Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| phospholipase a2 as a probe of phospholipid distribution in erythrocyte membranes. factors influencing the apparent specificity of the reaction. | the action of snake venom phospholipases a2 in intact human erythrocytes was investigated in detail. the basis phospholipase from agkistrodon halys blomhifii was found to induce both hydrolysis of membrane phospholipids and total cell hemolysis under certain experimental conditions. the hydrolytic action of the basic enzyme was found to consist of two sequential events: (a) hydrolysis of 70% of the total cell ph osphatidylcholine without any evident hemolysis; and (b) complete hydrolysis of the ... | 1975 | 54 |
| kinetic study of the action of snake venom phospholipase a2 on human serum high density lipoprotein 3. | the hydrolysis of the phospholipids of intact human serum high density lipoprotein 3 (hdl3) by pure alpha-phospholipase a2 from crotalus adamanteus was studied by ph-stat titration. the enzyme quantitatively hydrolyzed phosphatidylcholine and phosphatidylethanolamine and left sphinogomyelin intact, yielding a stable and water-soluble modified hdl. lysophospholipids and free fatty acids, the products of hydrolysis, remained in the lipoprotein. when 1 mol of defatted bovine serum albumin/mol of su ... | 1976 | 5436 |
| vinylglycine and proparglyglycine: complementary suicide substrates for l-amino acid oxidase and d-amino acid oxidase. | proparglyglycine (2-amino-4-pentynoate) and vinylglycine (2-amino-3-butenoate) have been examined as substrates and possible inactivators of two flavo enzymes, d-amino acid oxidase from pig kidney and l-amino acid oxidase from crotalus adamanteus venom. vinylglycine is rapidly oxidized by both enzymes but only l-amino acid oxidase is inactivated under assay conditions. the loss of activity probably involves covalent modification of an active site residue rather than the flavin adenine dinucleoti ... | 1976 | 8082 |
| effect of purified phospholipases on the binding of tetrodotoxin to axon plasma membrane. | the role of phospholipids in the binding of [3h]tetrodotoxin to garfish olfactory nerve axon plasma membrane was studied by the use of purified phospholipases. treatment of the membranes with low concentrations of either phospholipase a2 (crotalus adamanteus and naja naja) or phospholipase c (bacillus cereus and clostridium perfringens) resulted in a marked reduction in tetrodotoxin binding activity. a 90% reduction in the activity occurred with about 45% hydrolysis of membrane phospholipids by ... | 1979 | 39172 |
| oxidative deamination of epsilon-n-acetylthialysine and epsilon-n-acetylselenalysine by snake venom l-aminoacid oxidase. | epsilon-n-acetylthialysine and epsilon-n-acetylselenalysine are oxidatively deaminated by crotalus adamanteus l-aminoacid oxidase, giving rise to the corresponding alpha-ketoacids, identified by some chemical and chromatographic tests and by comparison with synthetic compounds. no cleavage of the c-s or c-se bonds of the substrates occurs during the reaction. the enzyme acts as well on the epsilon-n-acetylderivatives of thialysine and selenalysine as on epsilon-n-acetyllysine. the substitution o ... | 2014 | 121995 |
| postitional specificity of fatty acids in pyrophosphatidic acid from cryptococcus neoformans. | pyrophosphatidic acid isolated from cryptococcus neoformans was degraded to phosphatidic acid in aqueous pyridine. the phosphatidic acid was hydrolyzed by phospholipase a (ec 3.1.1.4) of crotalus adamanteus to lysophosphatidic acid and 2-positioned fatty acids. from the analyses of the fatty acid composition of pyrophosphatidic acid and its degraded products (phosphatidid acid, lysophosphatidic acid, and fatty acid), it was concluded that most of the saturated fatty acids of pyrophosphatidic a ... | 1975 | 168186 |
| a simple method for preparation of snake venom phosphodiesterase almost free from 5'-nucleotidase. | a simple method, involving nad+-sepharose chromatography, was developed for the preparation of snake venom phosphodiesterase (ec 3.1.4.1) almost free from 5'-nucleotidase (ec 3.1.3.5). using an nad+-sepharose 4b column, phosphodiesterase was eluted in the unadsorbed fraction, whereas 5'nucleotidase was strongly adsorbed. the latter enzyme was desorbed when 0.2 m sodium bicarbonate buffer containing 1mm beta-nadh was used as a solvent. the affinity column could be used at least four times without ... | 1975 | 168189 |
| organization of phospholipids in human red cell membranes as detected by the action of various purified phospholipases. | 1. the action of eight purified phospholipases on intact human erythrocytes has been investigated. four enzymes, e.g. phospholipases a2 from pancreas and crotalus adamanteus, phospholipase c from bacillus cereus, and phospholipase d from cabbage produce neither haemolysis nor hydrolysis of phospholipids in intact cells. on the other hand, both phospholipases a2 from bee venom and naja naja cause a non-haemolytic breakdown of more than 50% of the lecithin, while sphingomyelinase c from staphyloco ... | 1975 | 169915 |
| an endonuclease activity of venom phosphodiesterase specific for single-stranded and superhelical dna. | a homogeneous preparation of venom phosphodiesterase from crotalus adamanteus possesses an intrinsic endonuclease activity, specific for superhelical (form i) and single-stranded dna. the phosphodiesterase degrades single-stranded t7 dna by endonucleolytic cleavages. duplex t7 dna is hydrolyzed by the liberation of acid-soluble products simultaneously from the 3' and 5' termini but without demonstrable internal scissions in duplex regions. since venom phosphodiesterase is known to hydrolyze olig ... | 1977 | 200616 |
| a simple and high yield purification of crotalus adamanteus phospholipases a2. | a new, high yield, procedure for the purification of the phospholipases a2 of crotalus adamanteus venom is described. the procedure involves precipitation of the bulk of venom proteins with 50% isopropanol, precipitation of the enzymes from the isopranol soluble material with neodynium chloride, and final purification on deae cellulose. an overall yield of approximately 80% is achieved. | 1975 | 237535 |
| search for relationships among the hemolytic, phospholipolytic, and neurotoxic activities of snake venoms. | several snake venom neurotoxins are larger and more complex than the well-studied group of postsynaptic toxins exemplified by alpha-bungarotoxin. several of these, exemplified by beta-bungarotoxin, show phospholipase a2 activity (phosphatide 2-acylhydrolase, ec 3.1.1.4) when tested in the presence of detergents. the high hemolytic activity of crotoxin, the neurotoxin of crotalus durissus terrificus, in the presence of lecithin has been attributed to this activity. the phospholipase a2 activity o ... | 1978 | 273221 |
| low concentrations of indomethacin inhibit phospholipase a2 of rabbit polymorphonuclear leukocytes. | inhibition of prostaglandin synthesis by indomethacin, a drug with anti-inflammatory properties, has been attributed to its action on fatty acid cyclooxygenase. however, prostaglandin synthesis would also be inhibited if precursor fatty acids were not supplied. we find that indomethacin inhibits phospholipase a2 (phosphatide 2-acylhydrolase, ec 3.1.1.4) of rabbit polymorphonuclear leukocytes in dose-dependent fashion. inhibition is immediate and readily detected at 1 micrometer. the extent of in ... | 1978 | 275865 |
| purification and some properties of two proteinases from crotalus adamanteus venom that inactivate human alpha 1-proteinase inhibitor. | two proteinases (proteinases i and ii) have been purified from crotalus adamanteus venom to the stage of electrophoretic homogeneity and proteinase ii has been crystallized. the proteinase differ slightly in molecular weight and amino acid composition. both are metalloenzymes requiring zn2+ or ca2+, or both; neither requires thiol compounds for activation. the proteinases are free of esterolytic activity against benzoly-l-arginine ethyl ester and benzoyl--tyrosine ethyl ester. proteinase ii clea ... | 1978 | 309470 |
| characterization of the inactive fragment resulting from limited proteolysis of human alpha1-proteinase inhibitor by crotalus adamanteus proteinase ii. | the inactive 50,000-dalton fragment of human plasma alpha1-proteinase inhibitor resulting from limited proteolysis of the inhibitor by crotalus adamanteus proteinase ii has been isolated and partially characterized. the amino acid composition of the inactivated inhibitor indicates the loss of a peptide fragment from the intact inhibitor. both intact and inactivated inhibitor contain cooh-terminal lysine. however, the nh2 terminus of the intact inhibitor is glx, whereas that of inactivated inhibi ... | 1979 | 447652 |
| trans fatty acids: positional specificity in brain lecithin. | fifteen-day-old rats were divided into three groups: one group received an intracerebral injection of 5 microci of 9-trans,12-trans [1-(14)c] octadecadienoic acid; the second group was given 5 microci of the same compound plus an equal wt of nonradioactive all cis arachidonic acid; the third group was given 5 microci of 9-trans [1-(14)c] octadecenoic acid. all animals were sacrificed 8 hr after injection. glycerophosphocholine (gpc) was isolated and partically deacylated with phospholipase a2 fr ... | 1979 | 449627 |
| a new method for purification of the thrombin-like enzyme from the venom of the eastern diamondback rattlesnake. | 1979 | 505414 | |
| in vitro actions of some antibiotics on phospholipases. | the effects of some antibiotics on activities of phospholipase a2, b and c were investigated in vitro. tetracyclines, macrolides, chloramphenicol and carbenicillin inhibited the activity of crotalus adamanteus phospholipase a2 towards phospholipids of egg-yolk emulsions. when the ability to inhibit the activity of penicillium notatum phospholipase b towards mixed micelles of phosphatidylcholine and triton x-100 was investigated, polymyxin b was found to be inhibitory while chloramphenicol and ca ... | 1979 | 541266 |
| incorporation of 3h from delta-(l-alpha-amino (4,5-3h)adipyl)-l-cysteinyl-d-(4,4-3h)valine into isopenicillin n. | 1. delta-(l-alpha-amino[4,5-3h]adipyl)-l-cysteinyl-d-[4,4-3h]valine has been synthesized from its constituent amino acids, the l-alpha-amino[4,5-3h]adipic acid being obtained by reduction with 3h2 of methyl 5-acetamido-5,5-diethoxycarbonylpent-2-enoate and subsequent decarboxylation and hydrolysis. 2. in a cell-free system prepared by lysis of protoplasts of cephalosporium acremonium 3h was incorporated from the doubly labelled tripeptide into a compound that behaved like penicillin n or isopeni ... | 1979 | 575040 |
| thrombin-like enzyme from the venom of crotalus adamanteus (eastern diamondback rattlesnake). | 1977 | 854881 | |
| amino acid sequence of phospholipase a2-alpha from the venom of crotalus adamanteus. a new classification of phospholipases a2 based upon structural determinants. | the complete amino acid sequence of crotalus adamanteus venom phospholipase a2-alpha has been determined by analysis of the five tryptic peptides from the citraconylated, reduced, and s-[14c]carboxamidomethylated enzyme. earlier studies (tsao, f. h. c., keim, p. s., and heinrikson, r. l. (1975) arch. biochem. biophys. 167, 706) provided the information necessary to align the tryptic fragments so that secondary cleavage procedures to establish overlaps were unnecessary. the subunit in the phospho ... | 1977 | 873920 |
| heterogeneity of exonuclease from the venom of crotalus adamanteus. | 1977 | 912500 | |
| positional and fatty acid specificity of monoacyl- and diacylglycerol 3-phosphate formation by rabbit heart microsomes. | fatty acid selectivity of acyl-coa:glycerol-3-phosphate acyltransferase (ec 2.3.1.15) and acyl-coa:monoacylglycerol-3-phosphate acyltransferase (ec 2.3.1.52) of the microsomal fraction prepared from rabbit heart was studied. 1. the rate of acylation of glycerol 3-phosphate was increased proportionally with the concentration of acyl-coa. the maximum rate was reached at 0.3 mumol acyl-coa per ml. palmitoyl-, oleoyl- and linoleoyl-coa all served equally well as acyl donors, and produced approximate ... | 1976 | 952977 |
| effects of local anaesthetics on phospholipases. | 1. the effects of six local anaesthetics have been studied on the activities of soluble phospholipases a2 (ec 3.1.1.4) and lysophospholipase (ec 3.1.1.5). 2. phospholipase a2 activity in human seminal plasma towards sonicated radioactively-labelled phosphatidylethanolamine was slightly stimulated a low and inhibited at high concentrations of all anaesthetic compounds employed. the order of decreasing potency was chlorpromazine, dibucaine, tetracaine, lidocaine, cocaine and procaine. in line with ... | 1976 | 952985 |
| enzymatic reactions of methionine sulfoximine. conversion to the corresponding alpha-imino and alpha-keto acids and to alpha-ketobutyrate and methane sulfinimide. | l-methionine sulfoximine is a substrate of l-amino acid oxidase (crotalus adamanteus), glutamine transaminase, and gamma-cystathionase. in the reaction catalyzed by l-amino acid oxidase, methionine sulfoximine is converted to aplph-imino-gamma-methylsulfoximinylbutyrate, which undergoes rapid gamma elimination yielding methane sulfinimide and 2-imino-3-butenoic acid. methane sulfinimide is converted to methane sulfonamide, methane sulfinic acid, and methane sulfonic acid; 2-imino-3-butenoic acid ... | 1976 | 977592 |
| characterization of a thrombin-like enzyme from crotalus adamanteus (eastern diamondback rattlesnake) [proceedings]. | 1976 | 1014024 | |
| crotalus adamanteus phospholipase a2-alpha: subunit structure. nh2-terminal sequence, and homology with other phospholipases. | 1975 | 1124937 | |
| kinetic study of the hydrolysis of lecithin monolayers by crotalus adamanteus alpha-phospholipase a2. monomer--dimer equilibrium. | 1975 | 1133380 | |
| crystalline basic protein from venom of crotalus adamanteus. | 1979 | 1145639 | |
| rapid purification of phospholipase a2 from crotalus adamanteus venom by affinity chromatography. | we have used alkyl ether analogs of ethanolamine and choline phospholipids as ligands to purify phospholipase a2 (ec 3.1.1.4) from crotalus adamanteus venom by affinity chromatography. one of the affinity columns was prepared with rac-1-(9-carboxy)nonyl-2-hexadecylglycero-3-phosphocholine linked to ah-sepharose 4b via the carboxyl group. specific adsorption of phospholipase a2 to this column was achieved in buffer containing ca2+, and the enzyme was eluted in buffer containing edta. the two enzy ... | 1975 | 1171865 |
| relation between various phospholipase actions on human red cell membranes and the interfacial phospholipid pressure in monolayers. | the action of purified phospholipases on monomolecular films of various interfacial pressures is compared with the action on erythrocyte membranes. the phospholipases which cannot hyorolyse phospholipids of the intact erythrocyte membrane, phospholipase c from bacillus cereus, phospholipase a2 from pig pancreas and crotalus adamanteus and phospholipase d from cabbage, can hydrolyse phospholipid monolayers at pressure below 31 dynes/cm only. the phospholipases which can hydrolyse phospholipids of ... | 1975 | 1174576 |
| translocation and binding of adenine nucleotides by rat liver mitochondria partially depleted of phospholipids. | 1. rat liver mitochondria were partially depleted of their phospholipids using phospholipase a prepared from porcine pancreas (substrate specificity, cardiolipin greater than phosphatidylethanolamine greater than phosphatidylcholine) or from crotalus adamanteus venom (substrate specificity, phosphatidylethanolamine = phosphatidylcholine greater than cardiolipin). 2. removal of only about 1% of the mitochondrial phospholipid with the pancreatic enzyme leads to 50% and 25% losses in adp and atp tr ... | 1976 | 1259954 |
| transformation of n epsilon-cbz-l-lysine to cbz-l-oxylysine using l-amino acid oxidase from providencia alcalifaciens and l-2-hydroxy-isocaproate dehydrogenase from lactobacillus confusus. | biotransformations were developed to oxidize n epsilon-carbobenzoxy(cbz)-l-lysine and to reduce the product keto acid to l-cbz-oxylysine. lysyl oxidase (l-lysine: o2 oxidoreductase, ec 1.4.3.14) from trichoderma viride was relatively specific for l-lysine and had very low activity with n epsilon-substituted derivatives. l-amino acid oxidase (l-amino acid: o2 oxidoreductase [deaminating], ec 1.4.3.2) from crotalus adamanteus venom had low activity with l-lysine but high activity with n epsilon-fo ... | 1992 | 1368913 |
| citrate is an endogenous inhibitor of snake venom enzymes by metal-ion chelation. | citrate levels in selected snake venoms were determined by an enzymatic assay coupled to nadp+ reduction. citrate concentrations in different viper venoms (n = 5) varied from 95 to 150 mm, in crotalids (n = 3) from 63 to 142 mm, and in elapids (n = 4) from 17 to 163 mm. in bothrops asper venom ca(2+)-ion concentrations varied from 2.5 to 3.6 mm, suggesting that the high relative citrate levels may serve to chelate endogenous divalent metal cations, thereby inactivating divalent cation requiring ... | 1992 | 1440629 |
| 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 |
| sphingolipid metabolism and signal transduction: inhibition of in vitro phospholipase activity by sphingosine. | sphingosine inhibits protein kinase c activity in vitro and has been used to implicate this enzyme in signal transduction and cell function. we report that sphingosine directly inhibits phospholipases a2 and d. sphingosine inhibits ca(2+)-dependent phospholipases a2 from naja naja, porcine pancreas, crotalus adamanteus, human disc and neutrophil in a dose-dependent manner with ic50 values ranging from 5-40 microm using [1-14c]oleate-labelled autoclaved e. coli (20 microm) as substrate. inhibitio ... | 1992 | 1504102 |
| an immunohistochemical study of phospholipase a2 in peripheral nerve during wallerian degeneration. | antiserum raised against purified crotalus adamanteus venom phospholipase a2 (pla2) was used to localise the enzyme in normal and crushed sciatic nerve to determine the effect of nerve trauma on pla2 distribution in the pns. the tissue was bouin's fixed, and stained immunohistochemically using the vectastain abc technique. anti-pla2 antiserum showed weak reactivity with normal rat myelin, while only 'resident' macrophages stained in normal mouse sciatic nerve. post-crush, in the mouse, myelin st ... | 1992 | 1619038 |
| 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 |
| peroxidation and phospholipase a2 hydrolytic susceptibility of liposomes consisting of mixed species of phosphatidylcholine and phosphatidylethanolamine. | the relationship between lipid peroxidation and phospholipase a2 (pla2) hydrolytic activity was studied using unilamellar vesicles (liposomes) as model membranes. hydrolytic specificity was examined using vesicles prepared with pure bovine heart phosphatidylcholine (pc), bovine heart phosphatidylethanolamine (pe), or mixtures of these phospholipids, using two preparative procedures, i.e., sonication or extrusion. lipid peroxidation was induced by incubating vesicles with cumene hydroperoxide and ... | 1992 | 1643097 |
| reversibility of the activation of soluble phospholipase a2 on lipid bilayers: implications for the activation mechanism. | the time-courses of hydrolysis of large vesicles of dipalmitoylphosphatidylcholine were compared using four species of phospholipase a2 (agkistrodon piscivorus piscivorus, crotalus adamanteus and naja naja venoms and porcine pancreatic). in all four cases, the hydrolysis rate suddenly increases 10 to 100-fold at the time (tau) when a specific mole fraction of reaction products has accumulated. the intrinsic fluorescence emission of the three venom enzymes also increases suddenly at time tau. bot ... | 1992 | 1643108 |
| identification of a 15-kilodalton surface glycoprotein on sporozoites of cryptosporidium parvum. | an immunoglobulin a monoclonal antibody (mab5c3) was developed against a 15-kda surface glycoprotein (gp15) of cryptosporidium parvum sporozoites. indirect immunofluorescence and colloidal gold immunoelectron microscopy revealed that the antibody reacted with both the sporozoite and merozoite surface plasma membranes. on western immunoblots, mab5c3 binding was found to be strongly inhibited when 200 mm n-acetylglucosamine was used as a competing sugar. n-acetylgalactosamine inhibited binding of ... | 1991 | 1705238 |
| regional differences in content of small basic peptide toxins in the venoms of crotalus adamanteus and crotalus horridus. | 1. reverse-phase hplc and organic solvents were used to isolate small basic peptide (sbp) toxins from the venoms of crotalus adamanteus, c. durissus terrificus, c. horridus, c. scutulatus scutulatus, c. viridis concolor, c. viridis helleri and c. viridis viridis. 2. acid-dep analyses indicated a high degree of toxin purity which was obtained with a single hplc run. 3. the combined results of hplc, immunodiffusion and electrophoresis analyses of venoms from different geographical regions indicate ... | 1991 | 1756621 |
| interleukin-1 alpha stimulates the release of prostaglandin e2 and phospholipase a2 from fetal rat calvarial cells in vitro: relationship to bone nodule formation. | we have shown previously that interleukin-1 (il-1) has biphasic effects on the formation of bone nodules in long-term cultures of fetal rat calvarial (rc) cells (ellies and aubin, cytokine 2:430-437, 1990). to determine the role of arachidonic acid metabolism in this process, we have examined the release of prostaglandin e2 (pge2) and phospholipase a2 (pla2) from rc cells under conditions that allowed concomitant analysis of the formation of bone nodules. recombinant human il-1 alpha (rhil-1 alp ... | 1991 | 1785374 |
| amino acid sequence of a myotoxin from venom of the eastern diamondback rattlesnake (crotalus adamanteus). | the complete amino acid sequence of a myotoxin isolated from crotalus adamanteus venom (cam-toxin) was determined. the total number of amino acid residues was 45, giving a mol. wt of 5202. the amino acid sequence was compared with those of previously determined crotalus myotoxins. the cam-toxin shows a surprisingly close relationship to those of peptide c (c. v. helleri), myotoxin a (c. v. viridis), crotamine (c. d. terrificus), myotoxin i and ii (c. v. concolor) with homologies of approximately ... | 1991 | 1862521 |
| 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 |
| behaviour of phospholipase modified-hdl towards cultured hepatocytes. ii. increased cell cholesterol storage and bile acid synthesis. | human total hdl (hydrated density 1.070-1.210), hdl2 (1.070-1.125), hdl3 (1.125-1.210) or hdl separated by heparin affinity chromatography were treated with or without purified phospholipase a2 from crotalus adamanteus. control and treated hdl were reisolated and were then incubated with cultured hepatocytes. 1. mass measurements evidenced a time-dependent cholesterol enrichment in hepatocytes cultured in the absence of lipoproteins. addition of hdl2 still enhanced by 25% the cell cholesterol co ... | 1991 | 1998740 |
| 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 |
| a new affinity adsorbent for the purification of phospholipases a1 and a2 from animal venoms. | dimethyl-dl-2,3-distearoyloxy-propyl-2'-hydroxy-ethylammonium++ + (rosenthal's inhibitor) was coupled to carboxyhexyl-sepharose 4b, through carbodiimide chemistry. phospholipase a2 from heloderma horridum horridum and crotalus adamanteus bind to the immobilized ligand in the presence of ca2+ and can be easily eluted under acidic conditions or in the presence of a chelating agent, respectively. this affinity media proved to be effective also in the purification of a ca2(+)-independent phospholipa ... | 1991 | 2028470 |
| selective inhibition of receptor-coupled phospholipase c-dependent processes in human platelets and polymorphonuclear neutrophils. | aggregation of human platelets induced by a variety of agonists was inhibited by 1-[6-[[17 beta-3-methoxyestra-1,3,5(10)-trien-17-yl] amino]hexyl]-1h-pyrrole-2,5-dionel (u-73122) (ic50 values 1-5 microm), but not by the close analog 1-[6-[[17 beta-3-methoxyestra- 1,3,5(10)-trien-17-yl]amino]hexyl]-2,5-pyrrolidine-dione (u-73343) in which pyrrolidinedione was substituted for pyrroledione. inhibition by u-73122 was not mediated by an increase in intracellular cyclic amp. in contrast, the productio ... | 1990 | 2147038 |
| purification and characterization of a soluble phospholipase a2 from guinea pig lung. | guinea pig lung cytosolic phospholipase a2 was purified to near homogeneity by chromatography on a phosphocellulose column, followed by q-sepharose, s-sepharose, gel filtration chromatography and reverse-phase hplc. the purified enzyme exhibited an apparent molecular weight of 16,700 by sds-polyacrylamide gel electrophoresis. active enzyme eluted from the gel at an apparent molecular weight of 16,700. the purified enzyme exhibited a ph optimum of 9.0 and was calcium-dependent. guinea pig lung ph ... | 1990 | 2252913 |
| behaviour of phospholipase-modified hdl towards cultured hepatocytes. i. enhanced transfers of hdl sterols and apoproteins. | human hdl subfractions (hdl2, hdl3, or hdl separated by heparin affinity chromatography) were labelled either on their apolipoprotein moiety with 125i or on their sterols: unesterified [14c]cholesterol and [3h]cholesteryl linoleyl ether, a non-hydrolysable analog of esterified cholesterol. hdl subfractions were then treated with or without phospholipase a2 from crotalus adamanteus in presence of albumin leading to a 72-82% phosphatidylcholine degradation. control and treated hdl were reisolated ... | 1990 | 2322573 |
| 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 |
| evaluation of fluorescent and colored phosphatidylcholine analogs as substrates for the assay of phospholipase a2. | two fluorescent phospholipid analogs, 1-o-[12-(2-naphthyl)-dodec-11-enyl]-2-o-decanoyl-sn-glycero-3-phos phocholine and dansyl-pc [rac 1-o-(n-dansyl-11- amino-1-undecyl)-2-o-decanoyl-glycero-3-phosphocholine], and a red-colored analog, dabsyl-pc [rac 1-o-(n-dabsyl-11-amino-1-undecyl)-2-o-decanoyl-glycero-3- phosphocholine], were evaluated as substrates for the assay of phospholipase a2 (pla2) (crotalus adamanteus). the assay reaction was monitored by separation of the fluorescent or colored subs ... | 1990 | 2344049 |
| purification and partial characterization of the hemorrhagic factor from the venom of crotalus adamanteus (eastern diamondback rattlesnake). | a proteinase from crotalus adamanteus venom has been isolated to the stage of electrophoretic homogeneity by chromatography of the crude venom on cm-sepharose, phenyl-sepharose, ultrogel aca 44 and deae-sepharose. the proteinase accounts for 100% of the detectable hemorrhagic activity in the venom, and the name c. adamanteus proteinase h is suggested. proteinase h is a single chain glycoprotein with a molecular weight of 85,700. proteinase h is active on casein and hide powder azure, but does no ... | 1985 | 2414864 |
| snake venom hemorrhagins: neutralization by commercial antivenoms. | one monovalent (habu-antivenom) and five polyvalent antivenoms (crotalidae; orient, north, central and south africa) were tested for their ability to neutralize the hemorrhagic activity of 12 snake venoms (agkistrodon, bothrops, crotalus, sistrurus, trimeresurus, bitis, echis spp.) when mixed prior to injection into the hind leg of mice. considerable cross-neutralization was observed: antivenoms prepared against african snake venoms were equally or more potent in neutralizing the hemorrhagic act ... | 1988 | 2460973 |
| effects of exogenous phospholipase enzymes, arachidonic acid and 1-oleoyl-2-acetyl-sn-glycerol on ketogenesis in isolated rat hepatocytes. | studies were conducted to see whether exogenous phospholipase c from clostridium perfringens, phospholipase a2 from crotalus adamanteus venom, arachidonic acid and 1-oleoyl-2-acetyl-sn-glycerol (oag) mimic the anti-ketogenic action of vasopressin in isolated rat hepatocytes. exogenous phospholipase c inhibited ketogenesis in the presence of 0.5 mm oleate. experiments employing [1-14c]oleate, however, indicated that the mechanism involved in the anti-ketogenic action of exogenous phospholipase c ... | 1989 | 2499356 |
| effects of mepacrine on the oxidation of [1-14c]oleate in isolated rat hepatocytes. | in isolated rat hepatocytes, mepacrine stimulated the conversion of [1-14c]oleate into 14co2 and depressed the formation of acid-soluble products from [1-14c]oleate. the action of mepacrine on [1-14c]oleate oxidation was not affected by exogenously applied phospholipase a2 (from crotalus adamanteus venom) or arachidonic acid. it is suggested that mepacrine may exert its metabolic effects in isolated rat hepatocytes by a mechanism independent of phospholipase a2 inhibition. | 1989 | 2503651 |
| cross-neutralization of thrombin-like enzymes in snake venoms by polyvalent antivenoms. | five polyvalent antivenoms (crotalidae; orient, north, central and south africa) were tested for their ability to neutralize the thrombin-like activity of snake venoms (bitis gabonica, agkistrodon acutus, bothrops asper, b. atrox, crotalus adamanteus). considerable cross-neutralization was observed. anti-coagulase antibodies were isolated from an antivenom by affinity chromatography using a purified enzyme from bitis gabonica venom. these antibodies neutralized the activity of most snake venom c ... | 1989 | 2629180 |
| 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 |
| hydrolysis of a phospholipid in an inert lipid matrix by phospholipase a2: a 13c nmr study. | a new approach to study phospholipase a2 mediated hydrolysis of phospholipid vesicles, using 13c nmr spectroscopy, is described. [13c]carbonyl-enriched dipalmitoylphosphatidylcholine (dppc) incorporated into nonhydrolyzable ether-linked phospholipid bilayers was hydrolyzed by phospholipase a2 (crotalus adamanteus). the 13c-labeled carboxyl/carbonyl peaks from the products [lyso-1-palmitoylphosphatidylcholine (lppc) and palmitic acid (pa)] were well separated from the substrate carbonyl peaks. th ... | 1989 | 2790021 |
| conversion of 6-mercaptopurine to 6-thioguanylic acid in l-1210 cells and human leukemia cells. | the metabolism of 6-mercaptopurine (6-mp) in l-1210 mouse leukemia cells and human chronic myelocytic leukemia cells (cml cells) was examined. the acid-soluble fractions obtained from cells incubated with [8-14c]6-mp were chromatographed on a dowex-1 formate resin column using a formic acid linear gradient elution system. chromatography of the extract of l-1210 cells revealed four principal radioactive peaks. the fraction containing the third peak was hydrolyzed by snake venom 5'-nucleotidase (c ... | 1985 | 2858424 |
| fluorometric assay for adp-ribosylarginine cleavage enzymes. | a continuous fluorometric assay for enzyme activities which remove adp-ribose linked to proteins at arginine was developed. the substrate analog, n alpha-dansyl-n omega-(1,n6-etheno-adp-ribosyl)arginine methyl ester, was used to assay the catalytic activities of dinitrogenase reductase activating glycohydrolase from rhodospirillum rubrum and nucleotide pyrophosphatase from crotalus adamanteus. the assay is based on the increase in fluorescent emission by ethenoadenine accompanying the enzyme-cat ... | 1987 | 3032020 |
| gyroxin, a toxin from the venom of crotalus durissus terrificus, is a thrombin-like enzyme. | we report a simple method for the isolation of gyroxin, a protein from the venom of the south american rattlesnake crotalus durissus terrificus. the intravenous injection of gyroxin into mice produces temporary episodes characterized by opisthotonos and rotations around the long axis of the animal. we found gyroxin to be a glycoprotein with thrombin-like and esterase activities. gyroxin loses its ability to produce the gyroxin syndrome, its thrombin-like activity and its esterase activity with h ... | 2011 | 3059581 |
| comparison of two methods for proteolytic enzyme detection in snake venom. | an acrylamide gel system containing fibrinogen was used to detect proteolytic enzymes in snake venoms. proteolytic activity was observed as a clear area on a blue background after electrophoresis and overnight incubation in tris buffer, prior to staining with coomassie blue. venoms from eastern and western diamondback and west coast mexican rattlesnakes, crotalus adamanteus, c. atrox and c. basiliscus basiliscus, respectively, and southern copperhead, agkistrodon contortrix contortrix, were anal ... | 1986 | 3087029 |
| 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 |
| 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 |
| 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 |
| antitumor action of crotalase, a defibrinogenating snake venom enzyme. | recent reports have shown that malignant cells release a variety of factors that modulate the tumor microenvironment. these factors, after release or shedding, work in concert to produce extravasation of fibrinogen from surrounding blood vessels with subsequent fibrin deposition around the tumor cells. this fibrin deposit could act to mask the tumor from the host's immune surveillance system. fibrin deposits have been observed by investigators in the vicinity of various malignant tumors of man a ... | 1986 | 3538422 |
| the action of various venoms on escherichia coli. | the antibacterial activity of honeybee venom (apis mellifera), three snake venoms (naja naja sputatrix, vipera russellii and crotalus adamanteus) and the polypeptide melittin was investigated against escherichia coli. minimum inhibitory concentration values, cell lysis and alterations in cell permeability were determined and action against e. coli was in the order: a. mellifera venom greater than melittin greater than n. naja sputatrix venom much greater than v. russellii venom greater than c. a ... | 1986 | 3542922 |
| synthesis of prodan-phosphatidylcholine, a new fluorescent probe, and its interactions with pancreatic and snake venom phospholipases a2. | a new fluorescent probe, prodan-pc, was synthesized by incubating thio-pc, a thiol ester analogue of phosphatidylcholine [1,2-bis(decanoylthio)-1,2-dideoxy-sn-glycero-3-phosphocholine], with acrylodan, a fluorescent thiol-reactive reagent [6-acryloyl-2-(dimethylamino)naphthalene], in the presence of phospholipase a2, which served to generate lysothio-pc in situ. prodan-pc (ppc) showed maximum absorption in ethanol at 370 nm. the fluorescence emission spectrum showed maximum emission at 530 nm in ... | 1987 | 3651404 |
| stereospecific analysis of fatty acid esters of chloropropanediol isolated from fresh goat milk. | the fatty acid esters of chloropropanediol isolated from goat milk fat in small quantities were subjected to a stereospecific analysis via phospholipase c and phosphocholine esters as intermediates. synthetic rac-1-chloro-2,3-dioleoyl-propanediol was prepared by standard methods and was used as a control. the stereospecific analyses were performed following a release of the fatty acids from the primary positions of each chloropropanediol diester with pancreatic lipase. the resulting x-1-chloro-2 ... | 1986 | 3724368 |
| 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 |
| distribution of high-density lipoprotein 2 and 3 constituents during in vitro phospholipid hydrolysis. | human high-density lipoproteins hdl2 (d = 1.068-1.125) and hdl3 (d = 1.125-1.210) doubly labelled with [3h]cholesterol/cholesteryl ester and with [acyl-14c]phosphatidylcholine were further incubated with phospholipases. highly purified phospholipase a2 from crotalus adamanteus allowed gradual degrees of lipolysis (30-90%) on both hdl2 and hdl3. moderate phospholipid hydrolyses were achieved using hepatic triacylglycerol lipase, partially purified from post-heparin plasma. moreover, the latter en ... | 1987 | 3803386 |
| two new inhibitors of phospholipase a2 produced by penicillium chermesinum. taxonomy, fermentation, isolation, structure determination and biological properties. | plastatin and the known fungal metabolite, luteosporin, have been isolated from fermentations of penicillium chermesinum as inhibitors of porcine pancreatic phospholipase a2 (pla2). structure 1 for plastatin was deduced from its spectroscopic properties. plastatin and luteosporin inhibited pancreatic pla2 competitively with ki values of 0.89 microm and 12.8 microm, respectively. pla2 preparations from naja naja and crotalus adamanteus were not significantly inhibited by plastatin and luteosporin ... | 1985 | 3839502 |
| purification and partial characterization of a high molecular weight metalloproteinase from the venom of crotalus adamanteus (eastern diamondback rattlesnake). | chromatography of crotalus adamanteus venom on cm-sepharose, cibacron blue-sepharose and phenyl-sepharose, followed by gel filtration on ultrogel aca 44, has resulted in the isolation in homogeneous condition of a metalloproteinase active on casein and hide powder azure. the proteinase has an alkaline isoelectric point, and the trivial name proteinase b ('basic proteinase') is suggested to distinguish it from previously characterized c. admanteus metalloproteinases. proteinase b is a single chai ... | 1985 | 3911494 |
| determination of the protein content of crystals formed by mastigocladus laminosus c-phycocyanin, chroomonas spec. phycocyanin-645 and modified human fibrinogen using an improved ficoll density gradient method. | we demonstrated for several protein crystals of known protein content that the simple ficoll density gradient method for crystal density determination as described by westbrook (1976) often leads to quite erroneous results. in particular, the apparent density of loosely packed crystals can show a tremendous change within the first minutes of measurement. in order to derive the correct protein content the apparent crystal density must be followed as a function of time and has to be extrapolated b ... | 1985 | 3924073 |
| aggregation studies on fluorescein-coupled cobra venom phospholipase a2. | phospholipase a2 from naja naja naja venom (indian cobra) undergoes a concentration-dependent aggregation, and at an assay concentration of 1 microgram ml-1, it exists as a monomer. however, there is some evidence that the enzyme is actually active as a dimer or higher order aggregate. previous attempts to determine the aggregation state of the enzyme under actual assay conditions were thwarted by experimental difficulties due in part to the low enzyme concentrations required. this aggregation h ... | 1985 | 3936540 |
| activation, aggregation, and product inhibition of cobra venom phospholipase a2 and comparison with other phospholipases. | the kinetics of phospholipid hydrolysis by cobra venom phospholipase a2 were examined and compared to those of phospholipase a2 from porcine pancreas, crotalus adamanteus (rattlesnake) venom, and bee venom. only the enzyme from naja naja naja (cobra) venom was found to be activated significantly by phosphorylcholine-containing compounds when hydrolyzing phosphatidylethanolamine. the cobra venom enzyme was also the only one in which these activators induced protein aggregation. the parallel speci ... | 1985 | 4030786 |
| biosynthetic incorporation of cis-parinaric acid into radioactive sn-3-phosphatidic acid. | isolated guinea pig liver microsomal membranes catalyzed the incorporation of naturally occurring cis-parinaric acid into sn-3-[u-14c]glycerophosphate. this resulted in the formation of sn-3-[14c](parinaroyl)phosphatidic acid, which was isolated by chelex-100 and deae-cellulose column chromatography and further purified by sephadex-g 25. the sn-3-[14c](parinaroyl)phosphatidic acid thus obtained exhibited absorption and fluorescence spectra substantially different from the cis-parinaric acid. dis ... | 1985 | 4034509 |
| d-dihexanoylphosphatidylcholine is not a pure competitive inhibitor of phospholipase a2 hydrolysis of l-dihexanoylphosphatidylcholine. | the inhibition of crotalus adamanteus phospholipase a2 hydrolysis of l-dihexanoylphosphatidylcholine by d-dihexanoylphosphatidylcholine was investigated with inhibitor and substrate in the monomeric concentration range. the results showed that the d-enantiomer acts as a partial (not pure) competitive inhibitor of the enzyme. these results suggest that an esi complex exists, in which hydrolysis of the substrate still occurs. thus, binding of the d-enantiomer to the enzyme decreases the affinity f ... | 2016 | 4042254 |
| crotalus adamanteus basic protein toxin: electron microscopic evaluation of myocardial damage. | 1973 | 4125228 | |
| a new acute phase protein elicited in mice by streptolysin o and other toxic or infectious agents. | a new acute phase plasma component has been found in mice exposed to certain toxic materials and pathogenic bacteria. the abnormal component, detected by immunodiffusion employing absorbed antiserum, was chiefly studied in plasma of streptolysin o-treated mice where it appears within 24 hours after intravenous administration of a sublethal dose of the toxin. the new factor is a protein having the electrophoretic mobility of a slow alpha2-globulin. it is devoid of lipid and separate from the stre ... | 1965 | 4158436 |
| thrombic enzyme from crotalus adamanteus. | 1970 | 4194151 | |
| hydrolysis of dinucleoside monophosphates containing arabinose in various internucleotide linkages by exonuclease from the venom of crotalus adamanteus. | 2014 | 4293396 | |
| purification of exonuclease (phosphodiesterase) from the venom of crotalus adamanteus. | 1974 | 4374207 | |
| a purified procoagulant enzyme from the venom of the eastern diamondback rattlesnake (crotalus adamanteus): in vivo and in vitro studies. | 1972 | 4623612 | |
| spectral perturbations of crotalus adamanteus phospholipase a 2 induced by divalent cation binding. | 1973 | 4734660 | |
| effects of chemical modification on the activity of crotalus adamanteus phospholipase a 2 . evidence for an essential amino group. | 1973 | 4734661 | |
| distribution and excretion of 3h-venoms of crotalus adamanteus, crotalusatrox, and agkistrodon piscivorus and 3h-serum of lampropeltis getulus in rats. | 1972 | 5058627 | |
| a kinetic study of the phospholipase a 2 (crotalus adamanteus) catalyzed hydrolysis of 1,2-dibutyryl-sn-glycero-3-phosphorylcholine. | 1972 | 5062536 | |
| purification and properties of a thrombin-like enzyme from the venom of crotalus adamanteus (eastern diamondback rattlesnake). | 1971 | 5132665 | |
| evidence that the phospholipase a 2 of crotalus adamanteus venom are dimers. | 1971 | 5168611 | |
| spectral peculiarities of the monomer-dimer transition of the phospholipases a 2 of crotalus adamanteus venom. | 1971 | 5168612 | |
| evidence for o-acyl cleavage during hydrolysis of 1,2-diacyl-sn-glycero-3-phosphorylcholine by the phospholipase a 2 of crotalus adamanteus venom. | 1971 | 5168779 | |
| diagnosis, symptoms, treatment and sequelae of envenomation by crotalus adamanteus and genus ancistrodon. | 1968 | 5646640 | |
| studies on phospholipase a. i. isolation and characterization of two enzymes from crotalus adamanteus venom. | 1969 | 5777339 | |
| venom neutralization by rattlesnake serum albumin. | the blood serum of the eastern diamond back rattlesnake (crotalus adamanteus) neutralizes lethal doses of c. adamanteus venom in mice. the protective capacity of the serum is associated with the serum albumin, rather than the immunoglobulin fraction of the blood. neither the serum nor its albumin fraction form precipitin bands on immunophoresis against venom. | 1969 | 5783711 |
| afibrinogenemia in man following the bite of a rattlesnake (crotalus adamanteus). | 1969 | 5822979 | |
| the diagnosis, symptoms, treatment and sequella of envenomation by crotalus adamanteus and genus agkistrodon. | 1966 | 6004039 | |
| on the reaction mechanism of crotalus adamanteus l-amino acid oxidase. | 1967 | 6067195 |