Naja Naja Venom Research Articles

Cardiotoxin of the Indian cobra(Naja naja) is a pyrophosphatase

An inorganic pyrophosphatase has been purified to apparent homogeniety from Indian cobra(Naja naja) venom, with a ten-fold increase in specific activity. The enzyme activity is intrinsic to a protein fraction in the venom which is normally termed cardiotoxin, cobramine, cytotoxin and so on. The enzyme shows a lowK m (70 μI) and high heat stability. The enzyme was active against sodium pyrophosphate; it also hydrolyses a few mononucletides and sugar phosphates at much lower rates. The physiological significance of inorganic pyrophosphatase in venom is discussed.

Biochemical characterization of a toxin from indian cobra ( Naja naja naja) venom

A major toxic component was isolated from the venom of Indian cobra ( Naja naja naja) by ammonium sulfate fractional precipitation followed by carboxymethyl cellulose column chromatography and Sephadex gel filtration. This component constituted 2% of the venom and produced a block of neuromuscular transmission in nerve muscle preparations. Three other toxic fractions comprising 3% of the venom were also detected. The major toxic component was homogeneous on starch and polyacrylamide gel electrophoresis and on rechromatography on CM-cellulose. Its molecular weight was approximately 6300. This toxin contained 61 amino acid residues including 8 half-cystine residues whereas alanine, methionine and phenylalanine were totally absent. Its ld 50, as determined by i.p. injection in mice, was 0·2 mg per kg body weight. The fraction did not possess any enzymatic, hemolytic or hemagglutinin activities of crude venom but showed a close resemblance to the major neurotoxin of Formosan cobra venom.

The primary structure of toxin C from the venom of the Indian cobra (Naja naja).

The primary structure of toxin C, a neurotoxin isolated from Indian cobra (Naja naja) venom, was determined. Toxin C is a highly toxic polypeptide consisting of 71 amino acid residues (molecular weight 7800) crosslinked by five disulfide bridges. A high degree of homology is observed among the long-chain neurotoxins. Toxin C differs from toxin A only in having -Ala-28 and -Lys-49 in place of -Gly-28 and -Arg-49, and from toxin B in having -Ala-28, -Ile-32 and -Lys-49 in place of -Gly-28, -Ser-32 and -Arg-49 residues. The amino acid sequence of toxin C is the same as that of Naja naja siamensis neurotoxin 3.

Source of carbohydrate in a toxic protein from Indian cobra ( Naja naja naja) venom

The principal neurotoxin of Indian cobra venom has been investigated to locate the source of carbohydrate present in it. The data indicate that the neurotoxin is not a glycoprotein, but contaminated with extraneous carbohydrate particles which might have originated from the cellulose or dextran medium employed in the purification procedures.

Peripheral versus central action of a toxin from indian cobra ( Naja naja naja) venom

A homogeneous toxin (NT fraction) purified from Indian cobra venom produced (at 0·25–1·0 mg/kg) predominant respiratory paralysis prior to any effect on the contractions of tibialis anterior muscle (cats) and gastrocnemius muscle (rabbits). NT fraction produced no direct effects on cardiovascular system or nerve action potential. The preferential action of the toxin on the respiratory process, over the tibialis anterior muscle twitches, was well differentiated at lower doses of NT fraction. Recovery from the respiratory and peripheral muscle paralytic effects was observed in cats assisted with artificial ventilation, suggesting that the toxin could be removed from the neuromuscular receptor sites, possibly by metabolic degradation. Phrenic nerve discharges and diaphragm contractions were unaffected at a time when animals stopped spontaneous breathing. In contrast, the electrical activity of the intercostal muscles disappeared at a faster rate, concurrent with the respiratory impairment. It is concluded that the effect of NT fraction on respiration is of peripheral origin and is possibly related to paralysis of the muscles of respiration among which the intercostal muscles appear to be the most susceptible. The neurotoxin does not seem to exert any direct effect on central respiratory mechanisms.

A simple method for purification of cardiotoxin from indian cobra ( Naja naja naja) venom

A simple method for purification of cardiotoxin from indian cobra ( Naja naja naja) venom

Isolation and characterization of a noncytotoxic mast-cell activator from cobra venom

A protein has been isolated and partially purified from the venom ofNaja naja which causes the noncytolytic release of amines from rat peritoneal mast cells. This protein, termed CVA protein, has been demonstrated to have a molecular weight of 18,500 and sedimentation coefficient of approximately 2s. The activity of CVA protein is destroyed by treatment for 5 min at 100°C, but is not affected at 75°C for 30 min. The ability of CVA protein to initiate mast-cell degranulation has been demonstrated to require both cell energy and calcium. The temperature sensitivity and the cellular requirements distinguish the CVA protein from phospholipase A.

Cytocidal activity of cytotoxin from Indian cobra venom and its derivatives against experimental tumors: Iwaguchi, T., 1Takechi, M. and Hayashi, K., 2 (1) Cancer Institute, Tokyo, Japan and (2) Kyoto University, Kyoto, Japan

Cytocidal activity of cytotoxin from Indian cobra venom and its derivatives against experimental tumors: Iwaguchi, T., 1Takechi, M. and Hayashi, K., 2 (1) Cancer Institute, Tokyo, Japan and (2) Kyoto University, Kyoto, Japan

Role of cardiotoxin and phospholipase A in the blockade of nerve conduction and depolarization of skeletal muscle induced by cobra venom.

1. The effects of phospholipase A (PhA), cardiotoxin (CTX) and neurotoxin (cobrotoxin) isolated from Formosan cobra (Naja naja atra) venom on conduction of the rat phrenic nerve and membrane potential of the rat diaphragm were studied.2. Phospholipase A, lysolecithin and cobrotoxin were without effect on the axonal conduction. Cardiotoxin was the only active agent in cobra venom, but it was less potent than the crude venom.3. The blocking action of cardiotoxin was markedly accelerated by the simultaneous administration of phospholipase A. However, the minimum effective concentration of cardiotoxin (100 mug/ml), was not decreased by phospholipase A. Pretreatment of the nerve with phospholipase A, followed by washout, did not alter the activity of cardiotoxin.4. Cardiotoxin (3 mug/ml) completely depolarized the membrane of superficial muscle fibres within 60 min, being 3 times more potent than the crude venom. Phospholipase A, on the other hand, needed a dose 30 times higher and a prolonged period of incubation to induce depolarization of similar extent. Cobrotoxin was without effect on membrane potentials.5. CaCl(2) (10 mM) effectively antagonized the nerve blocking as well as the depolarizing effect of the crude venom, cardiotoxin or cardiotoxin plus phospholipase A. By contrast, the slow depolarizing effect of phospholipase A was enhanced by high concentrations of calcium.6. Cardiotoxic fractions of Indian cobra venom affected both nerve conduction and diaphragm membrane potential in exactly the same way as cardiotoxin. Toxin A of the same venom was without effect.7. It is concluded that the active agent in cobra venoms either on axonal conduction or on muscle membrane is cardiotoxin. The synergistic effect of phospholipase A on cardiotoxin appears to be due to acceleration rather than potentiation of its action. The mechanism of action of cardiotoxin and its synergism by phospholipase A are discussed.

Long-lasting convulsant effect on the cerebral cortex of Naja naja venom.

1. A neurotoxic fraction has been prepared from Indian cobra venom (Naja naja) by column chromatography on CM Sephadex.2. When assayed for lethality in mice, or for neuromuscular blocking potency in the rat phrenic nerve-diaphragm preparation, this fraction was 2.4-2.9 times as potent as whole venom.3. Application of either whole venom (0.5-1.0 mg/ml) or the neurotoxic fraction (0.25-1.0 mg/ml) to the exposed cerebral cortex of the rat led to the appearance in the somatosensory evoked potential of abnormal negative waves, resembling in amplitude and latency those produced by the cortical application of strychnine or curare.4. This effect differed from that produced by strychnine or curare in that after washing off the toxin the abnormal responses persisted for as long as the experiment continued (8-9 hours).

Isolation of three different neurotoxins from indian cobra ( Naja naja) venom and the relation of their action to phospholipase a

Six fractions of the venom of the Indian cobra (Naja naja) were separated by paper electrophoresis of which four (fractions 6, 3, 2 and 1) were toxic in anaesthetized cats or in mice, or in both species. Of the four toxic fractions only fraction 6 contained phospholipase ; it was toxic to cats but not to mice. Fraction 3 was toxic to cats and mice and fractions 1 and 2 were toxic to mice but not to cats. Thus three different neurotoxic fractions were separated. In the anaesthetized cat the intravenous injection of fraction 6 caused the same effect as the injection of whole or boiled venom, i.e., a diphasic circulatory shock—an initial rapid fall in arterial blood pressure followed after partial recovery by a delayed gradual fall—with depression of cerebral cortical activity. The central vasoregulating mechanisms were apparently not affected during the shock since records taken from the cervical sympathetic showed increased activity. Fraction 3 did not produce the initial fall in arterial blood pressure but only the delayed phase of shock. In mice, the toxic effects of an intraperitoneal injection of whole venom resulted in convulsions, excitement, motor impairment and respiratory arrest; the injection of fractions 1 and 2 resulted in apathy, motor depression and convulsions before death, and the injection of fraction 3 in excitement, convulsions, repeated laboured respiration, and curling of the tail.

ACTIONS OF WHOLE AND FRACTIONATED INDIAN COBRA (NAJA NAJA) VENOM ON SKELETAL MUSCLE

ACTIONS OF WHOLE AND FRACTIONATED INDIAN COBRA (<i>NAJA NAJA</i>) VENOM ON SKELETAL MUSCLE

Fractionation of Indian cobra venom by column chromatography: I. Dextran gels

Lyophilized Indian cobra venom ( Naja naja) was fractionated by gel filtration on columns of dextran polymers with three different degrees of cross-linkage. The eluants used were water, acetic and hydrochloric acid. The best resolution—five components—was obtained from the dextran gel with medium cross-linkage. Two of the components had toxic activity and were found to be heterogeneous by zone electrophoresis. Two of the nontoxic components appeared to contain nucleic acid. Several experimental parameters were tested; of these the ratio of gel volume to sample size was most critical. Highest yields and best resolution were obtained with minimal amounts of gel for a given amount of sample. This approach favored molecular-sieve action instead of adsorption. The use of mixed columns of two gels with different cross-linkage to utilize the selectivity in fractionation offered by each was not successful. Successive fractionations from the same column were not as reproducible as those from freshyl packed columns.

A comparative investigation into the antigenic properties of detoxicated Indian and African venoms and the cross action exerted by the respective antivenenes

The potency of samples of Indian Daboia (Russell's viper) and Naia tripudians (Indian cobra) venoms has been compared with that of African viperine and colubrine venoms. Strong solutions of both Indian venoms may be detoxicated and converted into anavenoms by the same methods evolved by us for treating African venoms. The anavenoms retain their antigenic properties as shown by the immunization of laboratory animals, but from the results obtained on a necessarily small number of animals it would appear that the antigenic value of the Indian cobra anavenom is not relatively as high as that of Cape cobra anavenom. The venoms of Daboia and Bitis arietans are so antigenically dissimilar that neither African not Indian concentrated antivenenes exert any appreciable neutralizing action on the heterologous venom. A comparable lack of action was observed when a sample of South American anti-rattlesnake serum was tested against puff adder venom. The colubrine venoms, Indian cobra and Cape cobra, appear to be very closely allied ; Indian concentrated antivenene exerts a moderate group action on Cape cobra and other African colubrine venoms, whilst concentrated African antivenene exerts an even more powerful neutralizing action against Indian cobra venom than it does against the Cape cobra venom from which it was produced. A final point of interest is the fact that antivenenes of a comparable cross potency, as far as colubrine venoms are concerned, may be produced on the one hand by the use of unmodified venoms and on the other by employing only formalized anavenoms ; this furnishes further evidence of the practical utility of the rapid method of producing African polyvalent antivenene of high potency, as successfully employed in our Serum Department during the past 3 years.

XIII. A contribution to the study of the action of indian cobra venom

At the suggestion of Sir Thomas Fraser, H. M. Secretary of State for India very kindly placed me on special duty for Snake Venom research in the Pharmacological Laboratory of the University of Edinburgh. Professor Fraser, under whose superintendence I was directed to work, suggested that I should carefully study the pharmacology of Indian Cobra venom, and the work herein set forth is the outcome of that suggestion. Professor Schäfer also very kindly placed his laboratory at my disposal, and both to him and to Sir Thomas Fraser I owe my most cordial acknowledgments for their unvarying kindness and for their very valuable and always ready assistance. Some of the earliest work done on the pharmacological action of Cobra venom was that by Lauder Brunton and Fayrer, published about thirty years ago. They considered that Cobra venom selected the cerebro-spinal nerve centres for its seat of action; it paralysed these, and in large doses it acted also on the ganglia of the heart, causing arrest of cardiac action. They laid little stress on the rôle played by circulatory failure, and in support of their views they quoted a number of experiments in which cardiac pulsations continued after the apparent death of the animal. In volume 22 they go on to discuss the subject still further. With the facts at their disposal they were unable to come to any definite conclusion as to the exact influence of the venom on the heart, but they thought that the heart’s arrest in systole, which they at times observed was due to “some action on the cardiac ganglia.” They drew attention to the great difference observed in the effect of venom according as it was applied to the surface or to the interior of the heart. In this connection they quote an experiment in which they perfused the frog-heart with a solution of Cobra venom, and obtained arrest of it in a position midway between systole and diastole. The strength of solution used is not stated and details are wanting, but the experiment is of great interest, as it is the only record I can find in any writer’s works of an attempt to perfuse an isolated part with Cobra venom. They thought the action was due to an influence on the cardiac ganglia. They found that in large doses Cobra venom destroyed the inhibitory power of the vagus, which it did not do in small doses. That the inhibitory branches of the vagus were sometimes affected they were confident, but they do not seem to have been able to differentiate clearly between a direct action of the venom on the vagal system, and the indirect effects brought about by means of interference with respiration. In dealing with the last-named subject, they clearly observed the paralysis of the phrenic nerve ends, and divided the responsibility for respiratory failure between this and a direct interference with the centre in the medulla oblongata.