snornas) are encoded in the first intron of the two genes. the snornas in naja naja atra were amplified from the venom glands cdna mixtures of naja naja atra by reverse transcription-polymerase chain reaction using the primers designed from the first intronic sequences of cobrotoxin and cardiotoxin 4 genes. likewise, the snornas in bungarus multicinctus were also ...	1997	9245733
flavonoids as phospholipase a2 inhibitors: importance of their structure for selective inhibition of group ii phospholipase a2.	the inhibitory effect of the plant flavonoid, rutin, on group i phospholipase a2 (pla2-i) from porcine pancreas and naja naja, and on group ii phospholipase a2 (pla2-ii) from vipera russelli and crotalus atrox was investigated. rutin efficiently inhibited pla2-ii from both vipera russelli and crotalus atrox but was only a weak inhibitor of pla2-i from porcine pancreas and naja naja. the lack of strong inhibition of pancreatic pla2-i was not due to contaminating proteins in the enzyme preparation ...	1997	9246576
the action of taiwan cobra venom on methionine enkephalin: a useful assay for oligopeptidase content.	the pentapeptide methionine enkephalin is readily hydrolysed by the oligopeptidase activity contained in taiwan cobra (naja naja atra) venom. it is a significantly better substrate than the peptides previously used to identify the presence of this enzyme, but it retains many of the sequence characteristics shared by these other peptides. analysis of the manner of hydrolysis by means of high-performance liquid chromatography and electrospray mass spectrometry revealed the simultaneous actions of ...	1997	9248009
naja naja cobra bite.	most venomous snakes in the united states are of the crotalidae family. another family of snakes, the elapidae, are not so common, but their bites may be a threat to zoo keepers and persons who have exotic snakes as pets. because elapidae envenomation is not common, signs and symptoms of such envenomation may not be recognized. elapidae venom, because of a curare-like property, can produce respiratory compromise followed by death within 10 minutes. antivenin, cholinesterase inhibitors, and mecha ...	1997	9288976
a study of epidemiology, risk factors and preventive measures against snake bites.	the epidemiology and exposing causes of snake bites were studied in 274 patients between 1 january 1982 and 30 december 1990. they comprised 142 males (51.82%) and 132 females (48.18%). their ages ranged from 1 month to 86 years old. the age group most frequently bitten found in this study was between 15 to 29 years old amounting to 106 cases (38.69%). of those 274 cases, 212 (77.37%) were the victims of poisonous snakes, namely, the green pit viper (trimeresurus spp.) 156 cases (73.58%), the co ...	1997	9347666
specificity of helix-induction by 2,2,2-trifluoroethanol in polypeptides.	the specificity of helix-induction in polypeptides by 2,2,2-trifluoro ethanol (tfe) is studied using an all beta-sheet protein such as cardiotoxin analogue i (ctx i) from the taiwan cobra (naja naja atra) and a homopolymer such as poly-l-lysine. it is found that alcohols including tfe can 'non-specifically' induce helix at high concentrations both in ctx i and polylysine at neutral ph. however, among the alcohols used, only tfe could transform the heat-induced beta-sheet conformation of polylysi ...	1997	9352368
genomic structures of cardiotoxin 4 and cobrotoxin from naja naja atra (taiwan cobra).	two genomic dnas with the size of 2.3 kb and 2.4 kb, which were isolated from the liver of naja naja atra (taiwan cobra), encoded the precursors of cardiotoxin 4 and cobrotoxin, respectively. both genes shared virtually identical overall organization with three exons separated by two introns, which were inserted in the similar positions of the gene's coding regions. moreover, their nucleotide sequences shared approximately 84.2% identity. this result reveals the evolutionary relationship between ...	1997	9367842
zanhasaponins a and b, antiphospholipase a2 saponins from an antiinflammatory extract of zanha africana root bark.	a meoh extract from z. africana was examined for topical antiinflammatory activity and proved to be active against arachidonic acid (aa) acute edema, 12-o-tetradecanoylphorbol 13-acetate (tpa)-induced chronic inflammation, and oxazolone delayed-type hypersensitivity in mice. the extract also showed significant inhibitory activity of naja naja phospholipase a2 when a polarographic method was used. two oleanane-type triterpene saponins, zanhasaponins a (1) and b (2), and the cyclitol pinitol (4), ...	1997	9392883
the hydrolysis of phosphatidyl-alcohols by phospholipases a2: effect of head group size and polarity.	the ability of a variety of secretory phospholipases a2 (spla2: ec 3.1.1.4) to bind to and hydrolyse a series of phosphatidyl-alcohol substrates, in the absence of detergent, was explored by both fluorescence-based kinetic and interfacial binding assays. the enzymes used were spla2 from porcine pancreas, naja naja venom and a recombinant human non-pancreatic enzyme. four dioleoyl phosphatidyl-alcohols were used with different headgroups, methanol, ethanol, propanol and butanol. comparative kinet ...	1997	9393676
comparison of the hemolytic activity and solution structures of two snake venom cardiotoxin analogues which only differ in their n-terminal amino acid.	cardiotoxin analogues iv (ctx iv) and ii (ctx ii) isolated from the venom of taiwan cobra (naja naja atra) differ in their amino acid sequence by a single amino acid at the n-terminal end. leucine at the n-terminal end in ctx ii is replaced by arginine in ctx iv. ctx iv is an unique snake venom cardiotoxin as it is the only cardiotoxin isoform known so far which possesses a positively charged residue at the n-terminal amino acid. all other cardiotoxins have a hydrophobic amino acid (leucine or i ...	1997	9398182
presynaptic snake beta-neurotoxins produce tetanic fade and endplate potential run-down during neuromuscular blockade in mouse diaphragm.	the present study investigated the ability of a number of presynaptic snake neurotoxins (snake beta-neurotoxins) to produce nerve-evoked train-of-four fade, tetanic fade and endplate potential run-down during the development of neuromuscular blockade in the isolated mouse phrenic-hemidiaphragm nerve-muscle preparation. all the snake beta-neurotoxins tested, with the exception of notexin, produced train-of-four and tetanic fade of nerve-evoked isometric muscle contractions. train-of-four fade was ...	1997	9402043
cardiotoxin-like basic protein (clbp) from naja naja atra is not a cardiotoxin.		1997	9403962
main-chain dynamics of cardiotoxin ii from taiwan cobra (naja naja atra) as studied by carbon-13 nmr at natural abundance: delineation of the role of functionally important residues.	cardiotoxin analogue ii (ctx ii) is an all beta-sheet, small molecular mass (6.8 kda), basic protein possessing a wide array of biological properties. nearly complete assignment of the protonated carbon resonances has been achieved by heteronuclear nmr experiments. the study shows that the correlation between the carbon-13 chemical shifts and ctx ii structure is good in general, but interesting deviations are also noticed. to characterize the internal dynamics of ctx ii, longitudinal, transverse ...	1998	9425035
molecular mechanics calculations of proteins. comparison of different energy minimization strategies.	a general strategy for performing energy minimization of proteins using the sybyl molecular modelling program has been developed. the influence of several variables including energy minimization procedure, solvation, dielectric function and dielectric constant have been investigated in order to develop a general method, which is capable of producing high quality protein structures. avian pancreatic polypeptide (app) and bovine pancreatic phospholipase a2 (bp pla2) were selected for the calculati ...	1997	9439995
cardiolipin hydrolysis by human phospholipases a2. the multiple enzymatic activities of human cytosolic phospholipase a2.	the ability of mammalian phospholipases a2 (pla2) to hydrolyse cardiolipin (diphosphatidylglycerol) was monitored with a fluorescent displacement assay which allows the use of natural phospholipid substrates. the mammalian enzymes used were porcine pancreatic (group i) secretory pla2 (spla2), human non-pancreatic (group ii) spla2 and human cytosolic pla2 (cpla2). high activity was observed with porcine pancreas spla2 whereas the human spla2 demonstrated only minimal activity with this substrate. ...	1998	9487141
identification of diphtheria toxin via screening as a potent cell cycle and p53-independent cytotoxin for human prostate cancer therapeutics.	metastatic human prostate cancer requires novel therapeutic strategies in order to overcome its low proliferative rate and its resistance to conventional chemotherapeutic agents. to identify potential cytotoxin gene products for use in experimental therapeutics such as in vivo gene therapy, an in vitro screen was designed.	1998	9496900
a novel neurotoxin, cobrotoxin b, from naja naja atra (taiwan cobra) venom: purification, characterization, and gene organization.	a novel neurotoxin, cobrotoxin b, was isolated from naja naja atra (taiwan cobra) venom by successive chromatographies on gel filtration and sp-sephadex c-25 columns. the yield of this novel toxin was 5% of that of cobrotoxin from the same venom. its neurotoxicity determined as the inhibition of acetylcholine-induced muscle contractions was approximately 50% of that of cobrotoxin. cobrotoxin b consists of 61 amino acid residues including 8 cysteine residues. moreover, there are 12 amino acid sub ...	1997	9498573
the role of acetic acid in the prevention of salt-induced aggregation of snake venom cardiotoxins.	snake venom cardiotoxins (ctxs) exhibit a strong tendency to aggregate upon desalting and hence it is extremely difficult to prepare salt-free cardiotoxin(s). in the present study, we describe a new method for preparation of salt-free ctx based on dialysis against acetic acid. based on experimental observation and the three dimensional solution structure of cardiotoxin analogue iii from the taiwan cobra (naja naja atra), a molecular mechanism for the prevention of aggregation of cardiotoxins by ...	1998	9503145
purification and characterization of a new cystatin inhibitor from taiwan cobra (naja naja atra) venom.	cobra cystatin, a new cysteine-proteinase inhibitor of the cystatin superfamily, was isolated from the venom of the taiwan cobra (naja naja atra) by affinity chromatography on s-carboxymethylpapain-sepharose and reverse-phase chromatography. the venom contained two forms of the inhibitor, one of 11870 da and the other of 12095 da, as determined by ms, and pi values of 6.2 and 6.1. cobra cystatin strongly inhibits cysteine proteinases of the papain family, but not calpain. papain, cathepsin l, ca ...	1998	9512485
two novel alpha-neurotoxins isolated from taiwan cobra: sequence characterization and phylogenetic comparison of homologous neurotoxins.	two novel postsynaptic neurotoxins (alpha-neurotoxins) isolated and purified from the taiwan cobra venom (naja naja atra) possess distinct primary sequences and different neurotoxicities as compared with the most abundant and lethal component in the venom, i.e., cobrotoxin characterized before from the same venom. the complete sequences of two neurotoxin analogues were determined by n-terminal edman degradation and comparison of amino acid compositions of proteolytic toxin fragments with other h ...	1998	9535272
events in the kinetic folding pathway of a small, all beta-sheet protein.	the folding of cardiotoxin analogue iii (ctx iii), a small (60 amino acids), all beta-sheet protein from the venom of the taiwan cobra (naja naja atra) is here investigated. the folding kinetics is monitored by using a variety of techniques such as nmr, fluorescence, and circular dichroism spectroscopy. the folding of the protein is complete within a time scale of 200 ms. the earliest detectable event in the folding pathway of ctx iii is the formation of a hydrophobic cluster, which possess stro ...	1998	9553067
inhibition of secreted phospholipases a2 by annexin v. competition for anionic phospholipid interfaces allows an assessment of the relative interfacial affinities of secreted phospholipases a2.	the ability of annexins, particularly annexin 1 (lipocortin 1), to inhibit phospholipase a2 (pla2) is well known and a substrate depletion mechanism is now widely accepted as the explanation for most inhibitory studies. in this investigation we have examined the substrate depletion mechanism of annexin v using a variety of phospholipid substrates and secreted pla2's (spla2). the results suggest that the term interfacial competition best describes the inhibitory effect of annexin v although the o ...	1998	9555096
six isoforms of cardiotoxin in malayan spitting cobra (naja naja sputatrix) venom: cloning and characterization of cdnas.	cardiotoxins are the most abundant toxin components of cobra venom. although many cardiotoxins have been purified and characterized by amino acid sequencing and other pharmacological and biochemical studies, to date only five cardiotoxin cdnas from taiwan cobra (naja naja atra), three cdnas from chinese cobra (naja atra) and two more of uncertain origin (either chinese or taiwan cobra) have been reported. in this paper we show the existence of four isoforms of cardiotoxin by protein analysis and ...	1998	9565688
labeling of torpedo californica nicotinic acetylcholine receptor subunits by cobratoxin derivatives with photoactivatable groups of different chemical nature at lys23.	different photoactivatable derivatives of toxin 3 (ctx) naja naja siamensis were obtained after ctx reaction with n-hydroxysuccinimide esters of p-azidobenzoic, p-azidotetraflourobenzoic, p-benzoylbenzoic and p-[3-(trifluoromethyl)-3h-diazirin-3-yl]benzoic acids. the ion-exchange hplc profiles for the reaction products were very similar in four cases, with one predominant peak corresponding to the derivative containing the label at lys23. after [125i]iodination, ctx photoactivatable derivatives ...	1998	9578481
unfolding and refolding of cardiotoxin iii elucidated by reversible conversion of the native and scrambled species.	cardiotoxin analogue iii (ctx iii) isolated from the venom of the taiwan cobra (naja naja atra) is a small molecular weight, all beta-sheet protein, cross-linked by four disulfide bridges. the unfolding and refolding mechanisms of ctx iii have been examined by monitoring the reversible conversion of the native and scrambled species. it is found that, in the presence of a denaturant (urea/guanidinium hydrochloride) and a thiol catalyst, ctx iii forms a mixture of scrambled species by shuffling it ...	1998	9578558
petrosaspongiolides m-r: new potent and selective phospholipase a2 inhibitors from the new caledonian marine sponge petrosaspongia nigra.	five new bioactive sesterterpenes (1-5) have been isolated from the new caledonian marine sponge petrosaspongia nigra bergquist and named petrosaspongiolides m-r. their chemical structures were determined from 1d and 2d nmr studies and ms data. all compounds inhibited different preparations of phospholipase a2 (pla2) by irreversibly blocking these enzymes (particularly human synovial and bee venom, see table 3), with ic50 values in the micromolar range. interestingly, these compounds displayed a ...	1998	9599251
polybitoxins: a group of phospholipases a2 from the venom of the neotropical social wasp paulistinha (polybia paulista).	the neotropical wasp polybia paulistinha is very aggressive and endemic in south-east brazil, where it frequently causes stinging accidents. by using gel filtration on sephadex g-200, followed by ion-exchange chromatography on deae-cellulose under a ph gradient, a group of four toxins (designated as polybitoxins-i, ii, iii and iv) presenting phospholipase a2 (pla2) activities was purified. these toxins are dimeric with mol. wts ranging from 115,000 to 132,000 and formed by different subunits. th ...	1998	9604292
suppression of inflammatory responses by surfactin, a selective inhibitor of platelet cytosolic phospholipase a2.	surfactin inhibits platelet and spleen cytosolic 100 kda phospholipase a2 (pla2). in contrast, this same compound enhances rat platelet group ii pla2 activity by approximately 2-fold and slightly increases group i pla2 activity from porcine pancreas and naja naja venom in vitro. surfactin does not affect a ca2+ -independent pla2 partially purified from bovine brain. thus, this compound inhibits selectively the cytosolic form of pla2. based on in vitro studies utilizing preincubation of surfactin ...	1998	9605421
elucidation of a new biological function of an old protein: unique structure of the cobra serum albumin controls its specific toxin binding activity.	although few proteins have been studies as thoroughly as serum albumin, a new biological property of this evolutionary ancient protein was recently discovered: the ability of cobra serum albumin (csa) to specifically sequester lethal endogenous toxins. a study of the structural basis of this property is reported in this contribution. two independent approaches were used to alter the structure of the csa at defined positions: directed mutagenesis and limited proteolysis. the conserved pattern of ...	1998	9608676
structures of two novel crystal forms of naja naja naja phospholipase a2 lacking ca2+ reveal trimeric packing.	three crystal forms of naja naja naja phospholipase a2 were discovered through random crystallization screening, including two heretofore uncharacterized forms. the crystallization conditions for both of these novel crystal forms are ca(2+)-free whereas previously reported conditions include ca2+. one of the new crystal forms has a cubic lattice in the space group p2(1)3 (a = b = c = 69.24 a), the other has an orthorhombic lattice in the space group p2(1)2(1)2(1) (a = 67.22 a, b = 73.48 a, c = 8 ...	1998	9636712
isolation and characterization of an endogenous inhibitor of phospholipase a2 from indian cobra (naja naja naja) venom.	a pla2-inhibitor has been purified from indian cobra (naja naja naja) venom by the combination of ion-exchange and gel-filtration chromatography. the inhibitor, nn-i3 was a peptide with mol.wt 6500 and has a fluorescence emission maxima ca 340 nm. nn-i3 specifically inhibited the enzyme activity of the three acidic pla2 from the same venom. the inhibition of nn-i2d-pla2 and nn-i2c-pla2 by nn-i3 was of mixed type and nn-i2c-pla2 was of uncompetitive type. neither the inhibitor nor the individual ...	1998	9643477
enkephalin-processing oligopeptidases in cobra venom: inhibition by thiorphan and bestatin reveals co-operative actions.	the peptidase inhibitors thiorphan and bestatin were tested for their ability to inhibit the actions of the oligopeptidases contained in the venom of the taiwan cobra (naja naja atra). with methionine enkephalin (tyrglyglyphemet) as substrate, thiorphan was an effective inhibitor of cleavage of the glyphe peptide bond while bestatin inhibited cleavage of the tyrgly peptide bond. thiorphan and bestatin also inhibited subsequent cleavage of the fragments glyglyphemet and tyrglygly respectively. th ...	1998	9655632
purification and characterization of three acidic, cytotoxic phospholipases a2 from indian cobra (naja naja naja) venom.	three acidic phospholipases a2 (nn-i2c-pla2, nn-i2d-pla2 and nn-i2c-pla2) were purified by successive chromatography of indian cobra (naja naja naja) venom on cm-sephadex c-25, sephadex g-50 and qae sephadex a-25 columns. they have molecular weights of 13,000-14,500 by sodium dodecyl sulphate polyacrylamide gel electrophoresis. they showed tryptophan specific fluorescence emission spectra (approximately 345 nm). all the three phospholipases a2 were enzymatically highly active with specific activ ...	1998	9663698
conversion of tyrosine to phenolic derivatives by taiwan cobra venom.	we have examined the ability of taiwan cobra (naja naja atra) venom to transform in vitro the amino acid tyrosine to phenolic oxidation products via 4-hydroxyphenylpyruvate. this amino acid can be released from neuropeptide substrates by oligopeptidases present in the venom. using a variety of analytical techniques to probe a complicated series of reactions, we confirm that the l-amino acid oxidase present in the venom initially releases the keto form of 4-hydroxyphenylpyruvic acid and hydrogen ...	1998	9690784
chemically modified non-antimicrobial tetracyclines inhibit activity of phospholipases a2.	tetracyclines have been recognized as useful agents for therapy of inflammatory arthritides. however, prolonged use of tetracyclines is limited by their detrimental antimicrobial properties. recently, a group of chemically modified tetracyclines (cmt) devoid of antimicrobial properties has been synthesized. some cmt were found to inhibit various matrix metalloproteinases (mmp). we reported previously that antimicrobial tetracyclines inhibit the activity of proinflammatory secretory group ii phos ...	1998	9733464
characterization of phospholipase a2 (pla2) from taiwan cobra: isoenzymes and their site-directed mutants.	extracellular and secretory phospholipase a2 (pla2), a class of phospholipid digesting enzyme, is widely distributed in animal venoms of reptiles and insects. two cdnas encoding pla2 isoenzymes from taiwan cobra (naja naja atra) were cloned into pqe-30 plasmid vector and expressed in escherichia coli. the recombinant products were subjected to refolding using sulfonation under reduction/oxidation conditions with glutathione and enterokinase removal of his-tag, resulting in the active recombinant ...	1998	9735349
structure and organization of the cardiotoxin genes in naja naja sputatrix.	we report the genomic structure, organization and the presence of multiple isoforms of the gene encoding cardiotoxins (ctx) of naja naja sputatrix. the cardiotoxin gene consists of six ctx isoforms, each (2.2 kb) having three exons and two introns. two possible transcription initiation sites as well as consensus tata boxes and transcription factor binding motifs, ap-2, nfil-6/c/ebp, nf-kappab and puf have been identified in the 5'-region of the gene. the ctx gene isoforms show nucleotide variati ...	1998	9738945
identification of arg-30 as the essential residue for the enzymatic activity of taiwan cobra phospholipase a2.	taiwan cobra (naja naja atra) phospholipase a2 (pla2) was inactivated by arginine-specific reagents, phenylglyoxal and 1, 2-cyclohexanedione. kinetic analyses of the modification reaction revealed that the inactivation of pla2 followed pseudo-first-order kinetics and the loss of activity was correlated with the incorporation of one molecule of modification reagent per pla2 molecule. this was confirmed by the results of amino acid composition determination, that showed that a marked decrease in e ...	1998	9756621
snake envenomation and protective natural endogenous proteins: a mini review of the recent developments (1991-1997).	the properties of several factors--antihaemorrhagic, antineurotoxic, antimyotoxic--isolated from the blood serum or plasma of different animals are described with more emphasis placed on the structural differences and similarities among the factors of the snake (trimeresurus flavoviridis) and mammals (didelphis marsupials and herpestes edwardsii). classification of antihaemorrhagic factors of snake and mammals according to structural homologies, and their effectiveness in neutralizing venom haem ...	1998	9792161
lys49 phospholipase a2 myotoxins lyse cell cultures by two distinct mechanisms.	three lys49 phospholipase a2 (pla2) myotoxins from agkistrodon contortrix laticinctus (aclmt), bothrops jararacussu (bothropstoxin-i) and bothrops asper (myotoxin ii) snake venoms are enzymatically inactive on artificial substrates, yet addition of these toxins to cell cultures causes the release of fatty acids derived from the hydrolysis of membrane phospholipids. bothropstoxin-i treated with p-bromophenacyl bromide is no longer enzymatically active on cell cultures, suggesting the toxin, not t ...	1998	9792171
cdna sequence analysis and expression of four long neurotoxin homologues from naja naja atra.	the novel cdnas encoding four long neurotoxin homologues were firstly cloned from the venom gland of naja naja atra by reverse transcriptase-polymerase chain reaction. amino acid sequence comparison showed that they may come from two different evolutionary origins. the mature proteins were expressed as soluble fusion proteins in escherichia coli and purified for immunoblotting. the results revealed that they displayed different immunochemical properties.	1998	9838137
four new postsynaptic neurotoxins from naja naja sputatrix venom: cdna cloning, protein expression, and phylogenetic analysis.	cdnas encoding 4 short chain alpha-neurotoxins from malayan spitting cobra (naja naja sputatrix) venom were cloned and expressed in escherichia coli. the recombinant toxins possessed identical amino acid sequences to alpha-neurotoxins. this is the first report on cloning and expression of isoforms of neurotoxins from a species of spitting cobra. two of these isoforms were also identified in the crude venom by reverse phase-high performance liquid chromatography (rp-hplc), capillary electrophores ...	1998	9839671
carbonothioate phospholipids as substrate for a spectrophotometric assay of phospholipase a2.	a continuous spectrophotometric assay for phospholipase a2 (pla2) was developed using novel carbonothioate phospholipids. these phospholipid analogues contain a carbonothioate bond in the place of the sn-2 ester of the natural substrates of phospholipase a2 and were synthesized in a one-pot two-step reaction. phospholipase a2 from cobra venom (naja naja atra) hydrolyzes carbonothioate phospholipids and liberates a free thiol, alkylmercaptan, which is reacted with 5,5'-dithiobis(2-nitrobenzoic ac ...	1998	9866705
characterization and cloning of long neurotoxin homolog from naja naja atra.	the cdna encoding a long neurotoxin homolog was constructed from the cellular rna isolated fom the venom glands of naja naja atra (taiwan cobra) by reverse transcription-polymerase chain reaction. blast searches for sequence similarity in the genbank databases reveal that the cdna sequence of the long neurotoxin homolog is not highly homologous with long and short neurotoxins. although the long neurotoxin homolog exhibited an activity to inhibit acetylcholine-induced muscle contractions as naja ...	1998	9891854
isolation and amino acid sequence of a phospholipase a2 inhibitor from the blood plasma of the sea krait, laticauda semifasciata.	a phospholipase a2 (pla2) inhibitor was purified from the blood plasma of a sea krait, laticauda semifasciata, by sequential chromatography on sephadex g-200, mono q, and phenyl sepharose columns. the purified inhibitor was found to be the same type as the pla2 inhibitors, named pligamma, that had been purified from the blood plasma of the thai cobra naja naja kaouthia [ohkura et al. (1994) biochem. biophys. res. commun. 200, 784-788] and chinese mamushi agkistrodon blomhoffii siniticus [ohkura ...	1999	9990137
structurally homologous toxins isolated from the taiwan cobra (naja naja atra) differ significantly in their structural stability.	cardiotoxin and neurotoxin analogues isolated from snake venom sources are highly homologous proteins (>50% homology) with similar three-dimensional structures but exhibit drastically different biological properties. in the present study, we compare the conformational stability of cardiotoxin analogue iii (ctx iii) and cobrotoxin (cbtx), a neurotoxin analogue, from the taiwan cobra (naja naja atra), using circular dichroism spectroscopy and hydrogen-deuterium (h/d) exchange techniques in conjunc ...	1999	10049504
benzophenone-type photoactivatable derivatives of alpha-neurotoxins and alpha-conotoxins in studies on torpedo nicotinic acetylcholine receptor.	by chemical modification of different lysine residues, benzoylbenzoyl (bzbz) groups were introduced into neurotoxin ii naja naja oxiana (nt-ii), a short-chain snake venom alpha-neurotoxin, while p-benzoylphenylalanyl (bpa) residue was incorporated in the course of peptide synthesis at position 11 of alpha-conotoxin g1, a neurotoxic peptide from marine snails. although the crosslinking yields for iodinated bzbz derivatives of nt-ii and for bpa analogue of g1 to the membrane-bound torpedo californ ...	2014	10071785
postsynaptic alpha-neurotoxin gene of the spitting cobra, naja naja sputatrix: structure, organization, and phylogenetic analysis.	the venom of the spitting cobra, naja naja sputatrix contains highly potent alpha-neurotoxins (ntxs) in addition to phospholipase a2 (pla2) and cardiotoxin (ctx). in this study, we report the complete characterization of three genes that are responsible for the synthesis of three isoforms of alpha-ntx in the venom of a single spitting cobra. dna amplification by long-distance polymerase chain reaction (ld-pcr) and genome walking have provided information on the gene structure including their pro ...	1999	10077532
in situ hybridization and immunohistochemical analysis of the expression of cardiotoxin and neurotoxin genes in naja naja sputatrix.	secretory processes and their regulation have been extensively studied in mammalian salivary parotid glands. however, little is known regarding the secretory mechanism in the venom glands of snakes, which invariably produce one of the most complex of all animal secretions. the pharmacologically important and toxic components of the malayan spitting cobra (naja naja sputatrix) venom include postsynaptic neurotoxins (ntx), presynaptic neurotoxins (phospholipase a2, pla2), and cardiotoxins (ctx) wh ...	1999	10082757
effects of petrosaspongiolide m, a novel phospholipase a2 inhibitor, on acute and chronic inflammation.	the marine product petrosaspongiolide m is a novel inhibitor of phospholipase a2 (pla2), showing selectivity for secretory pla2 versus cytosolic pla2, with a potency on the human synovial enzyme (group ii) similar to that of manoalide. this compound was more potent than manoalide on bee venom pla2 (group iii) and had no effect on group i enzymes (naja naja and porcine pancreatic pla2). inhibition of pla2 was also observed in vivo in the zymosan-injected rat air pouch, on the secretory enzyme acc ...	1999	10087000
probing the role of c-1 ester group in naja naja phospholipase a2-phospholipid interactions using butanetriol-containing phosphatidylcholine analogues.	to understand the role of the ester moiety of the sn-1 acyl chain in phospholipase a2-glycerophospholipid interactions, we introduced an additional methylene residue between the glycerol c1 and c2 carbon atoms of phosphatidylcholines, and then studied the kinetics of hydrolysis and the binding of such butanetriol-containing phospholipids with naja naja phospholipase a2. hydrolysis was monitored by using phospholipids containing a nbd-labelled sn-2 acyl chain and binding was ascertained by measur ...	1999	10092841
comparison of three classes of snake neurotoxins by homology modeling and computer simulation graphics.	we present a systematic structure comparison of three major classes of postsynaptic snake toxins, which include short and long chain alpha-type neurotoxins plus one angusticeps-type toxin of black mamba snake family. two novel alpha-type neurotoxins isolated from taiwan cobra (naja naja atra) possessing distinct primary sequences and different postsynaptic neurotoxicities were taken as exemplars for short and long chain neurotoxins and compared with the major lethal short-chain neurotoxin in the ...	1999	10198241
elisa for the detection of venoms from four medically important snakes of india.	a double antibody sandwich enzyme linked immunosorbent assay (elisa) was developed to detect echis carinatus venom in various organs (brain, heart, lungs, liver, spleen and kidneys) as well as tissue at the site of injection of mice, at various time intervals (1, 6, 12, 18, 24 h and 12 h intervals up to 72 h) after death. the assay could detect e. carinatus venom levels up to 2.5 ng/ml of tissue homogenate and the venom was detected up to 72 h after death. a highly sensitive and species-specific ...	1999	10219987
histopathological studies of the acute inflammation in synovial tissue of rat knee joint following intra-articular injection of pla2 from chinese cobra (naja naja atra) venom.	a phospholipase a2 was purified from chinese cobra naja naja atra by a two-step procedure: gel filtration on superdex 75 and reverse-phase high-performance liquid chromatography (hplc) on a nucleosil 5 c18 column. purified phospholipase a2 was homogeneous, as indicated by capillary electrophoresis and electrospray mass spectrometry. it was a basic protein (pi = 8.2 +/- 0.03) with a molecular mass of 13,258 da. amino acid sequence analysis of the n-terminal demonstrated a high degree of homology ...	1999	10219989
binding of nucleotide triphosphates to cardiotoxin analogue ii from the taiwan cobra venom (naja naja atra). elucidation of the structural interactions in the datp-cardiotoxin analogue ii complex.	snake venom cardiotoxins have been recently shown to block the enzymatic activity of phospholipid protein kinase and na+,k+-atpase. to understand the molecular basis for the inhibitory effects of cardiotoxin on the action of these enzymes, the nucleotide triphosphate binding ability of cardiotoxin analogue ii (ctx ii) from the taiwan cobra (naja naja atra) venom is investigated using a variety of spectroscopic techniques such as fluorescence, circular dichroism, and two-dimensional nmr. ctx ii i ...	1999	10364232
effect of ranitidine bismuth citrate on the phospholipase a2 activity of naja naja venom and helicobacter pylori: a biochemical analysis.	helicobacter pylori has become recognized as a fundamental pathogen in the development of gastritis and peptic ulcer disease. bismuth compounds in combination with antibiotics are widely used to treat h. pylori associated peptic ulcer disease.	1999	10383521
cobrotoxin: structure and function.	cobrotoxin is the main neurotoxic protein isolated from the venom of taiwan cobra naja naja atra. it is a small, basic protein consisting of a single polypeptide chain of 62 amino acids, cross-linked by four disulfide bonds. the disulfide bonds and tyr-25 which is buried in the molecule form a central core to maintain and stabilize the active conformation of the toxin. selective and stepwise chemical modifications of cobrotoxin indicate that at least two cationic groups, an epsilon-amino group o ...	1999	10410333
two forms of cytotoxin ii (cardiotoxin) from naja naja oxiana in aqueous solution: spatial structures with tightly bound water molecules.	1h-nmr spectroscopy data, such as noe intraprotein and (bound water)/protein contacts, 3j coupling constants and deuterium exchange rates were used to determine the in-solution spatial structure of cytotoxin ii from naja naja oxiana snake venom (ctii). exploiting information from two 1h-nmr spectral components, shown to be due to cis/trans isomerization of the val7-pro8 peptide bond, spatial structures of ctii minor and major forms (1 : 6) were calculated using the torsion angle dynamics algorit ...	1999	10429199
muscarinic acetylcholine receptor (machr) inhibitor from snake venom: interaction with subtypes of human machr.	snake venoms can contain a variety of well-studied neurotoxins, especially nicotinic acetylcholine receptor inhibitor, normally called postsynaptic neurotoxin. karlsson first reported muscarinic acetylcholine receptor (machr) inhibitor from snake venom. in a previous study in our laboratory, we found a machr inhibitor from naja naja sputatrix venom that bound to rat brain synaptosomes. brain synaptosomes contain all subtypes of machrs, and thus the exact selectivity of the inhibitor could not be ...	1999	10462446
expression and mutagenesis studies of cobrotoxin from taiwan cobra.	the cdna encoding cobrotoxin was constructed from the cellular rna isolated from the venom glands of naja naja atra (taiwan cobra). the cdna was subcloned into the expression vector pet20b(+) and transformed into bl21(de3) escherichia coli strain. expressed cobrotoxin was isolated from inclusion bodies of e. coli and subjected to refolding into its folded structure. the refolded cobrotoxin was purified by high-performance liquid chromatography and exhibited a neurotoxicity in inhibiting acetylch ...	1999	10512733
roles of aromatic residues in high interfacial activity of naja naja atra phospholipase a2.	acidic phospholipase a2 (pla2) from the venom of chinese cobra (naja naja atra) has high activity on zwitterionic membranes and contains six aromatic residues, including tyr-3, trp-18, trp-19, trp-61, phe-64, and tyr-110, on its putative interfacial binding surface. to assess the roles of these aromatic residues in the interfacial catalysis of n. n. atra pla2, we mutated them to ala and measured the effects on its interfacial catalysis. enzymatic activities of the mutants toward various vesicle ...	1999	10587453
bioactivities of nerve growth factor from chinese cobra venom.	the nerve growth factor, ngf, from chinese cobra naja naja atra venom was isolated by gel-filtration and ion-exchange chromatography. cobra ngf was characterized by analytical hplc techniques as well as sds-page, and was proven to be a glycoprotein with a mol. wt. of 23 (+/- 2) kd and a pi of 9.2. the amino acid analysis and n-terminal sequencing were performed using conventional methods. bioassays with cultured chick embryos ganglia and rat pheochromocytoma pc-12 cells revealed a promotion of f ...	1999	10591039
predicted three-dimensional structural models of venom serine protease inhibitors and their interactions with trypsin and chymotrypsin.	three homology models of trypsin and chymotrypsin inhibitor polypeptides from snake venom of naja naja naja and leaf-nosed viper in the unbound state and in complex with trypsin and chymotrypsin were built based on homology to bovine pancreatic trypsin inhibitor (bpti). these venom inhibitors belong to the kunitz-type inhibitor family, which is characterized by a distinct tertiary fold with three-conserved disulfide bonds. the general folding pattern in these trypsin and chymotrypsin inhibitor h ...	1999	10591040
a nerve growth factor from the venom of chinese cobra (naja naja atra) and its effects on male reproductive system in rats.	a nerve growth factor (ngf) was isolated from the venom of chinese cobra (naja naja atra) by ion exchange chromatography, gel filtration and fast protein liquid chromatography (fplc). the n-terminal sequence of 22 amino acid residues was identical with other ngfs previously purified from the venom of the same genus. the ngf monomer molecular weight was estimated to be 13,500 by reducing sds-page and the isoelectric point was determined to be 7.2 by isoelectric focusing electrophoresis. ngf impro ...	1999	10622430
functional role of the noncatalytic subunit of complement c5 convertase.	the c5 convertase is a serine protease that consists of two subunits: a catalytic subunit which is bound in a mg2+-dependent complex to a noncatalytic subunit. to understand the functional role of the noncatalytic subunit, we have determined the c5-cleaving properties of the cobra venom factor-dependent c5 convertase (cvf, bb) made with cvf purified from the venom of naja naja (cvfn) and naja haje (cvfh) and compared them to those for two c3b-dependent c5 convertases (zymc3b,bb and c3b,bb). a co ...	2000	10640753
effect of crotapotin and heparin on the rat paw oedema induced by different secretory phospholipases a2.	the effects of crotapotin (a non-toxic and non-enzymatic acid polypeptide naturally complexed with phospholipase a2) and heparin on rat paw edema induced by different secretory phospholipases a2 (spla2) have been investigated. the ability of crotapotin to affect the enzymatic activity of the spla2(s) have also been evaluated. secretory pla2(s) obtained from both snake (naja naja, naja mocambique mocambique, crotalus adamanteus and crotalus durissus terrificus) and bee (apis mellifera) venoms as ...	2000	10665801
regional and accelerated molecular evolution in group i snake venom gland phospholipase a2 isozymes.	in accordance with detection of a few phospholipase a2 (pla2) isozyme genes by southern blot analysis, only two cdnas, named nnkpla-i , and nnkpla-ii, encoding group i pla2s, nnkpla-i and nnkpla-ii, respectively, were isolated from the venom gland cdna library of elapinae naja naja kaouthia of malaysia. nnkpla-i and nnkpla-ii showed four amino acid substitutions, all of which were brought about by single nucleotide substitution. no existence of clones encoding cm-ii and cm-iii, pla2 isozymes whi ...	2000	10669032
mapping the catalytic pocket of phospholipases a2 and c using a novel set of phosphatidylcholines.	a set of radioiodinatable phosphatidylcholines (pcs) derivatized with the bolton-hunter reagent (bhpcs) was synthesized to probe the substrate recognition and activity of phospholipases. a common feature of this series is the presence of a bulky 4-hydroxyphenyl group at the end of the fatty acyl chain attached to position sn-2. the distance between the end group and the glycerol backbone was varied by changing the length of the intervening fatty acyl chain (3-25 atoms). except for the shortest, ...	2000	10698694
the multiplicity of cardiotoxins from naja naja atra (taiwan cobra) venom.	four novel cardiotoxins were isolated from naja naja atra (taiwan cobra) venom by successive separation on a sp-sephadex c-25 column and a reverse phase column. amino acid sequences of the cardiotoxins were determined by edman degradation and carboxypeptidase digestion. it shows that these cardiotoxins comprise 60 amino acid residues. comparative analyses on the amino acid sequences of cardiotoxins from the venoms of n. naja atra and other naja species indicated that amino acid substitutions of ...	2000	10708798
membrane structure of the hepatitis b virus surface antigen particle.	expression of s protein, an envelope protein of hepatitis b virus, in the absence of other viral proteins, leads to the secretion of hepatitis b virus surface antigen (hbsag) particles that are formed by budding from the endoplasmic reticulum membranes. the hbsag particles produced by mouse fibroblast cells show a unique lipid composition, with 1,2-diacyl glycerophosphocholine being the dominant component. the lipid organization of the hbsag particles was studied by measuring electron spin reson ...	2000	10739944
roles of aromatic residues in high interfacial activity of naja naja atra phospholipase a(2)		2000	10747813
hemostatic disturbances observed in patients with snakebite in south china.	to investigate the hematological disorders after snakebite, we measured the maximum platelet aggregation rate (mar), antithrombin iii (at-iii) activity, alpha(2)-plasmin inhibitor (alpha(2)-pi) activity, concentration of fibrinogen (fg) and fibrin degradation products (fdp) in 25 samples from 17 patients with snakebite in south china. the results obtained in the patients before application of antivenom and patients with ophiophagus hannah (oh.) bite were as follows: (1) the mean mar values were ...	2000	10758271
agelotoxin: a phospholipase a(2) from the venom of the neotropical social wasp cassununga (agelaia pallipes pallipes) (hymenoptera-vespidae).	the neotropical wasp agelaia pallipes pallipes is aggressive and endemic in southeast of brazil, where very often it causes stinging accidents in rural areas. by using gel filtration on sephadex g-100, followed by high performance reversed phase chromatography in a c-18 column under acetonitrile/water gradient, the agelotoxin was purified: a toxin presenting phospholipase a(2) (pla(2)) activity, which occurs under equilibrium of three different aggregation states: monomer (mol. wt 14 kda), trime ...	2000	10758272
bacterial cell membrane hydrolysis by secreted phospholipases a(2): a major physiological role of human group iia spla(2) involving both bacterial cell wall penetration and interfacial catalysis.	the ability of human group iia secreted phospholipase a(2) (human spla(2)) to hydrolyse the phospholipid membrane of whole cell suspensions of gram-positive bacteria is demonstrated in real time using a continuous fluorescence displacement assay. micrococcus luteus is used as a model system and demonstrates an almost absolute specificity for this human enzyme compared with porcine pancreatic and naja naja venom spla(2)s. this specificity is due to selective penetration of the highly cationic hum ...	2000	10760469
activation of phospholipase a(2) by long chain fatty acyl groups involves a novel unstable linkage.	the acidic isoform of phospholipase a(2) from naja mossambica mossambica was activated by treatment with a molar equivalent of oleoyl imidazolide. modification of the protein was accompanied by 50% quenching of tryptophan fluorescence and a significant red shift. the (3)h(9,10) labeled oleoyl residue was co-eluted with the enzyme during gel filtration in the presence of 20% 1-propanol or excess albumin, both of which remove free oleic acid from the enzyme. in contrast, the adduct was labile as t ...	2000	10788797
elucidation of the solution structure of cardiotoxin analogue v from the taiwan cobra (naja naja atra)--identification of structural features important for the lethal action of snake venom cardiotoxins.	the aim of the present study is to understand the structural features responsible for the lethal activity of snake venom cardiotoxins. comparison of the lethal potency of the five cardiotoxin isoforms isolated from the venom of taiwan cobra (naja naja atra) reveals that the lethal potency of ctx i and ctx v are about twice of that exhibited by ctx ii, ctx iii, and ctx iv. in the present study, the solution structure of ctx v has been determined at high resolution using multidimensional proton nm ...	2000	10794406
permeation studies comparing cobra skin with human skin using nicotine transdermal patches.	cobra skin (naja naja khaotia) was used as a barrier for an in vitro permeation study using nicotine. fluxes of nicotine that permeated from nicotinell through cobra skin (cs) taken from the head, body, and tail were 233.93 +/- 16.08, 206.87 +/- 19.00, and 211.26 +/- 22.93 micrograms/cm2/hr1/2, respectively (n = 6). this indicated no significant difference (p > .05). abdominal human epidermis (he), obtained from cadavers, and the cs provided identical permeation kinetics for nicotine, which can ...	2000	10826111
comparison of the structural stability of two homologous toxins isolated from the taiwan cobra (naja naja atra) venom.	cardiotoxin analogue iii (ctx iii) and cobrotoxin (cbtx) isolated from the taiwan cobra venom (naja naja atra) are structurally homologous, small molecular weight, all-beta-sheet proteins, cross-linked by four disulfide bonds at identical positions. the conformational stabilities of these toxins are compared based on temperature-dependent chemical shifts and amide proton exchange kinetics using two-dimensional nmr spectroscopy. the structure of ctx iii is found to be significantly more stable th ...	2000	10913281
sequencing and model structure of a naja naja atra protein fragment.	we report the amino acid sequence of a basic protein isolated from the snake venom of naja naja atra. an automated edman sequencer was used to determine the 65-residue sequence, aided by electrospray ionization/mass spectrometry. online reduction and pyridylethylation of the peptide was performed to identify the cysteine residues. trypsin, chymotrypsin and aspartic digestions were carried out to derive peptide fragments for further sequencing. fragmented peptides were overlapped to obtain the co ...	2000	10917453
structure-function studies on taiwan cobra long neurotoxin homolog.	a novel long neurotoxin homolog was purified from naja naja atra (taiwan cobra) venom using the combination of ion exchange chromatography and reverse phase high performance liquid chromatography. the determined protein sequence was essentially the same as that deduced from the cdna amplified by reverse transcriptase-polymerase chain reaction. the long neurotoxin homolog exhibited an activity that inhibited acetylcholine-induced muscle contractions, as with n. naja atra cobrotoxin. the degree of ...	2000	11004569
one-month safety study of intraperitoneal vrctc-310-onco (crotoxin + cardiotoxin) in rats.	to evaluate the toxicity of vrctc-310-onco (crotalus durissus terrificus crotoxin + cardiotoxin from naja naja atra), 10 sprague-dawley rats were implanted with intraperitoneal slow-release devices and subjected to treatment with 0.5 microgram/g body weight/d for 14 days. biochemical evidence at days 7 and 14 showed blood, muscular, renal and metabolic disturbance, mostly reversed by day 28. no significant changes were found in necropsy. the limited toxicity of i.p. vrctc-310-onco in rats deserv ...	2000	11050707
[expression and characterization of two kinds of recombinant snake neurotoxins].	the cdna encoding the precursor of cobrotoxin was cloned from the venom gland of the chinese continental cobra (naja naja atra) by rt-pcr. its deduced amino acid sequence analysis showed that the mature protein was identical to that identified from the taiwan cobra (naja naja atra) by protein sequencing technique. the cdna encoding the mature protein was then subcloned into the expression vector pmal-p2. the gene of cm11, which was formed by ligation of the fragments of the synthetic oligonucleo ...	2000	11059270
secreted phospholipase a(2) induces vascular endothelial cell migration.	secreted phospholipase a(2) (spla(2)) regulates a variety of cellular functions. the present investigation was undertaken to elucidate the potential role of spla(2) in endothelial cell (ec) migration. bovine aortic endothelial cells (baecs) exposed to spla(2) placed in the lower compartment of a modified boyden chamber displayed increased migration compared to cells exposed to vehicle. the effect of spla(2) on ec migration was time and dose dependent. migration of baecs was observed at 30 minute ...	2000	11090064
influential factors affecting prognosis of snakebite patients management: kaohsiung chang gung memorial hospital experience.	the objective of this study was to determine the most influential factors affecting the prognosis of snakebite patients in kaohsiung chang gung memorial hospital.	2000	11126148
the composition of naja naja venom samples from three districts of west bengal, india.	the variation in the composition of naja naja venoms from three neighbouring districts of west bengal, eastern india and the corresponding differences in the severity of pathogenesis due to venom composition variation are reported. these venom samples differ with respect to chromatographic elution profile and enzyme activity associated with each fraction. presence of higher quantities of basic phospholipase and plasma protein hydrolase in the venom samples of burdwan and purulia make them more t ...	1998	11249011
prey specificity, comparative lethality and compositional differences of coral snake venoms.	toxicities of crude venoms from 49 coral snake (micrurus sp.) populations, representing 15 nominal taxa, were examined in both laboratory mice and in native prey animals and compared with data gathered from two non-micrurine elapids and a crotalid, which served as outgroups. these venoms were further compared on the basis of 23 enzymatic activities. both toxicities and enzymatic activities were analyzed with respect to natural prey preferences, as determined from stomach content analyses and lit ...	2001	11255115
structural studies on the cobra venom factor: isolation, purification, crystallization and preliminary crystallographic analysis.	cobra venom factor (cvf) is the complement-activating protein in cobra venom. it is a three-chain glycoprotein with a molecular weight of 149,000 da. in serum, cvf forms a bimolecular enzyme with the bb subunit of factor b. the enzyme cleaves c3 and c5, causing complement consumption in human and mammalian serum. cvf is frequently used to decomplement serum to investigate the biological functions of complement and serves as a tool to investigate the multifunctionality of c3. furthermore, cvf bea ...	2001	11264593
differential roles of ionic, aliphatic, and aromatic residues in membrane-protein interactions: a surface plasmon resonance study on phospholipases a2.	the roles of cationic, aliphatic, and aromatic residues in the membrane association and dissociation of five phospholipases a(2) (pla(2)), including asp-49 pla(2) from the venom of agkistrodon piscivorus piscivorus, acidic pla(2) from the venom of naja naja atra, human group iia and v pla(2)s, and the c2 domain of cytosolic pla(2), were determined by surface plasmon resonance analysis. cationic interfacial binding residues of a. p. piscivorus pla(2) (lys-10) and human group iia pla(2) (arg-7, ly ...	2001	11294634
topical anti-inflammatory activity of some asian medicinal plants used in dermatological disorders.	the topical anti-inflammatory activity of extracts from cassia angustifolia, rheum palmatum, coptis chinensis, phellodendron amurense and scutellaria baicalensis, plants used in traditional east asian medicine against different skin disorders, was studied. though in different degree, all the extracts significantly inhibited the edema induced by 12-o-tetradecanoylphorbol-13-acetate (tpa), in both single or multiple application, oxazolone, and arachidonic acid (aa). none of the extracts inhibited ...	2001	11295297
role of catalytic function in the antiplatelet activity of phospholipase a2 cobra (naja naja naja) venom.	three acidic phospholipases a2 from indian cobra (naja naja naja) venom inhibited platelet aggregation in platelet rich plasma induced separately by adp, collagen and epinephrine with different potencies. the order of inhibition was epinephrine > collagen > adp. they did not inhibit platelet aggregation induced by arachidonic acid (10 microm). the inhibition was dependent on concentration of the protein and the time of incubation of the phospholipases a2 with platelet rich plasma. parabromophena ...	2001	11354251
induction of platelet activation by cobra venom factor from naja naja atra in rat.	to study the effects of cobra venom factor (cvf) on platelets of rat platelet rich plasma (prp) and to elucidate its cellular mechanism.	2000	11360676
refolding of taiwan cobra neurotoxin: intramolecular cross-link affects its refolding reaction.	in order to explore the effect of intramolecular cross-linking in the folding reaction of cobrotoxin from naja naja atra (taiwan cobra) venom, the toxin molecule was modified with glutaraldehyde (ga). the monomeric ga-modified cobrotoxin (mga-cobrotoxin) was separated from the dimeric and trimeric derivatives using gel filtration. the results of electrophoretic and chromatographic analyses revealed that mga-cobrotoxin comprised two modified derivatives, which contained modified lys residues at p ...	2001	11370853
a simple method to obtain a covalent immobilized phospholipase a(2).	in the present work, we obtained an immobilized phospholipase a(2) system through covalent coupling by using an acrylic polymer eupergit c as support. the immobilized enzyme from cobra venom (naja naja naja) showed good retention activity and excellent stability. both properties are of great importance for biomedical applications such as hypercholesterolemia treatments.	2001	11425532
karl heinrich slotta (1895-1987) biochemist: snakes, pregnancy and coffee.	in 1923 karl h. slotta obtained his phd in chemistry from the university of breslau, germany, where he continued to work. at the instigation of the gynaecologist ludwig fraenkel, slotta made the first isolation of progesterone in 1933. in 1934 he proposed the correct structural formula. slotta was appointed professor of chemistry in 1935, but with the oppression of the nazi regime mounting, he soon left germany with his family to take a post at the instituto butantan, brazil. initially he worked ...	2001	11447968
binding to and hemolysis of human erythrocytes by pyrularia thionin and naja naja kaouthia cardiotoxin: inhibition by prothrombin.	pyrularia thionin and snake venom cardiotoxin are strongly basic proteins which bind to and induce hemolysis of erythrocytes, cause depolarization of muscle cells, and influence the order and properties of phospholipids in cellular membranes. earlier studies showed a competition between the thionin and cardiotoxin for a common binding site on erythrocytes, and the present study extends these studies to show a similar competition between prothrombin and both basic proteins. the competition betwee ...	2001	11491465
glutaraldehyde cross-linking alters the environment around trp(29) of cobrotoxin and the pathway for regaining its fine structure during refolding.	cobrotoxin, purified from the venom of naja naja atra (taiwan cobra), was subjected to modification with glutaraldehyde in order to prepare intra- and intermolecule cross-linked derivatives. monomeric and dimeric derivatives were separated from polymeric derivatives by gel filtration. the results of amino acid analysis and sequence determination revealed that only lys residues were selectively modified by glutaraldehyde. glutaraldehyde cross-linking was accompanied by a change in the gross confo ...	2001	11532076
inhibition of human platelet aggregation by l-amino acid oxidase purified from naja naja kaouthia venom.	l-amino acid oxidase (lao) widely exists in snake venoms. purification of lao from the naja naja kaouthia (monocellate cobra) venom has been reported (tan and swaminathan, 1992), but its structural characterization and physiological function remained to be determined. the function of snake venom laos in hemostasis, especially their effect on platelet aggregation, has been controversial. we determined the n-terminal amino acid sequence of the n. n. kaouthia lao named k-lao to be ddrrspleecfqqndye ...	2001	11600144