bungarotoxin การใช้

• There are two isoforms, ? 1-bungarotoxin and ? 2-bungarotoxin.
• There are two isoforms, ? 1-bungarotoxin and ? 2-bungarotoxin.
• ?-Bungarotoxin has played a large role in determining many of the specifics of nicotinic acetylcholine receptors.
• Viljoen et al . ( 1982 ) isolated a protein, a presynaptic toxin similar to bungarotoxin, but with different binding sites.
• The term ?-neurotoxin was coined by bungarotoxin with the ?-prefix because it happened to be slowest moving of the bungarotoxins under starch zone electrophoresis.
• Kappa-bungarotoxin is a high antagonist of nicotinic acetylcholine receptors ( nAChRs ), particularly of CHRNA3; it causes a post-synaptic blockade of neurotransmission.
• Kappa-bungarotoxin is a receptor antagonist, meaning it blocks the normal response of the receptor to acetylcholine, which inhibits neurotransmission and therefore causes neuromuscular paralysis.
• By coupling assayable enzymes such as horseradish peroxidase ( HRP ) or fluorescent proteins such as green fluorescent protein ( GFP ) to the ?-bungarotoxin, AChRs can be visualized and quantified.
• Like the alpha-bungarotoxins, kappa-bungarotoxin causes a post-synaptic blockade of signaling; this is in contrast to the beta-bungarotoxins which induce a pre-synaptic block.
• The ion channel diameter was shown to increase with this motion, although neither the twist nor the increase in channel diameter was observed when the nAChR was in complex with either one or two ?-bungarotoxin molecules.
• When compared in nAChR-binding studies, MLA was found to compete for 125 I-?-bungarotoxin binding sites ( i . e . ?7 sub-types ) over 1000x more strongly than did lycoctonine.
• Toxins are also used to determine the location of acetylcholine receptors at the neuromuscular junction . ?-Bungarotoxin is a toxin found in the snake species Bungarus multicinctus that acts as an ACh antagonist and binds to AChRs irreversibly.
• ?-Bungarotoxin is important for neuromuscular histology, it is known to bind irreversibly to receptors of the neuromuscular junction, and can be labelled with fluorescent proteins such as green fluorescent protein or the rhodamine dye tetramethylrhodamine isothiocyanate.
• The protein encoded by this gene forms a homo-oligomeric channel, displays marked permeability to calcium ions and is a major component of brain nicotinic receptors that are blocked by, and highly sensitive to, alpha-bungarotoxin.
• "Snake examples : king cobra ( Ophiophagus hannah ) ( known as hannahtoxin containing ?-neurotoxins ), sea snakes ( Hydrophiinae ) ( known as erabutoxin ), many-banded krait ( Bungarus multicinctus ) ( known as ?-Bungarotoxin ), and cobras ( Naja spp . ) ( known as cobratoxin )"
• "' ?-Bungarotoxin "'( ?-BTX ) is one of the bungarotoxins, components of the ?-neurotoxin, a neurotoxic protein that is known to bind competitively and in a relatively irreversible manner to the nicotinic acetylcholine receptor found at the neuromuscular junction, causing paralysis, respiratory failure and death in the victim.
• A significant advance was made towards understanding the pharmacology of MLA when Jennings and co-workers showed that MLA also competed with 125 I-?-bungarotoxin ( K i ~ 1 x 10  " 9 M ) and tritiated (  " )-nicotine ( K i ~ 4 x 10  " 6 M ) in a receptor preparation from rat brain.
• If the succinimide ring is deleted so as to leave only the-NH 2 group attached to the benzene ring ( as in the alkaloid anthranoyllycoctonine, which also occurs naturally ), the resulting compound is intermediate between MLA and lycoctonine in potency and toxicity : it is less acutely toxic than MLA by a factor of about 4, but its affinity for 125 I-?-bungarotoxin binding sites is over 200x lower than that of MLA.