Disease relevance of Bungarus

• These observations confirm the importance of neurotoxic symptoms following bites by these species but also suggest a contributory role of generalized rhabdomyolysis in krait victims and emphasize the problem of severe local tissue necrosis in cobra victims [1].
• The drug 3,4-diaminopyridine (DAP) is effective in other presynaptic paralytic conditions and was therefore tried in anaesthetized rabbits with respiratory paralysis induced by krait (Bungarus fasciatus) venom [2].
• Brain death confirmed by Tc(99m) DTPA scan in a case of subarachnoid haemorrhage following a krait bite [3].

High impact information on Bungarus

• These receptors are activated by acetylcholine and nicotine and are blocked by Bungarus toxin 3 [4].
• Inhibition of neuronal acetylcholine sensitivity by alpha-toxins from Bungarus multicinctus venom [5].
• The effects of alpha-toxins from Bungarus multicinctus (alpha BuTX) and Naja naja siamensis (alpha NTX) were studied on synaptic responses and on extrasynaptic responses to focally applied acetylcholine (ACh), histamine (Hm), gamma-aminobutyric acid (GABA), and glutamate (glu) in neurons of the marine mollusc, Aplysia californica [6].
• Using CAT constructs, we found that a DNA fragment from the Bungarus AChE gene stimulates expression of the reporter protein, whereas a homologous fragment from the rat AChE gene had no influence [7].
• The venom of the snake Bungarus fasciatus contains a hydrophilic, monomeric species of acetylcholinesterase (AChE), characterized by a C-terminal region that does not resemble the alternative T- or H-peptides [8].

Biological context of Bungarus

• Thus, the Bungarus AChE gene possesses alternatively spliced T and S exons but no H exon; the absence of an H exon may be a common feature of AChE genes in reptiles and birds [8].
• As deduced from cDNA clones, the catalytic domain of Bungarus fasciatus venom acetylcholinesterase (AChE) is highly homologous to those of other AChEs [9].
• The NAD glycohydrolase from Bungarus fasciatus venom was less sensitive to inhibition by ADP-HPD, exhibiting an IC50 of 260 microM [10].
• The nicotinic acetylcholine receptor (nAChR) carries two binding sites for snake venom neurotoxins. alpha-Bungarotoxin from the Southeast Asian banded krait, Bungarus multicinctus, is a long neurotoxin which competitively blocks the nAChR at the acetylcholine binding sites in a relatively irreversible manner [11].
• The kinetics of thermal inactivation of acetylcholinesterase from the venom of the snake, Bungarus fasciatus, were studied at 45-54 degrees C. An Arrhenius plot reveals an activation energy of 113 kcal/mol [12].

Anatomical context of Bungarus

• The neurotoxic phospholipase A(2), beta-bungarotoxin (beta-BuTx), is a component of the snake venom from the Taiwanese banded krait Bungarus multicinctus. beta-BuTx affects presynaptic nerve terminal function of the neuromuscular junction and induces widespread neuronal cell death throughout the mammalian and avian CNS [13].
• Ceruleotoxin, a toxin component of Bungarus caeuleus venom, blocks in vivo the depolarisation caused by carbamylcholine on the isolated electroplaque from Electrophorus electricus and in vitro in increase of 22Na+ and 42K+ efflux caused by cholinergie agonists on excitable receptor-rich microsacs prepared from Torpedo marmorata electric organ [14].
• The production of human AChE in transfected COS cells was increased nearly 2-fold with this modified construct, but still remained about 4-fold smaller than that of Bungarus AChE [15].

Associations of Bungarus with chemical compounds

• Adenosine diphosphoribose transfer reactions catalyzed by Bungarus fasciatus venom NAD glycohydrolase [16].
• Reactions catalyzed by purified Bungarus fasciatus venom NAD glycohydrolase were demonstrated to include ADP-ribose transfer from NAD to alcohols and to imidazole derivatives to produce a variety of ADP-ribosides [16].
• The NAD glycohydrolase (NADase) (EC 3.2.2.5) from Bungarus fasciatus (banded krait) venom was purified (1000-fold) to electrophoretic homogeneity through a 3-step purification procedure, the last step being affinity chromatography on Cibacron blue agarose [17].
• The recombinant Bungarus AChE, like the natural venom enzyme, showed a distinctive ladder pattern in nondenaturing electrophoresis, probably reflecting a variation in the number of sialic acids [9].
• beta-Bungarotoxin (beta-BTX) isolated from the venom of Bungarus multicinctus has previously been reported to be a neurotoxic protein [18].

Gene context of Bungarus

• Wild-type human AChE and its mutants Y337G and Y337W, as well as wild-type Bungarus fasciatus AChE and its mutants Y333G, Y333A and Y333W were studied [19].
• Identification of a novel type of alternatively spliced exon from the acetylcholinesterase gene of Bungarus fasciatus. Molecular forms of acetylcholinesterase in the snake liver and muscle [8].
• We also observed a thioredoxin-specific reduction with other disulfide proteins of venom from Bungarus multicinctus, scorpion (Androctonus australis), and bee (Apis mellifera) [20].
• However, modification of the conserved Trp-19 did not cause a precipitous drop in the enzymatic activity of Oh-DE-2 as observed with PLA2S from Naja naja atra and Bungarus multicinctus venoms [21].
• Cloning and expression of acetylcholinesterase from Bungarus fasciatus venom. A new type of cooh-terminal domain; involvement of a positively charged residue in the peripheral site [9].

Analytical, diagnostic and therapeutic context of Bungarus

• The N-terminal alpha-amino groups of beta 1-bungarotoxin (beta 1-Bgt) from Bungarus multicinctus venom were modified with trinitrobenzene sulfonic acid and the modified derivative was separated by high performance liquid chromatography [22].
• The other forms of treatment included administration of neostigmine, the banded krait (Bungarus fasciatus) antivenom (Thai Red Cross) and plasmapheresis without beneficial response [23].
• Venoms from Naja naja siamensis, Ophiophagus hannah, Bungarus fasciatus, Vipera russelli, Calloselasma rhodostoma and Trimeresurus albolabris have been studied by means of sodium dodecyl sulfate polyacrylamide gel electrophoresis and immunoblotting [24].
• The two most basic beta-bungarotoxins (beta 3- and beta 4-toxins) and another, less neurotoxic beta-bungarotoxin (beta 5-toxin) were purified from Bungarus multicinctus venom, by a combination of CM-Sephadex C-25 column chromatography and Sephadex G-75 gel filtration [25].

References