Alpha-Latrotoxin is a 130kDa protein toxin from the black widow spider venom and is�the only protein in the venom that affects mammals. Application of the toxin to presynaptic preparations induces, after a delay, a huge increase in spontaneous�neurotransmitter release, which can be evaluated by measuring the post synaptic response in the form of miniature end plate potentials. This toxin is widely used to induce and study neurotransmitter release, but the molecular�mechanism of its action is not fully determined.
It has been close to 30 years since alpha-Latrotoxin was first isolated from�the female black widow spider Latrodectus tredecimguttatus venom glands. For the past 10 years, Alomone Labs, had made this product available as a commercial research, following a modified isolation protocol as described by Frontali and Grasso.
Recently, a decision was made to switch from the venom glands to using captive female black widow�spider milked venom, in order to minimize the impact on the spider�s ecological niche. However, we were surprised to find that alpha-Latrotoxin isolated from this milked venom�was at least 10 fold more potent, for reasons not yet determined, than the alpha-Latrotoxin�isolated using venom glands. Electrophoresis analysis failed to detect any difference between alpha-Latrotoxin isolated using the venom glands and that isolated from milked venom. This dramatic increase in potency has indeed transformed alpha-Latrotoxin into a very affordable molecular tool for neuroscience laboratories.
Neurotoxins> Excitatory Neurotoxins.