Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| the interaction of crotalus atrox phospholipase a2 with calcium ion and 1-anilinonaphthalene-8-sulfonate. | 1977 | 18264 | |
| treatment of an encephalitogenic peptide from guinea pig myelin basic protein with alpha-protease and thermolysin. isolation of fragments and determination of cleavage sites. | two peptic fragments (residues 37-88 and 43-88) of guinea pig myelin basic protein which are capable of inducing experimental allergic encephalomyelitis in lewis rats were cleaved to shorter fragments with alpha-protease (crotalus atrox proteinase, ec 3.4.24.1) and thermolysin (ec 3.4.24.4). the fragments were isolated, purified, and identified by amino acid composition and nh2- and cooh-terminal residues. the time courses of the reactions, monitored by thin layer electrophoresis of the digests, ... | 1977 | 65352 |
| hemorrhagic toxins from western diamondback rattlesnake (crotalus atrox) venom: isolation and characterization of five toxins and the role of zinc in hemorrhagic toxin e. | five previously unknown hemorrhagic proteins, designated hemorrhagic toxins a,b,c,d, and e, were isolated from the venom of the western diamondback rattlesnake (crotalus atrox). molecular weights of hemorrhagic toxins a-e were determined to be 68 000, 24 000, 24 000, 24 000, and 25 700, respectively, by sodium dodecyl sulfate-phosphate gel electrophoresis using various polyacrylamide gel concentrations. amino acid composition showed a total of 636, 200, 213, 214, and 219 amino acids for hemorrha ... | 1978 | 210790 |
| effect of crotalus atrox venom on sodium transport across the frog skin (39885). | 1994 | 302948 | |
| the primary structure of a non-histone chromosomal protein. | the primary structure of the calf thymus non-histone chromosomal protein hmg-17 has been determined. the sequence was determined mainly from data provided by the peptides obtained by cleavage with staphylococcal protease. additional information was obtained from peptides produced by cleavage with trypsin and alpha-protease (from crotalus atrox venom) and by partial acid hydrolysis. the protein is 89 amino acid residues in length, and has molecular weight of 9247. the n-terminal two-thirds of the ... | 1977 | 330164 |
| heterogeneous catalysis by phospholipase a2: formulation of a kinetic description of surface effects. | the kinetics of hydrolysis of aqueous dispersion of long-chain, saturated phosphatidylcholines (pc) catalysed by crotalus atrox phospholipase a2 (pla) have been analyzed, and a reaction mechanism proposed which takes surface effects into account. pla is proposed to form an enzyme-substrate complex with surface substrate molecules, thereby undergoing a conformational change which exposes sites that interact with the lipid surface. after a hydrolytic event, the enzyme can either desorb from the su ... | 1979 | 427633 |
| the resistance of three species of warm-blooded animals to western diamondback rattlesnake (crotalus atrox) venom. | 1979 | 524385 | |
| kinetics of hydrolysis of dispersions of saturated phosphatidylcholines by crotalus atrox phospholipase a2. | dispersions of lamellar phase dipalmitoyl phosphatidylcholine (ddpc) and dimyristoyl phosphatidylcholine (dmpc) in 0.01 m cacl2 were subjected to hydrolysis by phospholipase a2 (ec 3.1.1.4) from crotalus atrox venom. the reaction was followed continuously by titrating the released fatty acids. for hydrolysis of gel phase phosphatides, the steady-state initial velocities were hyperbolic functions of bulk lipid concentrations. at the 'pre-transition' temperature (34 degrees c for dppc, 15 degrees ... | 1978 | 580900 |
| resistance of woodrats (neotoma micropus) to crotalus atrox venom. | 1978 | 635934 | |
| bites by foreign venomous snakes in britain. | in 1970-7 17 people in britain were the victims of 32 bites by foreign venomous snakes. crotalus atrox caused eight of these bites, bitis arietans five, and the remaining 19 bites were caused by 12 different species. all the victims were bitten while handling the snake, and 24 bites were incurred by private individuals in their own homes. poisoning was negligible in 17 of the 32 bites but life-threatening in at least two cases. thus in the early stages snake bite may be unpredictable as a clinic ... | 1978 | 656831 |
| chemical modification of crotalus atrox phospholipase a2 by means of a photolabile phosphatidylethanolamine analog. | 1978 | 665363 | |
| hemorrhagic toxins from rattlesnake (crotalus atrox) venom. pathogenesis of hemorrhage induced by three purified toxins. | the pathogenesis of hemorrhage induced by three purified components of rattlesnake (crotalus atrox) venom was studied at the light and electron microscopic levels. crude venom was fractionated by anion exchange and gel filtration in four steps. beta-alanine acetate disk gel electrophoresis was used to demonstrate electrophoretic homogeneity. white mice were injected intramuscularly with 0.1 ml of a sublethal dose of hemorrhagic toxin. gross examination revealed extensive hemorrhage 5 minutes aft ... | 1978 | 696805 |
| changes in coagulation effects by venoms of crotalus atrox as snakes age. | venom samples separately collected at monthly intervals from three crotalus atrox specimens as they aged from 2 to 22 months showed many quantitative changes of biological activities. but more important were qualitative changes of coagulation activity. up to 8 months the venoms clotted fibrinogen solutions directly. at 9 to 10 months, plasma was clotted but not fibrinogen. subsequently the venoms no longer clotted plasma. qualitative venom changes with growth of snakes could explain some of the ... | 1978 | 717632 |
| interaction of crotalus atrox venom with serum complement: kinetic analysis. | 1977 | 914317 | |
| purification, characterization and analysis of the mechanism of action of four anti-complementary factors in crotalus atrox venom. | 1977 | 914318 | |
| some blood values of the western diamond-back rattlesnake (crotalus atrox) from south texas. | hematologic values of the western diamond-back rattlesnake (crotalus atrox) from south texas were determined by standard techniques. the means of the principal blood measurements were 0.68 +/- 0.20 million erythrocytes/mm3, 31.9 +/- 4.6% hematocrit and 10.0 +/- 1.8 gm% hemoglobin. a comparison of hematologic values of snakes is given. | 1977 | 916141 |
| fatty acid and prostaglandin composition of left ventricular myocardium from dexamethasone-treated dogs with severe low output syndrome (los). | the effects of dexamethasone (dex) administration on the left ventricular myocardial content of fatty acids and prostaglandins e1, e2 and f2alpha were studied. following a complete right and left cardiac catheterization, either dex (8 mg/kg) or an equivalent volume of its vehicle was given intravenously 30 minutes prior to low output syndrome (los induction, and supplemental doses of dex (4 mg/kg) or vehicle administered at 15 and 75 minutes post-los induction. low output syndrome was induced by ... | 1976 | 935523 |
| isolation and characterization of reptilian insulin: partial amino acid sequence of rattlesnake (crotalus atrox) insulin. | 1976 | 939409 | |
| comparative biochemistry and pharmacology of salivary gland secretions. iii. chromatographic isolation of a myocardial depressor protein (mdp) from the venom of crotalus atrox. | a protein has been isolated from the venom of the western diamondback rattlesnake (crotalus atrox) which induces acute myocardial depression when administered to experimental animals. purification was achieved by gel filtration on sephadex g-100, deae- and cm-cellulose ion-exchange chromatography, ultra-filtration, and adsorption chromatography on hydroxyapatite. amino acid analysis of the highly purified protein indicated n-terminal isoleucine and c-terminal tyrosine residues, and the absence o ... | 1976 | 965463 |
| hypotension--a hypotensive peptide isolated from crotalus atrox venom: purification, amino acid composition and terminal amino acid residues. | 1976 | 976484 | |
| effect of diethylenetriaminepentaacetic acid and procaine on hemorrhage induced by rattlesnake venom. | nineteen compounds and seven combinations of compounds were tested for their ability to neutralize the hemorrhagic activity of crotalus atrox venom in vitro and in vivo. two compounds and four combinations were effective in reducing hemorrhage in an in vivo test in which the venom was injected before injection of compounds. dtpa plus procaine hcl was the most effective combination and reduced hemorrhage when injected 1, 5, or 15 minutes after injection of venom. dtpa-procaine reduced hemorrhage ... | 1975 | 1133218 |
| nephrotoxic action of rattlesnake and sea snake venoms: an electron-microscopic study. | the fine structure of renal corpuscles and proximal convoluted tubules of the right kidneys of suiss mice were studied 9 hr after the injection of the venom of crotalus atrox (western diamond-back rattlesnake) or the venom of laticauda semifasciata (broad-banded blue sea snake). rattlesnake envenomation resulted in several ultrastructural changes in the renal corpuscles and proximal convoluted tubules. visceral epithelial changes included intracellular oedema, blebbing, vesiculations, the format ... | 1987 | 1255307 |
| amino acid sequence of fibrolase, a direct-acting fibrinolytic enzyme from agkistrodon contortrix contortrix venom. | the complete amino acid sequence of fibrolase, a fibrinolytic enzyme from southern copperhead (agkistrodon contortrix contortrix) venom, has been determined. this is the first report of the sequence of a direct-acting, nonhemorrhagic fibrinolytic enzyme found in snake venom. the majority of the sequence was established by automated edman degradation of overlapping peptides generated by a variety of selective cleavage procedures. the amino-terminus is blocked by a cyclized glutamine (pyroglutamic ... | 2004 | 1304358 |
| [hydrolysis of 5'-phosphonates and nucleoside phosphates by phosphatases of various origin and human and calf serum]. | the hydrolysis of 5'-phosphonates of 2'-deoxythymidine and its 3'-modified analogs, inhibiting the hiv reproduction, by the e. coli alkaline, calf intestine and human placenta phosphatases as well as by the crotalus atrox venom 5'-nucleotidase were studied. transformations of 5'-phosphonates of adenosine and its analogs during incubation with human and fetal calf blood sera were investigated. the nucleotide derivatives modified at the phosphate residue were not hydrolyzed by any of the phosphata ... | 1992 | 1335121 |
| rattlesnake and scorpion antivenoms from the egg yolks of immunized hens. | antivenoms used to treat poisonous bites and stings are usually derived from horse sera. consequently, they contain horse immunoglobulins, which frequently cause complement mediated side effects, and other proteins that can cause serum sickness and, occasionally, anaphylactic shock. here we describe a new, avian source of antivenoms that precludes these complications, and an efficient and gentle means for preparing antivenoms composed solely of venom-specific antibodies. we demonstrate that anti ... | 1990 | 1366776 |
| sequence of a cdna clone encoding the zinc metalloproteinase hemorrhagic toxin e from crotalus atrox: evidence for signal, zymogen, and disintegrin-like structures. | the sequence of two overlapping cdna clones for the zinc metalloproteinase hemorrhagic toxin e (also known as atrolysin e, ec 3.4.24.44) from the venom gland of crotalus atrox, the western diamondback rattlesnake, is presented. the assembled cdna sequence is 1975 nucleotides in length and encodes an open reading frame of 478 amino acids. the mature hemorrhagic toxin e protein as isolated from the crude venom has a molecular weight of approximately 24,000 and thus represents the processed product ... | 1992 | 1378300 |
| structure-function relationship for the highly toxic crotoxin from crotalus durissus terrificus. | the three-dimensional structure of the highly toxic crotoxin from crotalus durissus terrificus was modelled based on sequence analysis and the refined structure of calcium-free phospholipase of crotalus atrox venom. small-angle x-ray scattering experiments were performed on aqueous solutions of crotoxin. the radial distribution function derived from these scattering experiments and the one calculated from the model structure are in good agreement. crotoxin consists of a basic and an acidic subun ... | 1992 | 1425475 |
| comparison of the purity and efficacy of affinity purified avian antivenoms with commercial equine crotalid antivenoms. | antivenoms were raised in laying hens by repeated immunizations with detoxified crotalid snake venoms and purified from egg yolks by affinity chromatography. while the affinity purified avian antivenoms were essentially pure igg, commercial equine (wyeth) and w.h.o. international reference antivenoms (trimeresurus flavoviridis) contained several non-immunoglobulin contaminants. in standard mouse protection assays, the purified avian crotalus atrox and t. flavoviridis antivenoms were 6.3 and 2.0 ... | 1992 | 1440638 |
| evaluation of four different immunogens for the production of snake antivenoms. | four different immunogens were used to produce polyvalent antivenom in rabbits to the venoms of bothrops atrox, crotalus atrox, crotalus adamanteus and crotalus durissus terrificus. the immunogens were: (1) unfractionated mixture of the four crude venoms, and three fractions of the mixture as follows, (2) hplc gel filtration high (> 50,000) mol. wt fraction, (3) hplc gel filtration medium (14,000-50,000) mol. wt fraction, and (4) hplc gel filtration low (< 14,000) mol. wt fraction. the resultant ... | 1992 | 1485332 |
| sequence determination and characterization of a phospholipase a2 isozyme from trimeresurus gramineus (green habu snake) venom. | in addition to phospholipase a2-i (pla2-i) reported previously (oda et al., 1991, toxicon 29, 157), a new pla2 named pla2-ii was isolated from trimeresurus gramineus (green habu snake) venom, and its amino acid sequence was determined by sequencing the native protein and the peptides produced by enzymatic (achromobacter protease i and clostripain) cleavages of the carboxamidomethylated derivative of the protein. the protein consisted of 122 amino acid residues and his-47, asp-48, and asp-98 whic ... | 1992 | 1485333 |
| effects of constriction bands on rattlesnake venom absorption: a pharmacokinetic study. | to determine whether the use of a constriction band alters systemic absorption of rattlesnake venom in pigs and whether constriction band use alters local swelling. | 1992 | 1514719 |
| inhibition of the proteolytic activity of hemorrhagin-e from crotalus atrox venom by antihemorrhagins from homologous serum. | antihemorrhagic proteins from crotalus atrox serum were tested for their ability to inhibit the proteolytic activity of the hemorrhagic toxin-e from crotalus atrox venom and of several other proteolytic enzymes: trypsin, collagenase and thermolysin. the antihemorrhagic proteins inhibited the proteolytic activity of hemorrhagin-e when tested on gelatin type i and collagen type iv, the proteolytic activity of trypsin on photofilm gelatin and the proteolytic activity of whole venom when tested on a ... | 2006 | 1519250 |
| characterization of a protease with alpha- and beta-fibrinogenase activity from the western diamondback rattlesnake, crotalus atrox. | a metalloprotease from the rattlesnake crotalus atrox venom was isolated and purified from multiple-step chromatographies including anion-exchange chromatography, gel permeation and reversed-phase hplc. the fraction was shown to be homogeneous as judged by sds-gel electrophoresis. it also showed a high proteolytic activity against alpha- and beta-chains of fibrinogen molecules. further characterization of the purified fraction with fibrinogenase activity indicated that it is a single-chain prote ... | 1992 | 1520324 |
| evidence that a secondary binding and protecting site for factor viii on von willebrand factor is highly unlikely. | a binding domain for factor viii (f.viii) has been previously identified on the n-terminal portion of human von willebrand factor (vwf) subunit [amino acids (aa) 1-272]. in order to characterize other possible structures of vwf involved in its capacity to bind and to protect f.viii against human activated protein c (apc), we used a series of purified vwf fragments overlapping the whole sequence of the subunit. among those were fragments spiii (dimer; aa 1-1365), spii (dimer; aa 1366-2050) and sp ... | 1992 | 1531749 |
| endothelial cell spreading on fibrin requires fibrinopeptide b cleavage and amino acid residues 15-42 of the beta chain. | adhesion and spreading of cultured human umbilical vein endothelial cells on fibrin surfaces of varying structure were characterized to understand better the interactions occurring between endothelium and fibrin at sites of vascular injury. fibrin prepared with reptilase, which cleaves only fibrinopeptide a from fibrinogen, and fibrin prepared with thrombin, which cleaves both fibrinopeptide a and fibrinopeptide b, equally supported endothelial cell adhesion. in contrast, only fibrin made with t ... | 1992 | 1541676 |
| structure of acidic phospholipase a2 for the venom of agkistrodon halys blomhoffii at 2.8 a resolution. | the crystal structure of acidic phospholipase a2 from the venom of agkistrodon halys blomhoffii has been determined by molecular replacement methods based on the known structure of crotalus atrox pla2, a same group ii enzyme. the overall structures, except the calcium-binding regions, are very similar to each other. a calcium ion is pentagonally ligated to two carboxylate oxygen atoms of asp-49 and each carbonyl oxygen atoms of tyr-28, gly-30 and ala-31. a reason why the former enzyme functions ... | 1992 | 1567418 |
| isolation of a crotalase-like protease with alpha-fibrinogenase activity from the western diamondback rattlesnake, crotalus atrox. | venom toxins were isolated from rattlesnake (crotalus atrox) venom by cation-exchange chromatography. seven major fractions could be obtained by single-step ion-exchange chromatography with two fractions showing essentially apparent homogeneity by sds-gel electrophoresis. all fractions showed various extents of specific proteolytic activity against alpha- or beta-chains of fibrinogen molecules. further characterization of one of the purified fractions with alpha-fribrinogenase activity indicated ... | 1992 | 1616487 |
| citrate is a major component of snake venoms. | citrate has been identified as a major component of snake venoms by gas liquid chromatography and mass spectrometry. the venoms of bothrops asper, crotalus atrox, crotalus viridis viridis, crotalus adamanteus, sistrurus miliarius barbouri, crotalus horridus horridus, agkistrodon contortrix mokasen, agkistrodon contortrix contortrix and agkistrodon piscivorus piscivorus contain citrate at concentration levels which can serve as effective buffers. calcium, magnesium, zinc, iron, sodium and potassi ... | 1992 | 1626327 |
| antihemorrhagic factors from the blood serum of the western diamondback rattlesnake crotalus atrox. | several antihemorrhagic factors isolated from c. atrox serum are glycoproteins with mol. wt ranging from 65,000 to 80,000. the antihemorrhagic activity of these factors was stable at a ph range of 1.3-11.5 and at temperatures up to 85 degrees c, for 30 min. the isolated antihemorrhagins also neutralized the proteolytic activity of c. atrox venom, as tested with azocollagen and gelatin, and formed a complex with hemorrhagic toxin e isolated from the same venom. the neutralization capacity of the ... | 1991 | 1656547 |
| interaction of hemorrhagic metalloproteinases with human alpha 2-macroglobulin. | the interaction between four crotalus atrox hemorrhagic metalloproteinases and human alpha 2-macroglobulin was investigated. the proteolytic activity of the hemorrhagic toxins ht-c, -d, and -e against the large molecular weight protein substrates, gelatin type i and collagen type iv, was completely inhibited by alpha 2-macroglobulin. the proteolytic activity of ht-a against the same substrates was not significantly inhibited. each mole of alpha 2-macroglobulin bound maximally 2 mol of ht-e and 1 ... | 1990 | 1692735 |
| south american snake venom proteins antigenically related to bothrops asper myotoxins. | 1. the presence of proteins antigenically related to bothrops asper myotoxins in various snake venoms, mainly from south america, was investigated by using polyclonal and monoclonal antibodies. 2. myotoxin-like components were detected in ten bothrops venoms from south america, and in the venoms of crotalus atrox (north america), trimeresurus flavoviridis (japan), and micrurus alleni (costa rica). 3. cross-reactive components detected in several bothrops venoms show a common subunit of 15-16 kda ... | 1990 | 1710160 |
| proteolysis of interleukin-2, interferon and immunoglobulin by venoms. | limited proteolysis by venoms was analysed by the cleaved peptide band(s) in sds-polyacrylamide gel electrophoresis. the venom from crotalus atrox degraded interferon, interleukin-2, igg, igm, and a crude form of acetyl cholinesterase but had no effect on iga. although the venom from androctonus australis did not exert appreciable proteolysis on any of the immunoglobulins it had potent proteolytic activities against interferon and interleukin-2. the venom from vespula maculifrons had only a mino ... | 1991 | 1724747 |
| isolation from opossum serum of a metalloproteinase inhibitor homologous to human alpha 1b-glycoprotein. | fractionation of opossum (didelphis virginiana) serum with (nh4)2so4, followed by chromatography on deae-sepharose, phenyl-sepharose, and mono q hr 5/5, has resulted in the isolation in homogeneous condition of a metalloproteinase inhibitor designated oprin (opossum proteinase inhibitor). oprin is a single-chain glycoprotein (26% carbohydrate) with an estimated mr = 52,000, pi = 3.5, and e(1%/1 cm) = 11. oprin inhibited snake venom metalloproteinases, but showed no activity on venom serine prote ... | 1992 | 1731898 |
| proteolytic digestion of non-collagenous basement membrane proteins by the hemorrhagic metalloproteinase ht-e from crotalus atrox venom. | hemorrhagic toxin e (ht-e), a metalloproteinase isolated from the venom of the western diamondback rattlesnake crotalus atrox, digests laminin and nidogen, both in their isolated forms and when present in a purified soluble complex. the only common site of cleavage by ht-e of isolated nidogen and nidogen when complexed with laminin is at amino acid residue 336 in the amino terminal domain. additionally, nidogen in complex with laminin is also cleaved at sites 322, 351 and 840 as determined by se ... | 1991 | 1801753 |
| external na+ is not required for ca2+ mobilization in platelets stimulated with rattlesnake lectin or alpha-thrombin. | the effects of extracellular sodium on platelet aggregation and calcium mobilization in platelets stimulated with either rattlesnake (crotalus atrox) lectin (rsl) or alpha-thrombin were compared. the absence of extracellular sodium had no effect on platelet aggregation or calcium mobilization in response to all levels of rsl tested. in contrast platelet aggregation was sodium-dependent in response to less than or equal to .2 units/ml alpha-thrombin. surprisingly, calcium mobilization occurred in ... | 1991 | 1805450 |
| effect of inadequate antivenin stores on the medical treatment of crotalid envenomation. | the case of a 27-y-old male with a serious crotalus atrox envenomation is presented. his medical care was compromised by the lack of readily available polyvalent crotalidae antivenin. an investigation of antivenin stocking by health care facilities in arizona was undertaken. failure to stock sufficient quantities of antivenin to initiate treatment of a single patient with a severe envenomation was found in 43.5% of urban hospitals, 41.2% of rural hospitals within 25 miles of another hospital, 52 ... | 1991 | 1858308 |
| snake venom or antivenom induced urticaria. | an amateur herpetologist developed chills, diaphoresis and generalized urticaria 5 h after receiving antivenin (crotalidae) polyvalent (wyeth) for treatment of rattlesnake (crotalus atrox) envenomation. the patient had been bitten 8 mo earlier by a copperhead (agkistrodon contortrix mokeson) resulting in minimal envenomation. he also had been skin testing himself for 6 mo with both diluted crotalus atrox venom and antivenin (crotalidae) polyvalent (wyeth) to determine how sensitive he was to ant ... | 1991 | 1858314 |
| adaptability of restrained molecular dynamics for tertiary structure prediction: application to crotalus atrox venom phospholipase a2. | in order to assess the adaptability and/or applicability of the restrained molecular dynamics (rmd) simulation for building a possible tertiary structure of a protein from the x-ray crystal structure of a family reference protein, the tertiary structure prediction of crotalus atrox venom phospholipase a2 (pla2) was attempted based on the x-ray crystal structure of bovine pancreatic pla2. for the formation of secondary and tertiary structures from the fully extended starting structure, the rmd si ... | 1991 | 1881869 |
| effects of ph and calcium ion on self-association properties of two dimeric phospholipases a2. | the monomer-dimer equilibria of the dimeric phospholipases a2 from crotalus atrox and agkistrodon piscivorus piscivorus venoms were examined chromatographically as a function of ph and in the presence versus absence of the essential cofactor, calcium ion. at neutral ph without calcium, the subunits of both enzymes reequilibrated sufficiently slowly that dimer and monomer were separated by size exclusion chromatography. at ph 4.2 and lower, the dimers underwent rapid dissociation and reassociatio ... | 1991 | 1885568 |
| comparison of the catalytic properties of phospholipase a2 from pancreas and venom using a continuous fluorescence displacement assay. | phospholipases a2 from pig pancreas and the venoms from bee, naja naja and crotalus atrox have been studied by using a new continuous fluorescence displacement assay that utilizes normal phospholipid substrates [wilton (1990) biochem. j. 266, 435-439]. with limiting amounts of substrate, the assay demonstrated stoichiometric conversion into products with both pancreatic and venom enzymes, and thus would allow phospholipid determination at concentrations down to about 0.1 microm. the substrate sp ... | 1991 | 1898370 |
| immunological properties of the fibrinolytic enzyme (fibrolase) from southern copperhead (agkistrodon contortrix contortrix) venom and its purification by immunoaffinity chromatography. | an antibody to the fibrinolytic enzyme in southern copperhead venom was produced by immunizing rabbits with chromatographically purified enzyme. the antibody was purified from rabbit blood by ammonium sulfate fractionation and protein-a affinity chromatography. the purified antibody reacted only with the fibrinolytic enzyme in southern copperhead venom as demonstrated by immunodiffusion and immunoelectrophoresis. western immunoblotting revealed that several snake venoms, including agkistrodon pi ... | 1991 | 1926169 |
| neutralization of kinin-releasing enzymes of crotalid venoms by monospecific and polyspecific antivenoms. | the amounts of kinin-releasing enzymes in the venoms of crotalus atrox, crotalus adamanteus, crotalus scutulatus scutulatus and agkistrodon piscivorus piscivorus were measured by determining the amounts of kinin released from a sheep kininogen substrate by means of a specific radioimmunoassay. four monospecific and two commercial polyspecific antivenom igg samples were tested for their ability to reduce the kinin-releasing activities of the four crotalid venoms measured in vitro. all of the anti ... | 1991 | 1926178 |
| an indirect haemolytic assay for assessing antivenoms. | dilutions of antivenom, venom, human erythrocytes and a phosphatidylcholine suspension, were incubated for 30 min at 37 degrees c. after centrifugation, the liberated haemoglobin was measured spectrophotometrically. the assay was used to assess an ovine antivenom against the venom from the south american rattlesnake, crotalus durissus terrificus, and an equine wyeth antivenin (crotalidae, polyvalent). the ovine antivenom was more than five times as effective as the equine product. it also neutra ... | 1991 | 1949062 |
| specific binding of crotoxin to brain synaptosomes and synaptosomal membranes. | crotoxin, the presynaptic neurotoxin from crotalus durissus terrificus, was iodinated and used to demonstrate high affinity, specific binding to guinea-pig (cavia porcellus) brain synaptosomes and synaptosomal membrane fragments. 125i-crotoxin binding to the membrane fragments displays two binding plateaus, (kd1 = 4 nm and kd2 = 87 nm, bmax1 = 2 and bmax2 = 4 pmoles/mg membrane protein), but binding to whole synaptosomes revealed only one plateau (kd = 2 nm and bmax = 5 pmoles/mg membrane protei ... | 1991 | 1949068 |
| polymerization site in the beta chain of fibrin: mapping of the b beta 1-55 sequence. | the formation of a fibrin clot occurs through binding of putative complementary sites, called fibrin polymerization sites, located in the nh2- and cooh-terminal domains of fibrin monomer molecules. in this study, we have investigated the structure of the nh2-terminal fibrin polymerization site by using fibrinogen-derived peptides and fragments. fibrinogen was digested with crotalus atrox protease iii, to two major molecular species: a mr 325,000 derivative (fg325) and a peptide of mr 5000. the p ... | 1991 | 1988018 |
| complete primary structure of a galactose-specific lectin from the venom of the rattlesnake crotalus atrox. homologies with ca2(+)-dependent-type lectins. | the complete primary structure of a galactose-specific lectin contained in the venom of the rattlesnake, crotalus atrox, was determined. the lectin is composed of two covalently linked, identical subunits, each consisting of 135 amino acid residues. under physiological conditions the lectin proved to be highly aggregated. the venom lectin contained 9 half-cystines, 8 of which formed four intrasubunit disulfide bridges (cys3-cys14, cys31-cys131, cys38-cys133, and cys106-cys123), while cys86 was i ... | 1991 | 1989986 |
| monolayers of long chain lecithins at the air/water interface and their hydrolysis by phospholipase a2. | the behavior of phosphatidylcholine monolayers at the air/water interface was studied by measuring their surface isotherm, surface potential, surface viscosity, and rate of hydrolysis by the dimeric phospholipase a2 from the venom of crotalus atrox. the monolayers showed typical liquid-expanded behavior. in this phase, the surface potential was linearly dependent on surface concentration and extrapolated at zero concentration to a value characteristic of a liquid hydrocarbon/water interface. the ... | 1991 | 1999420 |
| suicide-inhibitory bifunctionally linked substrates (siblinks) as phospholipase a2 inhibitors. mechanistic implications. | novel phospholipids that function as mechanism-based inhibitors for phospholipase a2 (pla2) are described. pla2-catalyzed hydrolysis of the sn-2 ester of these suicide-inhibitory bifunctionally linked substrates (siblinks) followed by a cyclization reaction generates a cyclic anhydride at the active site of the enzyme which leads to inhibition. structure/activity relationships for the siblinks substituents in the sn-1 and sn-2 position are delineated. time courses and efficiency of siblinks inhi ... | 1991 | 2002046 |
| the hypotensive activity of crotalus atrox (western diamondback rattlesnake) venom: identification of its origin. | viperidae snakes belonging to the genus crotalus, subfamily crotalinae, include the species durissus terrificus, durissus durissus, adamanteus, atrox, cerastes, horridus, molossus, scutulatus, viridis and others. all of them, except for the first 2, are found in north america. crotalus atrox, or diamondback rattlesnakes, live in the southwest united states and in mexico. this paper describes the fractionation of c. atrox venom in order to isolate and identify its hypotensive agents. | 1991 | 2035756 |
| reduction of rattlesnake-venom-induced myonecrosis in mice by hyperbaric oxygen therapy. | hyperbaric oxygen therapy (hbot) at 1, 2, and 2.75 atmospheres absolute (ata) was used to treat rattlesnake (crotalus atrox) venom-induced tissue damage and edema in thigh muscles of mice. tissue damage was evaluated by double-blind histopathologic examination: tissue edema was determined by measuring tissue water content. a total of 10 intermittent exposures to oxygen over a period of 4 days at 2 and 2.75 ata did not influence the resolution of venom-induced tissue edema, whereas tissue damage ... | 2007 | 2045641 |
| amino acid sequence of a phospholipase a2 from the venom of trimeresurus gramineus (green habu snake). | two phospholipases a2, named phospholipases a2-i and a2-ii, were purified to homogeneity from the venom of trimeresurus gramineus (green habu snake). the complete amino acid sequence of phospholipase a2-i was determined by sequencing the native protein and the peptides produced by enzymatic (achromobacter protease i, clostripain, and chymotrypsin) and chemical (hydroxylamine) cleavages of the s-pyridylethylated derivative of the protein. the protein consisted of 122 amino acid residues and was s ... | 1991 | 2048135 |
| structure of recombinant human rheumatoid arthritic synovial fluid phospholipase a2 at 2.2 a resolution. | phospholipases a2 (pla2s) may be grouped into distinct families of proteins that catalyse the hydrolysis of the 2-acyl bond of phospholipids and perform a variety of biological functions. the best characterized are the small (relative molecular mass approximately 14,000) calcium-dependent, secretory enzymes of diverse origin, such as pancreatic and venom pla2s. the structures and functions of several pla2s are known. recently, high-resolution crystal structures of complexes of secretory pla2s wi ... | 1991 | 2062381 |
| molecular dynamics simulations of phospholipases a2. | an extensive molecular dynamics study of phospholipases a2 from pancreatic bovine and crotalus atrox venom has shown that the well-conserved homologous core of the phospholipases a2, including the so called catalytic network, is very stable during the course of the calculations. the fluctuations which occur are located in segments which have significantly different three-dimensional conformations in the two phospholipases a2 studied, suggesting that a particularly stable core conformation gives ... | 1990 | 2075191 |
| dimeric character of a basic phospholipase a2 from cobra venom: experimental and modelling study. | when it is gel filtered on sephadex in the absence of calcium ions, basic phospholipase a2 from naja nigricollis venom elutes as a dimer. in order to study the possibility of this dimerization from a structural point of view, three-dimensional models of both monomeric and dimeric n. nigricollis phospholipases a2 have been graphically built on the basis of homologies with the phospholipases a2 from pancreatic bovine and crotalus atrox venom. the building of a dimeric model is made possible by the ... | 1990 | 2075192 |
| primary structure of a hemorrhagic metalloproteinase, ht-2, isolated from the venom of crotalus ruber ruber. | crotalidae and viperidae snake venoms contains several kinds of metalloproteinases which cause localized hemorrhage by direct action on blood vessel walls. we report here the entire amino acid sequence and the disulfide bridge locations of ht-2, one of the hemorrhagic toxins isolated from the venom of crotalus ruber ruber (red rattlesnake). the non-reduced protein was first cleaved at methionine residues to provide a set of 8 fragments, which covered the entire sequence of ht-2. the disulfide br ... | 1990 | 2081731 |
| isoforms of a highly specific b beta-chain fibrinogenase from the venom of crotalus atrox: preliminary observations. | three variants of a crotalus atrox venom enzyme that cleaves primarily the arg42 - ala bond of the b beta-chain of human fibrinogen were separated by high-performance liquid chromatography and were shown by n-terminal sequence analysis to be amino acid isoforms. all are single-chain glycoproteins whose approximate molecular weights lie between 26,000 and 28,000. the isoenzymes also cleaved the a alpha-chain at arg491 - his, though much more weakly, with strengths for both bonds that varied among ... | 1990 | 2133222 |
| hydrolysis of supported pyrenephospholipid monolayers by phospholipase a2. | hydrolysis by pancreatic and snake venom (crotalus atrox) phospholipase a2 of fluorescent monolayers of pyrene-labelled phosphatidylglycerol on solid support was studied. we used a fluorescence microscope equipped with video camera, video recorder and an image analyzer to monitor changes in fluorescence. decrease in pyrene excimer emission was evident when pyrene phosphatidylglycerol monolayers transferred onto quartz glass slides (at a surface pressure of 15 mn m-1) were subjected to enzymatic ... | 1990 | 2208445 |
| kinetics of the hydrolysis of mixed micelles of dipalmitoyllecithin with triton x-100 catalyzed by a phospholipase a2 from the venom of agkistrodon halys blomhoffii. | the ph dependence of kinetic parameters for the hydrolysis of mixed micelles of 1,2-dipalmitoyl-sn-glycero-3-phosphorylcholine (dic16pc) with triton x-100, catalyzed by the intact and the n-terminal alpha-nh2-modified phospholipases a2 (pla2s) of agkistrodon halys blomhoffii, was studied at 25 degrees c and ionic strength 0.1 in the presence of saturating amounts of ca2+. the ph dependence of the kinetic parameters for the hydrolysis of monodispersed dic6pc, catalyzed by the modified enzyme, was ... | 1990 | 2229006 |
| structure of an engineered porcine phospholipase a2 with enhanced activity at 2.1 a resolution. comparison with the wild-type porcine and crotalus atrox phospholipase a2. | the crystal structure of an engineered phospholipase a2 with enhanced activity has been refined to an r-factor of 18.6% at 2.1 a resolution using a combination of molecular dynamics refinement by the gromos package and least-squares refinement by tnt. this mutant phospholipase was obtained previously by deleting residues 62 to 66 in porcine pancreatic phospholipase a2, and changing asp59 to ser, ser60 to gly and asn67 to tyr. the refined structure allowed a detailed comparison with wild-type por ... | 1990 | 2254938 |
| comparison of the immunogenicity and antigenic composition of several venoms of snakes in the family crotalidae. | crude venoms from the prairie rattlesnake (crotalus viridis viridis), the western diamondback rattlesnake (crotalus atrox), the eastern diamondback rattlesnake (crotalus adamanteus) and the timber rattlesnake (crotalus horridus horridus) were used to prepare monovalent antivenoms in rabbits. each of these four monovalent antivenoms was reacted against six different venoms using the technique of immunoblotting (western blot) to determine the relative immunogenicity of the four venoms and to compa ... | 1990 | 2339435 |
| glycerol monoethers in the scent gland secretions of the western diamondback rattlesnake (crotalus atrox; serpentes, crotalinae). | 1-o-monoalkylglycerols with c12 to c20 chains were identified in the scent gland secretions of the western diamondback rattlesnake (crotalus atrox). this is the first documentation of these compounds in the skin secretions of a reptile. | 1990 | 2373208 |
| identification of the cleavage sites by a hemorrhagic metalloproteinase in type iv collagen. | type iv collagen, solubilized from engelbreth-holm-swarm (ehs) tumor basement membranes is digested by a hemorrhagic metalloproteinase, ht-e, isolated from the crude venom of the western diamondback rattlesnake, crotalus atrox. the major proteolytic products have mr 141,000, 132,000, 87,000, 71,000, 33,000 and approximately 18,000 as estimated by sds-gel electrophoresis of pepsinized type iv collagen fragments. sequence analysis of the digestion products reveal that the mr 141,000, 71,000 and ap ... | 1990 | 2374521 |
| kinetic and inhibition studies of phospholipase a2 with short-chain substrates and inhibitors. | the action of the phospholipases a2 (pla2s) from naja naja naja, naja naja atra, and crotalus atrox venoms as well as the enzyme from porcine pancreas on a number of short-chain, water-soluble substrates was studied. the inhibition of these enzymes by short-chain phosphonate- and thiophosphonate-containing phospholipid analogues was also examined. the kinetic patterns observed for the action of the venom pla2s on substrates containing phosphocholine head groups all deviated from a classical mich ... | 1990 | 2383571 |
| the complete amino acid sequence of the high molecular mass hemorrhagic protein hr1b isolated from the venom of trimeresurus flavoviridis. | hemorrhage is a common occurrence in a victim bitten by crotalid and viperid snakes, and hemorrhagic components in these various venoms have been isolated and characterized. previously, we have shown that a low molecular weight hemorrhagic protein (hr2a, 202 amino acid residues) isolated from the venom of trimeresurus flavoviridis is a member of a new subfamily of metalloproteinases. we now report the complete amino acid sequence of a high molecular mass hemorrhagic protein isolated from the sam ... | 1990 | 2398046 |
| solubilization of calcium channel antagonist binding sites from rat brain. | calcium antagonist binding sites were solubilized from rat brain membranes using the detergent 3-[(3-cholamidopropyl)dimethylammonio] 1-propanesulfonate (chaps). chaps-solubilized [3h]nitrendipine binding sites are saturable over a range of 0.05-4 nm and scatchard analysis reveals a single, high-affinity (kd = 0.49 +/- 0.10 nm), low-capacity (bmax = 56 +/- 4 fmol/mg of protein) binding site. reversible ligand competition experiments using solubilized binding sites demonstrated appropriate pharma ... | 1987 | 2440991 |
| platelet-aggregation is stimulated by lactose-inhibitable snake venom lectins. | five lactose-specific lectins from snake venoms were tested for the ability to stimulate the aggregation of human platelets. three of the lectins, bushmaster (lachesis muta), cottonmouth (ancistrodon piscivorous leukostoma) and rattlesnake (crotalus atrox) lectins, consistently stimulated secretion and aggregation. thrombolectin (bothrops atrox) occasionally caused aggregation. copperhead (agkistrodon contortrix contortrix) lectin did not by itself cause platelet aggregation. lactose, a specific ... | 1989 | 2530646 |
| conservation of human fibrinogen conformation after cleavage of the b beta chain nh2 terminus. | human fibrinogen exposed to protease iii from crotalus atrox venom is cleaved near the nh2 terminus of the b beta chain yielding a species of mr 325,000 (fg325) with impaired thrombin clottability. the derivative was compared with intact fibrinogen in a number of ways to determine whether the functional defect resulted from a conformational change or from the loss of a polymerization site. nh2-terminal amino acid sequencing of isolated a alpha, b beta, and gamma chains showed that fg325 containe ... | 1985 | 2579073 |
| catroxobin, a weakly thrombin-like enzyme from the venom of crotalus atrox. nh2-terminal and active site amino acid sequences. | two thrombin-like isoenzymes, termed catroxobins, were purified by gel filtration and ion exchange chromatography to electrophoretic homogeneity from the venom of the western diamondback rattlesnake, crotalus atrox. by sds-polyacrylamide gel electrophoresis their molecular weights were estimated to be 25,000 and 26,200. a 43-residue nh2-terminal sequence, containing the active histidine residue, was the same for the two isoenzymes. in addition, a 33-residue internal peptide from catroxobin i con ... | 1989 | 2617466 |
| investigation of an active site histidine-aspartate couple in trimeresurus flavoviridis phospholipase a2. | when trimeresurus flavoviridis phospholipase a2 was reacted with methyl p-nitrobenzenesulfonate, its activity decreased following first-order kinetics. the ph dependence of the rate constants of inactivation showed that his-48 with an apparent pka of 6.5 controls the reaction. in the ph region below 6.5, n1-methylhistidine was predominantly formed. on the other hand, n1,n3-dimethylhistidine was almost exclusively produced in the ph region above 6.5. no n3-methylhistidine was detected at any ph t ... | 1989 | 2628422 |
| thrombolysis with a snake venom protease in a rat model of venous thrombosis. | a fibrin(ogen)olytic protease isolated from the venom of crotalus atrox (the western diamondback rattlesnake) was tested for thrombolytic activity. the protease, called atroxase, solubilized fibrin when tested on fibrin plates and hydrolyzed fibrinogen rendering it incoagulable with a specific fibrinogenolytic activity of 42 mg fibrinogen/min/mg protein. atroxase was unable to activate plasminogen. in vivo, fibrinolytic activity was tested on artificial thrombi induced in the posterior vena cava ... | 1989 | 2646751 |
| comparative enzymatic study of hplc-fractionated crotalus venoms. | 1. ten venoms of the genus crotalus (crotalus adamanteus, crotalus atrox, crotalus durissus durissus, crotalus horridus horridus, crotalus lepidus, crotalus polystictus, crotalus molossus molossus, crotalus pusillus, crotalus scutulatus scutulatus, venom b, and crotalus viridis lutosus) were fractionated using hplc anion and cation exchange chromatography. 2. hplc venom fractions were tested for hemorrhagic, hemolytic, and proteolytic activities. 3. crude virginia opossum (didelphis virginiana) ... | 1989 | 2680253 |
| antigenic relationships of fractionated western diamondback rattlesnake (crotalus atrox) hemorrhagic toxins and other rattlesnake venoms as indicated by monoclonal antibodies. | seven hemorrhagic factors have been isolated from crotalus atrox venom, but their antigenic relationships have not been well studied. in this study, two different monoclonal antibodies, c. atrox peak 8 (ca-p-8) and c. atrox subclone 5 (ca-5+), were produced against two c. atrox venom hemorrhagic fractions and used in an elisa (enzyme-linked immunosorbent assay) to determine if the hemorrhagic factors in c. atrox venom are antigenically related. the same elisa test was used to determine cross-rea ... | 1989 | 2718192 |
| amino acid sequence of a crotalus atrox venom metalloproteinase which cleaves type iv collagen and gelatin. | the hemorrhagic toxin ht-d from venom of the western diamondback rattlesnake is a metalloproteinase with a molecular weight of 23,234. peptides were obtained from enzymatic and chemical digestions, separated by reverse-phase chromatography, and sequenced in a gas-phase sequenator. the sequence showed a putative zinc binding site similar to that of thermolysin and other metalloproteinases but no overall significant similarity to the sequences of other metalloproteinases and may represent a new su ... | 1989 | 2745407 |
| preliminary observations on the effects of hyperbaric oxygen therapy on western diamondback rattlesnake (crotalus atrox) venom poisoning in the rabbit model. | intermittent hyperbaric oxygen therapy has been shown to reduce skeletal muscle necrosis in a compartment syndrome animal model. to study whether intermittent exposure to hyperbaric oxygen augments antivenin therapy in reducing muscle necrosis, we injected sublethal doses of western diamondback rattlesnake (crotalus atrox) venom intramuscularly into the hind legs of new zealand white rabbits. in this pilot study, the animals were divided into three treatment groups. the first group received one ... | 1989 | 2757285 |
| degradation of extracellular matrix proteins by hemorrhagic metalloproteinases. | the proteolytic activity of four hemorrhagic metalloproteinases (ht-a, c, d, and e) isolated from the venom of the western diamondback rattlesnake (crotalus atrox) was investigated using isolated extracellular matrix (ecm) proteins. we determined that all of the proteinases are capable of cleaving fibronectin, laminin, type iv collagen, nidogen (entactin), and gelatins. however, none of the proteinases were proteolytic against the interstitial collagen types i and iii or type v collagen. with al ... | 1989 | 2817904 |
| [nle4, d-phe7]-alpha-msh: a superpotent melanotropin with prolonged action on vertebrate chromatophores. | the in vitro and in vivo responses of integumental chromatophores to alpha-msh and a related analogue, [nle4, d-phe7] -alpha-msh, were studied in a number of vertebrate species: the teleost, lebistes reticulatus; the amphibians, rana pipiens, r. catesbeiana, xenopus laevis, bufo alvarius, and b. cognatus; the lizard, anolis carolinensis; the rattlesnake, crotalus atrox. the alpha-melanotropin analogue was a superpotent agonist in the in vitro frog (r. pipiens, r. catesbeiana) and lizard (a. caro ... | 1985 | 2859941 |
| proteolytic specificity of hemorrhagic toxin b from crotalus atrox (western diamondback rattlesnake) venom. | in our effort to identify the proteolytic specificity of various hemorrhagic toxins isolated from western diamondback rattlesnake venom, hemorrhagic toxin b was isolated in homogeneous form by previously published methods. hemorrhagic toxin b hydrolyzed glucagon, producing six fragments. the proteolytic sites were identified as thr(5)-phe(6), thr(10)-ser(11), asp(15)-ser(16), asp(21)-phe(22) and try(25)-leu(26). when oxidized insulin b chain was used, proteolysis occurred at four sites: asn(3)-g ... | 1985 | 2865065 |
| the stereoselectivity of the clostridium perfringens phospholipase c: hydrolysis of thiophosphate analogs of phosphatidylcholine. | thiophosphate containing analogs of phosphatidylcholine have been synthesized with varying degrees of structural complexity. these analogs have been used in a continuous spectrophotometric assay for phospholipase c from clostridium perfringens in order to examine the requirement for substrate ester functionalities and the stereoselectivity of the enzyme. the substrate analogs with ester groups in the nonpolar portion of the molecule were acceptable substrates for phospholipase c, while those ana ... | 1987 | 2890329 |
| immunofluorescent localization of the ca2+-dependent proteinase and its inhibitor in tissues of crotalus atrox. | the native 108,000 dalton ca2+-dependent proteinase (cdp) and its 115,000 dalton protein inhibitor (cdpi) were purified from bovine skeletal muscle using native polyacrylamide gel electrophoresis and were used to elicit antibody production in rabbits and balb/c mice. polyclonal antibodies were purified as igg fractions by column chromatography; monoclonal antibodies were produced by the hybridoma technique. indirect immunofluorescence localization of cdp and cdpi in tissues of crotalus atrox sho ... | 1987 | 3035058 |
| studies on the mechanism of hemorrhage production by five proteolytic hemorrhagic toxins from crotalus atrox venom. | the sites and relative rates of peptide bond hydrolysis of the oxidized b chain of bovine insulin by two hemorrhagic proteinases, ht-a and ht-b, isolated from the venom of the western diamondback rattlesnake, crotalus atrox, were investigated. the results were compared with previous results on the digestion of the same substrate by the c. atrox hemorrhagic proteinases ht-c, d, and e. both toxins, ht-a and ht-b, were found to cleave the his5-leu6, his10-leu11, ala14-leu15, and tyr16-leu17 bonds o ... | 1988 | 3060135 |
| cross-reactivity and neutralization by rabbit antisera raised against crotoxin, its subunits and two related toxins. | antisera were raised against intact crotoxin (crotalus durissus terrificus), mojave toxin (crotalus scutulatus scutulatus) and concolor toxin (crotalus viridis concolor), as well as the subunits of crotoxin. double immunodiffusion and enzyme-linked immunosorbent assays (elisa) demonstrated antigenic similarity between these three purified toxins and their subunits. additionally, when crotoxin antisera were pre-incubated with each of the three toxins before injection, the lethal activity of all w ... | 1986 | 3095955 |
| characterization of two hemorrhagic zinc proteinases, toxin c and toxin d, from western diamondback rattlesnake (crotalus atrox) venom. | two hemorrhagic proteinases from crotalus atrox venom, hemorrhagic toxin c (ht-c) and hemorrhagic toxin d (ht-d), were characterized and compared to one another. the two toxins are zinc metalloproteinases which both have molecular weights of 24,000. their isoelectric points are slightly acidic, ht-c being the more basic of the two with an isoelectric point of 6.2, whereas ht-d has an isoelectric point of 6.1. only minor differences were found in the amino acid compositions of the two toxins. the ... | 1987 | 3101740 |
| bacillus cereus phospholipase c: carboxylic acid ester specificity and stereoselectivity. | thiophosphate analogs of phosphatidylcholine have been synthesized with varying structural complexity. these analogs have been used in a continuous spectrophotometric assay for phospholipase c (bacillus cereus) to estimate the minimal structural requirements associated with the non-polar portion of the substrate phospholipid. the analogs were of three types containing zero, one or two carboxylic acid ester functionalities. the analogs with one or two ester groups acted as substrates for phosphol ... | 1987 | 3111540 |
| atrotoxin: a specific agonist for calcium currents in heart. | a specific label for voltage-dependent calcium channels is essential for the isolation and purification of the membrane protein that constitutes the calcium channel and for a better understanding of its function. a fraction of crotalus atrox that increases voltage-dependent calcium currents in single, dispersed guinea pig ventricular cells was isolated. in the doses used, neither sodium nor potassium currents were changed. the fraction was active in the absence of detectable phospholipase or pro ... | 1985 | 3160111 |
| purification and biochemical characterization of atroxase, a nonhemorrhagic fibrinolytic protease from western diamondback rattlesnake venom. | crotalus atrox venom contains a variety of proteases which render fibrinogen incoagulable and solubilize fibrin. one of these proteases was purified by using ion-exchange and gel permeation liquid chromatography. the protease, called atroxase, consists of a single nonglycosylated polypeptide chain with a molecular weight of 23,500 and an isoelectric point of ph 9.6. amino acid analysis indicates atroxase to contain 206 residues with no sulfhydryl groups. metal analysis found zinc and potassium a ... | 1988 | 3167016 |
| classification of myonecrosis induced by snake venoms: venoms from the prairie rattlesnake (crotalus viridis viridis), western diamondback rattlesnake (crotalus atrox) and the indian cobra (naja naja naja). | the pathogenesis of myonecrosis induced by three different snake venoms was studied by light microscopic examination of skeletal muscle tissue taken at time periods ranging from 0.25 hr to 4 weeks after an intramuscular injection of the venom into mice. it was possible to identify different types of myonecrosis based on the abnormal morphologic states of the damaged cells. the types of myonecrosis observed correlated with the types of components present in the venom injected. venoms containing d ... | 1988 | 3188052 |
| preparation of a crotoxin neutralizing monoclonal antibody. | crotoxin is a heterodimeric protein composed of an acidic and basic subunit from the venom of crotalus durissus terrificus and is representative of a number of presynaptically acting neurotoxins found in the venom of rattlesnakes. four different monoclonal antibodies, typed as igg1 subclass, were raised against the basic subunit of this toxin. one was a potent neutralizing antibody of intact crotoxin, which could neutralize approximately 1.6 moles of purified crotoxin per mole of antibody. the m ... | 1988 | 3201488 |
| efficacy of delayed administration of crotalid antivenom and crystalloid fluids. | clinical and research reports suggest that the efficacy of antivenom declines when its administration is delayed after envenomation. a controlled sequential trial was performed comparing the efficacy of three treatments to untreated controls when applied 1 hr after subcutaneous injection of rats with crotalus atrox venom. survival was decreased in all groups when treatment was delayed for 1 hr. survival was highest in animals treated with both antivenom and saline, followed by antivenom alone, s ... | 1988 | 3238705 |
| proton nmr resonance assignments and surface accessibility of tryptophan residues of a dimeric phospholipase a2 from trimeresurus flavoviridis. | proton nmr spectra of a dimeric phospholipase a2 from trimeresurus flavoviridis have been recorded. n-1 proton resonances of the tryptophan indole rings have been detected and assigned to specific positions, trp-3/trp-30, trp-68 and trp-108, by comparing the spectra of the enzyme derivatives with tryptophans oxidized to differing extents. photo-cidnp experiments have revealed that trp-68 and trp-108 are exposed while trp-3 and trp-30 are buried in the molecule. this is consistent with the x-ray ... | 1988 | 3350151 |
| synthesis and some properties of constrained short-chain phosphatidylcholine analogues: (+)- and (-)-(1,3/2)-1-o-(phosphocholine)2,3-o- dihexanoylcyclopentane-1,2,3-triol. | reported herein is the synthesis of (+)- and (-)-(1,3/2)-1-o-(phosphocholine)-2,3-o-dihexanoylcyclopentane-1,2, 3-triol. these are the enantiomers of a contrained analogue of dihexanoylphosphatidylcholine in which the glycerol backbone is replaced by all-trans cyclopentane-1,2,3-triol. evidence is presented to demonstrate that the (-)-enantiomer is a substrate for phospholipase a2 (pla2) (crotalus atrox) while the (+)-enantiomer is not. this strict enantiomeric (and positional) specificity was e ... | 2012 | 3370720 |