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Beghini DG, Rodrigues-Simioni L, Toyama MH, Novello JC, da Cruz-Höfling MA, Marangoni S. Neurotoxic and myotoxic actions of crotoxin-like and Crotalus durissus cascavella whole venom in the chick biventer cervicis preparation. Toxicon 2004; 43:255-61. [PMID: 15033323 DOI: 10.1016/j.toxicon.2003.12.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2003] [Accepted: 12/02/2003] [Indexed: 11/26/2022]
Abstract
Crotoxin from Crotalus durissus cascavella venom was purified by a combination of molecular exclusion chromatography (Superdex 75 column) and HPLC molecular exclusion (Protein Pack 300SW column). Neurotoxic and myotoxic effects from C. durissus cascavella whole venom and its main fraction, the crotoxin-like, were studied in the chick biventer cervicis (CBC) nerve-muscle preparation. Both venom and its crotoxin showed significant (p < 0.05) blockade of neuromuscular transmission at concentrations as low as 0.2-1, 5 and 25 microg/ml, but no significant effect has been shown with a concentration of 0.04 microg/ml (n = 5 each). The time required to produce 50% neuromuscular blockade with the venom and its crotoxin was 53.6+/-8.2 and 65.9+/-4.9 min (0.2 microg/ml), 29.7+/-1.9 and 34.3+/-1.9 min (1 microg/ml), 24.8+/-1.6 and 21.1+/-1.5 min (5 microg/ml), 20.9+/-3.7 and 20.1+/-1.4 min (25 microg/ml), respectively. The addition to the incubation bath of acetylcholine (55 and 110 microM) or KCl (20.1 mM), either before or after the venom or the crotoxin induced contracture in the presence of a total blockade, in all the concentrations used. Morphological analysis showed that the damage caused by C. durissus cascavella venom is stronger than that caused by crotoxin. The myonecrotic picture was more marked at higher venom and crotoxin doses (1, 5 or 25 microg/ml). Only at 25 microg/ml concentrations of the venom and crotoxin, marked muscle fiber changes were detected. We concluded that the crotoxin-like and the whole venom from C. durissus cascavella possess a preponderant and quite potent neurotoxic action in this preparation, and a myotoxic action which is observed only at higher doses.
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Damico DCS, Freire MGM, Gomes VM, Toyama MH, Marangoni S, Novello JC, Macedo MLR. Isolation and characterization of a lectin from Annona muricata seeds. JOURNAL OF PROTEIN CHEMISTRY 2003; 22:655-61. [PMID: 14714732 DOI: 10.1023/b:jopc.0000008730.50675.de] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
A lectin with a high affinity for glucose/mannose was isolated from Annona muricata seeds (Annonaceae) by gel filtration chromatography on Sephacryl S-200, ion exchange chromatography on a DEAE SP-5 PW column, and molecular exclusion on a Protein Pak Glass 300 SW column. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (PAGE) yielded two protein bands of approximately 14 kDa and 22 kDa. However, only one band was seen in native PAGE. The Mr of the lectin estimated by fast-performance liquid chromatography-gel filtration on Superdex 75 was 22 kDa. The lectin was a glycoprotein with 8% carbohydrate (neutral sugar) and required divalent metal cations (Ca2+, Mg2+, and Mn2+) for full activity. Amino acid analysis revealed a large content of Glx, Gly, Phe, and Lys. The lectin agglutinated dog, chicken, horse, goose, and human erythrocytes and inhibited the growth of the fungi Fusarium oxysporum, Fusarium solani, and Colletotrichum musae.
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Toyama MH, de Oliveira DG, Beriam LOS, Novello JC, Rodrigues-Simioni L, Marangoni S. Structural, enzymatic and biological properties of new PLA(2) isoform from Crotalus durissus terrificus venom. Toxicon 2003; 41:1033-8. [PMID: 12875878 DOI: 10.1016/s0041-0101(03)00085-0] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
We isolated a new PLA(2) from the Crotalus durissus terrificus venom that designated F15, which showed allosteric behavior with a V(max) of 8.5nmol/min/mg and a K(m) of 38.5 mM. The incubated heparin salt of this isolated F15 act a positive allosteric effector by increasing the V(max) to 10.2 nmol/min/mg, with decreasing the V(max) value to 20.5 mM. The crotapotin, on the other hand acts as a negative allosteric effector by increasing the V(max) values to 58.4 mM. F15 also showed high calcium dependence for its catalysis similar to that found for other PLA(2) enzymes isolated from these snake venoms. The replacement of calcium by other divalent ions such Mg(2+), Mn(2+), Cd(2+), Sn(2+) and Cu(2+) resulted in lower enzymatic activity. The optimum pH and temperature for the enzyme was 8.5 and 18 degrees C, respectively. F15 alone showed moderate neurotoxic activity in isolated mouse phrenic nerve diaphragm in comparison to other strong myotoxic PLA(2) such as bothropstoxin-I (BThtx-I), but this activity was highly neurotoxic in a chick biventrer cervis preparation, whereas BthTx-I did not reveal this high neurotoxicity. This new protein showed a high bactericidal effect against both Gram-negative and Gram-positive bacterial strains. F15 contained 122 amino acid residues, with a primary structure of: HLLQFNKMIKFETRKNAVPFYAFYGCYCGWGGQRRPKDATDRCCFVHDCCYGKLTKCNTKWDIYRYSLKSGYITCGKGTWCKEQICECDRVAAECLRRSLSTYKNEYMFYPKSRCRRPSETC. Its molecular mass and isoeletric point were 14.5 kDa and 8.85, both estimated by two dimensional electrophoresis. The amino acid sequence of the F15 revealed high sequence homology with F16 and F17. F15 and the other PLA(2)s revealed highly conserved amino acid sequences principally for calcium binding loop and active site helix. F15 also showed a high homology with the lysine-rich region of myotoxic PLA(2).
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Borja-Oliveira CR, Durigon AM, Vallin ACC, Toyama MH, Souccar C, Marangoni S, Rodrigues-Simioni L. The pharmacological effect of Bothrops neuwiedii pauloensis (jararaca-pintada) snake venom on avian neuromuscular transmission. Braz J Med Biol Res 2003; 36:617-24. [PMID: 12715081 DOI: 10.1590/s0100-879x2003000500009] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The neuromuscular effects of Bothrops neuwiedii pauloensis (jararaca-pintada) venom were studied on isolated chick biventer cervicis nerve-muscle preparations. Venom concentrations of 5-50 micro g/ml produced an initial inhibition and a secondary increase of indirectly evoked twitches followed by a progressive concentration-dependent and irreversible neuromuscular blockade. At venom concentrations of 1-20 micro g/ml, the responses to 13.4 mM KCl were inhibited whereas those to 110 micro M acetylcholine alone and cumulative concentrations of 1 micro M to 10 mM were unaffected. At venom concentrations higher than 50 micro g/ml, there was pronounced muscle contracture with inhibition of the responses to acetylcholine, KCl and direct stimulation. At 20-24 degrees C, the venom (50 g/ml) produced only partial neuromuscular blockade (30.7 +/- 8.0%, N = 3) after 120 min and the initial inhibition and the secondary increase of the twitch responses caused by the venom were prolonged and pronounced and the response to KCl was unchanged. These results indicate that B.n. pauloensis venom is neurotoxic, acting primarily at presynaptic sites, and that enzyme activity may be involved in this pharmacological action.
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Bertelli DF, Ueno M, Amaral MEC, Toyama MH, Carneiro EM, Marangoni S, Carvalho CRO, Saad MJA, Velloso LA, Boschero AC. Reversal of denervation-induced insulin resistance by SHIP2 protein synthesis blockade. Am J Physiol Endocrinol Metab 2003; 284:E679-87. [PMID: 12453826 DOI: 10.1152/ajpendo.00345.2002] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Short-term muscle denervation is a reproducible model of tissue-specific insulin resistance. To investigate the molecular basis of insulin resistance in denervated muscle, the downstream signaling molecules of the insulin-signaling pathway were examined in intact and denervated soleus muscle of rats. Short-term denervation induced a significant fall in glucose clearance rates (62% of control, P < 0.05) as detected by euglycemic hyperinsulinemic clamp and was associated with a significant decrease in insulin-stimulated tyrosine phosphorylation of the insulin receptor (IR; 73% of control, P < 0.05), IR substrate 1 (IRS1; 69% of control, P < 0.05), and IRS2 (82% of control, P < 0.05) and serine phosphorylation of Akt (39% of control, P < 0.05). Moreover, denervation reduced insulin-induced association between IRS1/IRS2 and p85/phosphatidylinositol (PI) 3-kinase. Nevertheless, denervation caused an increase in PI 3-kinase activity associated with IRS1 (275%, P < 0.05) and IRS2 (180%, P < 0.05), but the contents of phosphorylated PI detected by HPLC were significantly reduced in lipid fractions. In the face of the apparent discrepancy, we evaluated the expression and activity of the 5-inositol, lipid phosphatase SH2 domain-containing inositol phosphatase (SHIP2), and the serine phosphorylation of p85/PI 3-kinase. No major differences in SHIP2 expression were detected between intact and denervated muscle. However, serine phosphorylation of p85/PI 3-kinase was reduced in denervated muscle, whereas the blockade of SHIP2 expression by antisense oligonucleotide treatment led to partial restoration of phosphorylated PI contents and to improved glucose uptake. Thus modulation of the functional status of SHIP2 may be a major mechanism of insulin resistance induced by denervation.
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Barbosa PSF, Havt A, Facó PEG, Sousa TM, Bezerra ISAM, Fonteles MC, Toyama MH, Marangoni S, Novello JC, Monteiro HSA. Renal toxicity of Bothrops moojeni snake venom and its main myotoxins. Toxicon 2002; 40:1427-35. [PMID: 12368112 DOI: 10.1016/s0041-0101(02)00156-3] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Acute renal failure is one the most common systemic complications after snakebite, however, its pathogenesis remains obscure. In this study we evaluated the renal effects of Bothrops moojeni venom and its myotoxins (Bmtx-I and BmtxII) in rat isolated perfused kidneys. The myotoxins were purified by ion-exchange chromatography and reverse phase HPLC. The whole venom (10 microg/ml) and myotoxins (5 microg/ml) were added to the perfusion system 30 min after the beginning of each perfusion. The renal effects were compared to a control group perfused with modified Krebs-Henseleit solution alone. B. moojeni venom decreased the perfusion pressure (PP), renal vascular resistance (RVR), and the percent sodium, potassium and chloride tubular transport (%TNa(+), %TK(+), %TCl(-)). In contrast, the venom increased the urinary flow (UF), glomerular filtration rate (GFR), and the sodium, potassium and chloride excretion (ENa(+), EK(+), ECl(-)). The renal effects of myotoxin I was very similar to those of the whole venom, but there was an increase rather than a decrease in the PP and RVR. Myotoxin II had no effect on renal physiology, except for a transient decrease in %TK(+). In conclusion, B. moojeni venom caused intense alterations in renal physiology, including a drop in vascular resistance associated with diuresis, natriuresis and kaliuresis. Bmtx-I had an opposite effect when compared to whole venom, showed in the parameters of PP and RVR. Bmtx-II had a mild effect in %TK(+). The apparent inability of Bmtx-II to induce the renal effect similarly to Bmtx-I should be explained by the absence in the Bmtx-II of the C-terminal lysine rich region.
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Pando SC, Macedo MLR, Freire MGM, Toyama MH, Novello JC, Marangoni S. Biochemical characterization of a lectin from Delonix regia seeds. JOURNAL OF PROTEIN CHEMISTRY 2002; 21:279-85. [PMID: 12168698 DOI: 10.1023/a:1019797320348] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
A lectin from Delonix regia (DRL) seeds was purified by gel filtration on Sephadex G-100 followed by ion-exchange chromatography on diethylaminoethyl-Sepharose and reverse-phase high-performance liquid chromatography on a C18 column. Hemagglutinating activity was monitored using rat erythrocytes. DRL showed no specificity for human erythrocytes of ABO blood groups. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) revealed a single protein in the presence of 0.1 M of dithiothreitol (DTT) and in nonreducing conditions. Native-PAGE showed that DRL is a monomer with a molecular mass of about 12 kDa, as determined by denaturing gel electrophoresis and gel filtration chromatography. An amino acid composition revealed the absence of cysteine residues, the presence of 1 mol methionine/mol protein and a high proportion of acidic amino acids and glycine. The N-terminal sequence of DRL was determined by Edman degradation, and up to 16 amino acid residues showed more than 90% homology with other lectins from the Leguminosae family. The optimal pH range for lectin activity was between pH 8.0 and 9.0, and the lectin was active up to 60 degrees C. The lectin required Mn2+ for hemagglutinating activity and remained active after reduction with 0.1 M of DTT, but lost activity in the presence of 8 M of urea. Sodium metaperiodate had no effect on the activity of DRL.
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Ponce-Soto LA, Toyama MH, Hyslop S, Novello JC, Marangoni S. Isolation and preliminary enzymatic characterization of a novel PLA2 from Crotalus durissus collilineatus venom. JOURNAL OF PROTEIN CHEMISTRY 2002; 21:131-6. [PMID: 12018613 DOI: 10.1023/a:1015332314389] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
A crotoxin homolog was purified from the Crotalus durissus collilineatus venom using molecular exclusion and reverse-phase HPLC. This crotoxin contained one PLA2 (Cdcolli III F6) and four crotapotin isoforms, whereas crotoxin from Crotalus durissus terrificus venom had three PLA2 iso forms and two crotapotin isoforms. SDS-PAGE showed that the C. d. collilineatus PLA2 and crotapotin had relative molecular mass of 15 and 9 kDa, respectively. Neither the PLA2 (Cdcolli III F6) nor the crotapotins (Cdcolli III F3 and F4) had any neurotoxicity in mouse phrenic nerve-diaphragm preparations when tested alone. However, when PLA2 and crotapotin were coincubated before testing, the neurotoxicity was restored to a level similar to test in the venom in native crotoxin. The two crotapotins (Cdcolli III F3 and F4) differed in their ability to inhibit PLA2 activity, perhaps because of variations in their affinities for this enzyme. Cdcolli III F6 showed allosteric enzymatic behavior, with maximal activity at pH 8.3 and 36 degrees C. Full PLA2 activity required the presence of a low Ca2+ concentration and was inhibited by Cu2+ and Zn2+ and by Cu2+ and Mg2+ in the presence and absence of Ca2+, respectively. These results indicate that crotoxin from C. d. collineatus venom is very similar enzymatically to crotoxin from C. d. terrificus.
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Oliveira DG, Toyama MH, Novello JC, Beriam LOS, Marangoni S. Structural and functional characterization of basic PLA2 isolated from Crotalus durissus terrificus venom. JOURNAL OF PROTEIN CHEMISTRY 2002; 21:161-8. [PMID: 12018617 DOI: 10.1023/a:1015320616206] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The venom of Crotalus durissus terrificus was fractionated by reverse-phase HPLC to obtain crotapotins (F5 and F7) and PLA2 (F15, F16, and F17) of high purity. The phospholipases A2 (PLA2S) and crotapotins showed antimicrobial activity against Xanthomonas axonopodis pv. passiflorae, although the unseparated crotoxin did not. The F17 of the PLA2 also revealed significant anticoagulant activity, althrough for this to occur the presence of Glu 53 and Trp 61 is important. The F17 of the PLA2 showed allosteric behavior in the presence of a synthetic substrate. The amino acid sequence of this PLA2 isoform, determined by automatic sequencing, was HLLQFNKMLKFETRK NAVPFYAFGCYCGWGGQRRPKDATDRCCFVHDCCYEKVTKCNTKWDFYRYSLKSGY ITCGKGTWCKEQICECDRVAAECLRRSLSTYKNEYMFYPDSRCREPSETC. Analysis showed that the sequence of this PLA2 isoform differed slightly from the amino acid sequence of the basic crotoxin subunit reported in the literature. The homology with other crotalid PLA2 cited in the literature varied from 60% to 90%. The pL was estimated to be 8.15, and the calculated molecular weight was 14664.14 as determined by Tricine SDS-PAGE, two-dimensional electrophoresis, and MALDI-TOFF. These results also suggested that the enzymatic activity plays an important role in the bactericidal effect of the F17 PLA2 as well as that of anticoagulation, although other regions of the molecule may also be involved in this biological activity.
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Toyama MH, Carneiro EM, Marangoni S, Amaral MEC, Velloso LA, Boschero AC. Isolation and characterization of a convulxin-like protein from Crotalus durissus collilineatus venom. JOURNAL OF PROTEIN CHEMISTRY 2001; 20:585-91. [PMID: 11838547 DOI: 10.1023/a:1013377331569] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
A convulxin (Cvx)-like protein was isolated from Crotalus durissus collilineatus venom by a combination of molecular exclusion and reversed-phase HPLC chromatographies. The molecular mass of the Cvx-like protein in the absence and presence of DTT was 78 kDa and 12-13 kDa, respectively. The Cvx-like protein consisted of two nonidentical polypeptide chains (alpha and beta). The N-terminal amino-acid sequences of the alpha and beta subunits were GLHCPSDWYAYDGHCYKIFNEEMNWED and GFCCPSHWSSYSRYCYKFFSQEMNWEDAEK, respectively, with both subunits having a high content of Glu, Ser, Cys, and Asp. The Cvx-like protein showed high homology with other venom C-type lectins, but had low hemagglutinating activity on intact and trypsinized erythrocytes. The Cvx-like protein stimulated insulin receptor phosphorylation and potentiated insulin secretion from isolated islets in the presence of sub- (2.8 mM) or supra-physiological (16.7 mM) glucose concentrations. These results suggest that the increase in insulin secretion induced by Cvx-like protein may be mediated by a protein tyrosine kinase-dependent pathway and may involve other membrane receptors, such as GP VI or Scr family proteins.
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Bonfim VL, Toyama MH, Novello JC, Hyslop S, Oliveira CR, Rodrigues-Simioni L, Marangoni S. Isolation and enzymatic characterization of a basic phospholipase A2 from Bothrops jararacussu snake venom. JOURNAL OF PROTEIN CHEMISTRY 2001; 20:239-45. [PMID: 11565904 DOI: 10.1023/a:1010956126585] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
A novel basic phospholipase A2 (PLA2) isoform was isolated from Bothrops jararacussu snake venom and partially characterized. The venom was fractionated by HPLC ion-exchange chromatography in ammonium bicarbonate buffer, followed by reverse-phase HPLC to yield the protein Bj IV. Tricine SDS-PAGE in the presence or absence of dithiothreitol showed that Bj IV had a molecular mass of 15 and 30 kDa, respectively. This enzyme was able to form multimeric complexes (30, 45, and 60 kDa). Amino acid analysis showed a high content of hydrophobic and basic amino acids as well as 14 half-cysteine residues. The N-terminal sequence (DLWSWGQMIQETGLLPSYTTY...) showed a high degree of homology with basic D49 PLA2 myotoxins from other Bothrops venoms. Bj IV had high PLA2 activity and produced moderate myonecrosis in skeletal muscle, but showed no neuromuscular activity in mouse phrenic nerve-diaphragm preparations. Bj IV showed allosteric enzymatic behavior, with maximal activity at pH 8.2 and 35-45 degrees C. Full PLA2 activity required Ca2+ but was inhibited by Cu2+ and Zn2+, and by Cu2+ and Mg2+ in the presence and absence of Ca2+, respectively. Crotapotins from Crotalus durissus terrificus rattlesnake venom significantly inhibited the enzymatic activity of Bj IV. The latter observation suggested that the binding site for crotapotin in this PLA2 was similar to that in the basic PLA2 of the crotoxin complex from C. d. terrificus venom. The presence of crotapotin-like proteins capable of inhibiting the catalytic activity of D49 PLA2 could partly explain the low PLA2 activity of Bothrops venoms.
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Lee WH, da Silva Giotto MT, Marangoni S, Toyama MH, Polikarpov I, Garratt RC. Structural basis for low catalytic activity in Lys49 phospholipases A2--a hypothesis: the crystal structure of piratoxin II complexed to fatty acid. Biochemistry 2001; 40:28-36. [PMID: 11141053 DOI: 10.1021/bi0010470] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Asp49 plays a fundamental role in supporting catalysis by phospholipases A2 by coordinating the calcium ion which aids in the stabilization of the tetrahedral intermediate. In several myotoxins from the venoms of Viperidae snakes, this aspartic acid is substituted by lysine. The loss of calcium binding capacity by these mutants has become regarded as the standard explanation for their greatly reduced or nonexistent phospholipolytic activity. Here we describe the crystal structure of one such Lys49 PLA2, piratoxin-II, in which a fatty acid molecule is observed within the substrate channel. This suggests that such toxins may be active enzymes in which catalysis is interrupted at the stage of substrate release. Comparison of the present structure with other PLA2s, both active and inactive, identifies Lys122 as one of the likely causes of the increased affinity for fatty acid in Lys49 enzymes. Its interaction with the mainchain carbonyl of Cys29 is expected to lead to hyperpolarization of the peptide bond between residues 29 and 30 leading to an increased affinity for the fatty acid headgroup. This strongly bound fatty acid may serve as an anchor to secure the toxin within the membrane thus facilitating its pathological effects.
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de Castro RC, Landucci EC, Toyama MH, Giglio JR, Marangoni S, De Nucci G, Antunes E. Leucocyte recruitment induced by type II phospholipases A(2) into the rat pleural cavity. Toxicon 2000; 38:1773-85. [PMID: 10858516 DOI: 10.1016/s0041-0101(00)00107-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Bothropstoxin-I (BthTX-I) and bothropstoxin-II (BthTX-II) are Lys-49 and Asp-49 phospholipases A(2) (PLA(2)s), respectively, isolated from Bothrops jararacussu venom. Piratoxin-I (PrTX-I) is a Lys-49 PLA(2) isolated from Bothrops pirajai venom. In this study, the ability of BthTX-I, BthTX-II and PrTX-I to recruit leucocytes into the rat pleural cavity and potential mechanisms underlying this effect were investigated. Intrapleural injection of either BthTX-I or PrTX-I (10-100 microg/cavity each) caused a significant leucocyte infiltration at 12 h after injection. The maximal cell migration was observed with the dose of 30 microg/cavity (14.9+/-15.5 and 17.6+/-1. 6x10(6) cells/cavity, respectively). Leucocyte counts consisted mainly of mononuclear cells, but significant amounts of neutrophils and eosinophils were also observed. Intrapleural injection of BthTX-II (10-100 microg/cavity) caused a marked leucocyte infiltration at 6 and 12 h after injection. The maximal response was observed with the dose of 100 microg/cavity (57.3+/-3.4x10(6) cells/cavity, 6 h). The leucocyte counts were mainly composed of neutrophils and mononuclear cells. The treatment of either BthTX-I (30 microg/cavity, 12 h) or BthTX-II (30 microg/cavity, 6 h) with the PLA(2) inhibitor p-bromophenacyl bromide (p-BPB) had no effect on the total and differential leucocyte counts induced by these proteins. The same treatment partially reduced the PrTX-I-induced pleural leucocyte infiltration. In rats depleted of the histamine and 5-hydroxytryptamine (5-HT) stores by chronic treatment with compound 48/80, the total leucocyte counts in response to BthTX-I, BthTX-II and PrTX-I was not significantly affected compared to control animals. In addition, BthTX-I, BthTX-II and PrTX-I (100 microg/ml each) significantly degranulated pleural mast cells in vitro leading to the release of [(14)C]5-hydroxytryptamine ([(14)C]5-HT). p-BPB and heparin (50 IU/ml) significantly reduced the [(14)C]5-HT release induced by these PLA(2)s. Our results demonstrate that BthTX-I, BthTX-II and PrTX-I recruit leucocyte into the pleural cavity of the rat by mechanisms unrelated to enzymatic activity and pleural mast cell degranulation.
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Toyama MH, Leite GB, Rodrigues-Simioni L, Hernandez OS, Novello JC, Marangoni S. Isolation and characterization of novel neurotoxins from south american rattlesnake crotalus durissus terrificus: Optimization of chromatographic procedure. Protein Pept Lett 2000. [DOI: 10.2174/092986650706221207162104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Abstract:
Molecular exclusion HPLC chromatography on a Protein Pak SW 300 column and reversed phase HPLC on a µ-Bondapack Cl8 column were used to purify four novel neurotoxins (rom the crotoxin complex, and five crotoxin subunits (PLA2 and crotapotin) as well as two crotamine isoforms. A single preparative reversed phase HPLC steps yielded a major basic myotoxin followed by the subunits of crotoxin (three PLA2 isoforms
and two crotapotin isoforms). This modified procedure may be useful for the rapid, large-scale purification of
toxins from Crotalid venoms.
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Beghini DG, Toyama MH, Hyslop S, Sodek LC, Novello, Marangoni S. Enzymatic characterization of a novel phospholipase A2 from Crotalus durissus cascavella rattlesnake (Maracambóia) venom. JOURNAL OF PROTEIN CHEMISTRY 2000; 19:679-84. [PMID: 11307952 DOI: 10.1023/a:1007152303179] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The PLA2 and crotapotin subunits of crotoxin from Crotalus durissus cascavella venom were purified by a combination of high-performance liquid chromatography (HPLC) molecular exclusion (Protein Pack 300SW column) and reverse-phase HPLC (RP-HPLC). Tricine SDS-PAGE showed that the PLA2 and crotapotins migrated as single bands with estimated molecular masses of 15 and 9 kDa, respectively. The amino acid composition of the PLA2 showed the presence of 14 half-cysteines and a high content of basic residues (Lys, Arg, His), whereas the crotapotins were rich in hydrophobic, negatively charged residues and half-cysteines. The PLA2 showed allosteric behavior, with maximal activity at pH 8.3 and 35-40 degrees C. C. d. cascavella PLA2 required Ca2+ for activity but was inhibited by Cu2+ and Zn2+ and by Cu2+ and Mg2+ in the presence and absence of Ca2+, respectively. Crotapotin (F3) and heparin inhibited the catalytic activity of the PLA2 by acting as allosteric inhibitors.
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Beghini DG, Toyama MH, Hyslop S, Sodek L, Novello JC, Marangoni S. Enzymatic characterization of a novel phospholipase A2 from Crotalus durissus cascavella rattlesnake (Maracambóia) venom. JOURNAL OF PROTEIN CHEMISTRY 2000; 19:603-7. [PMID: 11233174 DOI: 10.1023/a:1007123329817] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The PLA2 and crotapotin subunits of crotoxin from Crotalus durissus cascavella venom were purified by a combination of HPLC molecular exclusion (Protein Pack 300SW column) and reverse-phase HPLC (RP-HPLC). Tricine SDS-PAGE showed that the PLA2 and crotapotins migrated as single bands with estimated molecular masses of 15 and 9 kDa, respectively. The amino acid composition of the PLA2 showed the presence of 14 half-cysteines and a high content of basic residues (Lys, Arg, His), whereas the crotapotins were rich in hydrophobic, negatively charged residues and half-cysteines. The PLA2 showed allosteric behavior, with maximal activity at pH 8.3 and 35-40 degrees C. The C. d. cascavella PLA2 required Ca2+ for activity, but was inhibited by Cu2+ and Zn2+ and by Cu2+ and Mg2+ in the presence and absence of Ca2+, respectively. Crotapotin (F3) and heparin inhibited the catalytic activity of the PLA2 by acting as allosteric inhibitors.
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Toyama MH, Carneiro EM, Marangoni S, Barbosa RL, Corso G, Boschero AC. Biochemical characterization of two crotamine isoforms isolated by a single step RP-HPLC from Crotalus durissus terrificus (South American rattlesnake) venom and their action on insulin secretion by pancreatic islets. BIOCHIMICA ET BIOPHYSICA ACTA 2000; 1474:56-60. [PMID: 10699490 DOI: 10.1016/s0304-4165(99)00211-1] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Crotamine, a neurotoxin present in the venom of the South American rattlesnake Crotalus durrisus terrificus exists as several polymorphic variants, as demonstrated by recombinant DNA technology (Smith and Schmidt, Toxicon 28 (1990) 575-585). We have isolated native crotamine by chromatography on Sephadex G75, and have purified two crotamine isoforms (F2 and F3) by a single step of RP-HPLC. Native crotamine and RP-HPLC fractions F2 and F3 produced skeletal muscle spasms and spastic paralysis in mice. At low glucose concentrations (2.8-5.6 mmol/l), none of the crotamines altered the insulin secretion by rat isolated islets. In the presence of 16.7 mmol glucose/l, F2 (5 microg/ml), but not F3, increased insulin secretion two-fold, whereas native crotamine (1.5, 5 and 16.5 microg/ml) potentiated the secretion dose-dependently. The increase in insulin secretion induced by F2 fraction (5 microg/ml) was similar to that obtained with 16.5 microg of native crotamine/ml. These results indicate that the mode of action of the F2 and F3 isoforms in beta-cells is different from that in muscle cells. This difference may be related to the binding affinity of each isoform for the Na(+) channels located in the beta-cell membrane. Crotamine isoforms may be valuable tools for studying the involvement of Na(+) channels in the mechanism of insulin secretion.
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Toyama MH, Soares AM, Wen-Hwa L, Polikarpov I, Giglio JR, Marangoni S. Amino acid sequence of piratoxin-II, a myotoxic lys49 phospholipase A(2) homologue from Bothrops pirajai venom. Biochimie 2000; 82:245-50. [PMID: 10863008 DOI: 10.1016/s0300-9084(00)00202-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The complete amino acid sequence of the 121 amino acid residues of piratoxin II, a phospholipase A(2) like myotoxin from Bothrops pirajai venom, is reported. PrTX-II is a basic protein with a molecular mass of 13740 Da, a calculated pI of 9.03, but an experimental pI of 8.4 +/- 0.2, showing sequence similarity with other bothropic (90-99%) or non-bothropic ( approximately 80%) Lys49 PLA(2)-like myotoxins. This similarity falls to approximately 70% when this sequence is aligned with that of Asp49 PLA(2). Due to the substitution of Asp49 by Lys49 and alterations in the calcium binding loop structure, as the replacement of Gly32 by Leu32, piratoxin-II shows no PLA(2) activity when assayed on egg yolk. Piratoxin-II showed the same primary structure as piratoxin-I, except that it has Lys116 for Leu116. Despite this slightly higher basicity at the C-terminal region, piratoxin-II was shown to be less myotoxic than piratoxin-I. The change Leu --> Lys induced an alteration of the molecule surface shape and probably of the environment charge high enough to slightly decrease the myotoxic activity. When aligned with B. jararacussu bothropstoxin-I and with B. asper Basp-II, piratoxin-II revealed a single (position 132) and a quintuple (positions 17, 90, 111, 120 and 132) amino acid substitution, respectively, suggesting a common evolutionary origin for these three myotoxins.
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Soares AM, Andrião-Escarso SH, Angulo Y, Lomonte B, Gutiérrez JM, Marangoni S, Toyama MH, Arni RK, Giglio JR. Structural and functional characterization of myotoxin I, a Lys49 phospholipase A(2) homologue from Bothrops moojeni (Caissaca) snake venom. Arch Biochem Biophys 2000; 373:7-15. [PMID: 10620318 DOI: 10.1006/abbi.1999.1492] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Myotoxin-I (MjTX-I) was purified to homogeneity from the venom of Bothrops moojeni by ion-exchange chromatography on CM-Sepharose. Its molecular weight, estimated by SDS-PAGE, was 13,400 (reduced) or 26, 000 (unreduced). The extinction coefficient (E(1.0 mg/ml)(1.0 cm)) of MjTX-I was 1.145 at lambda = 278 nm, pH 7.0, and its isoelectric point was 8.2 at ionic strength mu = 0.1. When lyophilized and stored at 4 degrees C, dimeric, trimeric, and pentameric forms of the protein were identified by SDS-PAGE. This "heterogeneous" sample could be separated into three fractions by gel filtration on Sephadex G-50. The fractions were analyzed by isoelectric focusing, immunoelectrophoresis, and amino acid composition, which indicated that heterogeneity was the result of different levels of self-association. Protein sequencing indicated that MjTX-I is a Lys49 myotoxin and consists of 121 amino acids (M(r) = 13,669), containing a high proportion of basic and hydrophobic residues. It shares a high degree of sequence identity with other Lys49 PLA(2)-like myotoxins, but shows a significantly lower identity with catalytically active Asp49 PLA(2)s. The three-dimensional structure of MjTX-I was modeled based on the crystal structures of three highly homologous Lys49 PLA(2)-like myotoxins. This model showed that the amino acid substitutions are conservative, and mainly limited to three structural regions: the N-terminal helix, the beta-wing region, and the C-terminal extended random coil. MjTX-I displays local myotoxic and edema-inducing activities in mice, and is lethal by intraperitoneal injection, with an LD(50) value of 8.5 +/- 0.8 mg/kg. In addition, it is cytotoxic to myoblasts/myotubes in culture, and disrupts negatively charged liposomes. In comparison with the freshly prepared dimeric sample, the more aggregated forms showed significantly reduced myotoxic activity. However, the edema-inducing activity of MjTX-I was independent of molecular association. Phospholipase A(2) activity on egg yolk, as well as anticoagulant activity, were undetectable both in the native and in the more associated forms. His, Tyr, and Trp residues of the toxin were chemically modified by specific reagents. Although the myotoxic and lethal activities of the modified toxins were reduced by these treatments, neither its edema-inducing or liposome-disrupting activities were significantly altered. Rabbit antibodies to native MjTX-I cross-reacted with the chemically modified forms, and both the native and modified MjTX-I preparations were recognized by antibodies against the C-terminal region 115-129 of myotoxin II from B. asper, a highly Lys49 PLA(2)-homologue with high sequencial similarity.
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Costa PD, Toyama MH, Marangoni S, Rodrigues-Simioni L, da Cruz-Höfling MA. Effects of Bothrops pirajai venom on the mouse extensor digitorum longus (EDL) muscle preparation. Toxicon 1999; 37:1143-53. [PMID: 10400298 DOI: 10.1016/s0041-0101(98)00250-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The effects of Bothrops pirajai snake venom on the mouse extensor digitorum longus (EDL) preparation were examined using myographic, histopathological and biochemical approaches. B. pirajai venom (10, 25 or 50 microg/ml) dose dependently and irreversibly blocked the contractile response of indirectly stimulated EDL muscle. Histopathological analysis of EDL muscle incubated with venom showed dose-dependent damage with a loss of the normal tissue structure and the appearance of highly dark, edematous fibers together with myofibrils in various stages of condensation. At high doses of venom (50 microg/ml), loss of muscle cells was observed. In non-stimulated EDL, B. pirajai venom (10 and 50 microg/ml) caused a time-dependent release of CK which was maximal after 120 min. These results suggest that a component(s) present in the B. pirajai venom has a direct myolytic action on the skeletal muscle.
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Polikarpov I, Junior MS, Marangoni S, Toyama MH, Teplyakov A. Crystal structure of neurotoxin Ts1 from Tityus serrulatus provides insights into the specificity and toxicity of scorpion toxins. J Mol Biol 1999; 290:175-84. [PMID: 10388565 DOI: 10.1006/jmbi.1999.2868] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The crystal structure of neurotoxin Ts1, a major component of the venom of the Brazilian scorpion Tityus serrulatus, has been determined at 1.7 A resolution. It is the first X-ray structure of a highly toxic anti-mammalian beta-toxin. The folding of the polypeptide chain of Ts1 is similar to that of other scorpion toxins. A cysteine-stabilised alpha-helix/beta-sheet motif forms the core of the flattened molecule. All residues identified as functionally important by chemical modification and site-directed mutagenesis are located on one side of the molecule, which is therefore considered as the Na+channel recognition site. The distribution of charged and non-polar residues over this surface determines the specificity of the toxin-channel interaction. Comparison to other scorpion toxins shows that positively charged groups at positions 1 and 12 as well as a negative charge at position 2 are likely determinants of the specificity of beta-toxins. In contrast, the contribution of the conserved aromatic cluster to the interaction might be relatively small. Comparison of Ts1 to weak beta-toxins from Centruroides sculpturatus Ewing reveals that a number of basic amino acid residues located on the face of the molecule opposite to the binding surface may account for the high toxicity of Ts1.
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Lee WH, Toyama MH, Soares AM, Giglio JR, Marangoni S, Polikarpov I. Crystallization and preliminary X-ray diffraction studies of piratoxin III, a D-49 phospholipase A2 from the venom of Bothrops pirajai. ACTA CRYSTALLOGRAPHICA SECTION D: BIOLOGICAL CRYSTALLOGRAPHY 1999; 55:1229-30. [PMID: 10329793 DOI: 10.1107/s0907444999004576] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Piratoxin III (PrTX-III) is a phospholipase A2 (PLA2, E.C. 3.1.1.4, phosphatide sn-2 acylhydrolase) isolated from Bothrops pirajai. Crystals of PrTX-III were obtained using the vapour-diffusion technique and X-ray diffraction data have been collected to 2.7 A resolution. The enzyme was crystallized in the space group C2 with unit-cell parameters a = 60.88, b = 100.75, c = 48.19 A, beta = 123. 89 degrees. A molecular-replacement solution of the structure has been found using bothropstoxin I from the venom of B. jararacussu as a search model.
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Homsi-Brandeburgo MI, Toyama MH, Marangoni S, Ward RJ, Giglio JR, Hartley BS. The amino acid sequence of ribitol dehydrogenase-F, a mutant enzyme with improved xylitol dehydrogenase activity. JOURNAL OF PROTEIN CHEMISTRY 1999; 18:489-95. [PMID: 10449046 DOI: 10.1023/a:1020601011846] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
A mutant ribitol dehydrogenase (RDH-F) was purified from Klebsiella aerogenes strain F which evolved from the wild-type strain A under selective pressure to improve growth on xylitol, a poor substrate used as sole carbon source. The ratio of activities on xylitol (500 mM) and ribitol (50 mM) was 0.154 for RDH-F compared to 0.033 for the wild-type (RDH-A) enzyme. The complete amino acid sequence of RDH-F showed the mutations. Q60 for E60 and V215 for L215 in the single polypeptide chain of 249 amino acid residues. Structural modeling based on homologies with two other microbial dehydrogenases suggests that E60 --> Q60 is a neutral mutation, since it lies in a region far from the catalytic site and should not cause structural perturbations. In contrast, L215 --> V215 lies in variable region II and would shift a loop that interacts with the NADH cofactor. Another improved ribitol dehydrogenase, RDH-D, contains an A196 --> P196 mutation that would disrupt a surface alpha-helix in region II. Hence conformational changes in this region appear to be responsible for the improved xylitol specificity.
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Toyama MH, Costa PD, Novello JC, de Oliveira B, Giglio JR, da Cruz-Höfling MA, Marangoni S. Purification and amino acid sequence of MP-III 4R D49 phospholipase A2 from Bothrops pirajai snake venom, a toxin with moderate PLA2 and anticoagulant activities and high myotoxic activity. JOURNAL OF PROTEIN CHEMISTRY 1999; 18:371-8. [PMID: 10395455 DOI: 10.1023/a:1021051831740] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
MP-III 4R PLA2 was purified from the venom of Bothrops pirajai venom (Bahia's jararacussu) after three chromatographic steps which started with RP-HPLC. The complete amino acid sequence of MP-III 4R PLA2 from Bothrops pirajai was determined by amino acid sequencing of reduced and carboxymethylated MP-III 4R and the isolated peptides from clostripain and protease V8 digestion. MP-III 4R is a D49 PLA2 with 121 amino acid residues and has a molecular weight estimated at 13,800 Da, with 14 half-cysteines. This protein showed moderate PLA2 and anticoagulant activity. This PLA2 does not have a high degree of homology with other bothropic PLA2-like myotoxins (approximately 75%) and nonbothropic myotoxins (approximately 60%). MP-III 4R is a new PLA2, which was isolated using exclusively analytical and preparative HPLC methods. Based on the N-terminal sequence and biological activities, MP-III 4R was identified as similar to piratoxin-III (PrTX-III), which was isolated by conventional chromatography based on molecular exclusion ion exchange chromatography. Clinical manifestations indicate that at the site of toxin injection, there may be pain of variable intensity, because animals continue to lick the limb. No clinical sign indicating general toxicity was noticed. Myotoxicity was observed in gastrocnemius muscle cells after exposure to MP-III 4R, with a high frequency (70%) of affected muscle fibers.
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Golubev AM, Lee W, Marangoni S, Novello JC, Oliveira B, Toyama MH, Polikarpov I. Crystallization and preliminary diffraction data of neurotoxin Ts-gamma from the venom of the scorpion Tityus serrulatus. ACTA CRYSTALLOGRAPHICA SECTION D: BIOLOGICAL CRYSTALLOGRAPHY 1998; 54:1440-1. [PMID: 10089532 DOI: 10.1107/s0907444998007197] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Scorpion neurotoxin Ts-gamma was isolated from Tityus serrulatus venom and purified to apparent homogeneity by ion-exchange HPLC. Crystals of the toxin were grown using polyethylene glycol 6000 as precipitant and were found to belong to the monoclinic space group P21 with cell parameters a = 22.20, b = 36.90, c = 31.57 A, beta = 100.85 degrees. The crystals diffract beyond 1.73 A resolution at a synchrotron beamline, being notably stable during X-ray exposure. The structure has been solved by molecular replacement using the very high resolution structure of Sahara scorpion Androctonus australis Hector (PDB code 1AHO) as a search model.
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Lee W, Gonçalez MC, Ramalheira RM, Kuser PR, Toyama MH, Oliveira B, Giglio JR, Marangoni S, Polikarpov I. Crystallization and preliminary X-ray diffraction studies of piratoxin II, a phospholipase A2 isolated from the venom of Bothrops pirajai. ACTA CRYSTALLOGRAPHICA SECTION D: BIOLOGICAL CRYSTALLOGRAPHY 1998; 54:1437-9. [PMID: 10089531 DOI: 10.1107/s0907444998007082] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The phospholipases A2 (PLA2, E.C. 3.1.1.4, phosphatide sn2 acylhydrolases) are the major components of the venom of several snakes. They are responsible for several important pharmacological effects observed in ophidian incidents. PLA2 piratoxin II from Bothrops pirajai has been crystallized by the vapour-diffusion technique. X-ray diffraction data have been collected to 2.04 A resolution (90.2% complete, Rmerge = 0.070). The space group is P21 and the cell parameters are a = 46.19, b = 60.36, c = 58.74 A and beta = 96.05 degrees. The structure has been solved by molecular replacement using the crystallographic structure of PLA2 from Bothrops asper (PDB code 1CLP) as a search model.
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Toyama MH, Soares AM, Vieira CA, Novello JC, Oliveira B, Giglio JR, Marangoni S. Amino acid sequence of piratoxin-I, a myotoxin from Bothrops pirajai snake venom, and its biological activity after alkylation with p-bromophenacyl bromide. JOURNAL OF PROTEIN CHEMISTRY 1998; 17:713-8. [PMID: 9853687 DOI: 10.1007/bf02780974] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
The complete sequence of the 121 amino acid residues of piratoxin-I (PrTX-I), a phospholipase A2 (PLA2)-like myotoxin from Bothrops pirajai snake (Bahia jararacussu) venom, is reported. From the sequence, an M, of 13,825 and an approximate pI of 8.3 were calculated. PrTX-I shows a high sequence homology with Lys-49 myotoxins from other bothropic (approximately 95%) and nonbothropic (approximately 80%) venoms, but only 70-75% homology when aligned with the catalytically active Asp-49 PLA2s. When compared with bothropstoxin-I from Bothropsjararacussu, which is morphologically almost identical to B. pirajai, only two changes out of 121 total amino acid residues have been observed. The approximate minimal lethal dose LD50 (mice, i.p., 24 hr) of PrTX-I was 8 (6.8-9.1) mg/kg, and the minimal edematogenic dose (MED) in a rat paw model was 39.5+/-1.8 ug. After alkylation of His-48 with p-bromophenacyl bromide, the MED was 40.1+/-1.9 ug, but up to 4 LD50 were unable to cause death in any of a group of eight mice after 72 hr. Therefore the edematogenic activity was retained and apparently did not involve His-48, suggesting that at least two biologically active sites are present in PrTX-I.
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Soares AM, Rodrigues VM, Homsi-Brandeburgo MI, Toyama MH, Lombardi FR, Arni RK, Giglio JR. A rapid procedure for the isolation of the Lys-49 myotoxin II from Bothrops moojeni (caissaca) venom: biochemical characterization, crystallization, myotoxic and edematogenic activity. Toxicon 1998; 36:503-14. [PMID: 9637370 DOI: 10.1016/s0041-0101(97)00133-5] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Bothtrops moojeni snake venom was fractionated on a CM-Sepharose column which was previously equilibrated with 0.05 M ammonium bicarbonate buffer at pH 8.0 and subsequently eluted with an ammonium bicarbonate concentration gradient from 0.05 to 0.5 M at constant pH (8.0) and temperature (25 degrees C). The fraction which eluted last (M-VI) showed, after direct lyophilization, a single band by polyacrylamide gel electrophoresis (PAGE) and SDS-PAGE, indicating an approximate Mr of 14000 and 27000, in the presence and absence of dithiothreitol, respectively. Its amino acid composition revealed a high level of hydrophobic and basic amino acids as well as 14 half-cystine residues. Its isoelectric point and extinction coefficient (E(1.0 mg/ml) (1.0 cm) at 278 nm and pH 7.0) were 8.2 and 1.170, respectively. M-VI was devoid of phospholipase A2 (PLA2) activity on egg yolk, as well as of hemorrhagic, anticoagulant and coagulant activities, but could induce drastic necrosis on skeletal muscle fibres as well as rapid and transient edema on the rat paw. Its N-terminal sequence: SLFELGKMILQETGKNPAKSYGVYGCNCGVGGRGKPKDATDRCCYVHKCCYK... revealed high homology with other Lys 49 PLA2-like myotoxins from other bothropic venoms. Orthorhombic crystals of M-VI, which diffracted to a maximal resolution of 1.6 A, were obtained and indicated the presence of a dimer in the asymmetrical unit.
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Sampaio SV, Coutinho-Netto J, Arantes EC, Toyama MH, Novello JC, Giglio JR. TsTX-VII, a new toxin from Tityus serrulatus scorpion venom able to induce the release of neurotransmitters from rat brain synaptosomes not blocked by tetrodotoxin. BIOCHEMISTRY AND MOLECULAR BIOLOGY INTERNATIONAL 1997; 41:1255-63. [PMID: 9161721 DOI: 10.1080/15216549700202351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
A procedure for the isolation of the toxin Tityustoxin VII (TsTX-VII) from Tityus serrulatus scorpion venom and its biochemical characterization is reported. This protein has a M(r) = 6,700-6,800, eight half-cystine residues accounting for four disulfide bridges and no His. Its N-terminal sequence GHZGYGS ... characterizes it as a new toxin, able to release glutamic acid and gamma aminobutyric acid from rat brain synaptosomes "in vitro". This release was also induced by the whole venom. Tetrodotoxin however blocked the effect of the whole venom but not that of TsTX-VII, thus suggesting that the releasing mechanism by TsTX-VII does not involve Na+ but perhaps K+ or Ca++ channels.
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Farah MF, One M, Novello JC, Toyama MH, Perales J, Moussatché H, Domont GB, Oliveira B, Marangoni S. Isolation of protein factors from opossum (Didelphis albiventris) serum which protect against Bothrops jararaca venom. Toxicon 1996; 34:1067-71. [PMID: 8896201 DOI: 10.1016/0041-0101(96)00034-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The fractionation of Didelphis albiventris serum by DEAE-Sephadex A50 yields a fraction (DA2) which protects the opossum against Bothrops venom. One polypeptide (DA2-II) responsible for this protection was isolated from fraction DA2 by ion exchange chromatography and biochemically characterized. DA2-II is a 43,000 mol. wt glycoprotein with the following N-terminal sequence: LKAMDTTPPLKIKKEPVK. Pairwise comparison of the amino acid sequence with four anti-hemorrhagic factors isolated from other opossum species indicated that DA2-II possesses high similarity (60-80%) with these proteins.
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Toyama MH, Mancuso LC, Giglio JR, Novello JC, Oliveira B, Marangoni S. A quick procedure for the isolation of dimeric piratoxins-I and II, two myotoxins from Bothrops pirajai snake venom. N-terminal sequencing. BIOCHEMISTRY AND MOLECULAR BIOLOGY INTERNATIONAL 1995; 37:1047-55. [PMID: 8747534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Two myotoxins, MP-I and MP-II, from Bothrops pirajai snake venom, have been purified by a quick high performance liquid chromatography (HPLC) procedure. Based on the HPLC coelution profile, amino acid composition, N-terminal sequence, polyacrylamide gel electrophoresis (PAGE) migration, as well as lack of phospholipase-A2 (PLA2) and proteolytic activities, MP-I and MP-II were identified as piratoxin-I (PrTX-I) and II (PrTX-II), respectively. This procedure affords, aside the reduced operation time, a high yield (35% of the applied sample in terms of A280nm) of MP-I, which is the major myotoxin of the venom. The N-terminal sequences of MP-I, MP-II, PrTX-I and PrTX-II, up to the 51st, 41st, 46th and 39th residues, respectively, have been determined, revealing MP-I (and hence PrTX-I) as a Lys-49 PLA2-like myotoxin. Both MP-I and MP-II have been shown, by SDS-PAGE, to occur in dimeric isoforms.
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Marangoni S, Toyama MH, Arantes EC, Giglio JR, da Silva CA, Carneiro EM, Gonçalves AA, Oliveira B. Amino acid sequence of TsTX-V, an alpha-toxin from Tityus serrulatus scorpion venom, and its effect on K+ permeability of beta-cells from isolated rat islets of Langerhans. BIOCHIMICA ET BIOPHYSICA ACTA 1995; 1243:309-14. [PMID: 7727504 DOI: 10.1016/0304-4165(94)00142-k] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Highly purified Tityustoxin V (TsTX-V), an alpha-toxin isolated from the venom of the Brazilian scorpion Tityus serrulatus, was obtained by ion exchange chromatography on carboxymethylcellulose-52. It was shown to be homogeneous by reverse phase high performance liquid chromatography, N-terminal sequencing (first 39 residues) of the reduced and alkylated protein and by polyacrylamide gel electrophoresis in the presence of sodium dodecylsulfate and tricine. Following enzymatic digestion, the complete amino acid sequence (64 residues) was determined. The sequence showed higher homology with the toxins from the venoms of the North African than with those of the North and South American scorpions. Using the rate of 86Rb+ release from depolarized rat pancreatic beta-cells as a measure of K+ permeability changes, TsTX-V (5.6 micrograms/ml) was found to increase by 2.0-2.4-fold the rate of marker outflow in the presence of 8.3 mM glucose. This effect was persistent and slowly reversible, showing similarity to that induced by 100 microM veratridine, an agent that increases the open period of Na+ channels, delaying their inactivation. It is suggested that, by extending the depolarized period, TsTX-V indirectly affects beta-cell voltage-dependent K+ channels, thus increasing K+ permeability.
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