Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| the chemical basis for interfacial activation of monomeric phospholipases a2. autocatalytic derivatization of the enzyme by acyl transfer from substrate. | a basic monomeric phospholipase a2 from the venom of the american water moccasin, agkistrodon piscivorus piscivorus, undergoes ca2+-dependent, autocatalytic acylation during the course of hydrolysis of both model and natural phospholipid substrates. acylation occurs at 2 lysine residues, lys-7 and lys-10, in the nh2-terminal alpha-helical segment of the enzyme, and when both positions are fully derivatized, the stable bisacylphospholipase a2 becomes a dimer in solution. the acylated enzyme is fu ... | 1988 | 3403524 |
| geographic and ontogenic variation in venom of the western diamondback rattlesnake (crotalus atrox). | venom samples from western diamondback rattlesnakes (crotalus atrox) from 13 localities in the united states were tested for i.v. and s.c. lethality for mice, protease activity, hemorrhagic activity, and the presence of mojave toxin. electrophoresis on polyacrylamide gel was used to compare protein composition. the neutralizing effect of two commercial antivenoms was evaluated against selected samples of venom. venom of young snakes from north texas was compared with that of adults from the same ... | 1986 | 3513378 |
| substrate specificities and inhibition of two hemorrhagic zinc proteases ht-c and ht-d from crotalus atrox venom. | the proteolytic specificities of two zinc hemorrhagic toxins (ht-c and ht-d), isolated from crotalus atrox venom, were investigated by using the oxidized b chain of bovine insulin and synthetic peptide substrates. the enzymes cleaved the ala14-leu15 bond of the insulin b chain most rapidly and the tyr16-leu17 slightly more slowly. the his5-leu6, his10-leu11, and gly23-phe24 bonds were also cleaved but at considerably slower rates. in order to assess the substrate length preferences of the enzyme ... | 1986 | 3514216 |
| amino acid sequence of trimeresurus flavoviridis phospholipase a2. | the amino acid sequence of phospholipase a2 from the venom of trimeresurus flavoviridis (the habu snake) was determined. the enzyme subunit has a molecular weight of 13,764 and consists of a single polypeptide chain of 122 amino acids and seven disulfide bonds. the fragmentation was conducted by digesting the reduced and s-carboxymethylated derivative of the protein with achromobacter protease i, chymotrypsin, and trypsin, respectively. achromobacter protease i peptides were used for alignment a ... | 1986 | 3514593 |
| helodermatine, a kallikrein-like, hypotensive enzyme from the venom of heloderma horridum horridum (mexican beaded lizard). | we have purified and characterized the major n-benzoyl-l-arginine ethyl ester hydrolase from the venom of heloderma horridum horridum. the enzyme belongs to the serine proteinase family, and its activity vs. peptide amide substrates and human high-molecular-weight kininogen suggests a similarity to the family of kallikreins. this interpretation is corroborated by its reactivity with the natural inhibitors soybean trypsin inhibitor and kunitz-type bovine pancreatic trypsin inhibitor (aprotinin). ... | 1986 | 3537191 |
| life-threatening airway obstruction from rattlesnake bite to the tongue. | we describe the case of a 41-year-old man who suffered a bite to the tongue from the western diamondback rattlesnake (c atrox). life-threatening obstruction of his upper airway secondary to massive edema of the tongue and other soft tissue structures quickly followed envenomation. nasotracheal intubation, iv antivenin, and supportive care resulted in complete recovery with no permanent deficits. rattlesnake bites to the tongue are rare and pose an unusual cause of airway obstruction. | 1987 | 3592340 |
| fatal rattlesnake envenomation in arizona: 1969-1984. | case histories of the last nine fatalities (1969-1984), in which the cause of death on the state of arizona certificate of death was snakebite, were reviewed. six males and three females ranged in age from 2 to 77 years, and were bitten between 0800-2100 hours from april to september. bites in three adult males were "illegitimate" and of these, two were by captive mojave rattlesnakes, crotalus s. scutulatus. the latter two victims had been bitten previously and remained at home, refusing treatme ... | 1986 | 3701904 |
| ability of polyvalent (crotalidae) antivenom to neutralize local myonecrosis induced by crotalus atrox venom. | wyeth's polyvalent (crotalidae) antivenom was tested in mice for its ability to neutralize local myonecrosis induced by crude crotalus atrox venom. a light microscopic assay was used to quantitate myonecrosis after i.m. injection of antivenom-venom mixtures. the results indicate that antivenom neutralizes the local myotoxicity of up to 15 micrograms venom per g body weight of mice. this neutralization is significantly better than that previously reported for crotalus viridis viridis venom. | 1986 | 3705097 |
| synthetic peptides related to the n-terminal amino acid sequence of a pharmacologically active decapeptide isolated from crotalus atrox snake venom. | synthesis is described of some peptides and peptide derivatives related to the n-terminal amino acid sequence of a pharmacologically active decapeptide (pol-236) recently isolated from crotalus atrox snake venom. the synthetic compounds were tested for hypotensive activity in anaesthetized normotensive rats. at the used doses all compounds failed to show the immediate hypotensive effect noted after pol-236 administration. | 1986 | 3743744 |
| a complete amino acid sequence for the basic subunit of crotoxin. | the complete amino acid sequence of the basic subunit of crotoxin from the venom of crotalus durissus terrificus has been determined. fragmentation of the protein was achieved by using cyanogen bromide and arginine- and lysine-specific endoproteases. sixteen glx and asx residues reported by fraenkel-conrat et al. (1980) in natural toxins (d. eaker and t. wadstrom, eds.), pp. 561-567, pergamon, oxford.) have been resolved as glu or gln and asp or asn residues, respectively. most of the remaining ... | 1986 | 3753003 |
| self-association and active enzyme forms of naja naja naja and crotalus atrox phospholipase a2 studied by analytical ultracentrifugation. | the dimerization of phospholipase a2 (plpa2) from naja naja naja (pakistani cobra) and crotalus atrox (western diamondback rattlesnake) has been studied from ph 2.5 to 11 at 20 degrees c in 1 mm cacl2, 0.21 m ionic strength. for the c. atrox enzyme, it was found necessary to use a combination of sedimentation equilibrium and fluorescence yield data to analyze the association. sedimentation equilibrium in the analytical ultracentrifuge sufficed for the study of the n. naja plpa2. in the region of ... | 1986 | 3801457 |
| hydrolysis of 1-palmitoyl-2-[6-(pyren-1-yl)]hexanoyl-sn-glycero- 3-phospholipids by phospholipase a2: effect of the polar head-group. | the effect of the phospholipid polar head-group on the porcine pancreatic phospholipase a2 (phosphatidylcholine 2-acylhydrolase, ec 3.1.1.4) reaction was studied using 1-palmitoyl-2-[6-(pyren-1-yl)]hexanoyl-sn-glycero-3- phosphatidylcholine, -ethanolamine, -glycerol, -monomethylester and -serine as substrates. except for the monomethylester analogue, which was maximally activated by 3.5 mm cacl2, maximal enhancement of hydrolysis of the other pyrenephospholipids was obtained at 2 mm ca2+. sodium ... | 1987 | 3801511 |
| dissociation of 5-fluorouracil-induced dna fragmentation from either its incorporation into dna or its cytotoxicity in murine t-lymphoma (s-49) cells. | we have shown previously (w. b. parker and p. klubes, cancer res., 45:4249-4256, 1985) that uridine (10 microm) enhanced the cytotoxicity of 5-fluorouracil (fura) in cultured mouse t-lymphoma (s-49) cells. here we show, by the use of colony formation assays, that approximately 50% of the cytotoxicity of fura plus uridine could be prevented by the simultaneous administration of thymidine (2.5 to 10 microm). in order to explain our observation of a thymidine-preventable component of the cytotoxici ... | 1987 | 3802103 |
| identification of the tryptophan residue located in the calcium binding site of trimeresurus flavoviridis phospholipase a2. | when phospholipase a2 from the venom of trimeresurus flavoviridis (the habu snake) was oxidized with n-bromosuccinimide at ph 4.0, its activity decreased linearly with increase in the extent of oxidation of tryptophan residues. oxidation of two of the four tryptophan residues caused an apparent loss of activity. the accessibilities of the tryptophan residues were analyzed with differently oxidized phospholipase a2 preparations and were determined to be in the following order: trp-3 approximately ... | 1986 | 3818568 |
| an isoelectric focusing study of seasonal variation in rattlesnake venom proteins. | adult specimens of seven southern pacific rattlesnakes (crotalus viridis helleri), four northern black-tailed rattlesnakes (crotalus molossus molossus), and six western diamondback rattlesnakes (crotalus atrox) were housed under controlled light and temperature and milked of venom monthly for 20 months. ambient conditions were modelled to simulate seasonal change. weighed amounts of lyophilized venom from each snake were compared chronologically for variation in isoelectric focusing patterns, us ... | 1986 | 3824406 |
| monoclonal antibodies against an intracellular phospholipase a2 from rat liver and their cross-reactivity with other phospholipases a2. | the membrane-associated phospholipase a2 from rat liver mitochondria was solubilized and partially purified by aca 54 gel filtration and matrex gel blue a chromatography. the approximately 2500-fold purified preparation was injected into mice to prepare monoclonal antibodies against phospholipase a2 after fusion of spleen cells and mouse sp2/0 myeloma cells. hybridoma supernatants were assayed for antibody production in enzyme-linked immunosorbent assay with partially purified phospholipase a2 a ... | 1987 | 3830178 |
| a new peptide from crotalus atrox snake venom. | the presence of new hypotensive peptides, possibly not related to ace inhibition, has been investigated on 66 snake venoms from crotalid, viperid and elapid families. only the venom of crotalus atrox showed a substantial amount of a new decapeptide, called pol-236, with the following aminoacid sequence: pyr-leu-trp-pro-arg-pro-gln-ile-pro-pro. pharmacological assays performed on the synthesized peptide revealed effects on blood pressure, probably derived from vascular and cardiac interferences. | 1985 | 3831966 |
| isolation and characterization of hemorrhagic toxin g from the venom of crotalus atrox (western diamondback rattlesnake). | hemorrhagic toxin g (ht-g) was isolated from crotalus atrox (western diamondback rattlesnake) venom using a five-step purification procedure to obtain approximately equal to 5.9 mg of purified ht-g from 2.0 g of crude venom. the purified toxin was homogeneous by disc electrophoresis on polyacrylamide gel at ph 8.3 and 4.3, and by isoelectric focusing. ht-g possessed lethal, hemorrhagic and proteolytic activities. these activities of toxin were inhibited by ethylenediamine-tetraacetic acid (edta) ... | 1985 | 3834802 |
| specificity of hemorrhagic proteinase from crotalus atrox (western diamondback rattlesnake) venom. | hemorrhagic proteinase, htb, isolated from crotalus atrox (western diamondback rattlesnake) venom was studied for its specificity. htb showed fibrinogenase activity, hydrolyzing the a alpha chain of fibrinogen first, followed by the cleavage of the b beta chain. htb is different from thrombin and did not produce a fibrin clot. the degradation products of fibrinogen were found to be different, indicating that the cleavage sites in the a alpha and b beta chains are different from those of thrombin ... | 1985 | 3888273 |
| separation of crotalus atrox (western diamondback rattlesnake) alpha-proteinase from serine proteinase and hemorrhagic factor activities. | a method for obtaining crotalus atrox alpha-proteinase (ec 3.4.24.1) in a pure form has been developed. fractionation of the crude venom on deae-sepharose, followed by gel filtration on bio-gel p-150 and chromatography on cm-sepharose, yielded an alpha-proteinase preparation which showed a single band on disc and sodium dodecyl sulfate-polyacrylamide gel electrophoresis and had an activity on casein approximately twice that previously reported. the enzyme is a nonglycosylated single-chain polype ... | 1985 | 3913334 |
| primary structure of the reactive site of human c1-inhibitor. | human c1-inhibitor (c1-inh) forms an equimolar complex with complement proteinase c1s that is resistant to dissociation by sodium dodecyl sulfate. the formation of this stable complex results in the cleavage of a peptide bond near the carboxyl terminus of the inhibitor and, whereas the bulk of c1-inh remains covalently bound to the light chain of c1s, the postcomplex inhibitor peptide can be isolated under denaturing conditions. we have sequenced the amino-terminal region of this peptide and ded ... | 1985 | 3919001 |
| rattlesnake bite of glans penis. | the envenomation of the glans penis by a western diamondback rattlesnake (crotalus atrox) is presented. effects of envenomation, first aid, and hospital management are briefly reviewed. | 1985 | 4012978 |
| the refined crystal structure of dimeric phospholipase a2 at 2.5 a. access to a shielded catalytic center. | the 2.5-a crystal structure of the calcium-free form of the dimeric venom phospholipase a2 from the western diamondback rattlesnake crotalus atrox, has been refined to an r-factor of 17.8% (i greater than 2 sigma) and acceptable stereochemistry. the molecule is a nearly perfect 2-fold symmetric dimer in which most of the catalytic residues of both subunits face an internal cavity. the restricted access to the putative catalytic sites is especially puzzling as the optimal substrates for this and ... | 1985 | 4019493 |
| a comparison of the crystal structures of phospholipase a2 from bovine pancreas and crotalus atrox venom. | the refined high resolution crystal structure of the bovine phospholipase a2 was compared with its counterpart from the venom of crotalus atrox, the western diamondbacked rattlesnake. the strong similarity in their backbone conformations forms the basis of a common numbering system for the amino acid sequence. the three common major helices and much of the extended chain form a nearly identical "homologous core" structure. the variations in conformation usually arise from deletions/insertions or ... | 1985 | 4044572 |
| effects of fasting on the blood chemistry of the rattlesnake, crotalus atrox. | 1973 | 4146626 | |
| effect of ph, temperature, antivenin and functional group inhibitors on the toxicity and enzymatic activities of crotalus atrox venom. | 1966 | 4309654 | |
| collagenolytic activity of snake venom: the absence of collagenolytic activity in the trypsin-like enzyme from crotalus atrox venom. | 1971 | 4332276 | |
| the interaction of alpha2-macroglobulin with proteinases. binding and inhibition of mammalian collagenases and other metal proteinases. | 1. experiments were performed to determine whether the specific collagenases and other metal proteinases are bound and inhibited by alpha(2)-macroglobulin, as are endopeptidases of other classes. 2. a specific collagenase from rabbit synovial cells was inhibited by human serum. the inhibition could be attributed entirely to alpha(2)-macroglobulin; alpha(1)-trypsin inhibitor was not inhibitory. alpha(2)-macroglobulin presaturated with trypsin or cathepsin b1 did not inhibit collagenase, and pretr ... | 1974 | 4374931 |
| [further studies on the amino acid sequence of melittin, ii. preferential cleavage of valine-, leucine- and isoleucine bonds by alpha-protease from crotalus atrox venom]. | 1969 | 4389597 | |
| [enzymatic cleavage of native cysteine-containing polypeptides by thermolysin (ec 3.4.4.). ii. comparison of thermolysin with alpha-protease from crotalus atrox venom and subtilisin]. | 1969 | 4391355 | |
| the action of phospholipase a2 purified from crotalus atrox venom on specifically labelled 2-acyl-1-alk-1'-enyl- and 2-acyl-1-alkyl-sn-glycero-3-phosphorylcholine. | 1974 | 4416084 | |
| the activity of pure phospholipase a2 from crotalus atrox venom on myelin and on pure phospholipids. | 1974 | 4433546 | |
| yield of venom obtained from crotalus atrox by electrical stimulation. | 1972 | 4665361 | |
| lung surface-active fraction as a model system for macromolecular ultrastructural studies with crotalus atrox venom. | the dog lung surface-active fraction and phosphatidylcholine constituents were subjected to hydrolysis by crotalus atrox phospholipase a(2). relative rates of hydrolysis were: dipalmitoyl glycerophosphorylcholine > phosphatidylcholine isolated from the surface-active fraction > phosphatidylcholine as an integral component of the intact surface-active macromolecular structure. cholesterol markedly inhibited, whereas tripalmitin increased, the rate of hydrolysis with both pure phosphatidylcholine ... | 1973 | 4739813 |
| elastolytic activity from venom of the rattlesnake crotalus atrox. | 1973 | 4746906 | |
| pathogenesis of hemorrhage induced by rattlesnake venom. an electron microscopic study. | the pathogenesis of hemorrhage induced by rattlesnake (crotalus atrox) venom was investigated at the electron microscopic level. swiss-webster white mice were injected intramuscularly with one-fifth the ld(50) dose of whole venom. muscle samples were obtained by biopsy 2 minutes, 30 minutes and 3 hours after venom injection. capillaries in the endomysium were in various stages of degeneration. endothelial cells of damaged capillaries contained dilatated endoplasmic reticulum and perinuclear spac ... | 2016 | 4843388 |
| phospholipa2se a from crotalus atrox venom. i. purification and some properties. | 1969 | 4979754 | |
| observations on the phospholipase a 2 of crotalus atrox. molecular weight and other properties. | 1971 | 5161032 | |
| effect of enzymatic functional group inhibitors on the esterases of crotalus atrox venom. rep no. 627. | 1965 | 5295048 | |
| detoxification of crotalus atrox venom by photooxidation in the presence of methylene blue. rep no. 628. | 1965 | 5295050 | |
| studies on the phospholipase a activity of crotalus atrox venom.rep no. 630. | 1965 | 5295166 | |
| precipitin and neutralizing antibody response elicited by crotalus atrox venom antivenom precipitate. report no. 649. | 1966 | 5296740 | |
| collagenolytic activity from venom of the rattlesnake crotalus atrox. | 1971 | 5560678 | |
| [on the evolution of endopeptidases. ii. properties of the alpha-protease from the venom of crotalus atrox]. | 1967 | 5586897 | |
| application of crotalus atrox venom alpha-protease for amino acid sequence determination. | 1967 | 5625443 | |
| [specificity of snake venom proteases (crotalus atrox)]. | 1965 | 5847962 | |
| stress and the toxicity of venoms. | animals injected with venom of the scorpion centruroides sculpturatus ewing or venom of the rattlesnake crotalus atrox baird and girard were subjected to high-and low-temperature stress. unconditioned animals transferred to a modified temperature were less refractory to the venoms than those conditioned for 48 hours, but all animals stressed were less refractory than unstressed animals. animals receiving a series of small doses of epinephrine were similarly affected. this apparent change in toxi ... | 1965 | 5853934 |
| detoxification of crotalus atrox venom by photooxidation in the presence of methylene blue. | 1966 | 5938781 | |
| studies on the phospholipase a activity of crotalus atrox venom. | 1966 | 5938784 | |
| precipitin and neutralizing antibody response elicited by crotalus atrox venom-antivenom precipitate. | 1966 | 5944887 | |
| lipid monolayers: action of phospholipase a of crotalus atrox and naja naja venoms on phosphatidyl choline and phosphatidal choline. | the activity of phospholipase a on phosphatidyl choline and phosphatidal choline spread as monolayers on phosphate buffers containing snake venom (crotalus atrox or naja naja) was studied by measuring the fall of surface potential as a function of time, ph, film pressure, temperature, and concentrations of phosphate and venom. at 25 degrees c, ph 7.0, and 0.2 micrograms of venom per ml, optimal activity was observed with both venoms on both substrates at 12 dynes/cm film pressure on 0.04 m phosp ... | 1966 | 5947040 |
| electron microscopy of the thymus in two species of snakes, crotalus atrox and lampropeltis getulus. | 1967 | 6035292 | |
| a method for estimating crotalus atrox venom concentrations. | 1967 | 6036248 | |
| differential resistance of mice at various time levels to the lethality of rattlesnake venom (crotalus atrox). | 1967 | 6064845 | |
| presence of zinc in proteolytic hemorrhagic toxin isolated from agkistrodon acutus venom. | 1. hemorrhagic toxin (ac1-proteinase) was isolated from the venom of agkistrodon acutus (formosa) and the zinc content was determined (1.15 mol/mol protein). the results we extensively compared with hemorrhagic toxin e of crotalus atrox venom (u.s.a.). comparable results were obtained for zinc content, hemorrhagic and proteolytic activities for native hemorrhagic toxins from two different venoms. it is of interest that the zinc content of hemorrhagic toxins is identical even though the venoms ar ... | 1982 | 6125319 |
| isolation and identification of a collagenolytic enzyme from the venom of the western diamondback rattlesnake (crotalus atrox). | a collagenolytic enzyme, with a molecular weight of 58,000 daltons and isoelectric point of 5.1, was isolated and purified from the venom of the rattlesnake crotalus atrox by sephadex g-100 gel filtration followed by chromatography on deae-bio-gel a. the enzyme released alpha-chains from beta-chains of the native collagen and cleaved in the helical region similar to other animal collagenases. the enzyme also hydrolyzed the pz-peptide, however, it did not hydrolyze synthetic substrates for serine ... | 1982 | 6285554 |
| simultaneous determination of phenytoin and phenobarbital in serum or plasma by substrate-labeled fluorescent immunoassay. | this assay system for simultaneously determining phenytoin and phenobarbital in serum and plasma is based on the substrate-labeled fluorescent immunoassay technique. a beta-galactosylcoumarin derivative of phenobarbital and a 4-methylcoumarin phosphodiester derivative of phenytoin are used as substrate labels for escherichia coli beta-galactosidase and crotalus atrox phosphodiesterase i, respectively. the smallest measurable concentrations are about 1.6 mg/l for phenytoin, 2.7 mg/l for phenobarb ... | 1983 | 6303626 |
| an iron-dependent 5'-nucleotide phosphoribohydrolase activity in the venom of crotalus atrox and its effect upon the determination of mammalian ribonucleotide reductase. | there is an iron-dependent activity in the venom of crotalus atrox which appears to hydrolyze the n-glycosidic sugar-base bond of pyrimidine and purine nucleotides. maximal activation of this activity occurred at 1.0 mmol/l and 0.8 mmol/l fecl3 for cytidine diphosphate (cdp) and adp substrates, respectively. the release of free base affects the background values of control experiments carried out during nucleotide-labelled assays of ribonucleotide reductase which require the conversion of nucleo ... | 1983 | 6307681 |
| inhibition of epithelial chloride channels by a semi-purified fraction of crotalus atrox venom. | rattlesnake venom has a strong effect on the ionic permeability of plasma membranes. rattlesnake venom and one of its semipurified fractions (cav-c2) has been implicated in affecting both sodium and chloride transfer across epithelia. the mechanism of cav-c2 action on epithelia, however, is still open to question. aplysia californica intestine has been shown to contain both chloride conductive channels and sodium dependent chloride uptake mechanisms in the mucosal membrane of its enterocytes whi ... | 1984 | 6320211 |
| proteolytic specificity and cobalt exchange of hemorrhagic toxin e, a zinc protease isolated from the venom of the western diamondback rattlesnake (crotalus atrox). | 1983 | 6351911 | |
| unique degradation of human fibrinogen by proteases from western diamondback rattlesnake (crotalus atrox) venom. | thrombin-coagulability of both human fibrinogen and plasma was rapidly lost upon incubation with western diamondback rattlesnake (crotalus atrox) venom. the dose- and time-dependent effect was due to direct proteolytic degradation of fibrinogen (mr 340,000) by venom enzymes. using purified fibrinogen as the substrate it was demonstrated that the venom degraded the a alpha chain first and then the b beta chain. the degradation pattern of fibrinogen in plasma was different to that of purified fibr ... | 1983 | 6353668 |
| kallikrein-like enzymes from crotalus atrox venom. | the symptoms which immediately follow envenomation by many crotalid snakes include hypotension, hypovolemia, hemoconcentration, and shock. we have isolated and characterized two proteases (ei and eii) from the venom of crotalus atrox which may be involved in the onset of these symptoms. ei and eii have molecular weights of 27,500 and 29,200 and isoelectric points of 4.7 and 4.3, respectively. specific esterolytic activities of ei and eii on n alpha-p-tosyl-l-arginine methyl ester are 51.5 mumol ... | 1983 | 6355088 |
| isolation and characterization of fibrinogenase from western diamondback rattlesnake venom and its comparison to the thrombin-like enzyme, crotalase. | a new type of fibrinogenase was isolated from the venom of the western diamondback rattlesnake (crotalus atrox). unlike thrombin, the newly isolated fibrinogenase did not cause formation of a fibrin clot. various properties of the fibrinogenase we isolated were compared with crotalase isolated from the venom of c. adamanteus. it was found that fibrinogenase has considerable similarity to crotalase isolated by markland and damus in 1971. crotalase is a thrombin-like enzyme and produces a fibrin c ... | 1983 | 6362974 |
| anticoagulant proteases from western diamondback rattlesnake (crotalus atrox) venom. | crotalus atrox venom contains agents that render human fibrinogen and plasma incoagulable by thrombin. to elucidate the mechanism of alteration of fibrinogen clotting function by the venom, four immunochemically different proteases, i, ii, iii, and iv, were purified from the venom by anion-exchange chromatography and column gel filtration. all four proteases had anticoagulant activity rendering purified fibrinogen incoagulable. proteases i and iv do not affect fibrinogen in plasma but in purifie ... | 1984 | 6367819 |
| the purification and characterization of an antihemorrhagic factor in woodrat (neotoma micropus) serum. | a protein antihemorrhagic factor was purified from the serum of the southern plains woodrat (neotoma micropus) by gel filtration and ion exchange chromatography. the homogeneity of the purified factor was measured by disc electrophoresis in polyacrylamide gel. the factor had an isoelectric ph of 4.1, a molecular weight of 54,000, and migrated with alpha-globulins in disc electrophoresis. the factor failed to form a precipitate with crude western diamondback rattlesnake (crotalus atrox) venom and ... | 1984 | 6372164 |
| isolation and biochemical characterization of hemorrhagic toxin f from the venom of crotalus atrox (western diamondback rattlesnake). | hemorrhagic toxin f (ht-f) was isolated from crotalus atrox (western diamondback rattlesnake) venom by a five-step purification procedure. homogeneity was established by the formation of a single band in acrylamide gel electrophoresis, isoelectric focusing, and sodium dodecyl sulfate (sds)-electrophoresis. ht-f has a molecular weight of 64,000 and contains 572 amino acid residues. it contains 1 mol of zinc per mol of protein. zinc is essential for both hemorrhagic and proteolytic activities. ht- ... | 1984 | 6375570 |
| isolation and characterization of three ca2+-dependent beta-galactoside-specific lectins from snake venoms. | three lactose-inhibited lectins from the venoms of the snakes agkistrodon contortrix contortrix (southern copperhead), ancistrodon piscivorous leukostoma (western cottonmouth moccasin) and crotalus atrox (western diamondback rattlesnake) have been isolated and newly characterized. the three lectins are similar to thrombolectin, a lectin isolated from the venom of bothrops atrox (fer-de-lance) (gartner, stocker & williams, 1980), with regard to sugar specificity, mr, ca2+ requirements and sensiti ... | 1984 | 6391472 |
| ultrastructural localization in the mouse lung of venom from the western diamondback (crotalus atrox) rattlesnake. | procedures which make immune complexes between venom antigens and their complementary antibodies visible have been applied to detect the site of deposition of rattlesnake venom in the lung tissue of mice after in vivo envenomation. lung tissue, from mice envenomated with reconstituted but otherwise unmodified crotalus atrox venom, was incubated in commercially available polyvalent antiserum (against north american crotalid snakes) which had been conjugated to the enzyme horseradish peroxidase. t ... | 1984 | 6441312 |
| production of a monoclonal antibody against hemorrhagic activity of crotalus atrox (western diamondback rattlesnake) venom. | crotalid venoms have cytotoxic properties which could be useful in medical research. crotalus atrox venom-hyperimmunized mouse spleen cells were fused with sp2/0 myeloma cells. forty-one wells containing the hybridoma cells were positive for c. atrox venom, as determined by the enzyme linked immunosorbent assay (elisa). cell line 1-e12 was cloned and used to produce ascites tumors in balb/c mice. the monoclonal antibody produced by cloned and subcultured 1-e12 cells reacted with both c. atrox ve ... | 1984 | 6523516 |
| an enzyme-linked immunoassay for detection of north american pit viper venoms. | we describe a method for immunodetection of north american pit viper venoms in clinical materials. antibody-enzyme conjugates prepared against venoms of the western diamondback rattlesnake (crotalus atrox), mojave rattlesnake (crotalus scutulatus), and copperhead (agkistrodon contortrix) detect homologous venoms in concentrations of 0.1-.01 mcg/ml using a double antibody sandwich technique. venoms of 10 additional species of u.s. pit vipers were detected in concentrations of 10 mcg/ml or less. v ... | 1984 | 6527395 |
| fibrinogenolytic afibrinogenemia after envenomation by western diamondback rattlesnake (crotalus atrox). | the absence of fibrinogen and the presence of plasmic fragments x, y, d, and e were demonstrated in a patient bitten by a western diamondback rattlesnake, crotalus atrox. the factor viii level and the platelet count were within normal limits. there were distinct changes of protease inhibitors in the patient's plasma. alpha-1-protease inhibitor was elevated. antithrombin-iii was only slightly decreased after the envenomation, but alpha 2-antiplasmin and alpha 2-macroglobulin were initially signif ... | 1984 | 6537796 |
| development of simple standard assay procedures for the characterization of snake venom. | in accordance with the recommendations of the report of a who coordination meeting on venoms and antivenoms, methods have been developed for the assessment of lethal, defibrinogenating, procoagulant, haemorrhagic, and necrotizing properties of venoms, and used to study 53 venoms from 30 different species of snakes of medical importance throughout the world. the venoms studied included echis carinatus (iran), naja naja kaouthia (thailand), notechis scutatus (australia), trimeresurus flavoviridis ... | 1983 | 6609011 |
| purification and characterization of a fibrinogenase from the venom of western diamondback rattlesnake (crotalus atrox). | a fibrinogenolytic enzyme was isolated from the venom of western diamondback rattlesnake (crotalus atrox) by a three-step procedure involving gel filtration and anion-exchange chromatography. the molecular weight was estimated as 22 900 by sds-polyacrylamide gel electrophoresis. the isoelectric point was found to be ph 4.65. the enzyme rapidly destroyed the ability of bovine fibrinogen to form a clot on incubation with thrombin. incubation of fibrinogen with the fibrinogenolytic enzyme for 5 min ... | 1983 | 6615843 |
| attachment of rattlesnake venom myotoxin a to sarcoplasmic reticulum: peroxidase conjugated method. | myotoxin a is a muscle-damaging toxin isolated from the venom of crotalus atrox (western diamondback rattlesnake) and is composed of 42 amino acid residues. earlier electron microscopic observation indicated that the toxin causes extensive swelling of the sarcoplasmic reticulum followed by disorganization of the sarcomers. in the present paper we describe the evidence for the attachment of peroxidase-conjugated myotoxin a to the membrane of sarcoplasmic reticulum of human muscle. it is thus sugg ... | 1983 | 6661395 |
| thermotropic change in phospholipid packing in microsomal membranes sensed by phospholipase a2. | a reversible, temperature-dependent change in phospholipid packing occurring between 0 degree c and 12 degrees c has been identified in microsomal membranes by the use of phospholipase a2 from crotalus atrox. it manifests itself as a drastic increase in susceptibility to the phospholipase and depends on non-lipid (presumably protein) membrane components. it is suggested that this change could underlie the change in transmembrane mobility of phospholipids which occurs in the same temperature rang ... | 1984 | 6697423 |
| a new method for quantitating hemorrhage induced by rattlesnake venoms: ability of polyvalent antivenom to neutralize hemorrhagic activity. | polyvalent (crotalidae) antivenin was tested for its ability to neutralize the hemorrhagic activity of two crotaline venoms when mixed with them prior to injection. hemorrhage was measured by two methods. in the first method an intradermal injection of venom produced a hemorrhagic spot which was quantitated by measuring diameters. in the second method the amount of hemoglobin in a muscle extract was measured after i.m. injection of venom. the results show that both methods are useful for quantit ... | 1984 | 6729841 |
| immunological, structural and functional relationships between an anti-complementary protein from crotalus atrox venom, cobra venom factor and human c3. | an anti-complementary protein which cross-reacts with antiserum to cobra venom factor (cof) has been highly purified from crotalus atrox venom (cav). on an equal weight basis, the c. atrox factor (ca-f) had one-third the anti-complementary activity of cof and similarly consumed the terminal components of complement via the alternative pathway. the subunit compositions of cof and cav were similar, each being composed of alpha and beta chains held together by covalent and non-covalent bonds. agaro ... | 1980 | 6769786 |
| purification of three arginine esterases from the venom of the western diamondback rattlesnake (crotalus atrox). | three acidic arginine esterases have been isolated from the venom of the western diamondback rattlesnake (crotalus atrox). these components demonstrated marked differences in ionic characteristics, as noted by kcl gradient elution from a deae-sephadex a-50 column. molecular weights, as determined from gel permeation chromatography, were estimated at 25,100 (fraction d), 24,000 (b); and 22,900 (f) for the three separate enzymes. the two larger enzymes (b and d) exhibited similar activities toward ... | 1982 | 6819657 |
| isolation of an anticomplement factor from the venom of the mojave rattlesnake (crotalus scutulatus scutulatus). | the venom of the mojave rattlesnake was fractionated by deae-sephadex column chromatography. a venom fraction, f5, inactivated both human and guinea pig complement. both serum and purified c3 were partially converted to a protein of faster electrophoretic mobility, indicating that f5 had a direct proteolytic effect on c3. this product was capable of passively lysing guinea pig red blood cells. f5 very effectively inactivated the classical pathway, but only partially inactivated the alternative p ... | 1983 | 6845386 |
| effect of a semi-purified fraction of crotalus atrox (western diamondback rattlesnake) venom on chloride transport across the frog skin. | 1980 | 6971502 | |
| proteolytic specificity of hemorrhage toxin a isolated from western diamondback rattlesnake (crotalus atrox) venom. | the proteolytic specificity of hemorrhagic toxin a from the venom of crotalus atrox (western diamondback rattlesnake) has been investigated by using the oxidized b chain of bovine insulin and other peptides as substrates. the toxin appears highly specific for x--leu bonds (cleaving the his10--leu11, ala14--leu15, and tyr16--leu17 bonds), with no detectable activity against the gly--phe, phe--phe, phe--tyr, and leu--tyr bonds also present in the insulin b chain. the x--leu bond of the peptides ty ... | 1981 | 7032585 |
| a comparative electron microscopic study of myonecrosis induced by crotalus atrox (western diamondback rattlesnake) in gray woodrats and mice. | the myonecrosis induced by western diamondback rattlesnake (crotalus atrox) venom in the woodrat (neotoma micropus) was studied at the electron microscopic level. woodrats and control white mice were injected i.m. with 0.1 ml of diluted venom. gross examination revealed extensive hemorrhage when 250 micrograms were injected into mice. electron microscopic examination showed muscle necrosis in mouse muscle tissue. no extensive hemorrhage or muscle damage was noted until 7.5 and 15 mg of venom wer ... | 1982 | 7043786 |
| crotalus atrox phospholipase a2. amino acid sequence and studies on the function of the nh2-terminal region. | 1982 | 7061414 | |
| western diamondback rattlesnake (crotalus atrox) poisoning. | 1982 | 7079204 | |
| fibrinolytic and fibrinogen clotting enzymes present in the venoms of western diamondback rattlesnake, crotalus atrox, eastern diamondback rattlesnake, crotalus adamanteus, and southern pacific rattlesnake, crotalus viridis helleri. | 1981 | 7222089 | |
| the kinetics of the phospholipase a2-catalyzed hydrolysis of egg phosphatidylcholine in unilamellar vesicles. product inhibition and its relief by serum albumin. | only the lecithin in the outer leaflet (representing 70% of the total) of egg lecithin unilamellar vesicles is hydrolyzed by crotalus atrox phospholipase a2. hydrolyzed vesicles remain intact and impermeable to ionic solutes. the fatty acids produced in the hydrolysis remain on the vesicle and are only partially ionized at neutral ph due to electrostatic repulsions. about 40% of the lysolecithin product is desorbed from the vesicle. in the presence of a large excess of bovine serum albumin, the ... | 1981 | 7240204 |
| clinical potential of fibrinolytic enzyme(s) of western diamondback rattlesnake (crotalus atrox) venom. | 1981 | 7255443 | |
| the 2.5 a crystal structure of a dimeric phospholipase a2 from the venom of crotalus atrox. | the crystal structure of the dimeric (alpha 2) phospholipase a2 from crotalus atrox has been determined by multiple isomorphous replacement to 2.5 a resolution. a skeletal model was fit to the electron density, and the stereochemistry of the backbone was idealized. the dimeric molecule is a well defined oblate ellipsoid composed of two covalently identical subunits related by a local dyad axis which is essentially "exact" except for deviations at the periphery induced by ionic lattice contacts w ... | 1981 | 7263673 |
| effects of western diamondback rattlesnake (crotalus atrox) venom on heart muscle. | 1981 | 7268801 | |
| the management of upper extremity pit viper wounds. | in a series of 56 rattlesnake bites, there were 31 injuries involving the upper extremity and hand with a clinical complication rate of 32% that ranged from volkmann's contracture to coagulopathies. the most frequent was tissue necrosis with functional joint stiffness and loss of sensibility. because these patients were treated with a variety of regimens, an animal model was developed to determine the efficacy of the individual treatments. sublethal intramuscular injections of crotalus atrox ven ... | 1980 | 7358958 |
| hydrolysis of phosphatidylethanolamine induced by nominally synthetic lysophosphoglycerides: methodological implications. | synthetic lysophosphatidylethanolamine (lpe) obtained from commercial sources augmented the apparent activity of phospholipase a2 (pla2) in cardiac mitochondrial and microsomal fractions. for elucidation of this phenomenon, 2-[1-14c]linoleylphosphatidylethanolamine was incubated in the absence of cell protein with selected concentrations of lpe, lysophosphatidylcholine (lpc), ca2+, ionic and nonionic detergents, and phospholipids with functional groups similar to those of lpe. hydrolysis of phos ... | 1980 | 7378384 |
| fibrinolytic enzyme(s) in western diamondback rattlesnake (crotalus atrox) venom. | 1980 | 7394818 | |
| heterogeneous catalysis by phospholipase a2: mechanism of hydrolysis of gel phase phosphatidylcholine. | hydrolysis of gel phase dipalmitoylphosphatidylcholine (dppc) at 37 degrees c catalysed by crotalus atrox phospholipase a2 (pla) is described extremely well by the "path 1" kinetic mechanism of tinker and wei (1979) (can. j. biochem. 57, 97-106), if reversible adsorption is allowed as a side reaction. progress curves show an initial rapid phase, the initial velocity being a michaelis-menten function dependent on the catalytic properties of the enzyme (kcat approximately equal to 9200 min-1, km a ... | 1980 | 7459686 |
| photoaffinity labeling of crotalus atrox phospholipase a2 by a substrate analogue. | a photolabile analogue of phosphatidylethanolamine (photolabile pe analogue), 1,2-di-o-hexylglycero-3-(ethyl diazomalonamidoethyl phosphate), was synthesized in nonisotopic and 14c-radiolabeled form and in both the l configuration (that of the naturally occurring phospholipids) and the racemic form. when the unlabeled racemic compound was photolyzed in the presence of phospholipase a2 of crotalus atrox, extensive enzyme inactivation was observed. the rate of inactivation was stimulated by ca2+ a ... | 1981 | 7470471 |
| the (dd)e complex is maintained by a composite fibrin polymerization site. | the (dd)e complex is the major cross-linked fibrin degradation fragment. structural components required for maintenance of the (dd)e complex were examined in order to better understand clot structure and the contribution of specific polypeptide chain segments in the process of polymerization. first, the (dd)e complex was reversibly dissociated by peptides derived from the alpha-chain nh2-terminus of fibrin having a minimal sequence of gpr (alpha 17-19). in addition, the complex was partially dis ... | 1994 | 7524657 |
| atrolysins: metalloproteinases from crotalus atrox venom. | 1995 | 7674933 | |
| purification and characterization of a coagulant enzyme, okinaxobin ii, from trimeresurus okinavensis (himehabu snake) venom which release fibrinopeptides a and b. | a coagulant enzyme, okinaxobin i, which was purified from trimeresurus okinavenis (himehabu snake) venom, released specifically fibrinopeptide b from fibrinogen to form fibrin clots. in the present study, its isozyme denoted as okinaxobin ii has been purified to homogeneity from the same venom by chromatographies on sephadex g-100, cm-toyopearl 650m, and fplc mono-q columns. differently from okinaxobin i, okinaxobin ii specifically cleaved fibrinopeptides a and b from fibrinogen similarly as fou ... | 1994 | 7725319 |
| kinetic and pharmacologic characterization of phospholipases a2 from bothrops neuwiedii venom. | two phospholipases a2 (pla2) (ec 3.1.1.4) were purified from bothrops neuwiedii venom (isoenzymes p-1 and p-2). the molecular weights of p-1 and p-2 as estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis were 15,000 and 16,200 and the isoelectric points were 4.8 and 4.6, respectively. the n-terminal 14-amino-acid sequences determined were asn-leu-val-gln-phe-glu-thr-leu-ile-met-met-ile-ala-gly and ser-leu-val-gln-phe-glu-thr-leu-ile-met-met-ile-ala-gly for p-1 and p-2, respect ... | 1995 | 7726575 |
| molecular cloning and expression of catrocollastatin, a snake-venom protein from crotalus atrox (western diamondback rattlesnake) which inhibits platelet adhesion to collagen. | a 50 kda protein that inhibits platelet adhesion to collagen has been isolated from snake venom of crotalus atrox (western diamondback rattlesnake) and has been named 'catrocollastatin'. the cdna cloning of catrocollastatin has been accomplished. a full-length cdna of 2310 bp with an open reading frame between nucleotides 51 and 1880 was obtained. the deduced amino acid sequence consists of 609 amino acids. the cdna-predicted amino acid sequence is highly similar to that of haemorrhagic metallop ... | 1995 | 7733877 |
| the effect of cleavage by a crotalus atrox alpha-proteinase fraction on the properties of c1-inhibitor. | the effect of cleavage of c1-inhibitor at pro36 by a crotalus atrox alpha-proteinase fraction on the properties of this serpin was studied. this truncated c1-inhibitor (des 1-36) was fully active as an inhibitor of kallikrein, beta-factor xiia, and c1s, and modulated the functions of c1 in a normal manner. also, the half-life of the truncated protein in the circulation of rabbits, both alone and in complex with c1, was not altered. these results show that shock-like symptoms caused by c. atrox e ... | 1995 | 7778129 |