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At least 163 records · Page 9Linked to original sources
PubMed1985

Allergens in Hymenoptera venom XIV: IgE binding activities of venom proteins from three species of vespids.

RAST disks were prepared with purified proteins from the venoms of Vespula squamosa, Dolichovespula maculata, and Polistes exclamans and tested against a panel of sera obtained from patients allergic to each of the venoms. By the use of several criteria, IgE binding was strongest to antigen 5 of V. squamosa and phospholipase of P. exclamans. Hyaluronidase from Polistes had little IgE binding activity. All five proteins tested from D. maculata bound IgE antibodies strongly. Linear correlation analysis suggested that all of the proteins were distinct allergens in each of the venoms. A variety of patterns of response were observed for individual sera with each of the venoms.

Allergens↗
PubMed1987

Allergens in Hymenoptera venom. XVII. Allergenic components of Solenopsis invicta (imported fire ant) venom.

Pure venom from Solenopsis invicta was collected by having the insects sting into a capillary tube. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) demonstrated that three major protein bands were present in the venom. A prototype commercial extract was compared and found to contain the three major venom proteins and additional components as well as high potency and specificity by RAST. Immunoblot studies were performed with sera from allergic individuals with blots prepared from denatured SDS-PAGE gels and from two types of nondenaturing gels. The nondenaturing systems demonstrated the presence of two major allergens and three other allergens, each reacting with a third of the sera. Three of the allergens detected in SDS-PAGE blots were of identical mobility to the three major proteins in the pure venom sample. IgE binding to the SDS-PAGE blots was significantly less than that to nondenaturing blots, suggesting that much of the allergenic activity is conformation dependent.

Allergens↗
PubMed1988

Allergens in Hymenoptera venom. XX. Isolation of four allergens from imported fire ant (Solenopsis invicta) venom.

Commercial Solenopsis invicta (Sol i) venom was fractionated by gel filtration and high-performance cation exchange chromatography. Four proteins were isolated and purified to homogeneity. The four proteins were tested with a panel of sera from patients allergic to fire ant venom; all proteins had significant allergenic activity. These proteins corresponded to four of the bands we previously reported to be allergenic by immunoblot analysis. Sol i I has an apparent molecular weight of 37,000 daltons and yields bands of 18,000, 16,500 and 14,000 daltons in sodium dodecyl sulfate-polyacrylamide gel electrophoresis; cation-exchange chromatography indicates that there are three charge forms. Sol i II has a native molecular weight of 28,000 daltons and appears to be easily cleaved into half molecules; it is a phospholipase structurally unlike either bee or wasp phopholipases. Sol i III has a native and denatured molecular weight of 26,000 daltons. Sol i IV has an apparent native molecular weight of 20,000 daltons and gives a single chain of 15,000 daltons in sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Sol i II and III are the major proteins in the venom; there are only small amounts of Sol i I and IV. All are significant allergens, and patients are found who react most strongly with each. Regression analysis of RAST data with highly purified allergens indicated that the IgE responses to the allergens were not related to each other. Amino acid compositions indicated that the four allergens were distinct and that the allergens were structurally different from each other. Four proteins identical to Sol i I to IV were isolated from hand-milked pure venom.

Adult↗
PubMed2006

Molecular dissection of venom from Chinese scorpion Mesobuthus martensii: identification and characterization of four novel disulfide-bridged venom peptides.

Scorpion venom is composed of a large repertoire of biologically active polypeptides. However, most of these peptides remain to be identified and characterized. In this paper, we report the identification and characterization of four novel disulfide-bridged venom peptides (named BmKBTx, BmKITx, BmKKx1 and BmKKx2, respectively) from the Chinese scorpion, Mesobuthus martensii (also named Buthus martensii Karsch). BmKBTx is composed of 58 amino acid residues and cross-linked by three disulfide bridges. The sequence of BmKBTx shows some similarities to that of the toxin, birtoxin, and its analogs. It is likely that BmKBTx is a beta-toxin active on Na+ channels, which is toxic to either insects or mammals. BmKITx is composed of 71 amino acid residues with four disulfide bridges. It is the longest venom peptide identified from M. martensii so far. BmKITx shows little sequence identity with scorpion alpha-toxins toxic to insects. It is likely that BmKITx is a new type of Na+ -channel specific toxin active on both insects and mammals. BmKKx1 contains 38 amino acid residues cross-linked by three disulfide bridges and shows 84% sequence identity with BmTx3, an inhibitor of A-type K+ channel and HERG currents. BmKKx1 has been classified as alpha-KTx-15.8. BmKKx2 is composed of 36 residues and stabilized by three disulfide bridges. BmKKx2 is a new member of the gamma-K+ -channel toxin subfamily (classified as gamma-KTx 2.2). The venoms of scorpions thus continue to provide novel toxins with potential novel actions on targets.

Amino Acid Sequence↗
PubMed1992

Effect of diacylglycerols on the activity of cobra venom, bee venom, and pig pancreatic phospholipases A2.

The effects of a series of diacylglycerols (DAGs) with varying acyl chain lengths and degree of unsaturation on the activity of cobra venom, bee venom, and pig pancreatic phospholipases A2 (PL-A2S) were studied using two lipid substrates: dipalmitoylphosphatidylcholine (DPPC) or bovine liver phosphatidylcholine (BL-PC). The activities of the phospholipases critically depended on the chain length and degree of unsaturation of the added DAGs and on the chemical composition of the substrate. The effects of DAGs on cobra or bee venom PL-A2S were similar, but significantly different from the pig pancreatic PL-A2. The data, taken together with our previous NMR studies on physicochemical effects of these DAGs on lipid bilayer structure [De Boeck, H., & Zidovetzki, R. (1989) Biochemistry 28, 7439; (1992) Biochemistry 31, 623], allowed detailed correlation of the type of a bilayer perturbation induced by DAG with the activation or inhibition of the phospholipase on the same system. In general, the activation of the phospholipases correlated with the DAG-induced defects of the lipid bilayer structure. The results, however, argue against general designation of DAGs as "activators" or "inhibitors" of PL-A2S. Thus, for example, diolein activated phospholipases with the BL-PC lipid substrate, but inhibited them with the DPPC substrate. Dihexanoylglycerol and dioctanoylglycerol inhibited pig pancreatic PL-A2 with both lipid substrates and inhibited cobra or been venom PL-A2 with the DPPC substrate, but activated the latter two enzymes with the BL-PC substrate. Longer-chain DAGs (C greater than 12), which induce lateral phase separation of the bilayers into the regions of different fluidities, activated all PL-A2S with both lipid substrates.(ABSTRACT TRUNCATED AT 250 WORDS)

1,2-Dipalmitoylphosphatidylcholine↗
PubMed1974

Characterization of ribonucleic acids from the venom glands of Crotalus durissus terrifucus (Ophidia, Reptilia) after manual extraction of the venom. Studies on template activity and base composition.

RNA synthesis in the venom glands of Crotalus durissus terrificus was stimulated by the manual extraction of the venom (milking). RNA was extracted from venom glands activated by milking and fractionated by centrifugation through sucrose density gradients. Template activity for protein synthesis and base composition of the RNA fractions were studied. RNA fractions that sediment between 18S and 4S had the highest template activity. The base composition analysis indicated that the 28S and 18S rRNA have a C+G content of 65.4 and 58% respectively. The ;melting' temperature (T(m)) of DNA in 0.15m-NaCl-0.015m-trisodium citrate, pH7.0, was 85 degrees C, corresponding to a C+G content of 38%. The base ratio of the RNA fractions that showed a high template activity was intermediate between that of rRNA and homologous DNA. The possible role of these fractions in the synthesis of the two main toxins (crotoxin and crotamine) of the South American rattlesnake's venom is discussed.

Animals↗
PubMed1994

Preferential antagonism of the interactions of the integrin alpha IIb beta 3 with immobilized glycoprotein ligands by snake-venom RGD (Arg-Gly-Asp) proteins. Evidence supporting a functional role for the amino acid residues flanking the tripeptide RGD in determining the inhibitory properties of snake-venom RGD proteins.

The inhibitory properties of a panel of snake-venom-derived RGD (Arg-Gly-Asp) proteins, including the disintegrins kistrin, elegantin and albolabrin, and the neurotoxin homologue dendroaspin, were investigated in a platelet-adhesion assay using three immobilized ligands of the glycoprotein IIb-IIIa complex (alpha IIb beta 3), namely fibrinogen, fibronectin and von Willebrand factor (vWF). The snake-venom proteins preferentially inhibited the adhesion of ADP-treated platelets to one or more of the immobilized ligands. Kistrin and dendroaspin exhibited similar inhibitory characteristics, abrogating platelet adhesion to fibrinogen and vWF at nanomolar concentrations, but poorly inhibiting adhesion to fibronectin. Kistrin and dendroaspin share little overall amino-acid-sequence identity, but a considerable level of sequence similarity exists around the RGD tripeptide. Synthetic cyclic peptides corresponding to these regions of kistrin and dendroaspin inhibited platelet adhesion to both fibrinogen and fibronectin with approximately equal potency, but were 100-fold weaker antagonists of the interactions of the alpha IIb beta 3 complex with fibrinogen than their parent proteins. The disintegrins elegantin and albolabrin, which share approx. 60% overall amino-acid-sequence similarity with kistrin but have different residues around the RGD tripeptide, exhibited different antagonistic preferences. Elegantin inhibited platelet adhesion to immobilized vWF and fibronectin, but was significantly less effective at disrupting adhesion to fibrinogen. Albolabrin selectively inhibited platelet adhesion to immobilized vWF and was less effective with fibrinogen and fibronectin as adhesive ligands. In contrast with the behaviour of these venom proteins, the adhesion of ADP-treated platelets to immobilized fibrinogen, fibronectin and vWF was inhibited non-selectively by a range of monoclonal antibodies with specificity for the alpha IIb beta 3 complex. These observations, therefore, define antagonistic preferences in this panel of venom proteins towards the interactions of the alpha IIb beta 3 complex with three immobilized glycoprotein ligands.

Amino Acid Sequence↗
PubMed1981

Von Willebrand syndrome induced by a Bothrops venom factor: bioassay for venom coagglutinin.

Hereditary deficiency of the macromolecular Factor VIII complex results in classic von Willebrand disease in man and animals, a bleeder state characterized by loss of the multiple biologic activities associated with the Factor VIII complex, including the platelet-aggregating von Willebrand factor. The bleeding time is also long. Venom coagglutinin, a Bothrops factor that causes platelet aggregation in vitro, depletes the plasma of its von Willebrand factor. The rate of platelet aggregation is a function of the amount of the coagglutinin present. Based on this observation, a sensitive and quantitative assay for the venom coagglutinin was developed. We administered the purified Bothrops factor to normal pigs and dogs and induced a von Willebrand syndrome similar to the inherited disease. The plasma von Willebrand factor was severely depleted; the antihemophilic factor and the Factor VIII-related antigen were not depleted as much. The bleeding time was normal. During the induction phase of the syndrome, transient thrombocytopenia with a long bleeding time occurred. The pig was less sensitive than the dog to the effect of coagglutinin. The severity of the syndrome is determined by the amount of venom coagglutinin administered. It is suggested that the syndrome could be induced in any mammalian species because the plasma of all mammals tested in vitro is sensitive to the venom factor. This model provides another avenue for the study of the heterogeneity of the Factor VIII complex and the pathophysiology of its components.

Animals↗
PubMed1981

Allergens in hymenoptera venom. VII. Species specific reactivity to yellow jacket venoms.

Venom from three species of yellow jacket, Vespula maculifrons, V. squamosa and Vespa crabro, was tested in direct and inhibition of RAST with a panel of 39 sera from three regions of the U.S. V. squamosa venom was found to be missing at least one allergen present in V. maculifrons. Patterns of reactivity were highly correlated with geography; reactivity with V. squamosa correlated with distribution of the species. Sera fron California recognized Vespa crabro; however, the insect is not found west of Indiana. This suggests that there are also some differences in the venom from the western species, V. pennsylvanica. No correlations were found with reactivity to hornet, wasp or bee venoms.

Allergens↗
PubMed1995

The molecular cloning of a phospholipase A2 from Bothrops jararacussu snake venom: evolution of venom group II phospholipase A2's may imply gene duplications.

The sequence coding for a snake venom phospholipase A2 (PLA2), BJUPLA2, has been cloned from a Bothrops jararacussu venom gland cDNA library. The cDNA sequence predicts a precursor containing a 16-residue signal peptide followed by a molecule of 122 amino acid residues with a strong sequence similarity to group II snake venom PLA2's. A striking feature of the cDNA is the high sequence conservation of the 5' and 3' untranslated regions in cDNAs coding for PLA2's from a number of viper species. The greatest sequence variation was observed between the regions coding for the mature proteins, with most substitutions occurring in nonsynonymous sites. The phylogenetic tree constructed by alignment of the amino acid sequence of BJUPLA2 with group II PLA2's in general groups them according to current taxonomical divisions and/or functional activity. It also suggests that gene duplications may have occurred at a number of different points during the evolution of snake venom group II PLA2's.

Amino Acid Sequence↗
PubMed1997

[Standardized rapid hyposensitization with purified hymenoptera venom in wasp venom allergy. Prospective study of development of tolerance and side-effect profile].

In Germany, insect allergies cause about 10-40 death per year. Starting a specific immunotherapy (SIT) and its maintenance may be lifesaving for the allergic patients. Performing a prospective study, we exactly documented effects and side effects during the induction phase of SIT using a purified aqueous yellow jacket venom preparation in 20 patients allergic to yellow jacket venom (clinical degree II-IV). Indication for the therapy was defined individually for each patient and was based on a score incorporating the following criteria: a) clinical symptoms, b) in-vivo- and in-vitro testing, c) risk of re-sting. SIT was started under inpatient conditions following a standardized 8 day protocol. At the end of the induction phase all patients tolerated the maintenance dose of 100 micrograms of yellow jacket venom without complications even though all showed local side effects (threshold doses 0.01-10 micrograms, median value 0.2 microgram). 40% of all patients showed subjective side effects (median value of threshold dose 30 micrograms, range 0.2-60 micrograms) and 30% showed objective side effects (median value of threshold dose 55 micrograms, range 20-80 micrograms); however, all side effects were clinically mild. When objective systemic side effects were seen, the cumulative daily dose was 39-210 micrograms (median value 135 micrograms), exceeding 100 micrograms in 83% of patients. Our prospective study confirmed that the chosen protocol for SIT is effective in inducing tolerance to the venom preparation. However, using a purified aqueous yellow jacket preparation did not result in reduction of side effects.

Adult↗
PubMed1978

Chemical and functional homology of myotoxin a from prairie rattlesnake venom and crotamine from South American rattlesnake venom.

Myonecrosis is a serious result of rattlesnake bite and constitutes a persistent clinical problem. In the current study we have isolated crotamine from the venom of Crotalus durissus terrificus to test its ability to cause structural damage to skeletal muscle, and to make direct chemical comparisons with Myotoxin a, a myotoxic polypeptide we recently isolated from prairie rattlesnake (Crotalus viridis viridis) venom. Disc gel electrophoresis, isoelectric focusing, circular dichroic spectroscopy, and amino acid analysis, all indicated a high degree of chemical similarity. Light microscope histology revealed that crotamine caused vacuolizationof skeletal muscle fibers, qualitatively the same as the vacuolization caused by Myotoxin a. The ability of these two basic snake venom polypeptides to cause structural damage to skeletal muscle fibers has significant implications toward more complete understanding of the cause of snake venom-induced myonecrosis.

Amino Acids↗
PubMed1993

A comparative study of the biological properties of venoms from juvenile and adult inland taipan (Oxyuranus microlepidotus) snake venoms.

The biological properties of adult and juvenile inland taipan (Oxyuranus microlepidotus) snake venoms were examined. The enzymatic activities, intravenous median lethal dose and procoagulant activity of the juvenile venom samples were not significantly different from those of the adult venom samples. Also, the juvenile and adult venoms exhibited similar electrophoretic patterns, indicating that they possessed similar protein composition.

Aging↗
PubMed1993

Immunity to jellyfish venoms: suppression of venom-induced immune responses in ultraviolet B-irradiated mice.

Lymph node and spleen cells from mice immunized with sea nettle (Chrysaora quinquecirrha) venom exhibited a proliferative response after exposure to the homologous antigen or that of a related jellyfish, Physalia (Portuguese man-o'-war). Native venom was a more effective stimulant than heated, non-lethal venom. Ultraviolet light treatments administered to the skin either before or after venom sensitization suppressed the proliferative response of these internal immune cells.

Animals↗
PubMed1977

Allergens in bee venom. III. Identification of allergen B of bee venom as an acid phosphatase.

Allergen B previously isolated from honeybee venom and shown to be a mildly acidic protein consisting of polymers of a chain of 49,000 d is shown to have acid phosphatase activity. Allergen B is homogeneous by several criteria. No acid phosphatase, alkaline phosphatase, or esterase activity was found in any other allergen or fraction of bee venom. Acid phosphatase activity was also found in yellow jacket venom and extracts of venom sacs from bumblebees and paper wasps.

Acid Phosphatase↗
PubMed1989

Further observations of stopping venom immunotherapy: comparison of patients stopped because of a fall in serum venom-specific IgE to insignificant levels with patients stopped prematurely by self-choice.

This study extends our experience applying the criterion of a fall in serum venom-specific IgE (RAST) to insignificant levels as an indication to stop venom immunotherapy (VIT) and compares the follow-up results with the results of re-stings in patients who stopped VIT "prematurely" by self-choice. All patients in both groups had a history of venom anaphylaxis, most with cardiovascular and/or respiratory symptoms and initial elevated serum venom-specific IgE; all patients received VIT. The groups were closely matched for age, sex, nature of initial sting reaction, and insect identification. In the group with low-level RAST titers, the duration of VIT was 6 months to 5 years (mean 2 1/2 years). Re-stings occurred from 1 month to 7 years (mean 2.2 years) after cessation of therapy. There were 75 re-stings in 41 patients with four systemic reactions (10% per patient and 5% per sting). All four reacting patients had tolerated several stings during cessation of VIT before the re-sting systemic reaction; two patients had subsequent stings with no reaction. In the group of patients who stopped VIT for other reasons, the duration of VIT was 5 months to 4 years (mean 1.8 years). Re-stings occurred from 4 months to 6 years (mean 2.1 years) after stopping therapy. There were 74 re-stings in 38 patients with seven systemic reactions in four patients (9.5% per patient and 10.5% per sting). Two of the reacting patients had tolerated stings before the re-sting reaction.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

A comparative study on the biological properties of venoms from juvenile and adult common tiger snake (Notechis scutatus) venoms.

1. The biological properties of venoms from juvenile and adult common tiger snakes (Notechis scutatus) were compared. 2. The lethality, procoagulant activity and enzymatic activities of the juvenile venom were not substantially different from those of the adult venom. 3. Electrophoretic studies, however, indicated some minor differences in the protein composition of the juvenile and adult venoms.

Aging↗
PubMed2005

Amino acid sequence of a basic aspartate-49-phospholipase A2 from Trimeresurus flavoviridis venom and phylogenetic analysis of Crotalinae venom phospholipases A2.

Trimeresurus flavoviridis snakes inhabit the southwestern islands of Japan: Amami-Oshima, Tokunoshima and Okinawa. A phospholipase A2 (PLA2) of basic nature (pI 8.5) was isolated from the venom of Amami-Oshima T. flavoviridis. Its amino acid sequence determined by the ordinary procedures was completely in accord with that predicted from the nucleotide sequence of the cDNA previously cloned from Amami-Oshima T. flavoviridis venom gland, which was named PLA-B'. It consists of 122 amino acid residues and has aspartate at position 49. It induced edema in a mouse footpad assay and caused necrosis in mouse skeletal muscles. PLA-B' is similar in sequence to PLA-B (Tokunoshima) and PL-Y (Okinawa), both basic [Asp49]PLA2s, with a few amino acid substitutions, indicating occurrence of interisland mutation. Although PLA2s of Crotalinae subfamily were phylogenetically classified into four types, PLA2 (acidic or neutral [Asp49]PLA2) type, basic [Asp49]PLA2 type, neurotoxic [Asp49]PLA2 type and [Lys49]PLA2 type, it was ascertained that PLA2s of PLA2 type and [Lys49]PLA2 type are most essential as toxic components for Crotalinae snake venoms and that basic [Asp49]PLA2-type PLA2s are uniquely contained only in the venoms of T. flavoviridis species. Prediction of physiological activities of some PLA2s was made based on their location in the phylogenetic tree. Relationship of divergence of PLA2s via accelerated evolution followed by less rapid mutation and physiological activities was discussed.

Amino Acid Sequence↗