| experimental allergic encephalomyelitis: role of fibrin deposition in immunopathogenesis of inflammation in rats. | the immunopathogenesis of experimental allergic encephalomyelitis (eae) is reviewed with special focus on the role of central nervous system fibrin deposition in the inflammatory cascade characterizing this autoimmune disease. among rats sensitized to whole spinal cord or myelin basic protein of either guinea pig or bovine origin, there is a striking degree of concordance of perivascular fibrin deposits and occurrence of clinical paralytic signs. neither paralytic signs nor fibrin deposition are ... | 1976 | 61895 |
| the effects of snake venoms and their neurotoxins on the nervous system of man and animals. | myasthenia gravis is a subject of tremendous interest ot neurologists. snake poisoning, however, which gives rise to a clinical picture resembling a myasthenic crisis, has evoked little interest among neurologists. this state of affairs exists partly because most snake bites occur in areas where physicians, let alone neurologists, are not commonly found. hence, few neurologists have seen a case of snake bite with nervous system involvement. this is unfortunate, because many of the published case ... | 1975 | 124647 |
| fragmentation of actin by thrombin-like snake venom proteases. | the effect of thrombin-like snake venom proteases (ancrod of agkistrodon rhodostoma and batroxobins of bothrops moojeni and bothrops marajoensis) on skeletal muscle actin was studied and compared to the thrombic cleavage of this protein. only edta-pretreated g- and f-actin were split by thrombin and ancrod, while batroxobins hydrolyzed native g-actin, too. the time course of digestion was followed by sodium dodecyl sulfate polyacrylamide gel electrophoresis. a split product of 37 500 daltons app ... | 1979 | 427215 |
| protection of pregnant mice with phospholipase c and with arvin against foetal death induced by bacterial lipopolysaccharide. | injection of bacterial lipopolysaccharide into pregnant mice resulted in fibrinogen accumulation, thrombosis and haemorrhage in the placental tissue and foetal death. depletion of circulating fibrinogen by a thrombin-like enzyme from the venom of malayan pit viper, arvin, prevents foetal death. foetal protection was also obtained by treating the mothers with a preparation of phospholipase c from bacillus cereus known to inactivate tissue thromboplastin. it is suggested the lipopolysaccharide cau ... | 1979 | 444421 |
| effect of five thai snake venoms on coagulation, fibrinolysis and platelet aggregation. | the effects of five thai snake venoms--malayan pit viper--mpv (ancistrodon rhodostoma); russell's viper--rvv (vipera russelli); cobra--cv (naja naja); king cobra--kcv (naja hannah) and banded krait--bkv (bungarus fasciatus)--on blood coagulation fibrinolysis and platelet aggregation were studied. mpv has strong thrombin-like coagulant action. rvv has activating effect most probably on factor x. other three venoms--cv, kcv and bkv have been shown to be anti coagulant, on both intrinsic and extrin ... | 1979 | 524153 |
| partial perfusion in awake neonatal lambs: a comparison of three methods. | a comparison of the effects of extended partial perfusion of conscious lambs was made between the use of a silicone-tube membrane oxygenator and a bubble oxygenator (infant temptrol). the survival time of the lambs was markedly shortened with the bubble oxygenator, although much longer than had been anticipated. a serious problem was uncontrollable bleeding from the cannulation wounds with a rapidly declining pcv. in a third group of experiments the suitability of ancrod (arvin-extract of the ve ... | 1977 | 599168 |
| the effects of ancrod, the coagulating enzyme from the venom of malayan pit viper (a. rhodostoma) on prothrombin and fibrinogen metabolism and fibrinopeptide a release in man. | the action of ancrod on fibrinogen and prothrombin metabolism was studied in six healthy individuals by the use of 131i-fibrinogen and 125i-prothrombin and by measurement of blood levels of fibrinopeptide a. two untreated healthy controls were studied at the same time. rapid defibrinogenation occurred during the initial 3 hr ancrod infusion, and fibrinogen levels were maintained near zero throughout the study. large quantities of non-thrombin-clottable tca-precipitable 131i material could be dem ... | 1978 | 641385 |
| the clotting of a snake (crotalus viridis helleri) plasma and its interaction with various snake venoms. | the clotting of c. v. helleri plasma is not accelerated by the factor x activator or thrombin-like enzymes from its own venom. clotting of the plasma is accelerated by the factor xactivator from russell's viper venom, but not by the thrombin-like enzyme from agkistrodon rhodostoma venom ("arvin"). the prothrombin activator from the taipan venom clots c.v. helleri plasma equally well as human plasma, but the thrombin which is produced has a marked specificity for its own fibrinogen, and clots bov ... | 1976 | 989631 |
| [arvin anticoagulant for prolonged extracorporeal membrane oxygenation (author's transl)]. | treatment of overwhelming but reversible respiratory failure has broadened to include extracorporeal support with a membrane lung. until recently, it has been necessary to rely on heparin to prevent clotting in an extracorporeal circuit. during prolonged bypass heparinisation may be attended by bleeding. we investigated the use of arvin for systemic anticoagulation in extracorporeal membrane lung bypass in lambs. arvin is a purified fraction of the venom of the malayan pit viper. effective antic ... | 1976 | 1008240 |
| significane of intravascular coagulation in canine endotoxin shock. | the contribution of disseminated fibrin clot formation to the pathogenesis of canine endotoxin shock was explored in control dogs and in those defibrinated with a purified fraction of malayan pit viper venom. the hemodynamic and humoral responses after the administration of an intravenous challenge dose of escherichia coli endotoxin were comparable as was mortality. it is concluded that, although the role of the coagulation sequence in canine endotoxin shock is unclear, it does not appear to be ... | 1975 | 1091556 |
| determination of human fibrinopeptide a by radioimmunoassay in purified systems and in the blood. | the formation of fibrin clots or circulating soluble fibrin is accompanied by the appearance of fibrinopeptides. measurement of the fibrinopeptide concentration in plasma can provide important information on the rate of conversion of fibrinogen to fibrin by thrombin. this rate varies under different physiologic and pathologic conditions. fibrinopeptide a is a better molecular marker of the conversion than fibrinopeptide b since it is the first peptide to be cleaved by thrombin. a radioimmunoassa ... | 1975 | 1209541 |
| [experimental analysis of the effects of the anticoagulant fraction of agkistrodon rhodostoma venom on the heart, the vascular and respiratory systems and on certain muscles]. | | 1975 | 1232572 |
| carbohydrate structure of a thrombin-like serine protease from agkistrodon rhodostoma. structure elucidation of oligosaccharides by methylation analysis, liquid secondary-ion mass spectrometry and proton magnetic resonance. | the carbohydrate side chains of the thrombin-like serine protease ancrod from the venom of the malayan pit viper agkistrodon rhodostoma were liberated from tryptic glycopeptides by treatment with peptide-n4-(n-acetyl-beta-glucosaminyl)asparagine amidase f and fractionated by high-performance liquid chromatography. glycans obtained were characterized by digestion with exoglycosidases, methylation analysis and, in part, by liquid secondary-ion mass spectrometry and 1h-nmr spectroscopy. the results ... | 1992 | 1315684 |
| a novel alpha-type fibrinogenase from agkistrodon rhodostoma snake venom. | by means of cm-sephadex c-50 column chromatography, gel-filtration on sephadex g-75 and sephacryl s-200 columns, a purified fibrinogenase, kistomin, was obtained from venom of agkistrodon rhodostoma. it was a single peptide-chain with a molecular mass of about 21,800 da containing about 202 amino-acid residues as revealed by amino acid analysis. kistomin preferentially cleaved a alpha- and subsequently the gamma-chain of fibrinogen, leaving the b beta-chain unaffected. its fibrinogenolytic activ ... | 1992 | 1477097 |
| intrinsic pathway activation of factor x and its activation peptide-deficient derivative, factor xdes-143-191. | the role of the activation peptide in determining the substrate specificity of intrinsic pathway factor x (fx) activation was studied by using a novel derivative of fx in which 49 residues were removed enzymatically from the nh2 terminus of the 52-residue activation peptide by an enzyme from the venom of the snake agkistrodon rhodostoma. the modified protein, designated fxdes-143-191, is inactive but is activated to alpha-fxa by either the intrinsic fx activation complex (intrinsic fxase) compos ... | 1992 | 1560014 |
| a national hospital-based survey of snakes responsible for bites in thailand. | snakes which had been killed and brought to hospital with the patients they had bitten were collected in 80 district and provincial hospitals throughout 67 provinces in thailand in order to establish the geographical distribution and relative medical importance of the venomous species. of the 1631 snakes collected, 1145 were venomous: malayan pit vipers (calloselasma rhodostoma), green pit vipers (trimeresurus albolabris) and russell's vipers (daboia russelii) were the most numerous, while t. al ... | 1992 | 1566285 |
| therapeutic defibrination with ancrod does not protect canine myocardium from reperfusion injury. | the purpose of this study was to determine whether normal fibrinogen contributes to the development of myocardial reperfusion injury by acting as a substrate in vivo for neutrophil adhesion. this was tested in a dog model of acute myocardial infarction that used pentobarbital anesthetized dogs subjected to 90 min regional myocardial ischemia and 5 h reperfusion. dogs were treated with 1 unit/kg ancrod (venom from the malayan pit viper, agkistrodon rhodostoma) or vehicle i.v. 60 min after left ci ... | 1991 | 1704437 |
| kistrin, a polypeptide platelet gpiib/iiia receptor antagonist, enhances and sustains coronary arterial thrombolysis with recombinant tissue-type plasminogen activator in a canine preparation. | kistrin is a 68-amino acid polypeptide from the venom of the malayan pit viper agkistrodon rhodostoma, which inhibits the platelet gpiib/iiia receptor. its effect on thrombolysis, reocclusion, and bleeding associated with administration of recombinant tissue-type plasminogen activator (rt-pa) was studied in a canine model of coronary artery thrombosis. | 1991 | 1900221 |
| animal models for arterial thrombolysis and prevention of reocclusion. erythrocyte-rich versus platelet-rich thrombus. | experimental animal models for erythrocyte-rich (er) and platelet-rich (pr) arterial thrombosis were developed in dogs and rabbits and used for the evaluation of the effect of antithrombin and antiplatelet agents on thrombolysis with recombinant tissue-type plasminogen activators (rt-pa). the canine models consist of a whole blood clot produced in the left anterior descending coronary artery (er thrombus) or a 1-cm everted (inside-out) segment graft in the circumflex coronary artery that predisp ... | 1991 | 2040069 |
| synergy of antithrombin iii concentrate and antivenom in preventing coagulopathy in a rat model of malayan pit viper envenoming. | the effects of unrefined equine antivenom and antithrombin iii (at-iii) concentrate on the coagulopathy induced by systemic envenomation by malayan pit viper (calloselasma rhodostoma; mpv) venom were investigated in a rat model. 37 rats received an intramuscular injection of mpv venom and serial blood samples were taken from the femoral vein for simple whole blood clotting tests and measurement of at-iii activity. 30 min after venom injection, treatment (antivenom, at-iii or both) was given intr ... | 1990 | 2096528 |
| bacteriological studies of the venom and mouth cavities of wild malayan pit vipers (calloselasma rhodostoma) in southern thailand. | venom and oropharyngeal swabs from freshly captured malayan pit vipers (calloselasma rhodostoma) in southern thailand and captive specimens in england were cultured aerobically and anaerobically to identify the bacterial flora which might contaminate wounds inflicted by bites of this species. the snakes' mouths contained a wider range of organisms than their venoms, especially gut-related gram-negative rods such as enterobacter and pseudomonas species and some staphylococci and clostridia. there ... | 1990 | 2136528 |
| in vivo defibrination results in markedly decreased amounts of fibrinogen in rat megakaryocytes and platelets. | recently evidence was provided for a pathway whereby circulating fibrinogen enters megakaryocyte granules by an endocytic mechanism. synthesis of fibrinogen by megakaryocytes has been reported. to determine the relationship between plasma fibrinogen and alpha-granule fibrinogen in megakaryocytes and platelets, the fibrinogen content of these cells was studied in rats defibrinated by use of ancrod, a thrombinlike enzyme purified from the venom of agkistrodon rhodostoma. unlike thrombin, ancrod do ... | 1990 | 2260627 |
| platelet glycoprotein iib-iiia protein antagonists from snake venoms: evidence for a family of platelet-aggregation inhibitors. | the purification, complete amino acid sequence, and biological activity are described for several homologous snake venom proteins that are platelet glycoprotein (gp) iib-iiia antagonists and potent inhibitors of platelet aggregation. the primary structures of kistrin (from agkistrodon rhodostoma), bitan (from bitis arietans), three isoforms of trigramin (from trimeresusus gramineus), and an isoform of echistatin (from echis carinatus) were determined by automated sequence analysis and fast atom ... | 1990 | 2320569 |
| comparative enzymatic degradation of h1 subfractions from syrian hamster tissues. | an additional hydrolysis site recognized by thrombin on histone h1 molecules was found. snakes venom proteases from agkistrodon rhodostoma, bothrops marajoensis and bothrops moojeni were further used for the analysis of h1 histones. the presence of the main cleavage site on h1 histone molecules has been established. this site is localized on main n-terminal thrombin peptide. the main venom protease peptides obtained from different h1 subfractions preserve differences of electrophoretic mobility ... | 1986 | 2946112 |
| inactivation of single-chain urokinase (pro-urokinase) by thrombin and thrombin-like enzymes: relevance of the findings to the interpretation of fibrin-binding experiments. | whereas crude bovine thrombin activated single-chain urokinase-type plasminogen activator (scu-pa), otherwise called pro-urokinase (pro-uk), purified human thrombin converted pro-uk (scu-pa) to a two-chain form that had no amidolytic activity. the two chains (mr approximately 33,000 and 22,000) were disulfide linked and resistant to subsequent activation by plasmin. by contrast, thrombin did not inactivate tissue plasminogen activator or two-chain urokinase. the enzyme from snake venom agkistrod ... | 1987 | 2949785 |
| primary specificity of ancrod, the coagulating serine proteinase from the malayan pit viper (agkistrodon rhodostoma) venom. | values of steady-state and pre-steady-state parameters for the hydrolysis of zargonp and zlysonp catalysed by ancrod, the coagulating serine proteinase from the malayan pit viper (agkistrodon rhodostoma) venom, have been determined, between ph 2.5 and 8 (i = 0.1 m) at 21 +/- 0.5 degrees c, and analysed in parallel with those of bovine alpha-thrombin and porcine pancreatic beta-kallikrein-b. in addition to the well-known coagulating behaviour, ancrod also shows catalytic properties, in the hydrol ... | 1986 | 3085714 |
| antigenic relationships and relative immunogenicities of venom proteins from six poisonous snakes of thailand. | venoms from naja naja siamensis, ophiophagus hannah, bungarus fasciatus, vipera russelli, calloselasma rhodostoma and trimeresurus albolabris have been studied by means of sodium dodecyl sulfate polyacrylamide gel electrophoresis and immunoblotting. the immunoblots were stained with rabbit homologous and heterologous antibodies. in general, the higher the mol. wt the protein the higher the immunogenicity although two proteins with mol. wts of 23,000 and 25,000 from o. hannah venom are extraordin ... | 1988 | 3201490 |
| factors contributing to fatal snake bite in the rural tropics: analysis of 46 cases in thailand. | records of 46 cases of fatal bites by identified snakes from 15 provincial hospitals throughout thailand contained sufficient information for detailed analysis. bungarus candidus and calloselasma rhodostoma were each responsible for 13 deaths, naja kaouthia for 12, vipera russelli for 7 and b. fasciatus for one. major causes of death among elapid victims were respiratory failure (26) and complications of prolonged mechanical ventilation (10), and among viper victims shock (12), intracranial haem ... | 1988 | 3257001 |
| oleic acid-induced lung injury in rabbits: effect of fibrinogen depletion with arvin. | the role of fibrinogen in the evolution of the increased permeability after oleic acid-induced lung injury was studied in new zealand white rabbits. animals depleted of fibrinogen by treatment with malayan pit viper venom were compared with untreated rabbits immediately and at 1 and 24 h after injury. the increased permeability to albumin and elevated extravascular lung water (evlw) associated with lung injury returned to control values by 24 h in untreated animals. fibrinogen-depleted animals h ... | 1988 | 3284872 |
| degradation of coagulation proteins by an enzyme from malayan pit viper (akistrodon rhodostoma) venom. | three hydrolases from the crude venom of the malayan pit viper (akistrodon rhodostoma) can be differentiated. the first, which we designate arh alpha, is the well-known fibrinogenolytic enzyme ancrod. the second, arh beta, which has not been described previously, is identified by its electrophoretic mobility after sodium dodecyl sulfate-polyacrylamide gel electrophoresis (sds-page), by its ability to hydrolyze h-d-phenylalanyl-l-piperyl-l-arginyl-rho-nitroanilide, and by inhibition of its activi ... | 1987 | 3322404 |
| randomized comparative trial of three monospecific antivenoms for bites by the malayan pit viper (calloselasma rhodostoma) in southern thailand: clinical and laboratory correlations. | three monospecific antivenoms for malayan pit viper (mpv) (calloselasma rhodostoma) were compared in southern thailand, where this species is the most common cause of snake bite morbidity. forty-six patients with proved mpv bites and incoagulable blood, indicating systemic envenoming, were randomly allocated for treatment with thai red cross (trc), thai government pharmaceutical organization (gpo), or twyford pharmaceutical monospecific antivenoms. both gpo and twyford antivenoms produced rapid ... | 1986 | 3538922 |
| ancrod decreases the frequency of cyclic flow variations and causes thrombolysis following acute coronary thrombosis. | the potential use of ancrod, a purified isolate from the venom of the malaysian pit viper, agkistrodon rhodostoma, in decreasing the frequency of cyclic flow variations in severely stenosed canine coronary arteries and causing thrombolysis of an acute coronary thrombus induced by a copper coil was evaluated. open-chest, anesthetized dogs were used. ancrod was given intravenously (8 u/kg) over 1 hour and caused a significant reduction in the frequency of cyclic flow variations (5.8 +/- 0.7 to 3.6 ... | 1987 | 3565240 |
| characterization of a potent platelet aggregation inhibitor from agkistrodon rhodostoma snake venom. | by means of cm-sephadex c-50 column chromatography and gel filtration on sephadex g-75 and g-50 columns, a potent platelet aggregation inhibitor was purified and characterized. it was a glycoprotein with a molecular weight of 31,000. it was devoid of phospholipase a, adpase, esterase and fibrino(geno)lytic activities. it inhibited dose-dependently the aggregation of washed platelets induced by collagen, thrombin, sodium arachidonate, platelet activating factor and ionophore a23187 with a similar ... | 1987 | 3620499 |
| purification and characterization of a platelet aggregation inducer from calloselasma rhodostoma (malayan pit viper) snake venom. | a potent platelet aggregation inducer was purified from calloselasma rhodostoma snake venom by sephadex g-75, cm-sephadex c-50 and sephacryl s-300 column chromatography. it was homogeneous as judged by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, with a molecular weight estimated to be 28,160 +/- 1280. it was devoid of phospholipase a2, fibrino(geno)lytic and thrombin-like activities. the venom inducer elicited platelet aggregation and the serotonin release reaction in rabbit plate ... | 1986 | 3775783 |
| detection of specific proenzyme activators in snake venoms by a new immunoabsorbant-chromogenic substrate method. | in separate experiments, antibodies to plasminogen, factor x and protein c were applied to microtitre trays as commonly used in enzyme-linked immunoassays. after incubation with dilute normal human plasma as a source of the corresponding proenzyme antigen, the wells were exposed to dilutions of various snake venoms. after thorough washing, the microtitre tray wells were tested overnight with chromogenic tripeptide substrates known to be relatively specific for the activated forms of the above fa ... | 1985 | 3841012 |
| inhibition of rabbit platelet aggregation by alpha-fibrinogenase purified from calloselasma rhodostoma (malayan pit viper) venom. | | 1985 | 3868694 |
| studies on type specific immunity to the whole venom and a fraction of agkistrodon rhodostoma. | | 1971 | 4109789 |
| pharmacology and toxicology of a defibrinating substance from malayan pit viper venom. | | 1968 | 4170830 |
| [anticoagulant activity of agkistrodon rhodostoma venom]. | | 1974 | 4448047 |
| studies on the coagulant enzyme from agkistrodon rhodostoma venom. isolation and some properties of the enzyme. | 1. arvin, a commercial preparation of the coagulant activity from the venom of agkistrodon rhodostoma, is shown to contain a non-coagulant caseinolytic fraction. 2. a method is described for the purification of the coagulant enzyme free from any detectable contaminating protein. 3. the coagulant enzyme is identified as a glycoprotein which probably consists of a single polypeptide chain containing approx. 29% by weight of carbohydrate. amino acid and carbohydrate analyses are reported and the n- ... | 1973 | 4737326 |
| the effect of malayan pit-viper (agkistroden rhodostoma) venom on ovine blood and the development of resistance to the anticoagulant activity of this venom. | | 1972 | 5043135 |
| plasma fibrinogen recovery rate after administration of malayan pit viper venom extracts in nonstressed and surgically stressed animals. | | 1972 | 5055800 |
| antithrombotic effect of malayan pit viper venom on experimental thrombosis of the inferior vena cava produced by a new method. | | 1966 | 5332583 |
| isotopic studies of therapeutic anticoagulation with a coagulating enzyme. | the kinetics of the depletion of plasma fibrinogen were studied in seven patients who received fibrinogen-(131)i 1 hr before an intravenous injection of the coagulating enzyme (ce) derived from the venom of the pit viper, agkistrodon rhodostoma. disappearance of the clottable radioactivity labeled fibrinogen from the circulation conformed to an exponential decay with an average half-life of 0.85 hr. the mean clearance rate for protein-bound radioactivity, composed of fibrinogen and it's split pr ... | 1970 | 5456799 |
| the effect of intraperitoneal malayan pit-viper venom on adhesion formation and peritoneal healing. | | 1970 | 5482314 |
| the proteolytic action of arvin on human fibrinogen. | 1. human fibrinogen was subjected to proteolysis by enzyme preparations (clinical arvin and irc-50 arvin) from the venom of agkistrodon rhodostoma. 2. irc-50 arvin releases three peptides from fibrinogen, and these were identified as fibrinopeptides ap, ay and a. 3. the less purified ;clinical' arvin releases, in addition to fibrinopeptides ap, ay and a, small amounts of two heptapeptides derived from fibrinopeptides ap and a, probably because it contains another enzyme as well as arvin. 4. no f ... | 1970 | 5529716 |
| the modification of experimental occlusive arterial thrombosis in the rat by malayan pit viper venom. | | 1968 | 5652231 |
| in vivo behaviour of the coagulant enzyme from agkistrodon rhodostoma venom: studies using 131-i-'arvin'. | | 1969 | 5802494 |
| the comparison of the antitomboc action of the thrombin-like fraction of malayan pit viper venom and heparin. | | 1969 | 5821043 |
| in vivo effects of agkistrodon rhodostoma venom: studies with fibrinogen-131i. | | 1966 | 5967698 |
| molecular cloning of cdna for the alpha, beta, and gamma chains of rat fibrinogen. a family of coordinately regulated genes. | recently, we have found that defibrination of rats with malayan pit viper venom induces a 10-38-fold increase in the levels of translatable fibrinogen mrna in the liver. we have used this response to obtain cdna clones for the three polypeptide chains of rat fibrinogen. a large cdna library was created in pbr322 from induced rat liver polyadenylated rna by the poly(dg, dc)-tailing method. part of this library was screened using colony hybridization with [32p]cdna prepared from induced and nonind ... | 1981 | 6169715 |
| a double antibody sandwich micro-elisa kit for the rapid diagnosis of snake bite. | a micro elisa assay was established to diagnose systemic poisoning for the rapid administration of specific antivenom. rabbit anti venom igg was bound to the solid phase to enable detection of venom from both the malayan pit viper (agkistrodon rhodostoma) and the common cobra (naja naja). this assay is read visually and takes 35 to 45 minutes to perform. it can detect 15.6 ng/ml of viper venom in 75 minutes and 7.8 ng/ml of cobra venom in 55 minutes. tests on sera from snake bite patients showed ... | 1983 | 6658505 |
| thrombin-induced lung vascular injury. roles of fibrinogen and fibrinolysis. | we examined the contributions of fibrin and the fibrinolytic mechanism in mediating the thrombin-induced lung vascular injury. studies were made in sheep in which alterations in lung transvascular fluid and protein exchange were assessed using the lung lymph fistula preparation. group i(n = 10) control sheep in which left atrial pressure was raised to increase pulmonary lymph flow (qlym); group ii(n = 8) control sheep in which thrombin was infused intravenously (58.3 +/- 12.6 u/kg) to induce pul ... | 1983 | 6870068 |
| coordinate accumulation of the mrnas for the alpha, beta, and gamma chains of rat fibrinogen following defibrination. | cell-free translation and hybridization to cloned cdna probes were used to study variations in fibrinogen mrna levels in the livers of rats injected with malayan pit viper venom and glucocorticoids. animals defibrinated with malayan pit viper venom showed a rapid and substantial increase in the relative abundance of hepatic mrnas for the a alpha, b beta, and gamma chains of fibrinogen. the onset, rate, and maximal extent of message accumulation were virtually identical for each of the three fibr ... | 1982 | 6896326 |
| aggretin, a novel platelet-aggregation inducer from snake (calloselasma rhodostoma) venom, activates phospholipase c by acting as a glycoprotein ia/iia agonist. | a potent platelet aggregation inducer, aggretin, was purified from malayan-pit-viper (calloselasma rhodostoma) venom by ionic-exchange chromatography, gel-filtration chromatography and hplc. it is a heterodimeric protein (29 kda) devoid of esterase, phospholipase a and thrombin-like activity. aggretin (> 5 nm) elicited platelet aggregation with a lag period in both human platelet-rich plasma and washed platelet suspension. edta (5 mm), prostaglandin e1 (1 microm) and 3,4,5-trimethoxybenzoic acid ... | 1995 | 7639679 |
| the antiplatelet activity of ancrod on administration to rabbits. | ancrod, a thrombin-like enzyme purified from the venom of calloselasma rhodostoma, was administered to rabbits intravenously, and blood samples were obtained at 1, 3, 6, 10, and 24 hours after infusion. ancrod caused a rapid and sustained defibrinogenation within the first 6 hours, with production of fibrinogen degradation products (fdps) peaking at 1 hour and declining to background level at 6 hours. no significant changes in platelet count, white cell count, or hematocrit was observed. citrate ... | 1995 | 7706907 |
| action of calloselasma rhodostoma (malayan pit viper) venom on human blood coagulation and fibrinolysis using computerized thromboelastography (cteg). | the effects of malayan pit viper (calloselasma rhodostoma) venom on human blood coagulation and fibrinolysis were studied in vitro using computerized thromboelastography. at low concentrations the venom had a coagulant effect shown by faster onset of the coagulation process (shortened sp and r), faster progress of the clot (increased angle and shortened k), and increased coagulation (teg) index. the maximum amplitude (ma) was not affected, suggesting that the venom had no apparent effect on plat ... | 1994 | 7725330 |
| antiplatelet protease, kistomin, selectively cleaves human platelet glycoprotein ib. | kistomin, a metalloprotease purified from venom of calloselasma rhodostoma, dose- and time-dependently prolonged the latent period of aggregation and inhibited atp secretion of human washed platelets stimulated by thrombin. it inhibited aggregation induced by low concentrations of thrombin (< or = 0.2 u/ml) whereas it had only slight effect on aggregation induced by high concentrations of thrombin (> or = 0.5 u/ml). meanwhile it also inhibited ristocetin-induced platelet aggregation in a dose- a ... | 1993 | 8251530 |
| kistrin, an integrin antagonist, blocks endocytosis of fibrinogen into guinea pig megakaryocyte and platelet alpha-granules. | recent data indicate that megakaryocyte/platelet alpha-granule fibrinogen is endocytosed from plasma. because fibrinogen is the major platelet protein present in high concentrations in alpha-granules, fibrinogen uptake into alpha-granules may occur via specific receptors. in that cells of the megakaryocyte/platelet lineage contain two integrins--alpha iib beta 3 (gp iib-iiia) and the vitronectin receptor (alpha v beta 3)--that can bind fibrinogen, one or both of these receptors may mediate the e ... | 1993 | 8423218 |
| glycosylation of recombinant ancrod from agkistrodon rhodostoma after expression in mouse epithelial cells. | the thrombin-like serine protease ancrod from the malayan pit viper agkistrodon rhodostoma was expressed in mouse epithelial cells (c127). oligosaccharide constituents were liberated from tryptic glycopeptides by treatment with peptide-n4-(n-acetyl-beta-glucosaminyl) asparagine amidase f. neutral oligosaccharide alditols obtained after reduction and enzymic desialylation were separated by two-dimensional hplc and characterized by methylation analysis, liquid secondary-ion mass spectrometry, matr ... | 1996 | 8620863 |
| role of the activation peptide domain in human factor x activation by the extrinsic xase complex. | the activation of factor x by the extrinsic coagulation system results from the action of an enzyme complex composed of factor viia bound to tissue factor on phospholipid membranes in the presence of calcium ions (extrinsic xase complex). proteolysis at the arg52-ile53 peptide bond in the heavy chain of factor x leads to the formation of the serine protease, factor xa, and the generation of a heavily glycosylated activation peptide comprising residues 1-52 of the heavy chain. the role of the act ... | 1996 | 8663201 |
| adhesion prevention with ancrod released via a tissue-adherent hydrogel. | the objective of this investigation was to evaluate the effect of ancrod, a fibrinogenolytic protease from malayan pit viper venom, locally delivered through a photopolymerized biodegradable hydrogel in preventing postoperative adhesions. the experimental model involved ischemic and serosal injury to the uterine horns of rats with measurement of adhesions 7 days after injury. ancrod was delivered intravenously for 5 days preoperatively through 3 days postoperatively, intraperitoneally for 5 days ... | 1996 | 8769943 |
| ancrod: the use of snake venom in the treatment of patients with heparin-induced thrombocytopenia and thrombosis undergoing coronary artery bypass grafting: nursing management. | heparin-induced thrombocytopenia and thrombosis, also known as heparin-associated thrombocytopenia and thrombosis, was diagnosed in a 73-year-old man who had sustained a pelvic fracture, which was complicated by a left, deep-vein thrombosis. heparin was administered and thrombocytopenia and arterial thrombosis of his left foot developed, which required amputation of three lateral toes. four years later, the patient experienced a heart attack, and subsequently postinfarction angina developed, whi ... | 1996 | 8950124 |
| glutathione s-transferase-rhodostomin fusion protein inhibits platelet aggregation and induces platelet shape change. | rhodostomin (rho) from agkistrodon rhodostoma venom, consisting of 68 amino acids with an arginine-glycine-aspartic acid (rgd) sequence and 12 cysteine residues, is a potent inhibitor of platelet aggregation. we previously demonstrated that cell culture plates coated with the bacterially produced fusion protein of glutathione s-transferase-rho [gst-rho(rgd)] can facilitate human hepatoma cell attachment via intergrin interaction within 15 min. in this study, we further characterized the effect o ... | 1997 | 9080576 |
| apoxin i, a novel apoptosis-inducing factor with l-amino acid oxidase activity purified from western diamondback rattlesnake venom. | venom of the western diamondback rattlesnake (crotalus atrox) induces apoptosis in human umbilical vein endothelial cells, which could result in hemorrhage in tissues bitten by the snake. to identify the hemorrhagic factor, we purified a novel protein, apoxin i, from rattlesnake venom. apoxin i induced apoptosis in human umbilical vein endothelial, human promyelocytic leukemia hl-60, human ovarian carcinoma a2780, and mouse endothelial kn-3 cells. amino acid sequence analysis of the apoxin i sho ... | 1997 | 9083096 |
| antithrombin iii and antivenom reversal of coagulopathy in rats envenomated with malayan pit viper venom. | the therapeutic effects of antithrombin iii (at-iii) and unrefined equine antivenom in the treatment of coagulopathy induced by malayan pit viper (calloselasma rhodostoma) venom were assessed in 42 adult wistar rats. following intramuscular venom injection (2 micrograms/g body weight), serial blood samples were taken from the femoral vein for measurement of whole blood clotting time and at-iii activity. there was progressive depletion of at-iii and blood ceased to clot a mean (s.e.) of 164 (8.3) ... | 1994 | 9237341 |
| proteolytic specificity of rhodostoxin, the major hemorrhagin of calloselasma rhodostoma (malayan pit viper) venom. | the proteolytic specificity of rhodostoxin, the major hemorrhagin from calloselasma rhodostoma (malayan pit viper) venom was investigated using oxidized b-chain of bovine insulin as substrate. six peptide bonds were cleaved: ser9-hist10, his10-leu11, ala14-leu15, tyr16-leu17, gly20-glu21 and phe24-phe25. deglycosylated rhodostoxin, however, cleaved primarily at arg22-gly23. | 1997 | 9241791 |
| prothrombin and factor x activator activities in the venoms of viperidae snakes. | a ca(2+)-dependent prothrombin activator, carinactivase-1 (ca-1), was previously found in the venom of echis carinatus leucogaster. in the present study, the activities of ca-1-like enzymes were screened in the venoms of various viperidae snakes. the addition of 1 mm ca2+ ions to the venoms of only echis snakes in viperidae produced considerably high prothrombin activator activity, indicating that only the echis snake venoms contain not only the ca(2+)-independent prothrombin activator, ecarin, ... | 1997 | 9428105 |
| rhodocytin, a functional novel platelet agonist belonging to the heterodimeric c-type lectin family, induces platelet aggregation independently of glycoprotein ib. | we isolated and characterized a functionally novel platelet agonist, designated as rhodocytin, from the calloselasma rhodostoma venom. rhodocytin was a disulfide-linked heterodimer consisting of 18- and 15-kda subunits. the respective n-terminal amino acid sequences of both subunits were homologous to each other and to those of the carbohydrate-recognition domains (crd) of c-type lectins. rhodocytin alone induced platelet aggregation. platelet agonists and antagonists constructed with crd-like s ... | 1998 | 9588185 |
| venomous snakebite in thailand. i: medically important snakes. | thailand has an abundance of venomous snakes. among the neurotoxic family elapidae, there are three species of the genus naja (cobras), three of the genus bungarus (kraits), and the king cobra of the genus ophiophagus. other elapidae snakes in thailand include sea snakes and asian coral snakes of the genus calliophis. they have potent venoms but rarely bite humans. tissue and hemotoxic snakes are represented by family viperidae, subfamilies viperinae and crotalinae. they remain an occupational h ... | 1998 | 9597848 |
| hugh alistair reid obe md: investigation and treatment of snake bite. | alistair reid was an outstanding clinician, epidemiologist and scientist. at the penang general hospital, malaya, his careful observation of sea snake poisoning revealed that sea snake venoms were myotoxic in man leading to generalized rhabdomyolysis, and were not neurotoxic as observed in animals. in 1961, reid founded and became the first honorary director of the penang institute of snake and venom research. effective treatment of sea snake poisoning required specific antivenom which was produ ... | 1998 | 9637363 |
| modulation of rgd sequence motifs regulates disintegrin recognition of alphaiib beta3 and alpha5 beta1 integrin complexes. replacement of elegantin alanine-50 with proline, n-terminal to the rgd sequence, diminishes recognition of the alpha5 beta1 complex with restoration induced by mn2+ cation. | several recent studies have demonstrated that the amino acid residues flanking the rgd sequence of high-affinity ligands modulate their specificity of interaction with integrin complexes. the present study has addressed the role of the residues flanking the rgd sequence in regulating the recognition by disintegrin of the alphaiib beta3 and alpha5beta1 complexes by construction of a panel of recombinant molecules of elegantin (the platelet aggregation inhibitor from the venom of trimerasurus eleg ... | 1998 | 9761721 |
| signal transduction pathways mediated by glycoprotein ia/iia in human platelets: comparison with those of glycoprotein vi. | human platelets were activated either by glycoprotein (gp) ia/iia agonist (rhodocytin) or by a gpvi agonist (collagen-related peptide, crp), and the intracellular signal transduction pathways were compared in the presence of various inhibitors. rhodocytin isolated from calloselasma rhodostoma venom was verified as a gpia/iia agonist, based on the inhibitory effects of three mabs directed against gpia. platelet activation mediated by gpia/iia led to overt platelet aggregation, elevation of intrac ... | 1999 | 10066433 |
| development of reversed passive latex agglutination for detection of thai cobra (naja kaouthia) venom. | a simple, rapid, and sensitive diagnostic kit for detecting thai cobra (naja kaouthia) venom was developed using latex particles sensitized with venom specific immunoglobulin. the kit is capable of detecting 25-50 ng/ml of thai cobra venom. the capability was not affected by human plasma. specificity of the kit was proven using snake venoms from vipera russelli, calloselasma rhodostoma, trimeresurus albolabris, naja siamensis, ophiophagus hannah, and bungarus fasciatus. the diagnostic kit does n ... | 1999 | 10410332 |
| serine proteinase inhibition by the active site titrant n alpha-(n, n-dimethylcarbamoyl)-alpha-azaornithine p-nitrophenyl ester. a comparative study. | kinetics for the hydrolysis of the chromogenic active-site titrant n alpha-(n,n-dimethylcarbamoyl)-alpha-azaornithine p-nitrophenyl ester (dmc-azaorn-onp) catalysed by bovine beta-trypsin, bovine alpha-thrombin, bovine factor xa, human alpha-thrombin, human factor xa, human lys77-plasmin, human urinary kallikrein, mr 33 000 and mr 54 000 species of human urokinase, porcine pancreatic beta-kallikrein-a and -b and ancrod (the coagulating serine proteinase from the malayan pit viper agkistrodon rho ... | 2000 | 10672036 |
| the structure of l-amino acid oxidase reveals the substrate trajectory into an enantiomerically conserved active site. | the structure of l-amino acid oxidase (laao) from calloselasma rhodostoma has been determined to 2.0 a resolution in the presence of two ligands: citrate and o-aminobenzoate (ab). the protomer consists of three domains: an fad-binding domain, a substrate-binding domain and a helical domain. the interface between the substrate-binding and helical domains forms a 25 a long funnel, which provides access to the active site. three ab molecules are visible within the funnel of the laao-ab complex; the ... | 2000 | 10944103 |
| alpha 2beta 1 integrin is not recognized by rhodocytin but is the specific, high affinity target of rhodocetin, an rgd-independent disintegrin and potent inhibitor of cell adhesion to collagen. | we have recombinantly expressed a soluble form of human alpha(2)beta(1) integrin that lacks the membrane-anchoring transmembrane domains as well as the cytoplasmic tails of both integrin subunits. this soluble alpha(2)beta(1) integrin binds to its collagen ligands the same way as the wild-type alpha(2)beta(1) integrin. furthermore, like the wild-type form, it can be activated by manganese ions and an integrin-activating antibody. however, it does not bind to rhodocytin, a postulated agonist of a ... | 2001 | 11121411 |
| development of a polymerase chain reaction to distinguish monocellate cobra (naja khouthia) bites from other common thai snake species, using both venom extracts and bite-site swabs. | a pcr technique was used in this study to identify and distinguish monocellate cobra snake bites using snake venoms and swab specimens from snake bite-sites in mice from bites by other common thai snakes. the sequences of nucleotide primers were selected for the cobrotoxin-encoding gene from the chinese cobra (naja atra) since the sequences of monocellate cobra (naja kaouthia) venom are still unknown. however, the 113-bp fragment of cdna of the cobrotoxin-encoding gene was detected in the monoce ... | 2001 | 11223099 |
| expression in pichia pastoris and characterization by circular dichroism and nmr of rhodostomin. | rhodostomin (rho) is a snake venom protein isolated from calloselasma rhodostoma. rho is a disintegrin that inhibits platelet aggregation by blocking the binding of fibrinogen to the integrin alpha(iib)beta3 of platelets. rho produced in escherichia coli inhibited platelet aggregation with a k(i) value of 263 nm. although functional, rho produced in e. coli is misfolded based on our 2d and 3d nmr studies. in order to correct the folding problem, rho was expressed in pichia pastoris. the recombin ... | 2001 | 11340665 |
| rhodocytin (aggretin) activates platelets lacking alpha(2)beta(1) integrin, glycoprotein vi, and the ligand-binding domain of glycoprotein ibalpha. | although alpha(2)beta(1) integrin (glycoprotein ia/iia) has been established as a platelet collagen receptor, its role in collagen-induced platelet activation has been controversial. recently, it has been demonstrated that rhodocytin (also termed aggretin), a snake venom toxin purified from the venom of calloselasma rhodostoma, induces platelet activation that can be blocked by monoclonal antibodies against alpha(2)beta(1) integrin. this finding suggested that clustering of alpha(2)beta(1) integ ... | 2001 | 11352922 |
| differential expression and geographic variation of the venom phospholipases a2 of calloselasma rhodostoma and trimeresurus mucrosquamatus. | to investigate the geographic variations in venoms of two medically important pitvipers, we have purified and characterized the phospholipases a2 (pla2s) from the pooled venoms of calloselasma rhodostoma from malaysia, thailand, indonesia, and vietnam, as well as the individual venom of trimeresurus mucrosquamatus collected from both north and south taiwan. enzymatic and pharmacological activities of the purified pla2s were also investigated. the complete amino acid sequences of the purified pla ... | 2001 | 11370849 |
| human lung adenocarcinoma alpha1,3/4-l-fucosyltransferase displays two molecular forms, high substrate affinity for clustered sialyl lacnac type 1 units as well as mucin core 2 sialyl lacnac type 2 unit and novel alpha1,2-l-fucosylating activity. | human lung tumor alpha1,3/4-l-fucosyltransferase (ft) was purified (2000-fold, 29% recovery) from 290 g of tissue by including a chromatography step on affinity gel-gdp. two molecular forms (fta, larger size carrying 15% alpha1,4-ft activity; ftb, the major form with 85% activity) were separated by further fractionation on a sephacryl s-100 hr column. a difference in the electrophoretic mobilities of these two activities was also found on native polyacrylamide gel electrophoresis (page). both fo ... | 2001 | 11425796 |
| purification and characterization of a variant of rhodocetin from calloselasma rhodostoma (malayan pit viper) venom. | rhodocetin is a novel c-type lectin-related protein (clp) purified from the venom of calloselasma rhodostoma. thus far, it is the only reported clp whose alpha and beta subunits are not linked by an interdisulfide bond. we report here the isolation of a variant of rhodocetin from a different source of venom. this variant of rhodocetin exhibited a different elution profile in reverse-phase hplc as compared to the rhodocetin reported in our original publication [wang et al., (1999), biochemistry 3 ... | 2001 | 11732690 |
| application of recombinant rhodostomin in studying cell adhesion. | rhodostomin from venom of agkistrodon rhodostoma (also called calloselasma rhodostoma) contains 68 amino acid residues including 6 pairs of disulfide bonds and an arginine-glycine-aspartic acid (rgd) sequence at positions 49-51. it has been known as one of the strongest antagonists to platelet aggregation among the family termed disintegrin. in this review paper, in addition to introducing the characteristics of disintegrin and its related molecules, the advantages of using recombinant dna techn ... | 1997 | 12386385 |
| antihemorrhagin in the blood serum of king cobra (ophiophagus hannah): purification and characterization. | king cobra (ophiophagus hannah) serum was found to possess antihemorrhagic activity against king cobra hemorrhagin. the activity was stronger than that in commercial king cobra antivenom. an antihemorrhagin has been purified by ion exchange chromatography, affinity chromatography and gel filtration with a 22-fold purification and an overall yield of 12% of the total antihemorrhagic activity contained in crude serum. the purified antihemorrhagin was homogeneous in disc-page and sds-page. its appa ... | 2003 | 12875876 |
| hyaluronidase inhibitors (sodium cromoglycate and sodium auro-thiomalate) reduce the local tissue damage and prolong the survival time of mice injected with naja kaouthia and calloselasma rhodostoma venoms. | experiments have been carried out to find potent inhibitors of hyaluronidases of naja kaouthia (nk) and calloselasma rhodostoma (cr) venoms with the aim of reducing local tissue damage and systemic toxicities caused by the venoms. seven drugs/chemicals known to inhibit hyaluronidases were tested for their activity on venom enzymes. these were: sodium cromoglycate (sc), sodium aurothiomalate (sat), apigenin, kaemferol, phenylbutazone, oxyphenbutazone and fenoprofen. the results showed that sc or ... | 2003 | 14602119 |
| immunogenicity of venoms from four common snakes in the south of vietnam and development of elisa kit for venom detection. | the antigenicity and antigenic relationship between venoms of four common snakes in the south of vietnam-trimeresurus popeorum, calloselasma rhodostoma, naja naja and ophiophagus hannah-were studied. most of venom components expressed antigenicity and produced high titre antivenoms. the venoms share common components and antivenoms cross-reacted along them. furthermore, cross-reactions were observed among non-common antigens, indicating that they share common epitopes. hence, using single compon ... | 2003 | 14604537 |
| aggretin, a snake venom-derived endothelial integrin alpha 2 beta 1 agonist, induces angiogenesis via expression of vascular endothelial growth factor. | aggretin, a collagen-like alpha 2 beta 1 agonist purified from calloselasma rhodostoma venom, was shown to increase human umbilical vein endothelial cell (huvec) proliferation and huvec migration toward immobilized aggretin was also increased. these effects were blocked by a2-iie10, an antibody raised against integrin alpha 2. aggretin bound to huvecs in a dose-dependent and saturable manner, which was specifically inhibited by a2-iie10, as examined by flow cytometry. aggretin elicited significa ... | 2004 | 14630793 |
| anti-venom potential of butanolic extract of eclipta prostrata against malayan pit viper venom. | the butanolic and purified butanolic extracts (pbes) of eclipta prostrata were evaluated for their anti-venom potential. inhibition of lethal, hemorrhagic, proteolytic, and phospholipase a2 activities of calloselasma rhodostoma (malayan pit viper (mpv)) venom by these extracts were determined. demethylwedelolactone was identified as their major constituent. the butanolic extract, at 2.5 mg per mouse, was able to completely neutralize the lethal activity of 2ld50 of mpv venom, but increasing the ... | 2004 | 15013200 |
| optical immunoassay for snake venom detection. | a sensitive and specific optical immunoassay (oia) has been developed for snake venom detection. the assay is based on the principle of detection of physical changes in thickness of molecular thin film resulting from specific binding events on an optical silicon chip (silas-i, thermobiostar, colorado, usa). the reflection of white light through the thin film results in destructive interference of a particular wavelength of the light from gold to purple-blue depending on the thickness of the thin ... | 2004 | 15046761 |
| purification, partial characterization, crystallization and structural determination of ahp-laao, a novel l-amino-acid oxidase with cell apoptosis-inducing activity from agkistrodon halys pallas venom. | a snake-venom protein named ahp-laao has been purified from agkistrodon halys pallas venom using four-stage chromatography. ahp-laao is a novel member of the snake-venom l-amino-acid oxidase family. its amino-acid sequence shows high homology to other members of this family. for l-leucine, the values of k(cat) and k(m) are 31.1 s(-1) and 0.25 mm, respectively. the molecular weight of ahp-laao is about 60.7 kda as determined by maldi-tof mass spectrometry. ahp-laao can also induce apoptosis of cu ... | 2004 | 15103157 |
| a study of 225 malayan pit viper bites in thailand. | this study evaluated factors affecting the severity of bite site necrosis and systemic symptoms resulting from envenomation among patients bitten by malayan pit vipers (calloselasma rhodostoma) in thailand. we studied 145 victims prospectively. an additional 80 medical records were obtained for a retrospective study. collected data included gender of the victims, anatomic locations of bites, where attacks took place, and predisposing factors and how they might have affected the clinical course. ... | 2005 | 15916307 |
| biochemical and biological activities of the venom of the chinese pitviper zhaoermia mangshanensis, with the complete amino acid sequence and phylogenetic analysis of a novel arg49 phospholipase a2 myotoxin. | zhaoermia mangshanensis (formerly trimeresurus mangshanensis, ermia mangshanensis) represents a monotypic genus of pitviper known only from mt mang in china's hunan province, and is among the largest and most spectacular of asian venomous snakes. the venom of zhaoermia exhibits high coagulant activity on bovine and human fibrinogen and human plasma, high phosphodiesterase and arginine ester hydrolytic activity, and moderate to low l-amino acid oxidase, kallikrein, caseinolytic, phospholipase a(2 ... | 2006 | 16635500 |
| mechanisms of cell death induction by l-amino acid oxidase, a major component of ophidian venom. | l-amino acid oxidase (laao) from the malayan pit viper induces both necrosis and apoptosis in jurkat cells. cell death by necrosis is attributed to h2o2 produced by oxidation of alpha-amino acids. in the presence of catalase that effectively scavenges h2o2, a switch to apoptosis is observed. the major factors contributing to apoptosis are proposed to be: (i) generation of toxic intermediates from fetal calf serum (ii) binding and internalization of laao. the latter process appears to be mediated ... | 2006 | 16770529 |
| the interaction of ancrod with human platelets. | ancrod, a serine protease purified from the venom of agkistrodon rhodostoma, has been used as a therapeutic anticoagulant for a number of indications, including replacement of heparin in patients with heparin-induced thrombocytopenia. ancrod has similar fibrinolytic activity to thrombin, but ancrod specifically cleaves only the alpha chain of fibrinogen, producing the characteristic fibrinopeptides a, ap and ay. because ancrod has been used in patients with heparin-induced thrombocytopenia, it i ... | 1999 | 16801067 |
| biochemical and functional characterization of an l-amino acid oxidase isolated from bothrops pirajai snake venom. | in this work we describe the isolation of a new l-amino acid oxidase (laao) referred to as bpirlaao-i from bothrops pirajai snake venom, which was highly purified using a combination of molecular exclusion, affinity, and hydrophobic chromatography steps. bpirlaao-i homodimeric acid glycoprotein (approximate mr and pi of 130,000 and 4.9, respectively) displays high specificity toward hydrophobic/aromatic amino acids, while deglycosylation does not alter its enzymatic activity. the n-terminal laao ... | 2006 | 16809041 |
| nk-cell-dependent acute xenograft rejection in the mouse heart-to-rat model. | acute humoral xenograft rejection is characterized by widespread intravascular thrombosis with a significant nk-cell and macrophage infiltrate. although in vitro and ex vivo data have shown that nk cells are capable of killing xenogeneic tissue, the precise role they play in vivo is still not certain. consequently, there are few tested strategies for dealing with nk-cell-mediated rejection, should this prove to be a problem. one reason for this has been the lack of a relevant rodent model in whi ... | 2006 | 16925664 |
| crystal structure of laao from calloselasma rhodostoma with an l-phenylalanine substrate: insights into structure and mechanism. | l-amino acid oxidase is a dimeric glycosylated flavoenzyme, a major constituent of the venom-from the snake calloselasma rhodostoma. the enzyme exhibits apoptosis inducing effects as well as antibacterial and anti-hiv activities. the structure of l-amino acid oxidase with its substrate (l-phenylalanine) has been refined to a resolution of 1.8 a. the complex structure reveals the substrate bound to the reduced flavin (fadred). alternative conformations for the key residues his223 and arg322 are e ... | 2006 | 17046020 |
| structural and functional properties of cr 5, a new lys49 phospholipase a2 homologue isolated from the venom of the snake calloselasma rhodostoma. | cr 5 pla(2) homologous (k49) was isolated from calloselasma rhodostoma venom in only one chromatographic step in reverse phase hplc (rp-hplc) (on mu-bondapack c-18). a molecular mass of 13.965 da was determined by maldi-tof mass spectrometry. the amino acid composition showed that cr 5 had a high content of lys, tyr, gly, pro, and 14 half-cys residues, typical residues of a basic pla(2). the complete amino acid sequence of cr 5 pla(2) contains 120 residues, resulting in a calculated pi value of ... | 2006 | 17123155 |
| molecular cloning, expression and purification of l-amino acid oxidase from the malayan pit viper calloselasma rhodostoma. | a cdna encoding laao from the malayan pit viper (calloselasma rhodostoma) was cloned into an expression vector of the methylotropic yeast pichia pastoris. the laao open reading frame was inserted after the alpha-mf-signal sequence. upon induction soluble and active laao is produced and exported into the culture supernatant at a concentration of up to 0.4 mg/l. recombinant laao was purified from this by ion exchange and molecular sieve chromatography to yield apparently homogeneous protein in qua ... | 2007 | 17127077 |