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PubMed2003

Stejnulxin, a novel snake C-type lectin-like protein from Trimeresurus stejnegeri venom is a potent platelet agonist acting specifically via GPVI.

Stejnulxin, a novel snake C-type lectin-like protein with potent platelet activating activity, was purified and characterized from Trimeresurus stejnegeri venom. Under non-reducing conditions, it migrated on a SDS-polyacrylamide gel with an apparent molecular mass of 120 kDa. On reduction, it separated into three polypeptide subunits with apparent molecular masses of 16 kDa (alpha), 20 kDa (beta1) and 22 kDa (beta2), respectively. The complete amino acid sequences of its subunits were deduced from cloned cDNAs. The N-terminal sequencing and cDNA cloning indicated that beta1 and beta2 subunits of stejnulxin have identical amino acid sequences and each contains two N-glycosylation sites. Accordingly, the molecular mass difference between beta1 and beta2 is caused by glycosylation heterogenity. The subunit amino acid sequences of stejnulxin are similar to those of convulxin, with sequence identities of 52.6% and 66.4% for the alpha and beta, respectively. Stejnulxin induced human platelet aggregation in a dose-dependent manner. Antibodies against alphaIIbbeta3 inhibited the aggregation response to stejnulxin, indicating that activation of alphaIIbbeta3 and binding of fibrinogen are involved in stejnulxin-induced platelet aggregation. Antibodies against GPIbalpha or alpha2beta1 as well as echicetin or rhodocetin had no significant effect on stejnulxin-induced platelet aggregation. However, platelet activation induced by stejnulxin was blocked by anti-GPVI antibodies. In addition, stejnulxin induced a tyrosine phosphorylation profile in platelets that resembled that produced by convulxin. Biotinylated stejnulxin bound specifically to platelet membrane GPVI.

Amino Acid Sequence↗
PubMed1985

Heat stable protein with anticoagulant and smooth muscle contractile actions isolated from Habu (Trimeresurus flavoviridis) venom.

The biological activity of a Habu (Trimeresurus flavoiridis) venom fraction with drug-metabolizing enzyme inhibitory action was studied. The venom fraction, which was isolated through Sephadex G-100 gel filtration and cation exchange chromatography on Amberlite CG50, caused an increase of vascular permeability and hemorrhage, but these actions were lost after heating at 70 degrees C for 5 min. The fraction showed anticoagulant activity on citrated blood, and this activity remained after heating of the venom. Guinea pig ileum was contracted by treatment with nonheated or heated venom fraction, and these contractions were inhibited with atropine and potentiated with physostigmine. These results suggest that the drug-metabolizing enzyme inhibitor isolated from Habu venom involves the heat stable component with anticoagulant activity and smooth muscle contractile action.

Animals↗
PubMed1981

Snake venoms. Purification, some properties and amino acid sequence of a phospholipase A2 (DE-I) from Trimeresurus okinavensis (Hime-habu) venom.

A phospholipase A2 (DE-I) was purified from Trimeresurus okinavensis (Hime-habu) venom by gel filtration on Sephadex G-50 followed by ion-exchange chromatography on DEAE-cellulose. It comprises 123 amino acid residues including 14 half-cystine residues. The primary structure of the enzyme has been elucidated. The sequence and invariant amino acid residues of DE-I resemble those of phospholipases A2 from venoms of Viperidae and Crotalidae (Group II) snake venoms. The phospholipase A2 from T. okinavensis contains two histidine residues which are located at the N-terminal residue and at the active centre (histidine-47). The acidic phospholipase A2 (DE-I) is not toxic.

Amino Acid Sequence↗
PubMed1989

Dark green pit viper (Trimeresurus popeorum) bite: clinical and serial coagulation profiles in 51 cases.

Trimeresurus popeorum, a dark green pit viper, is commonly found in Southeast Asia. This study describes the clinical picture and blood studies of 51 patients bitten by this snake. Affected limbs were swollen; and hemorrhagic blebs in fingers and toes were found in 12 patients. Lymphangitis was observed in 4 instances. Six individuals exhibited hypofibrinogenemia of 0-84 mg/dl, and 2 cases developed thrombocytopenia and bleeding. The presence of venom in the blood of these patients was demonstrated. Positive fibrin degradation products of 40-320 micrograms/ml were observed in 6 cases with hypofibrinogenemia, and in 8 other cases. Nineteen patients had short euglobulin lysis times of 51.8 +/- 24.7 min. Hyperfibrinogenemia of 626.7 +/- 288.9 mg/dl was found in 18 cases. Apart from bleeding, there were no systemic symptoms. Hypofibrinogenemia became normal in 3-12 days. The clinical course in all patients was uneventful, and none received antivenin.

Adolescent↗
PubMedDate not supplied

Effects of pH and lysine during detoxification of a hemorrhagic principle of Habu snake (Trimeresurus flavoviridis) venom with formalin on the immunogenicity of the toxoid.

A hemorrhagic principle (HR1B) isolated from the venom of Habu snake (Trimeresurus flavoviridis) was detoxified with formalin at pH 5, 7 and 9. Higher pH shortened the period needed for detoxification and lowered the final formalin concentration required for complete detoxification. The extent of polymerization and the immunogenicity of the toxoid formed were dependent upon pH during detoxification; the lower the pH, the higher the extent of polymerization and the immunogenicity of the toxoid. The higher immunogenicity possessed by the toxoid with higher extent of polymerization was confirmed by fractionation of the toxoid prepared at pH 7 on Sephadex G-200 and by comparing the immunogenicity of the toxoid fractions. The presence of lysine during detoxification brought about a partially polymerized toxoid having new immunogenic characteristics and a higher immunogenicity.

Animals↗
PubMed1999

Partial amino acid sequence and biological characterization of elegatoxin, hemorrhagic toxin from Trimeresurus elegans (Sakishimahabu) venom.

A hemorrhagic toxin, designated Elegatoxin, was isolated from the venom of Trimeresurus elegans using HW-55, DEAE-Sephacel, CM-Cellulose and Mono S column chromatographies. The purified toxin was shown to be homogeneous by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis, isoelectric electrophoresis, and Ouchterlony immunodiffusion. Elegatoxin has a molecular weight of 26,000 with an isoelectric point of 8.6. The toxin demonstrated both hemorrhagic and proteolytic activities. Hemorrhagic activity was inhibited by ethylenediaminetetraacetic acid (EDTA), ethyleneglycol-bis-(2-amino-ethylether)N,N'-tetraacetic acid (EGTA), o-phenanthroline, and N-bromosuccinimide, but not by amidinophenylmethanesulfonyl fluoride hydrochloride (APMSF). The minimum hemorrhagic dose was found to be 0.8 microgram/mouse. Elegatoxin possesses proteolytic activity as evidenced by hydrolyzing type IV collagen, actin and the A alpha, B beta, and gamma chains of bovine fibrinogen. This purified toxin contains 1 mol of zinc and 2 mols of calcium per mol of protein and a partial amino acid sequence was determined. The pathological and biochemical properties of Elegatoxin were investigated, and these results are reported in this paper.

Amino Acid Sequence↗
PubMed2001

Thrombin-like enzyme, flavovilase, with kinin-releasing activity from Trimeresurus flavoviridis (habu) venom.

A thrombin-like enzyme, flavovilase, with kinin-releasing activity was isolated, purified, and characterized from the venom of Trimeresurus flavoviridis (habu) using Sephadex G-100, DEAE-Cellulose, and CM-Cellulose column chromatographies. The final preparation was homogeneous as demonstrated by a single band on polyacrylamide gel electrophoresis, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and isoelectric focusing electrophoresis. The enzyme possesses a molecular weight of 26,500, an isoelectric point of 5.0, and consists of 247 total amino acid residues. Specific electrolytic activities of this enzyme on N-tosyl-L-arginine methyl ester (TAME) and N-benzoyl-L-arginine ethyl ester (BAEE) were determined to be 50.9 and 17.4 micromol/min/mg, respectively. The enzyme was inhibited by p-APMSF (p-amidinophenylmethanesulfonyl fluoride hydrochloride), beta-mercaptoethanol, and N-bromosuccinimide. Additionally, the enzyme was found stable to heat treatment. It was also observed that the enzyme cleaved a kininogen analog with the release of bradykinin.

Animals↗
PubMed2002

Alboluxin, a snake C-type lectin from Trimeresurus albolabris venom is a potent platelet agonist acting via GPIb and GPVI.

Alboluxin, a potent platelet activator, was purified from Trimeresurus albolabris venom with a mass of 120 kDa non-reduced and, after reduction, subunits of 17 and 24 kDa. Alboluxin induced a tyrosine phosphorylation profile in platelets that resembles those produced by collagen and convulxin, involving the time dependent tyrosine phosphorylation of Fc receptor gamma chain (Fc gamma), phospholipase Cgamma2 (PLCgamma2), LAT and p72SYK. Antibodies against both GPIb and GPVI inhibited platelet aggregation induced by alboluxin, whereas antibodies against alpha2beta1 had no effect. Inhibition of alphaIIb beta3 reduced the aggregation response to alboluxin, as well as tyrosine phosphorylation of platelet proteins, showing that activation of alphaIIb beta3 and binding of fibrinogen are involved in alboluxin-induced platelet aggregation and it is not simply agglutination. N-terminal sequence data from the beta-subunit of alboluxin indicates that it belongs to the snake C-type lectin family. The C-type lectin subunits are larger than usual possibly due to post-translational modifications such as glycosylation. Alboluxin is a hexameric (alphabeta)3 snake C-type lectin which activates platelets via both GPIb and GPVI.

Alprostadil↗
PubMed1999

A Novel Myotoxin from the Venom of Trimeresurus mucrosquamatus.

A novel myotoxin, designated TMPB, was purified from the venom of Trimeresurus mucrosquamatus by Sephadex G-100 superfine gel chromatography and fast protein liquid chromatography (FPLC). The N-terminal sequence of 24 amino acid residues was determined by protein sequencer. The sequence similarities between TMPB and other two phospholipase A(2) (PLA2s) previously purified from the same venom were 41.7% and 54.2%, respectively, but TMPB showed no detectable PLA(2) hydrolytic activity. Its molecular weight was estimated to be 16 000 by reducing SDS-PAGE and isoelectric point was determined to be 9.2 by isoelectric focusing electrophoresis. TMPB exhibited strong myotoxicity and platelet aggregation inhibiting activity, and the two activities could all be inhibited by heparin.

Journal Article↗
PubMed2002

A novel low molecular weight hemorrhagic toxin from Trimeresurus flavoviridis (Vorojima) venom.

A low molecular weight hemorrhagic toxin, LMHT, was isolated from the venom of Trimeresurus flavoviridis from Yorojima using Q-Sepharose column chromatography. The purified hemorrhagic toxin was homogeneous by disc polyacrylamide gel electrophoresis at pH 8.3, and Ouchterlony immunodiffusion. LMHT has a molecular weight of 16,500 and possesses hemorrhagic activity. It did not show casein, azocasein, azoalbumin, or TAME (tosyl-L-arginine methyl ester hydrochloride) hydrolytic activities. Hemorrhagic activity was inhibited by EDTA, TEP (tetraethylenepentamine), p-APMSF(p-amidinophenylmethanesulfonylfluoride HCl), and N-bromosuccinimide. The minimum hemorrhagic dose of this hemorrhagic toxin was 7.1 microg/mouse. LMHT induced hydrolysis of the Aa and Bbeta chains of bovine fibrinogen.

Animals↗
PubMed1996

Purification and Characterization of Phospholipase A(2) from the Venom of Snake Trimeresurus stejnegeri Schmidt.

A phospholipase A(2)(PLA(2)) was purified from the venom of the snake Trimeresurus stejnegeri Schmidt by Sephadex G-75 gel filtration, Mono Q ion exchange chromatography and Superose-12 gel filtration with FPLC and proved to be homogeneous as shown in SDS-PAGE and IEF. Its molecular weight is around 18 000 and isoelectric point is 4.7. Amino acid composition of PLA(2) was determined. Apart from hydrolyzing phosphatidylcholine, the enzyme has a potent inhibitory effect on platelet aggregation induced by ADP or collagen with half-inhibitory concentration of 10-15 &mgr;g/ml and 50-80 &mgr;g/ml respectively.

Journal Article↗
PubMed2002

L-amino acid oxidase from Trimeresurus jerdonii snake venom: purification, characterization, platelet aggregation-inducing and antibacterial effects.

An L-amino acid oxidase (LAO), designated as TJ-LAO, was purified to homogeneity from the venom of Trimeresurus jerdonii by Sephadex G-100 and Q Sepharose HP chromatography. The molecular weight of this enzyme was 110 kD as estimated by analytical gel filtration and was 55 kD by SDS-polyacrylamide gel electrophoresis, suggesting that the enzyme is composed of two subunits. The enzyme has an absorption spectrum characteristic of flavoproteins, containing 2 moles of FMN per mole of enzyme. The N-terminal sequence of TJ-LAO shares high homology with other viperid snake venom LAOs. Homology with elapid venom LAO is lower. TJ-LAO inhibited the growth of Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Bacillus megaterium. The antibacterial effect associated with LAO activity was elminated with the addition of catalase. Platelets in platelet-rich plasma aggregated upon the addition of TJ-LAO. The enzyme-induced aggregation was inhibited by catalase, suggesting formation of H2O2 was essential for TJ-LAO to induce platelet aggregation. These results showed H2O2 formation is important for the biological effects of LAO.

Amino Acid Oxidoreductases↗
PubMed2003

Purification, characterization and biological activity of an L-amino acid oxidase from Trimeresurus mucrosquamatus venom.

An L-amino acid oxidase (TM-LAO) from the venom of Hunan Trimeresurus mucrosquamatus was purified to homogeneity by three steps including DEAE Sephadex A-50 ion-exchange chromatography, Sephadex G-75 gel filtration and Resource Q ion-exchange chromatography. TM-LAO is composed of two identical subunits with a molecular weight of 55 kD by SDS-polyacrylamide gel electrophoresis. The molecular weight was different with that of LAO purified from the same species distributed in Taiwan that was 70 kD. The 24 N-terminal amino acid sequence of TM-LAO is ADNKNPLEECFRETNYEEFLEIAR, which shares high similarity with other Viperid snake venom LAOs and has moderate similarity with Elapid snake venom LAOs. Further studies found that TM-LAO inhibited the growth of E. coli, S. aurues and B. dysenteriae. TM-LAO also showed cytotoxicity and platelet aggregation activity. All the biological activities were eliminated by catalase, a H(2)O(2) scavenger. It was shown that these biological effects were possibly due to the formation of H(2)O(2) produced by TM-LAO.

Amino Acid Oxidoreductases↗
PubMed2003

Characterization of a new bradykinin-potentiating peptide (TmF) from Trimeresurus mucrosquamatus.

A novel bradykinin-potentiating peptide (BPP), designated as TmF, has been purified to homogeneity from the venom of Trimeresurus mucrosquamatus by 70% cold methanol extraction, Sephadex G-15 gel filtration and reverse-phase high performance liquid chromatography (RP-HPLC). The amino acid sequence of TmF was determined to be pGlu-Gly-Arg-Pro-Leu-Gly-Pro-Pro-Ile-Pro-Pro (pGlu denotes pyroglutamic acid), which shared high homology with other BPPs. The molecular mass of TmF was 1.1107 kD as determinated by electrospray ionization-mass spectrometry (ESI-MS), which was in accordance with the calculated value of 1.1106 kD. The potentiating unit of TmF to bradykinin-induced (BK-induced) contraction on the guinea-pig ileum in vitro was (1.13 +/-0.3) unit (mg/L), and TmF (5.0 x10(-4) mg/kg) increased the pressure-lowering-effect of bradykinin (5.0 x10(-5 )mg/kg) with approximate descent value of (14 +/-2) mmHg. In addition, TmF inhibited the conversion of angiotensin I to angiotensin II, 2 x10(-3) mg of TmF caused 50% inhibition (IC(50)) of angiotensin- converting enzyme (ACE) hydrolyzing activity to bradykinin.

Amino Acid Sequence↗
PubMed1992

Myotoxicity and physiological effects of three Trimeresurus flavoviridis phospholipases A2.

When basic proteins I and II from Trimeresurus flavoviridis (Habu snake) venom, which are Lys-49-phospholipase A2 (PLA2) with low activity, were injected intramuscularly into mice, myonecrosis was induced accompanied by a rapid increase of plasma creatine kinase level. This increase was about 2 times greater than that raised by highly active T. flavoviridis Asp-49-PLA2 which has been regarded as a myotoxic factor. Calcium-dependent depolarization of frog muscle fibers was observed with basic proteins I and II but not with Asp-49-PLA2. Indirect hemolysis of rat erythrocytes was induced by Asp-49-PLA2 but not by basic proteins I and II. Myotoxicity and depolarization effects appear to be not necessarily related to lipolytic activity of proteins although hemolytic effects is in parallel to lipolytic potency. Light microscopic observations of muscle preparations treated with three PLA2s showed similar histological changes, i.e., myolytic necrosis without hemorrhage and infiltration of polymorphonuclear cells. The structural and functional elements of PLA2s for eliciting myotoxicity are discussed.

Amino Acid Sequence↗
PubMed2003

Jerdonase, a novel serine protease with kinin-releasing and fibrinogenolytic activity from Trimeresurus jerdonii venom.

A novel kinin-releasing and fibrin(ogen)olytic enzyme termed jerdonase was purified to homogeneity from the venom of Trimeresurus jerdonii by DEAE Sephadex A-50 anion exchange, Sephadex G-100 (superfine) gel filtration and reverse-phase high performance liquid chromatography (RP-HPLC). Jerdonase migrated as a single band with an approximate molecular weight of 55 kD under the reduced conditions and 53 kD under the non-reduced conditions. The enzyme was a glycoprotein containing 35.8% neutral carbohydrate. The N-terminal amino acid sequence of jerdonase was determined to be IIGGDECNINEHPFLVALYDA, which showed high sequence identity to other snake venom serine proteases. Jerdonase catalyzed the hydrolysis of BAEE, S-2238 and S-2302, which was inhibited by phenylmethylsulfonyl fluoride (PMSF), but not affected by ethylenediaminetetraacetic acid (EDTA). Jerdonase preferentially cleaved the A alpha-chain of human fibrinogen with lower activity towards B beta-chain. Moreover, the enzyme hydrolyzed bovine low-molecular-mass kininogen and releasing bradykinin. In conclusion, all results indicated that jerdonase was a multifunctional venom serine protease.

Amino Acid Sequence↗
PubMed1992

Characterization of three alboaggregins purified from Trimeresurus albolabris venom.

Alboaggregins (AL-A, AL-B, AL-C) isolated from Trimeresurus albolabris snake venom represent a new family of proteins which bind to platelet glycoprotein Ib (GPIb). These alboaggregins were purified to homogeneity with ion exchange HPLC (Mono-Q column) and hydrophobic HPLC (TSK Phenyl-5PW column). On SDS-polyacrylamide gel electrophoresis, apparent molecular weights of AL-A, AL-B and AL-C were 52 kDa, 26 kDa, and 121 kDa respectively, under nonreducing conditions. Upon reduction, each alboaggregin showed two types of chains with apparent molecular weights in the range of 15-20 kDa. All three alboaggregins agglutinated formalin-fixed platelets. Agglutination activities and binding of labeled alboaggregins to GPIb were specifically inhibited by the monoclonal antibody AK2 which is directed against the 45 kDa N-terminal region on GPIb, but not by monoclonal antibodies against other epitopes on GPIb. 125I-alboaggregin binding to platelets was not altered by the presence of thrombin. Alboaggregins did not bind to GPIIb/IIIa. Alboaggregins were competitive inhibitors for 125I-bovine vWF binding to platelets. Mutual competition studies between AL-A, AL-B and AL-C for the binding of labeled bovine vWF and AL-B to platelets demonstrated that AL-B and AL-C had a significantly higher affinity than AL-A.

Agglutination↗
PubMed1991

Mechanism of action of a potent antiplatelet peptide, triflavin from Trimeresurus flavoviridis snake venom.

Triflavin, an antiplatelet peptide from Trimeresurus flavoviridis snake venom, inhibits aggregation of human platelets stimulated by a variety of agonists. However, triflavin does not affect the shape change and release reaction of platelets stimulated by thrombin and collagen. In this paper, we further investigate its effect on the intracellular events occurring after the activation of platelets. Triflavin does not inhibit the intracellular free calcium rise of Quin 2-AM loaded platelets stimulated by thrombin and it also has no significant effect on thromboxane B2 formation of platelets stimulated by thrombin. Triflavin does not affect the 3(H)-inositol monophosphate formation of the 3(H)-myoinositol loaded platelets. However, triflavin dose-dependently inhibits fibrinogen-induced aggregation and 125I-fibrinogen binding of ADP-stimulated platelets. In addition, triflavin dose-dependently blocks fibrinogen-induced aggregation of elastase-treated platelets. It is concluded that triflavin specifically inhibits fibrinogen binding to fibrinogen receptors associated with glycoprotein IIb/IIIa complex on platelet membrane surface without any inhibitory effect on the platelet-activation process.

Adenosine Diphosphate↗