Cobra Indian

The venoms of poisonous snakes contain (among other things) a class of enzymes known as phospholipases, enzymes that cause the breakdown of phospholipids. For example, the venoms of the eastern diamondback rattlesnake (Crotalus adamanteus) and the Indian cobra Naja naja) both contain phospholipase Ag, which catalyzes the hydrolysis of fatty acids at the C-2 position of glyc-erophospholipids. 

The phospholipid breakdown product of this reaction, lysoleeithin, acts as a detergent and dissolves the membranes of red blood cells, causing them to rupture. Indian cobras kill several thousand people each year. 

It is interesting to note that the first demonstration of tyrosinate fluorescence in a protein was made by Szabo et al.au> with two cytotoxins from the Indian cobra Naja naja. While exhibiting different relative amounts of the two emission bands, both toxins had fluorescence at 304 and 345 nm, with the 304-nm band being greatly reduced on excitation at 290 nm. Since these proteins have three tyrosine residues and no tryptophan, it was concluded that the 345-nm emission band was due to tyrosinate. Furthermore, tyrosinate appeared to be formed in the excited state from a hydrogen-bonded ground-state complex based on the absorption spectra. Szabo subsequently reexamined these peptide samples and found that they were contaminated with tryptophan (A. G. Szabo, personal communication). While Szabo s approach to the demonstration of tyrosinate fluorescence was correct based on his initial data, his subsequent finding exemplifies an important caution if tyrosinate emission is suspected, every effort must be made to demonstrate the... 

The discovery that the toxins of Elapid snakes bind almost irreversibly to the AChR also facilitated the isolation and study of this receptor. The structure of these venoms has been elucidated those most widely used experimentally are the a-bungarotoxin (BTX) of the Indian cobra and the toxin of the Siamese cobra. These compounds are peptides containing from 61 to 74 amino acids, five disulfide bridges, and a high proportion of basic arginine and lysine residues, often in close proximity. Venoms are toxic because they block cholinergic neurotransmission by binding to the receptor. 

T6. The Action of Phospholipases The venom of the Eastern diamondback rattler and the Indian cobra contains phospholipase A2, which catalyzes the hydrolysis of fatty acids at the C-2 position of glycerophospholipids. The phospholipid breakdown product of this reaction is lysolecithin (lecithin is phosphatidylcholine). At high concentrations, this and other lysophospholipids act as detergents, dissolving the membranes of erythrocytes and lysing the cells. Extensive hemolysis may be life-threatening. 

Certain snake toxins have been found to bind irreversibly to the acetylcholine receptor, thus blocking cholinergic transmissions. These include toxins such as alpha-bungarotoxin from the Indian cobra. The toxin is a polypeptide containing 70 amino acids which cross-links the alpha and beta subunits of the cholinergic receptor (see Section 11.14.). 

Not only the Kraits produce a-neurotoxins. The Indian Cobra Cobra naja naja) also utilises one of fhe mosf pofenf of all fhe snake toxins, cobratoxin, which is also an a-neurotoxin. Cobratoxin is phenomenally toxic only 4.5 mg is needed to kill a human. In fact, a single Cobra can produce sufficient toxin to kill ten men. The Sea Kraits (e.g. Laticauda semifasciata from Malaysia) are the most toxic of all snakes they produce erabutoxin which is an a-neurotoxin of unbelievable potency, but fortunately, as discussed earlier, they have small jaws, which makes it difficult for them to bite a human. 

Indian cobra venom Naja naja (Note A king cobra has enough venom to kill an elephant.)... 

The venoms of certain snakes contain enzymes called phospholipases that catalyze the hydrolysis of carboxylic ester bonds of phospholipids. The venom of the eastern diamondback rattlesnake (Crotalus adaman-teus) and that of the Indian cobra (Naja naja) both... 

Indian cobras kill several thousand people each year. 

The venom of some poisonous snakes contains a phospholipase, an enzyme that hydrolyzes an ester group of a phosphoglyceride. For example, both the eastern diamondback rattlesnake and the Indian cobra contain a phospholipase that hydrolyzes an ester bond of cephalins, which causes the membranes of red blood cells to rupture. 

Snake venom is produced by the modified saliva glands of poisonous snakes. When a snake bites, venom is ejected through the fang of the snake. The venom of the eastern dia-mondback rattlesnake and the Indian cobra contains phospholipases, which are enzymes that catalyze the hydrolysis of the fatty acid on the center carbon of glycerophospholipids in the red blood cells. The resulting product, called lysophospholipid, causes breakdown of the red blood cell membranes. This makes them permeable to water, which causes hemolysis of the red blood cells. 

Thus, the original work established that the enzyme from Naja naja (Indian cobra) venom was a phospholipase A2. The situation then turned full circle by the discovery of another enzyme in rat liver which was a phospholipase Aj. 

G. Eggertsen, P. Lind, and J. Sjdquist Molecular characterization of the complement activating protein in the venom of the Indian cobra Naja n. siamensis). 1981. Mol. Immunol. 18, 125-133. 

Amino acid sequences of mammalian NGFs have already been determined. However, until the nucleotide sequence of NGF cDNA cloned from the venom gland of the Thailand cobra Naja naja siamensis was determined (Selby et al, 1987), a tentative sequence of the Indian cobra Naja naja NGF (Hogue-Angeletti, et al, 1976), based on the partial sequence and amino acid compositions of the peptides which had been obtained by enzymatic digestion of the NGF, was the only information on the amino acid sequences of snake NGF available so far. 

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