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PubMed2000

Edema factor from the venom of Trimeresurus elegans (Sakishimahabu).

An edema factor was isolated from the venom of Trimeresurus elegans using HW-55, CM-Cellulose, and Mono S column chromatographies. Homogeneity was demonstrated by the formation of a single band in polyacrylamide gel electrophoresis (pH 8.3). The edema factor has a molecular weight of 25,500, an isoelectric point of 7.5, and express edema, proteolytic and capillary permeability-increasing activities. Edema, proteolytic and capillary permeability-increasing activities are inhibited by ethylenediaminetetraacetic acid (EDTA), o-phenanthroline, and N-bromosuccinimide. Additionally, this factor exhibits kinin-releasing activity. The edema factor possesses proteolytic activity as shown by hydrolyzing the Val(3)-Asn(4), His(5)-Leu(6), Ser(9)-His(10), Ala(14)-Leu(15), Leu(15)-Tyr(16), Tyr(16)-Leu(17), and Glu(21)-Arg(22) bonds of oxidized insulin B chain. The A alpha, B beta, and gamma chains of human fibrinogen were also hydrolyzed. The edema factor was found to contain 1 mol of zinc and 2 mols of calcium per mol of protein and the amino-terminal sequence was determined.

Amino Acid Sequence↗
PubMed2000

A new thrombin-like enzyme, flavoviridiobin from the venom of Trimeresurus flavoviridis (habu).

Fibrinopeptide A and B releasing enzyme, flavoviridiobin, was isolated from the venom of Trimeresurus flavoviridis using Q-Sepharose, CM-Cellulose, and Sephadex G-75 column chromatographies. Homogeneity was established by the formation of a single band in polyacrylamide gel electrophoresis, isoelectric focusing, and Ouchterlony immunodiffusion. The enzyme has a molecular weight of 48,000, isoelectric point of 8.1, consists of 237 total amino acid residues, and demonstrates clotting activity. However, no tosyl-L-arginine methyl ester (TAME) hydrolytic and kinin-releasing activities were observed. This clotting enzyme was inhibited by p-amidinophenylmethanesulfonyl fluoride hydrochloride (p-APMSF), benzamidine, and beta-mercaptoethanol, suggesting that serine, acidic amino acids, and disulfide bonds are involved in the expression of the enzyme's clotting activity. This thrombin-like enzyme hydrolyzes B beta-chain of human fibrinogen at first, followed by hydrolysis A alpha-chain. The enzyme was stable over the pH range of 7-10 and was shown to be heat resistant.

Animals↗
PubMed2002

Biochemical and biological properties of Trimeresurus jerdonii venom and characterization of a platelet aggregation-inhibiting acidic phospholipase A2.

Several biochemical and biological activities such as phospholipase A2, arginine esterase, proteolytic, L-amino acid oxidase, 5'nucleotidase, acetylcholinesterase, thrombin-like, anticoagulant, and hemorrhagic activities were determined for whole desiccated venom of Trimeresurus jerdonii. An acidic phospholipase (named TJ-PLA2) was purified by anionic exchange chromatography, gel filtration, and reverse phase HPLC. TJ-PLA2 had a molecular weight of 16,000 and a pI of 4.8. TJ-PLA2 was non-lethal to mice up to an i.p. dose of 15 mg/kg body weight and lacked neurotoxicity and myotoxicity. It induced edema in the footpads of mice. The purified enzyme inhibited ADP- and collagen-induced human platelet aggregation in a manner which was both dose- and time-dependent.

Animals↗
PubMed2002

Characterization of Habu thrombin-like enzyme (THLE) with a new n-terminal sequence from the venom of Trimeresurus flavoviridis (Habu).

A thrombin-like enzyme with a new amino-terminal sequence was isolated from the venom of Trimeresurus flavoviridis using Q-Sepharose, CM-Cellulose, and HW55 column chromatographies. Homogeneity was confirmed by the formation of a single band in polyacrylamide gel electrophoresis. The enzyme has a molecular weight of 29,000 Da. This thrombin-like enzyme was inhibited by p-amidinophenylmethanesulfonyl fluoride hydrochloride (p-APMSF), and dithiothreitol (DTT) suggesting that serines and disulfide bonds are involved in the expression of the enzyme's clotting activity. This thrombin-like enzyme hydrolyzes the Aalpha-chain and Bbeta-chain of bovine fibrinogen. The enzyme was stable to heat treatment.

Animals↗
PubMed2002

Purification and characterization of alpha-mucrofibrase, a novel serine protease with alpha-fibrinogenase activity from the venom of Chinese Habu (Trimeresurus mucrosquamatus).

A novel fibrinogenolytic protease, named alpha-mucrofibrase, was purified from the venom of Chinese Habu (Trimeresurus mucrosquamatus) by DEAE-Sephadex A-50 ion-exchange chromatography and Sephadex G-100 (super fine) gel filtration alpha-Mucrofibrase is a single-chain polypeptide of approximately 29 kDa. It is stable even at 95 degrees C, and the most susceptible hydrolysis substrate is S-2302. It cleaved primarily the Aalpha chain of fibrinogen followed by the Bbeta chain, while the gamma chain was partially affected. N-terminal sequence of this fibrinogenolytic enzyme has great homology with those of other snake venom serine proteases. The esterase activity of alpha-mucrofibrase is inhibited by phenylmethylsulfonyl fluoride (PMSF) but not by metal chelator (EDTA), suggesting this fibrinogenase belongs to the venom serine protease family.

Amino Acid Sequence↗
PubMed1993

Clinical features and hospital management of bites by the white-lipped green pit viper (Trimeresurus albolabris).

The clinical features and hospital management of 31 patients who were bitten by the white-lipped green pit viper (Trimeresurus albolabris) in Hong Kong are reviewed. The cardinal features in these patients were local pain and swelling and mild coagulation abnormalities. Hospital management should include prophylaxis against tetanus, analgesics and measures to reduce local effects such as elevation of the limb. The benefits of the use of prophylactic antibiotics remain to be established. Severe coagulation disturbances were uncommon and responded to fresh frozen plasma and platelet transfusion.

Adolescent↗
PubMed1998

Biological properties of kinin-releasing enzyme from Trimeresurus okinavensis (himehabu) venom.

A kinin-releasing enzyme was isolated and characterized from the venom of Trimeresurus okinavensis (himehabu) using Sephadex G-100, DEAE-Cellulose, and CM-Cellulose column chromatographies. The kinin-releasing enzyme was homogeneous as demonstrated by a single band on polyacrylamide gel electrophoresis, and isoelectric focusing. The enzyme possesses a molecular weight of 31,000 Da and isoelectric point of 8.2 and consists of 312 total amino acid residues. Specific esterolytic activities of the kinin-releasing enzyme on N-tosyl-L-arginine methyl ester (TAME) and N-benzoyl-L-arginine ethylester (BAEE) were determined to be 235.3 and 111.3 mumol/min/mg, respectively. The enzyme was inhibited by p-APMSF (p-amidinophenylmethanesulfonyl fluoride hydrochloride) and benzamidine. Additionally, the enzyme was found stable to heat treatment. The enzyme cleaved a kininogen analog with the release of bradykinin, resulting in an immediate drop in blood pressure, and contractions of the rat uterus were also observed.

Animals↗
PubMed1988

Transition of environmental polarity of tyrosine-76 of Trimeresurus flavoviridis phospholipase A2 upon active site ligand binding.

Modification of Trimeresurus flavoviridis phospholipase A2 with a 5-fold molar excess of tetranitromethane produced 40% active mononitrotyrosyl phospholipase A2 in which Tyr-76 was specifically nitrated. This is in contrast to the case of mammalian pancreatic phospholipases A2 where Tyr-70 but not Tyr-76 was nitrated. When Ca2+ was bound to T. flavoviridis mononitrotyrosyl phospholipase A2, nitrated tyrosine (Tyr(NO2))-76 moved from a less polar site to a polar site with the decrease of the pKa value of its hydroxyl group. Nitration of Tyr-76 did not influence the binding affinity to Ca2+. Addition of laurylphosphorylcholine to mononitrotyrosyl phospholipase A2 in the presence of Ca2+ caused the movement of Tyr(NO2)-76 from a polar environment to a less polar environment with the rise in the pKa value. Tyrosine-76 is located in the site whose environmental polarity is affected by the binding of the ligands to the active site. As Tyr-76 is located in the site not proximal to the active site, it could be assumed that the conformational change induced by the binding of the ligands extends to the region remote from the active site in T. flavoviridis phospholipase A2. This might provide evidence of long-range diffusional coupling between remote sites in the noncooperative globular protein.

Amino Acid Sequence↗
PubMedDate not supplied

Trimeresurus flavoviridis venom gland phospholipase A2 isozymes genes have evolved via accelerated substitutions.

As a step towards understanding the structure and function of phospholipases A2 (PLA2s), five cDNAs encoding Trimeresurus flavoviridis venom gland PLA2 isozymes have been sequenced. They revealed that the 5' and 3' untranslated regions are much more homologous than the protein-coding regions and that base substitutions have occurred at similar rates for the three positions of codons in the protein-coding regions. Such novel findings are of great interest from the viewpoint of molecular evolution. To gain a further insight into this evolutional phenomenon, we have isolated and sequenced six T. flavoviridis PLA2 isozyme genes. Each gene consisted of four exons and three introns and encoded protein of 138 amino-acid residues, including the signal sequence of 16 amino-acid residues. The introns were much more homologous than the protein-coding regions of exons except for the signal peptide-coding region of the first exon. The absence of apparent functional role in the introns suggested that the protein-coding regions, except for the signal peptide-coding domains, have evolved at greater substitution rates than introns. The fact that the numbers of nucleotide substitutions per non-synonymous site are close to or larger than the numbers of nucleotide substitutions per synonymous site for relevant pairs of genes revealed that Darwinian-type accelerated substitutions have occurred in the protein-coding regions of exons. This is compatible with the presence of PLA2 species with diverse physiological activities in the venom.

Amino Acid Sequence↗
PubMed2001

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 PLA2s were determined by sequencing the corresponding cDNAs from the venom gland and shown to be consistent with their molecular weight data and the N-terminal sequences. All the geographic venom samples of C. rhodostoma contain a major noncatalytic basic PLA2-homolog and two or three acidic PLA2s in different proportions. These acidic PLA2s contain Glu6-substitutions and show distinct inhibiting specificities toward the platelets from human and rabbit. We also found that the T. mucrosquamatus venoms from North Taiwan but not those from South Taiwan contain an Arg6-PLA2 designated as TmPL-III. Its amino acid sequence is reported for the first time. This enzyme is structurally almost identical to the low- or nonexpressed Arg6-PLA2 from C. rhodostoma venom gland, and thus appears to be a regressing venom component in both of the Asian pitvipers.

Amino Acid Sequence↗
PubMed1995

Characterization of multiple metalloproteinases with fibrinogenolytic activity from the venom of Taiwan habu (Trimeresurus mucrosquamatus): protein microsequencing coupled with cDNA sequence analysis.

Three fibrinogenolytic proteases were isolated and purified from the venom of Taiwan habu (Trimeresurus mucrosquamatus) using anion-exchange and gel-filtration chromatographies followed by cation-exchange HPLC. Further characterization of these purified fractions with fibrinogenase activity indicated that they are single-chain proteases of approximately 24 kDa, possessing strong cleaving activity mainly on the A alpha and less on B beta and gamma chains of fibrinogen subunit chains. Enzyme activities were strongly inhibited by EDTA or 1,10-phenanthroline and not by phenylmethanesulfonyl fluoride, suggesting that these fibrinogenases belong to the family of metalloproteinases and not thrombin-like serine proteases. N-Terminal sequence analysis of these proteases failed to show any free amino-terminal residues, thus hampering the sequence determination by conventional sequencing strategy. Microsequencing on the electroblotted fragments of CNBr-treated proteases separated on SDS-PAGE was then used to determine the partial sequences. Sequence comparison of the determined partial sequences of these proteins with published sequences of the protein data bank revealed that they showed sequence homology with H2-protease. HR2a and protrigramin, which were all shown to belong to metalloproteinases present in various snake venoms. Polymerase chain reaction (PCR) was employed to amplify cDNAs constructed from the poly(A)+RNA of fresh venom glands of the same snake species to facilitate cloning and sequencing of these proteases. Sequencing several positive clones containing amplified cDNAs revealed the existence of one fibrinogenase in the Taiwan habu, which was contained within one complete cDNA encoding the preproproteinase precursor of hemorrhagic metalloproteinases.

Amino Acid Sequence↗
PubMed1991

Rat hind-paw swelling effect of an edema-producing protein isolated from Trimeresurus mucrosquamatus snake venom.

TMV F-IV, isolated from the venom of Trimeresurus mucrosquamatus (TMV), caused rat hind-paw edema in a dose-dependent manner. The maximum hind-paw swelling was reached at 1.5-2 h after subplantar injection of TMV F-IV. The edematous response caused by TMV F-IV was suppressed by the s.c. pretreatment with diphenhydramine, methysergide, acetylsalicylic acid or dexamethasone, and by the subplantar co-injection with FPL 55712, a SRS-A antagonist, and BN 52021 or L 652731, both PAF antagonists. Polymorphonuclear (PMN) leukocyte infiltration appeared within 1 h and gradually increased in the rat paw 3-6 h after edema induction. Compound 48/80 or methotrexate pretreatment also inhibited paw edema caused by TMV F-IV. In isolated mast cells, TMV F-IV increased the formation of PGE2 and LTB4 and caused a dose-dependent release of histamine and beta-glucuronidase. Since there are no significant differences in paw edema and mast cell degranulation responses between TMV F-IV and its DFP-modified analogue, the esterase activity may not be necessary in these models. These results indicate that mast cells. PMN leukocytes and some inflammatory mediators such as histamine, serotonin, arachidonate metabolites and PAF are involved in TMV F-IV induced paw edema.

Animals↗
PubMed1977

Physicochemical properties of alpha- and beta-fibrinogenases of Trimeresurus mucrosquamatus venom.

alpha- and beta-Fibrinogenases (EC 3.4.21.5) were purified from Trimeresurus mucrosquamatus venom by the technique of recycling chromatography. Both enzymes were single polypeptide chains and homogeneous as judged by sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis and ultracentrifugation. The sedimentation constants of alpha- and beta-fibrinogenases were 2.52 and 3.04 respectively. The molecular weight of alpha-fibrinogenase was 21 500--23 400, and that of beta-fibrinogenase was 25 000--26 000. The contents of proline, glycine and tryptophan were higher in beta-fibrinogenase than in alpha-fibrinogenase. The isoelectric points of alpha- and beta-fibrinogenases were pH 8.1 and 5.7 respectively. The optimal pH of alpha-fibrinogenase was about 7.4 and that of beta-fibrinogenase was around 8.5. The activity of alpha-fibrinogenase was completely destroyed after 30 min at 60 degrees C, pH 5.6, 7.4 and 9.0, while that of beta-fibrinogenase was not significantly affected by the same treatment. Both enzymes showed proteolytic activities toward fibrinogen and casein, but were devoid of phospholipase A, alkaline phosphomonoesterase and phosphodiesterase activities of the crude venom. The tosyl-L-arginine methylester esterase activity of beta-fibrinogenase was about 17 times that of the crude venom, while alpha-fibrinogenase was completely devoid of this activity. The fibrinogenolytic activity of alpha-fibrinogenase was markedly inhibited by EDTA and cysteine, while that of beta-fibrinogenase was inhibited markedly by phenylmethane sulfonylfluoride and slightly by tosyl-L-lysine chloromethylketone and cysteine.

Amino Acids↗
PubMed1979

Alpha and beta-fibrinogenases from Trimeresurus gramineus snake venom.

By means of DEAE-Sephadex A-50 Column chromatography, Trimeresurus gramineus venom was separated into twelve fractions. The fibrinogenolytic activities were distributed in Fractions 1 and 10. These enzymes were further purified by gel filtration and were homogeneous as judged by cellulose acetate membrane, sodium dodecyl sulfate polyacrylamide gel electrophoresis and ultracentrifugal analysis. Both of them were single peptide chains. The sedimentation constants of alpha- (Fraction 1) and beta-fibrinogenases (Fraction 10) were 2.20 and 3.60, respectively. The molecular weights of alpha- and beta-fibrinogenases were 23 500 and 25 000 respectively. The contents of proline and glycine were higher in beta-fibrinogenase than in alpha-fibrinogenase. The isoelectric points of alpha-fibrinogenase and beta-fibrinogenase were pH greater than 10 and 4.5, respectively. The optimal pH of alpha-fibrinogenase was approx. 7.4 and that of beta-fibrinogenase was approx. 9.0. The activity of alpha-fibrinogenase was completely destroyed after 30 min at 60 degrees C, pH 5.4, 7.4 and 9.0, while that of beta-fibrinogenase was much less affected by the same treatment. The specific fibrinogenolytic activity alpha-fibrinogenase was 31 mg fibrinogen/min per mg protein, while that of beta-fibrinogenase was 9 mg fibrinogen/min per mg protein. alpha-Fibrinogenase cleaved specifically the alpha(A) chain of monomeric fibrinogen without cleaving the beta(B) chain and gamma-chain. beta-fibrinogenase preferentially cleaved the beta(B) chain, and the alpha(A) chain was also partially cleaved by beta-fibrinogenase, if the incubation time was prolonged. Both enzymes showed proteolytic activities toward fibrinogen, fibrin and casein, but were devoid of phospholipase A, alkaline phosphomonoesterase and phosphodiesterase activities found in the crude venom. The tosyl-L-arginine methylester esterase activity of beta-fibrinogenase was about 14 times that of crude venom, while alpha-fibrinogenase was completely devoid of this activity. The fibrinogenolytic activity of alpha-fibrinogenase was markedly inhibited by EDTA and cysteine, while that of beta-fibrinogenase was inhibited markedly by phenylmethanesulfonylfluoride. alpha- and beta-fibrinogenases exert their fibrinogenolytic activity by a direct action on fibrinogen or fibrin without activation of plasminogen.

Animals↗
PubMed1975

Purification and properties of the anticoagulant principle of Trimeresurus gramineus venom.

By means of DEAE-Sephadex A-50 column chromatography, Trimeresurus gramineus venom was separated into 12 fractions. Fraction 8 had marked anticoagulant action in the tests of whole blood clotting time, calcium clotting time and plasma prothrombin time. Fraction 8 was rechromatographed on Sephadex G-100, then on DEAE-Sephadex A-50 again, and finally on Sephadex G-100, and a single peak was obtained. The patterns of microzone and disc electrophoresis also showed a single band. A single symmetrical boundary with 1.70 Svedberg units was obtained by ultracentrifugation. The estimated molecular weight was 19 500. The isoelectric point was pH 4.5. Chemical analysis showed that the anticoagulant principle was a glycoprotein and that it was thermolabile. The anticoagulant activity of this purified principle was 3.5 times higher than that of the crude venom. Fraction 5 potentiated its anticoagulant activity to 10 times higher than that of the crude venom. This principle did not possess caseinolytic, tosyl-L-arginine methyl ester esterase, phospholipase A, phosphodiesterase, alkaline phosphomonoesterase, fibrinolytic, hemorrhagic or local irritating activities. The purified anticoagulant principle did not destroy fibrinogen, induce fibrinolysis, inactivate thrombin nor interfere with the interaction between thrombin and fibrinogen. However, a marked inhibition of prothrombin activation was caused by the anticoagulant principle. The inhibition of prothrombin activation was not due to the destruction of prothrombin or its activation factors, but due to an interference in the interaction between prothrombin and its activation factors because of the reversible binding of these factors with the anticoagulant principle of the venom.

Amino Acids↗
PubMed1976

Fibrinogenolytic enzymes of Trimeresurus mucrosquamatus venom.

By means of CM-Sephadex C-50 column chromatography, Trimeresurus mucrosquamatus venom was separated into twenty fractions. The fibrinogenolytic activity was concentrated in Fractions 8, 10, 12, 13 and 14. Fractions 8 adn 13 had the highest ratio of fibrinogenolytic and caseinolytic activities. Fraction 8 possessed tosyl-L-arginine methyl esterase activity, while the others did not. The caseinolytic activities of Fractions 10, 12, 13 and 14 were inhibited by EDTA, while that of Fraction 8 was not. Fractions 8 and 13 were further purified by CM-cellulose and gel filtration and were homogeneous as judged by electrophoresis on polyacrylamide gel and cellulose acetate membrane. The molecular weights of the purified Fractions 8 and 13 were 26 000 and 22 400, respectively. Both were single peptide chains. The specific fibrinogenolytic activity of Fraction 8 was 17 mg fibrinogen/min/mg protein, while that of Fraction 13was 100 mg fibrinogen/min/mg protein. Fraction 13 digested specifically the alpha(A) chain of monomeric fibrinogen to yield two cleavage products. Fraction 8 digested the beta(B) chain first to yield four cleavage products. When the incubation time was prolonged, the alpha(A) chain was also partially digested by Fraction 8 to yield two cleavage products.

Animals↗
PubMed1979

Resolution of the major hemorrhagic component of Trimeresurus flavoviridis venom into two parts.

1. The major hemorrhagic component (HR1) in the venom of Trimeresurus flavoviridis was purified further by gel filtration on Sephadex G-200, superfine, resulting in its resolution into two parts, 1A and 1B. 1A possessed proteolytic activity towards casein, while 1B was almost free from such activity. Both components were associated with lethal toxicity. 2. The purified preparations of 1A and 1B were homogeneous as judged by several criteria. The molecular weights of the purified principles determined by dodecyl sulfate gel electrophoresis were approximately 60 000. 1A shows anomalous behaviour on ultracentrifugation and gel filtration owing to concentration-dependent polymeric interaction. The purified components were acidic glycoproteins with isoelectric points of 4.4 and they contained neutral sugar, amino sugar and sialic acid altogether amounting to 17-18% on the total weight basis. 3. The two hemorrhagic components were closely related, if not identical, immunologically.

Animals↗
PubMed1988

Rat paw edema induced by trimucase II, a kinin-releasing enzyme from Trimeresurus mucrosquamatus venom.

Trimucase II, a proteolytic enzyme isolated from Trimeresurus mucrosquamatus venom, caused rat hind-paw edema dose dependently. Captopril potentiated significantly, while pretreatment with cellulose sulfate suppressed the trimucase II-induced edematous response. Pretreatment with diphenhydramine and methysergide reduced by 42 and 46% the edema induced by trimucase II and kallikrein, respectively. The residual response was significantly further depressed by [Thi5,8,D-Phe7]bradykinin and trasylol. Kinin generation by trimucase II was also found in vitro from plasma and was concentration- and time-dependent. Kinin formation was inhibited by soybean trypsin inhibitor, trasylol and endogenous kininase. The kinins released were destroyed by chymotrypsin. Unlike cellulose sulfate, trimucase II caused kinin formation from Factor XII-deficient and prekallikrein-deficient plasma but not from high molecular weight kininogen-deficient plasma. These data indicate that, in addition to the mediators released from mast cells, kinins have an important role in the edema caused by trimucase II, and that kinins are released from plasma, probably due to direct activation of kininogen.

Animals↗