University of Dhaka

Department of Genetic Engineering &
Biotechnology, University of Dhaka
Dhaka-1000, Bangladesh


Some components of venoms, called neurotoxins, affect the nervous system. The main site of snake neurotoxins is the neuromuscular junction, and they are either: (1) pre-synaptic neurotoxins irreversibly damaging the presynaptic terminal; or (2) post-synaptic neurotoxins that bind to the nicotinic acetylcholine receptor. Neuromuscular paralysis due to snake envenoming is common by elapid snakes such as kraits, cobras, coral snakes and many others.

Alpha-neurotoxins are a large group, with over 100 postsynaptic neurotoxins having been identified and sequenced. α-neurotoxins attack the Nicotinic acetylcholine receptors of cholinergic neurons. They mimic the shape of the acetylcholine molecule therefore fit into the receptors, as a consequence block the ACh flow & is responsible for feeling of numbness and paralysis. Dendrotoxins inhibit neurotransmissions by blocking the exchange of positive and negative ions across the neuronal membrane lead to no nerve impulse, thereby paralysing the nerves.

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