| role of ca2+ in the binding of phospholipase a2 with a monomeric substrate and with its amide-type analog. | effects of ca2+ on the kinetic parameters for the hydrolysis of monodispersed 1,2-dihexanoyl-sn-glycero-3-phosphorylcholine (dic6pc), catalyzed by group i phospholipases a2 (pla2s) from pseudechis australis, naja naja atra, and bovine pancreas and by group ii enzymes from vipera russelli russelli, agkistrodon halys blomhoffii, and trimeresurus flavoviridis, were studied by the ph-stat assay method at 25 degrees c, ph 7.5-8.2, and an ionic strength of 0.1 or 0.2 in the absence or presence of an a ... | 1994 | 7883763 |
| chemical modification and inactivation of phospholipases a2 by a manoalide analogue. | chemical modification and inactivation of bovine pancreatic, porcine pancreatic, naja naja atra and pseudechis australis phospholipases a2 (pla2s), belonging to group i, and of trimeresurus flavoviridis, vipera russelli russelli and agkistrodon halys blomhoffii pla2s, belonging to group ii, were investigated by the use of a manoalide (mld)-analogue, 1-(2,5-dihydro-hydroxy-5-oxo-3-furanyl)-8,12-dimethyl-4-formyl-3,7, 11-tridecatrienol. at appropriate time intervals, residual pla2 activities towar ... | 1995 | 7755577 |
| beta-rtx. a receptor-active protein from russell's viper (vipera russelli russelli) venom. | a single chain polypeptide, termed beta-rtx, with an apparent mr = 9600 has been isolated from the venom of vipera russelli russelli. it was purified by cation exchange chromatography, followed by preparative isoelectric focusing and chromatofocusing. purity was confirmed by gel filtration, high performance liquid chromatography, gel electrophoresis, and analytical ultracentrifugation. amino acid analysis revealed the presence of eight half-cystines, one being located at the nh2 terminus, which ... | 1983 | 6300128 |
| inhibition of red cell ca2+-dependent k+ channels by snake venoms. | we have investigated the effects of several snake venoms on the ca2+-dependent k+ channels of human red cells. a heat-resistant component of the venom of the snake notechis scutatus irreversibly inhibited ca2+-dependent k+ transport with a ki value of 0.1-0.2 micrograms/ml. metabolic changes of the cells modified the maximal effect of the venom. binding of the venom required extracellular ca2+ and was quick, but development of full inhibition required additional time. the effects of the venoms f ... | 1989 | 2930782 |
| purification and partial characterization of a haemorrhagin (vrh-1) from vipera russelli russelli venom. | a haemorrhagic toxin (vrh-1) has been purified to homogeneity from vipera russelli russelli venom by subjecting it to chromatography twice successively on cm-sephadex c-50. it is a protein of mol. wt 22,000 and contains one mole of mg2+. intradermal administration of this haemorrhagin in mice resulted in severe lung haemorrhage but produced little haemorrhage in skin. this apparent organ preference led us to develop a new haemorrhage assay method utilizing dye diffusion from lung in vitro. prote ... | 1993 | 8146873 |
| elisa for the detection of venoms from four medically important snakes of india. | a double antibody sandwich enzyme linked immunosorbent assay (elisa) was developed to detect echis carinatus venom in various organs (brain, heart, lungs, liver, spleen and kidneys) as well as tissue at the site of injection of mice, at various time intervals (1, 6, 12, 18, 24 h and 12 h intervals up to 72 h) after death. the assay could detect e. carinatus venom levels up to 2.5 ng/ml of tissue homogenate and the venom was detected up to 72 h after death. a highly sensitive and species-specific ... | 1999 | 10219987 |
| cdna sequence and molecular modeling of a nerve growth factor from bothrops jararacussu venomous gland. | the complete nucleotide sequence of a nerve growth factor precursor from bothrops jararacussu snake (bj-ngf) was determined by dna sequencing of a clone from cdna library prepared from the poly(a) + rna of the venom gland of b. jararacussu. cdna encoding bj-ngf precursor contained 723 bp in length, which encoded a prepro-ngf molecule with 241 amino acid residues. the mature bj-ngf molecule was composed of 118 amino acid residues with theoretical pi and molecular weight of 8.31 and 13,537, respec ... | 2002 | 12453640 |
| in vitro antimicrobial activity of natural toxins and animal venoms tested against burkholderia pseudomallei. | burkholderia pseudomallei are the causative agent of melioidosis. increasing resistance of the disease to antibiotics is a severe problem in treatment regime and has led to intensification of the search for new drugs. antimicrobial peptides are the most ubiquitous in nature as part of the innate immune system and host defense mechanism. | 2006 | 16784542 |
| a heat stable protein toxin (drct-i) from the indian viper (daboia russelli russelli) venom having antiproliferative, cytotoxic and apoptotic activities. | a heat stable 7.2kda protein toxin (drct-i) has been purified and crystallized from indian daboia russelli russelli venom (roy choudhury et al., 2006. acta cryst. f struct biol cryst commun, 62(pt. 3), 292). the n-terminal (first 20) amino acid sequence of drct-i was lkcnklvplfyktcpagknl, which showed sequence homology to cytotoxins isolated from naja venom. drct-i has been evaluated for anticancer activity against eac cells in vivo and human leukemic cells (u937, k562) in vitro. drct-i (125 mic ... | 2007 | 17055549 |
| thermal detoxification of the venom from daboia russelli russelli of eastern india with restoration of fibrinolytic activity. | the fibrinolytic components of venom have been evaluated for long in the enzymatic treatment of thrombosis. russell's viper venom has fibrinolytic activity that is associated with hemorrhagic activity. here it has been investigated whether the crude venom could be detoxified by thermal denaturation retaining fibrinolytic activity. the venom at 0.05 mg/ml in 20 mm k-phosphate, ph 7.5 when exposed to 100 °c for 5 min followed by cooling at 25 °c for 1 h led to its detoxification, while 80-85% of t ... | 2011 | 21333671 |
| viperatoxin-ii: a novel viper venom protein as an effective bactericidal agent. | infections caused by methicillin-resistant staphylococcus aureus (mrsa) have become a rising threat to public health. there is an urgent need for development of promising new therapeutic agents against drug resistant bacteria like s. aureus. this report discusses purification and characterization of proteins from indian russell's viper snake venom. novel 15-kda proteins called "viperatoxin" (viptx-i and viptx-ii) were extracted from the whole venom and evaluated using in vitro antimicrobial expe ... | 2015 | 26793432 |
| gene microarray analyses of daboia russelli russelli daboiatoxin treatment of thp-1 human macrophages infected with burkholderia pseudomallei. | burkholderia pseudomallei is the causative agent of melioidosis and represents a potential bioterrorism threat. in this study, the transcriptomic responses of b. pseudomallei infection of a human macrophage cell model were investigated using whole-genome microarrays. gene expression profiles were compared between infected thp-1 human monocytic leukemia cells with or without treatment with daboia russelli russelli daboiatoxin (drrdbtx) or ceftazidime (antibiotic control). microarray analyses of i ... | 2015 | 26592245 |
| antibacterial activity of snake, scorpion and bee venoms: a comparison with purified venom phospholipase a2 enzymes. | venoms of snakes, scorpions, bees and purified venom phospholipase a(2) (pla(2)) enzymes were examined to evaluate the antibacterial activity of purified venom enzymes as compared with that of the crude venoms. | 2007 | 17309613 |
| ability of a small, basic protein isolated from russell's viper venom (daboia russelli russelli) to induce renal tubular necrosis in mice. | russell's viper venom (rvv) induced acute renal failure involves both direct and indirect nephrotoxic actions where the specific component/s are yet to be identified. a basic cytotoxin of 7.2kda (rvv-7) has been identified as potential nephrotoxin. autoradiographic experiments demonstrated that only rvv-7 among rvv toxins binds specifically to mice kidney membrane. homogeneous preparation of rvv-7 confirmed its necrotic cell killing property having ec(50) of 4.79+/-3.28microm. tissue distributio ... | 2007 | 17499831 |
| characterization of a novel pro-coagulant metalloprotease (rvbcmp) possessing alpha-fibrinogenase and tissue haemorrhagic activity from venom of daboia russelli russelli (russell's viper): evidence of distinct coagulant and haemorrhagic sites in rvbcmp. | a novel, basic pro-coagulation metalloprotease (russell's viper basic coagulant metalloprotease, rvbcmp) with an approximate molecular weight of 15kda was purified from the venom of daboia russelli russelli (russell's viper) from eastern india. rvbcmp exerted dose-dependent coagulation of platelet-poor human plasma; however, rvbcmp possessed less coagulant activity as compared with the coagulant activity of crude russell's viper venom (rvv). rvbcmp did not show oedema induction, direct haemolysi ... | 2008 | 18249434 |
| enzymatic and structural characterization of a basic phospholipase a(2) from the sea anemone condylactis gigantea. | this work aimed at the isolation and structural/functional characterization of a phospholipase a(2) (cgpla(2)) from the extract of the anemone condylactis gigantea. cgpla(2) was isolated with a high purity level through three chromatographic steps, showing pi 8.6 and molecular weights of 14,500 and 29,000 for the monomer and dimer, respectively. cgpla(2) showed a high catalytic activity upon fluorescent phospholipids inducing no direct hemolytic activity. this enzyme, which is ca(2+)-dependent, ... | 2010 | 20562011 |
| in vitro and in vivo evaluation of polyherbal formulation against russell's viper and cobra venom and screening of bioactive components by docking studies. | the present study emphasizes to reveal the antivenom activity of aristolochia bracteolata lam., tylophora indica (burm.f.) merrill, and leucas aspera s. which were evaluated against venoms of daboia russelli russelli (russell's viper) and naja naja (indian cobra). the aqueous extracts of leaves and roots of the above-mentioned plants and their polyherbal (1 : 1 : 1) formulation at a dose of 200 mg/kg showed protection against envenomed mice with ld50 doses of 0.44 mg/kg and 0.28 mg/kg against ru ... | 2013 | 23533518 |
| molecular diversity in venom proteins of the russell's viper (daboia russellii russellii) and the indian cobra (naja naja) in sri lanka. | to examine the molecular diversity of the venom proteins of the russell's viper (daboia russellii russellii) and the indian cobra (naja naja) in sri lanka, we isolated 38 venom proteins through a combination of anion exchange chromatography followed by reversed-phase high performance liquid chromatography. from the venom of d. r. russellii we isolated 15 proteins: 5 isozymes of phospholipase a(2) (pla(2)), 4 serine proteases, 2 c-type lectin-like proteins, 2 l-amino acid oxidases, 1 cysteine-ric ... | 2010 | 20203422 |
| two l-amino acid oxidase isoenzymes from russell's viper (daboia russelli russelli) venom with different mechanisms of inhibition by substrate analogs. | two isoforms, l(1) and l(2), of l-amino acid oxidase have been isolated from russell's viper venom by sephadex g-100 gel filtration followed by cm-sephadex c-50 ion exchange chromatography. the enzymes, with different isoelectric points, are monomers of 60-63 kda as observed from size exclusion hplc and sds/page. partial n-terminal amino acid sequencing of l(1) and l(2) showed significant homology with other snake venom l-amino acid oxidases. both the enzymes exhibit marked substrate preference ... | 2008 | 18384385 |
| purification, crystallization and preliminary x-ray structural studies of a 7.2 kda cytotoxin isolated from the venom of daboia russelli russelli of the viperidae family. | a cytotoxin (mw 7.2 kda) from indian russell's viper (daboia russelli russelli) venom possessing antiproliferative activity, cardiotoxicity, neurotoxicity and myotoxicity has been purified, characterized and crystallized. the crystals belong to the tetragonal space group p4(1), with unit-cell parameters a = b = 47.94, c = 50.2 a. larger crystals, which diffracted to 1.5 a, were found to be twinned; diffraction data were therefore collected to 2.93 a resolution using a smaller crystal. molecular- ... | 2006 | 16511326 |
| the three-dimensional structures of two toxins from snake venom throw light on the anticoagulant and neurotoxic sites of phospholipase a2. | the three-dimensional structures of the class ii anticoagulant phospholipase a2 (pla2) toxin rvv-vd from the venom of russell's viper, vipera russelli russelli, and the class i neurotoxic pla2 notechis ii-5 from the, australian tiger snake, notechis scutatus scutatus, were determined to 2.2 a and 3.0 a resolution, respectively. both enzymes are monomeric and consist of 121 and 119 residues, respectively. a comparison of ten class i/ii pla2 structures showed, among other differences, that the bet ... | 1998 | 9604284 |
| phosphodiesterase from daboia russelli russelli venom: purification, partial characterization and inhibition of platelet aggregation. | phosphodiesterases (pdes) belong to a super-family of enzymes that have multiple roles in the metabolism of extracellular nucleotides and regulation of nucleotide-based intercellular signalling. a pde from russell's viper (daboia russelli russelli) venom (dr-pde) was purified by gel filtration, ion exchange and affinity chromatographies. homogeneity of the preparation was verified by sds-page, se-hplc and mass spectrometry. it was free from 5'-nucleotidase, alkaline phosphatase and protease acti ... | 2014 | 24932740 |
| factor v activator from daboia russelli russelli venom destabilizes β-amyloid aggregate, the hallmark of alzheimer disease. | formation of plaque by fibrils of β-amyloid (aβ) peptide in the brain is the characteristic feature of alzheimer disease (ad). inhibition of the process of aggregate formation from aβ-monomer and destabilization of the aggregate could be useful for prevention and propagation of the disease respectively. russell's viper venom (rvv) contains protein(s) that destabilize aβ aggregates as revealed from the thioflavin t assay. the active component was identified as factor v activator (rvv-v). among th ... | 2013 | 23986449 |
| haemorrhagic protein of russell's viper venom with fibrinolytic and esterolytic activities. | a haemorrhagic toxin specifically active on skin and muscle at the site of introduction in mice has been purified from vipera russelli russelli (indian subspecies of russell's viper) venom by cm-sephadex c-50 ion exchange chromatography and size exclusion (se)-hplc. this toxic protein also has strong fibrinolytic and arginine esterolytic activities. the purified preparation was a single polypeptide chain of molecular weight 73,000, as revealed by sds-page and se-hplc under native and denatured c ... | 2000 | 10775749 |
| enzymatic activities of some snake venoms from families elapidae and viperidae. | alkaline phosphomonoesterase, phosphodiesterase, l-amino acid oxidase, hyaluronidase, 5'-nucleotidase, arginine ester hydrolase, phospholipase a2 and proteinase activities were determined in eight snake venoms, including three from sea snake, of families elapidae and viperidae from pakistan. the species includes three sea snakes hydrophis cyanocinctus, enhydrina schsitosa, microcephalophis gracilis gracilis and two land snakes naja naja naja, bungarus caeruleus of family elapidae while three lan ... | 1996 | 16414774 |
| identification of a novel binding site for calmodulin in ammodytoxin a, a neurotoxic group iia phospholipase a2. | the molecular mechanism of the presynaptic neurotoxicity of snake venom phospholipases a2 (pla2s) is not yet fully elucidated. recently, new high-affinity binding proteins for pla2 toxins have been discovered, including the important intracellular ca2+ sensor, calmodulin (cam). in the present study, the mode of interaction of group iia pla2s with the ca2+-bound form of cam was investigated by mutational analysis of ammodytoxin a (atxa) from the long-nosed viper (vipera ammodytes ammodytes). seve ... | 2003 | 12846835 |
| isolation and characterization of a novel postsynaptic/cytotoxic neurotoxin from daboia russelli russelli venom. | a postsynaptic neurotoxin was purified from daboia russelli russelli venom using gel filtration, ion-exchange chromatography and reverse-phase high-performance liquid chromatography. the n-terminal sequence, molecular mass and pharmacological activities of the neurotoxin/cytotoxin indicate that it is a short-chain neurotoxin like that found in elapid venom. this is the first report on the presence of such a postsynaptic neurotoxin from d. r. russelli venom. | 2002 | 12010516 |
| purification and characterization of an organ specific haemorrhagic toxin from vipera russelli russelli (russell's viper) venom. | a haemorrhagic toxin (vrr-12) from vipera russelli russelli (russell's viper) venom has been purified by ion-exchange chromatography on cm-sephadex c-50 followed by size-exclusion hplc to electrophoretically homogeneous state. it is a 12 kda single polypeptide having 1 mole of zn+2 ion. this toxin induces intense intestinal haemorrhage and to a lesser extent skeletal muscle haemorrhage in mice. it does not show detectable proteolytic and esterolytic activity with selected substrates under specif ... | 2000 | 10983422 |
| purification and amino-acid sequence of a nerve growth factor from the venom of vipera russelli russelli. | nerve growth factor (ngf) was purified from the venom of vipera russelli russelli by sephadex g-50 gel filtration, s-sepharose column chromatography and blue-sepharose cl-6b column chromatography. the purified ngf was found to be a glycoprotein, whose apparent molecular mass was estimated to be about 17.5 kda by sds-page. the amino-acid sequence was determined by a combination of conventional methods. the v. r. russelli ngf was composed of 117 amino-acid residues with one residue, asn-21, being ... | 1992 | 1477101 |