digestion of native collagen in the gut.the digestion and absorption of collagen, native and artificially cross-linked, has been examined in the rat and the gaboon viper, by feeding known quantities and measuring the hydroxy-proline content of the faeces and of the contents of the gut at different levels, and comparing with an unabsorbable marker (polyethylene glycol). incubation of collagen in vitro with pepsin at 37 degrees c at ph 1.5 followed by trypsin or chymotrypsin converted about 40% into dialysable material.1978631645
effect of bitis gabonica venom on the action potentials of guinea-pig heart. preliminary results.the effect exerted by different doses (50 to 500 mg/kg body weight, or 1 or perfusing solution) of the lyophilised secretion of b. gabonica venom glands has been studied -by intracellular electrodes- on the electrical activity of atrial and ventricular cells from guinea-pigs hearts, by using both open-chested animals and isolated preparations. noticeable changes in the features and duration of the repolarization phase of the action potentials precede the abolition (reversible, after washing) of ...19817295395
the effect of the venom of bitis gabonica on mesenteric and external iliac blood flow. - a preliminary study in the dog.the activity of the venom of bitis gabonica on mesenteric and external iliac circulation was investigated in four anaesthetized dogs. venom doses of 0.125, 0.25 and 0.50 mg/kg were injected intravenously with an interval of 30 minutes between two successive injections. following the first and the second dose, a transient fall of the resistance was observed in the mesenteric and especially in the external iliac vascular bed. then, mesenteric resistance returned to normal, whereas external iliac r ...19817295396
the effect of bitis gabonica (gaboon viper) snake venom on blood pressure, stroke volume and coronary circulation in the dog. 19817268798
acid-base, plasma lactate and glucose changes in the rabbit following administration of gaboon viper (bitis gabonica) venom.the acid-base and metabolic effects of bitis gabonica venom administered intravenously to the anaesthetised rabbit were studied. doubling doses of venom from 0.125 mg/kg to 1.0 mg/kg were used. venom caused progressive and significant increases in plasma glucose and plasma lactate levels although oxygen consumption only became significantly lower after the fourth dose. standard base excess (sbe) became significantly more negative after the third dose of venom and the fall in ph became significan ...19892601558
an antiplatelet peptide, gabonin, from bitis gabonica snake venom.interaction of fibrinogen with its receptors (glycoprotein iib/iiia complex) on platelet membranes leads to platelet aggregation. by means of gel filtration, cm-sephadex c-50, and reverse-phase hplc, an antiplatelet peptide, gabonin, was purified from the venom of bitis gabonica. the purified protein migrates as a 21,100-da polypeptide on sodium dodecyl sulfate-polyacrylamide gel electrophoresis under nonreducing conditions and as a 11,000-da peptide in the presence of beta-mercaptoethanol, indi ...19921524422
haemodynamic effect of the venom of bitis gabonica in the dog.intravenous injection of 0.125 mg/kg of venom of bitis gabonica in the anaesthetized dog produces an immediate but reversible decrease in total peripheral and coronary vascular resistance. stroke volume show a transient increase followed by an irreversible reduction. a second dose of 0.25 mg/kg produces the same effect on total peripheral and coronary vascular resistance, but furtherly reduces the stroke volume. a third dose of 0.50 mg/kg kills the animal after an extreme reduction of the stroke ...1979550868
the effect of gaboon viper venom on iron exchange in the rat.plasma iron turnover (pit) has been measured by means of 59fe in rats treated with the haemorrhagic venom of the gaboon viper (bitis gabonica). venom was administered on 3 occasions over a period of 9 days and after this time pit had fallen from 1045 micrograms/kg/day in normal animals to 449 micrograms/kg/day in envenomated animals. plasma iron half-life was markedly increased from 64.8 min to 417.6 min and this change was associated with a reduced uptake of 59fe by the liver. however, marrow a ...1979508589
[effects of bitis gabonica venom on heart dynamics and circulatory resistance in the rabbit].the effect on the cardiovascular system of intravenous injections of bitis gabonica venom was studied on 10 urethan anesthetized rabbits, by giving the venom in three successive doses of .125 (i dose), .250 (ii dose) and .500 (iii dose) mg/kg. in partial agreement with already reported data, the results of our experiments showed a powerful but transient fall of total peripheral resistance, which seemed to be relatively independent of doses. a cardiotoxic action leading to severe reduction of car ...19827082483
two incidents of venomous snakebite on juvenile blue and sykes monkeys (cercopithecus mitis stuhlmanni and c. m. albogularis).although rarely observed, predation is thought to be an important factor in the evolution of primate life histories and behavior. here i describe two incidents of snake predation on cercopithecus mitis guenons from kenya. the first case involved a juvenile blue monkey (cercopithecus mitis stuhlmanni) in the kakamega forest, which died following a bite by a gaboon viper (bitis gabonica gabonica). the snake's attempts to ingest its prey were unsuccessful. in the second incident, a juvenile sykes m ...200818704624
the effect of gaboon viper (bitis gabonica) venom on cardiac stroke work in the anaesthetized rabbit.the effect of bitis gabonica venom administered intravenously in the rabbit at the dose of 0.125 mg/kg (approximately 10% of ld50) has been studied. venom caused marked changes in cardiovascular parameters principally a precipitous but transient fall in total peripheral resistance and arterial blood pressure. furthermore in the period occurring between 5 and 30 min after the injection of venom, a transient increase in stroke work was observed as a result of the ejection of an increased stroke vo ...19846708738
distribution of low molecular weight platelet aggregation inhibitors from snake assay of platelet aggregation inhibitors measured by the turbidimeter using aggregometer pam 8c (mebanix) was performed after each crude snake venom (57 species) was subjected to ultrafiltration using millipore ufp 1 lgc. the snake venoms of viperidae (three species), elapidae (11 species), and hydrophiidae (two species) inhibited adp-induced rabbit platelet aggregation. in particular, six venoms of bitis gabonica, pseudocerastes persicus, dendroaspis angusticeps, d. polylepis, ophiophagus ha ...200717141819
the effect of bitis gabonica (gaboon viper) snake venom on external iliac and mesenteric arterial circulation in the dog.the effects of gaboon viper (bitis gabonica) venom on external iliac and mesenteric arterial blood flow and resistance were investigated in eight anaesthetized, close-chest dogs. venom doses in the range 0.125-0.5 mg/kg produced a profound fall in external iliac and mesenteric arterial resistance, which recovered to control values after 30 min. after a third dose of venom, the mean arterial blood pressure failed to recover and the animals died after a period of severe hypotension. external iliac ...19836845387
evidence for the presence of histamine in gaboon viper (bitis gabonica) venom.venom from b. gabonica produced a dose-dependent contraction of both isolated guinea-pig ileum and rabbit aortic strip preparations. the venom-induced contraction was not antagonised by pretreatment with atropine, phentolamine, methysergide or indomethacin, however, it was blocked by the prior addition of chlorpheniramine or cyproheptadine. upon exhaustive dialysis of the venom, the dialysate contracted both preparations, while the dialysed venom had no effect. paper and thin-layer chromatograph ...19863564064
antibacterial properties of kwazulu natal snake venoms.the objective was to ascertain whether local snake venoms have antibacterial properties. the venoms of the common night adder (causus rhombeatus), gaboon adder (bitis gabonica), puff adder (bitis arietans), black mamba (dendroaspis polylepis), eastern green mamba (dendroaspis augusticeps), forest cobra (naja melanoleuca), snouted cobra (naja annulifera) and mozambique spitting cobra (naja mossambica) were collected and, by gel diffusion, tested against the bacteria staphylococcus aureus, escheri ...200010775753
bitis gabonica venom. the amino acid sequence of phospholipase a. 19744833747
separation and partial characterization of a coagulant enzyme from bitis gabonica venom. 19744843744
the action of staphylococcal alpha toxin and the venom from bitis gabonica on rat stomach strip. 19664303887
keratin-lipid structural organization in the corneous layer of snake.the shed epidermis (molt) of snakes comprises four distinct layers. the upper two layers, here considered as beta-layer, contain essentially beta-keratin. the following layer, known as mesos-layer, is similar to the human stratum corneum, and is formed by thin cells surrounded by intercellular lipids. the latter layer mainly contains alpha-keratin. in this study, the molecular assemblies of proteins and lipids contained in these layers have been analyzed in the scale of two species of snakes, th ...200919280640
[the big vipers of africa of the genus bitis gray, 1842 and their venom. zoological, biochemical and clinical data].after the suggestion of the genus bitis gray, 1842 snakes, we studied in details three species, among the largest and most widespread ones: bitis arietans, bitis gabonica and bitis nasicornis. the main morphological characteristics and some of the zoological data presented may be very useful, as well as the clinical signs, for physicians to identify, the snake that bits a patient. thus, an adapted treatment can be undertaken. the biochemical composition of the venoms and their experimental toxic ...20061943640
accidental envenoming by a gaboon viper (bitis gabonica): the haemostatic disturbances observed and investigation of in vitro haemostatic properties of whole venom.we report the successful treatment of envenoming by the gaboon viper (bitis gabonica) and include results of in vitro investigations of the haemostatic properties of the whole venom. the patient was admitted to casualty soon after the bite with chest tightness, dizziness, nausea and swelling at the site of the bite and was treated immediately with polyspecific antivenom, hydrocortisone, chlorpheniramine and antibiotics. results of haemostatic investigations were essentially normal on admission b ...20048465400
evolutionary analysis of novel serine proteases in the venom gland transcriptome of bitis gabonica rhinoceros.serine proteases are major components of viper venom and target various stages of the blood coagulation system in victims and prey. a better understanding of the diversity of serine proteases and other enzymes present in snake venom will help to understand how the complexity of snake venom has evolved and will aid the development of novel therapeutics for treating snake bites.201121731776
fatty acid analyses may provide insight into the progression of starvation among squamate reptiles.fasting-induced changes in fatty acid composition have been reported to occur within the body lipids of several types of animals; however, little is known about the changes in fatty acid profiles exhibited by reptiles subjected to prolonged fasting. this study characterizes the fatty acid profiles of six reptile species subjected to sublethal periods of fasting lasting 0, 56, 112, and 168 days. analyses of fatty acid methyl esters (fames) conducted on the total body lipids of rattlesnakes (crota ...200818657629
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 ...19892629180
venom production in snake venom gland cells cultured in vitro.the venom gland cells from a ghanaian specimen of bitis gabonica were established in tissue culture for over seven months. during this time the cells maintained their original morphology and divided actively. tests for the synthesis of venom using an immuno peroxidase technique (on the cells) were strongly positive and tests for the secretion of venom into tissue culture medium using elisa suggested secreted venom levels of at least 200 ng/ml culture fluid. the b. gabonica specimen used for thes ...19892617542
isolation and characterisation of two haemorrhagic proteins (hta and htb) from the venom of bitis gabonica (gaboon viper).two distinct haemorrhagic proteinases, hta and htb, were isolated from the venom of bitis gabonica by gel filtration and ion-exchange chromatography with native mol. wts of 180,000 and 111,000, respectively. after reduction with dithiothreitol, smaller mol. wts of 77,600 and 69,200 were recorded for hta and htb, suggesting that under native conditions the haemorrhagins exist as dimeric molecules. both toxins possessed caseinolytic and collagenase activity although hta was 15-36 times more potent ...19958588213
efficacy of north american crotalid antivenom against the african viper bitis gabonica (gaboon viper).envenomations by exotic snakes occur from zoological collections and private individual collectors. antivenoms to these snakes may not be readily available. the objective of this study is to determine the efficacy of north american crotalid antivenin in treating mice envenomated with venom of the african viper bitis gabonica (gaboon viper). the subjects of the study were swiss webster mice weighing approximately 30 g. the study was conducted in the university research laboratory. b. gabonica ven ...201020224996
skin lipid structure controls water permeability in snake molts.the role of lipids in controlling water exchange is fundamentally a matter of molecular organization. in the present study we have observed that in snake molt the water permeability drastically varies among species living in different climates and habitats. the analysis of molts from four snake species: tiger snake, notechis scutatus, gabon viper, bitis gabonica, rattle snake, crotalus atrox, and grass snake, natrix natrix, revealed correlations between the molecular composition and the structur ...201424157843
cardiac performance in the rabbit as affected by the venom of bitis gabonica. (a preliminary report).the effect of the venom of bitis gabonica administered intravenously in the rabbit at the dose of 0.125 mg/kg has been compared with that produced by the same dose of the compound in the dog. in the rabbit the effect on total peripheral resistance, aortic blood pressure and stroke volume is less marked and shorter than in the dog. furthermore in a period included between 5 and 30 min after the injection, in the rabbit a transient increase of stroke work is observed as a result of the ejection of ...19836671038
infrared imaging in vipers: differential responses of crotaline and viperine snakes to paired thermal targets.pit vipers use infrared-sensitive pit organs to accurately target homeothermic prey even in the absence of visual cues. it has been suggested that other vipers, including large ambush predators of the genus bitis, also may use radiant infrared information for predatory targeting. we compared behavioral responses of pit vipers and snakes of the viperine genus bitis to paired targets of different temperatures (i.e. cool and warm balloons), some scented with rodent odors. the rates of tongue flicki ...200415302110
[biochemical variations of west african snake venoms].electrophoretic patterns of bitis gabonica, bitis nasicornis, bitis arietans venoms have shown specific and individual variations; neither physiological nor seasonal differences were noticed. immunoelectrophoretic study of naja melanoleuca and naja nigricollis individual venoms revealed a variation in neurotoxin concentration from one venom to another. deletion of some minor fractions is noticed in few venoms. the authors think it of major interest to work on individual venoms.20137285271
muscle extract of hedgehog, erinaceus europaeus, inhibits hemorrhagic activity of snake venoms.the antihemorrhagic activity of muscle extract of hedgehog, erinaceus europaeus, was tested on various snake venoms with hemorrhagic activity. the extract inhibited strongly hemorrhagic activity of venoms from bitis arietans, bothrops jararaca and vipera latastei gaditana, and remarkably that of venoms from agkistrodon halys blomhoffi, bitis gabonica rhinoceros, bitis nasicornis, bothrops atrox asper, crotalus horridus horridus and vipera berus. the antihemorrhagic activity against eight other s ...19947846699
the effects of gaboon viper (bitis gabonica) venom on the electrical and mechanical activity of the guinea-pig myocardium.the effects of bitis gabonica venom were tested on guinea-pig heart, using both langendorff preparations and isolated atrial strips or papillary muscles. in the self-paced whole heart, a single passage of 50 micrograms of venom per ml produced in sequence: irregularities of the a-v conduction and decrease of the contractile strength, progressive failure to relax and systolic arrest of the heart. pretreatment with atropine reduced but did not abolish these effects. venom recycled through the hear ...19863952764
new proline-rich oligopeptides from the venom of african adders: insights into the hypotensive effect of the venoms.the snakes from the bitis genus are some of the most medically important venomous snakes in sub saharan africa, however little is known about the composition and effects of these snake venom peptides. considering that the victims with bitis genus snakes have exacerbate hypotension and cardiovascular disorders, we investigated here the presence of angiotensin-converting enzyme modulators on four different species of venoms.201525688758
rhinocetin, a venom-derived integrin-specific antagonist inhibits collagen-induced platelet and endothelial cell functions.snaclecs are small non-enzymatic proteins present in viper venoms reported to modulate hemostasis of victims through effects on platelets, vascular endothelial, and smooth muscle cells. in this study, we have isolated and functionally characterized a snaclec that we named "rhinocetin" from the venom of west african gaboon viper, bitis gabonica rhinoceros. rhinocetin was shown to comprise α and β chains with the molecular masses of 13.5 and 13 kda, respectively. sequence and immunoblot analysis o ...201222689571
purification and functional characterisation of rhiminopeptidase a, a novel aminopeptidase from the venom of bitis gabonica rhinoceros.snake bite is a major neglected public health issue within poor communities living in the rural areas of several countries throughout the world. an estimated 2.5 million people are bitten by snakes each year and the cost and lack of efficacy of current anti-venom therapy, together with the lack of detailed knowledge about toxic components of venom and their modes of action, and the unavailability of treatments in rural areas mean that annually there are around 125,000 deaths worldwide. in order ...201020706583
the gaboon viper, bitis gabonica: hemorrhagic, metabolic, cardiovascular and clinical effects of the venom.the effects of bitis gabonica venom have been studied in several animal species, including the monkey, dog, rabbit, rat and guinea pig. further information has been provided by observations on the effects of snake bite in man. bitis gabonica venom exerts a number of cytotoxic and cardiovascular effects: cytotoxic effects include widespread hemorrhage, caused by the presence of two hemorrhagic proteins. these hemorrhagins bring about separation of vascular endothelial cells and extravasation of b ...19979275005
african adders: partial characterization of snake venoms from three bitis species of medical importance and their neutralization by experimental equine alarming number of fatal accidents involving snakes are annually reported in africa and most of the victims suffer from permanent local tissue damage and chronic disabilities. envenomation by snakes belonging to the genus bitis, viperidae family, are common in sub-saharan africa. the accidents are severe and the victims often have a poor prognosis due to the lack of effective specific therapies. in this study we have biochemically characterized venoms from three different species of bitis, i. ...201525643358
gaboon viper venom--a comparative study of the coagulant, proteolytic and toxic properties of four commercial dried preparations and freshly collected venom. 19751145641
preclinical assessment of the efficacy of a new antivenom (echitab-plus-icp) for the treatment of viper envenoming in sub-saharan africa.a preclinical assessment was performed on the neutralizing efficacy of a whole igg polyspecific antivenom (echitab-plus-icp), designed for the treatment of snakebite envenomings in nigeria. it was generated by immunizing horses with the venoms of echis ocellatus, bitis arietans and naja nigricollis, the most medically important species in nigeria. antivenom was tested against the venoms of e. ocellatus, echis leucogaster, echis pyramidum leakeyi, b. arietans, bitis gabonica, bitis rhinoceros and ...201019699756
snake venomics of bitis species reveals large intragenus venom toxin composition variation: application to taxonomy of congeneric taxa.the protein composition of the venoms of the west african gaboon viper (bitis gabonica rhinoceros), the rhinoceros viper (bitis nasicornis), and the horned puff adder (bitis caudalis) were analyzed by rp-hplc, n-terminal sequencing, sds-page, maldi-tof peptide mass fingerprinting, and cid-ms/ms. in line with previous proteomic and transcriptomic analyses showing that snake venom proteins belong to only a few major protein families, the venom proteomes of bitis gabonica rhinoceros, bitis nasicorn ...200717559253
gaboon viper (bitis gabonica) envenomation resulting from captive specimens--a review of five cases.five cases of illegitimate bite by captive specimens of the gaboon viper (bitis gabonica) snake have demonstrated the dangers of keeping exotic african snakes in captivity.200717357384
snake venomics of bitis gabonica gabonica. protein family composition, subunit organization of venom toxins, and characterization of dimeric disintegrins bitisgabonin-1 and bitisgabonin-2.the protein composition of the venom of the east african gaboon viper (bitis gabonica gabonica) was analyzed using rp-hplc, n-terminal sequencing, maldi-tof peptide mass fingerprinting, and cid-ms/ms. in total, 35 proteins of molecular masses in the range of 7-160 kda and belonging to 12 toxin families were identified. the most abundant proteins were serine proteinases (26.4%), zn2+-metalloproteinases (22.9%), c-type lectin-like proteins (14.3%), pla2s (11.4%), and bitiscystatin (9.8%). other pr ...200717203976
severe envenoming by a gaboon viper (bitis gabonica). 200111219193
inactivation of arginine esterase e-i of bitis gabonica venom by irreversible inhibitors including a water-soluble carbodiimide, a chloromethyl ketone and isatoic anhydride.1. esterase e-i from bitis gabonica was inactivated with irreversible inhibitors which included studies with a water-soluble carbodiimide, an affinity labelling peptide and a mechanism-based inactivator. 2. the reaction with 1-ethyl-3(3-dimethylaminopropyl)-carbodiimide was biphasic and the dominant part followed saturation kinetics. at ph 5.5 a rate constant of 0.4 min-1 for inactive enzyme formation was calculated and a dissociation constant (ki) of 0.2 m for the enzyme-inhibitor complex. 3. i ...19911786852
a steady-state kinetic analysis of the reaction between arginine esterase e-i from bitis gabonica venom and synthetic arginine substrates and the influence of ph, temperature and solvent deuterium isotope.1. using synthetic arginines as substrates, steady-state kinetic studies showed a deviation from michaelis-menten kinetics for esterase e-i purified from the venom of bitis gabonica. graphical analysis indicated a rate equation of at least a degree of 3:3. 2. ph variation of the kinetic parameters indicated the involvement of groups with pk values of approximately 7 and approximately 9 which had to be in the ionic form for activity. 3. solvent isotope studies suggested transition states where pr ...19911786851
acidotic effect of gaboon viper (bitis gabonica) venom in the urethane-anaesthetized rat.1. intravenous venom (4 mg/kg) caused a non-compensated metabolic acidosis. 2. bicarbonate concentration, base excess, standard base excess and ph all fell dramatically. 3. a respiratory impairment occurred characterized by pulmonary oedema and a fall in arterial po2. 4. acidosis occurred soon after venom when po2 was still normal, indicating that changes in tissue metabolism contributed to the acidosis independently of reduced oxygen availability.19911904833
comparison of the physiological effects in rabbits of gaboon viper (bitis gabonica) venoms from different sources.the cardiovascular, respiratory and metabolic effects of b. gabonica venoms obtained from specimens originating from ghana, togo, nigeria, uganda and tanzania were examined in anaesthetized rabbits. intravenous injection of all venoms (0.125-2.0 mg/kg) induced hypotension. nigeria venom was the least potent in this respect. following doses of all venoms there was a brief bradycardia and a transient increase in respiratory rate and depth. at high doses (greater than or equal to 1.0 mg/kg), all ve ...19911801317
stable isotopes may provide evidence for starvation in reptiles.previous studies have attempted to correlate stable isotope signatures of tissues with the nutritional condition of birds, mammals, fishes, and invertebrates. unfortunately, very little is known about the relationship between food limitation and the isotopic composition of reptiles. we examined the effects that starvation has on delta13c and delta15n signatures in the tissues (excreta, carcass, scales, and claws) of six, distantly related squamate reptiles (gaboon vipers, bitis gabonica; ball py ...200818613003
adenosine in the venoms from viperinae snakes of the genus bitis: identification and quantitation using lc/ms and ce/ms.snake venoms are rich sources of toxic proteins and small molecules. this study was directed at molecules of molecular mass below 1 kda. thirty different venoms, of either neurotoxic or haemorrhagic type, were fractionated using size-exclusion chromatography. only venoms of the puff adder (bitis arietans), gaboon viper (bitis gabonica), and rhinoceros viper (bitis nasicornis) exhibited large absorbance peaks at lambda(280 nm) in the total volume range of the chromatographic column indicating the ...200515935989
gaboon viper venom and its effects. 19724624819
artificial respiration and survival time in anaesthetized rat after injection of gaboon viper (bitis gabonica) venom. 19863521677
thrombin-like enzyme from the venom of bitis gabonica. purification, properties, and coagulant actions.gabonase, an enzyme which acts on fibrinogen and factor xiii in uniquely thrombin-like ways, was purified to electrophoretic homogeneity from the venom of bitis gabonica. on sodium dodecyl sulfate-polyacrylamide electrophoresis, the reduced protein behaved as a single chain with mr = 30,600. the enzyme contains 20.6% carbohydrate, no free sulfhydryl groups and hence, from amino acid analysis, five disulfide bonds. its extinction coefficient (e1%1cm) at 280 nm is 9.6. its pi is 5.3. gabonase has ...19863522580
the gaboon viper (bitis gabonica): its biology, venom components and toxinology.the gaboon viper has acquired an impressive reputation which is at least partly unfounded. this handsome animal with such striking features is undoubtedly docile which accounts for the very low incidence of bite amongst humans. there are only six detailed clinical reports on the effect of bite and these are summarized in the review. the viper does indeed produce prodigious amounts of venom, but the toxicity, weight for weight, is rather low compared to other poisonous snakes. venom extractions h ...19846395443
deviation from michaelis-menten kinetics for esterase e-ii from the venom of bitis gabonica, using synthetic arginine amides as substrates.steady state kinetic studies on the reaction between esterase e-ii from the venom of bitis gabonica and the fluorogenic substrates, n-alpha-benzoyl-l-phenylalanyl-l-valyl-l-arginine-4-methylcoumaryl-7-amide and n-alpha-benzoyl-l-arginine-4-methylcoumaryl-7-amide were found to deviate from michaelis-menten kinetics. analysis of algebraic graphs and application of non-linear regression allowed an empirical rate law to be selected. the results revealed a rate equation of at least third degree at ph ...19836658807
electrophoretic patterns of the venoms from a litter of bitis gabonica snakes. 19827080059
thrombin-like and fibrinolytic enzymes in the venoms from the gaboon viper (bitis gabonica), eastern cottonmouth moccasin (agkistrodon p. piscivorus) and southern copperhead (agkistrodon c. contortrix) snakes.crude venom from b. gabonica contained weak fibrinogen clotting activity but no visible fibrinolytic activity, whereas venoms from a. p. piscivorus and a. c. contortrix exhibited fibrinolytic activity (by fibrin plate assay) but no thrombin-like activity. these snake venoms were fractionated on sephadex g-100 with the following results. thrombin-like activity in b. gabonica venom was eluted in a single protein peak with a molecular weight of 40,000. agkistrodon p. piscivorus venom contained a si ...19827043785
a steady state analysis of ph and temperature effects on the action of an arginine esterase from the venom of the gabon adder, bitis gabonica, on synthetic arginine substrate.the influence of ph and temperature on the kinetic properties of esterase e-ii from bitis gabonica venom has been studied. the ph profiles for the hydrolysis of n alpha-benzoyl-l-arginine ethyl ester showed that a group with pk approximately 7 must be ionized for activity. measurement of n alpha-benzyl-l-arginine-p-nitroanilide hydrolysis reveals that the pk of the active site is significantly lowered (i.e. to approximately 6.3) in the enzyme-substrate complex. the temperature effect on the pk s ...19817216165
a kinetic analysis of the hydrolysis of synthetic arginine substrates by arginine esterases from the venom of the gabooon adder, bitis gabonica.the kinetics of arginine esterases e-i, e-ii and e-iii from the venom of bitis gabonica were investigated. with n alpha-benzoyl-l-arginine ethyl ester as substrate linear competitive inhibition versus l-arginine was observed while ethanol gave rise to s-parabolic i-linear noncompetitive inhibition. hydrolysis of n alpha-benzoyl-l-arginine-p-nitroanilide was noncompetitively inhibited by p-nitroaniline. both slopes and intercepts of double reciprocal plots were a linear function of inhibitor conc ...19806991386
separation of bitis gabonica (gaboon adder) venom arginine esterases into kinin-releasing, clotting and fibrinolytic factors. 197935857
influence of ph on the kinetic and spectral properties of phospholipase a2 from bitis gabonica (gaboon adder) snake venom. 197933472
an essential tryptophan in the active site of phospholipase a2 from the venom of bitis gabonica.the role of tryptophan in phospholipase a2 (ec from the venom of the gaboon viper, bitis gabonica, has been investigated. modification of the enzyme with n-bromosuccinimide and 2-nitrophenylsulfenylchloride showed that the two tryptophan residues in the enzyme, viz. trp-28 and trp-59, differ in reactivity towards the reagents. only trp-28 reacted with n-bromosuccinimide while a preferential reaction occurred between trp-59 and 2-nitrophenyl-sulfenylchloride. in each case it was found th ...1976952941
spectral properties of bitis gabonica venom phospholipase a2 in the presence of divalent metal ion, substrate and hydrolysis products. 19751874
histopathological and histochemical changes in skeletal muscles after bitis gabonica envenomation. 19751145640
naja melanoleuca (forest cobra) venom. the amino acid sequence of phospholipase a, fraction de-iii.reduced and s-carboxymethylated phospholipase a (fraction de-iii) from naja melanoleuca venom was digested with trypsin, chymotrypsin and thermolysin. the resulting peptides were purified by ion-exchange chromatography on deae-cellulose, gel filtration on sephadex g-25 or g-50 and chromatography and electrophoresis on paper. the amino acid sequences of the intact enzyme and the pur peptides were determined by the edman procedure, either through the use of the automatic sequencer or by manual man ...19751122291
purification of phospholipase a from bitis gabonica venom. 19744458119
bitis gabonica venom. a kinetic analysis of the hydrolysis by phospholipase a2 of 1,2-dipalmitoyl-sn-glycero-3-phosphorylcholine. 19744424082
[snake venom kallikreins: purification and properties of a kinin-liberating enzyme from the venom of the viper bitis gabonica]. 19695391611
effect of gaboon viper (bitis gabonica) venom on blood coagulation, platelets, and the fibrinolytic enzyme system.the action of the venom of the gaboon viper (bitis gabonica) on blood coagulation, platelets, and the fibrinolytic enzyme system was studied. the results confirm that the venom of bitis gabonica has a marked anticoagulant action in vitro. the venom appears to impair clot formation by a direct proteolytic action on fibrinogen, releasing soluble breakdown products.19695814736
purification and functional characterisation of rhinocerase, a novel serine protease from the venom of bitis gabonica rhinoceros.serine proteases are a major component of viper venoms and are thought to disrupt several distinct elements of the blood coagulation system of envenomed victims. a detailed understanding of the functions of these enzymes is important both for acquiring a fuller understanding of the pathology of envenoming and because these venom proteins have shown potential in treating blood coagulation disorders.201020300193
the effects of gaboon viper (bitis gabonica) venom on voltage-clamped single heart cells.the effects of crude b. gabonica venom on single ventricular myocytes from guinea-pig hearts were studied using the patch clamp technique in the 'whole cell' mode. irreversible effects on the membrane currents, which became prominent within 15 min of venom application, were: (1) a decrease in the time invariant current (associated with the inward rectifying k+ current), most clearly seen over a voltage range negative to the resting membrane potential; and (2) a decrease in the peak inward curren ...19882459807
management of a gaboon viper bite: a case report. 197942493
histidine and lysine residues and the activity of phospholipase a2 from the venom of bitis gabonica.chemical modification of phospholipase a2 (phosphatide 2-acyl-hydrolase, ec from the venom of gaboon adder (bitis gabonica) showed that histidine and lysine residues are essential for enzyme activity. treatment with p-bromophenacyl bromide or pyridoxal 5'-phosphate resulted in the specific covalent modification of one histidine or a total of one lysine residue per molecule of enzyme, respectively, with a concomitant loss of enzyme activity. competitive protection against modification an ...200018191
gaboon viper envenomation: an unexpected big-city emergency.we report a pediatric case of envenomation by an extremely rare nonindigenous snake. the pathophysiology of injury is reviewed, and suggestions for appropriate treatment are given.19892602202
bitis gabonica (gaboon viper) snake venom gland: toward a catalog for the full-length transcripts (cdna) and proteins.the venom gland of the snake bitis gabonica (gaboon viper) was used for the first time to construct a unidirectional cdna phage library followed by high-throughput sequencing and bioinformatic analysis. hundreds of cdnas were obtained and clustered into contigs. we found mostly novel full-length cdna coding for metalloproteases (p-ii and p-iii classes), lys49-phospholipase a2, serine proteases with essential mutations in the active site, kunitz protease inhibitors, several c-type lectins, bradyk ...015276202
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