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Parabutoxin
Parabutoxin (PBTx) is a Shaker gene, Shaker-related voltage-gated K+ channel, voltage-gated K+ channel (Kvα1) inhibitor purified from different ''Parabuthus'' scorpion species found in southern Africa. It occurs in different forms: parabutoxin 1 (PBTx1), parabutoxin 2 (PBTx2), parabutoxin 3 (PBTx3) and parabutoxin (PBTx10). The different variants have different affinities towards Kvα1 channels. Sources Four different acidic peptides (PBTx1, PBTx2, PBTx3 and PBTx10) have been isolated and cloned from the venoms of three different ''Parabuthus'' scorpion species found in southern Africa. PBTx1 and PBTx3 were extracted from the venom of ''Parabuthus transvaalicus, P. transvaalicus'', PBTx2 from ''Parabuthus villosus, P. villosus'' and PBTx10 has been purified from ''P. granulatus''. Chemistry Scorpion toxins that target potassium channels have been classified into three K+ Toxin (KT) subfamilies α-KTx, β-KTx, and γ-KTx peptides. The α-KTx subfamilies are the best-studied tox ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parabuthus
''Parabuthus'', commonly known as the thick-tailed scorpion, is a genus of large and highly venomous Afrotropical realm, Afrotropical scorpions, that show a preference for areas of low rainfall. Their stings are medically important and human fatalities have been recorded.Larsen, Norman. Biodiversity Explorer, IZIKO. Scorpion stings and venom/ref> Characteristics They have thick and strong tails, with typically a rough surface to the first (proximal) and sometimes second segment, that is used to produce a warning sound when rubbed against the sting (save ''Parabuthus distridor, P. distridor''). Their thick tails are also employed in excavating their shallow burrows, as several are adapted to sandy environments. Some flatter-bodied species, however, take refuge in rock crevasses. Due to their stings' quick-acting venom, they rely to lesser extent on their slender pinchers (chelae) to hold onto prey. Three species, ''Parabuthus schlechteri, P. schlechteri'', ''Parabuthus transvaalic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shaker Gene
The ''shaker (Sh)'' gene, when mutated, causes a variety of atypical behaviors in the fruit fly, ''Drosophila melanogaster''. Under ether anesthesia, the fly’s legs will shake (hence the name); even when the fly is unanaesthetized, it will exhibit aberrant movements. Sh-mutant flies have a shorter lifespan than regular flies; in their larvae, the repetitive firing of action potentials as well as prolonged exposure to neurotransmitters at neuromuscular junctions occurs. In ''Drosophila'', the shaker gene is located on the X chromosome. The closest human homolog is KCNA3. Function The ''Sh'' gene plays a part in the operation of potassium ion channels, which are integral membrane proteins and are essential to the correct functioning of the cell. A working shaker channel is voltage-dependent and has four subunits, which form a pore through which ions flow, carrying type-A potassium current (IA). A mutation in the Sh gene reduces the conductance of charge across the neuron ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |