Types of reptile venoms
Neurotoxins
- Neurotoxic peptides mainly found in snakes of the families Elapidae and Hydrophiidae #
- Classified into α-, β- and κ-neurotoxins
- Act on the nervous system by inhibiting Ach action at the postsynaptic membranes, causing
paralysis, respiratory failure and death
- Species include Taiwanese banded krait (Bungarus multicinctus), Indo-Chinese spitting
cobra (Naja siamensis) and Black banded sea krait (Pseudolaticauda semifasciata)
- Examples: α-Bungarotoxin, Erabutoxin, Cobratoxin, β-Bungarotoxin, Crotoxin, Taipoxin, κ-
Bungarotoxin
Dendrotoxins
- Presynaptic neurotoxins produced by mamba snakes
- Blocks subtypes of voltage-gated potassium channels in neurons, enhancing the release of
Ach at neuromuscular junctions
- Over-stimulation of neuromuscular junction leads to hyper-excitability and convulsions
- Produced by the mamba snakes: Eastern green mamba (Dendroaspis angusticeps),
Jameson’s mamba (D. jamesoni), Black mamba (D. polylepis) and Western green mamba
(D. viridis)
- Examples: Dendrotoxins 1, 3, 7, Dendrotoxin K
Cardiotoxins
- Also known as cytotoxins, they are found in cobra venoms, and are characterized by a
three-fold structure
- These toxins disrupt the membranes of neuronal, skeletal and cardiac muscle cells,
resulting in Ca2+ influx, hence causing muscle contraction, cell lysis and cardiac arrest
- Suspected uses in cancer treatments
- Species include Black necked spitting cobra (Naja nigricollis), Taiwan cobra (Naja atra)
- Examples: Cardiotoxin III, Naja nigricollis y-toxin
Neurotoxins
- Neurotoxic peptides mainly found in snakes of the families Elapidae and Hydrophiidae #
- Classified into α-, β- and κ-neurotoxins
- Act on the nervous system by inhibiting Ach action at the postsynaptic membranes, causing
paralysis, respiratory failure and death
- Species include Taiwanese banded krait (Bungarus multicinctus), Indo-Chinese spitting
cobra (Naja siamensis) and Black banded sea krait (Pseudolaticauda semifasciata)
- Examples: α-Bungarotoxin, Erabutoxin, Cobratoxin, β-Bungarotoxin, Crotoxin, Taipoxin, κ-
Bungarotoxin
Dendrotoxins
- Presynaptic neurotoxins produced by mamba snakes
- Blocks subtypes of voltage-gated potassium channels in neurons, enhancing the release of
Ach at neuromuscular junctions
- Over-stimulation of neuromuscular junction leads to hyper-excitability and convulsions
- Produced by the mamba snakes: Eastern green mamba (Dendroaspis angusticeps),
Jameson’s mamba (D. jamesoni), Black mamba (D. polylepis) and Western green mamba
(D. viridis)
- Examples: Dendrotoxins 1, 3, 7, Dendrotoxin K
Cardiotoxins
- Also known as cytotoxins, they are found in cobra venoms, and are characterized by a
three-fold structure
- These toxins disrupt the membranes of neuronal, skeletal and cardiac muscle cells,
resulting in Ca2+ influx, hence causing muscle contraction, cell lysis and cardiac arrest
- Suspected uses in cancer treatments
- Species include Black necked spitting cobra (Naja nigricollis), Taiwan cobra (Naja atra)
- Examples: Cardiotoxin III, Naja nigricollis y-toxin
