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AG 489
AG 489 (or agatoxin 489) is a component of the venom produced by Agelenopsis aperta, a North American funnel web spider. It inhibits the ligand gated ion channel TRPV1 through a pore blocking mechanism. To identify new inhibitors, capsaicin receptor channels (TRPV1) were screened from a venom library for activity against these channels. In result, the robust inhibitory activity was found in the venom. Venom fractionation utilizing a reversed phase HPLC which led to the purification of the two acylpolyamine toxins, AG489 and AG505. Both of these inhibit the TRPV1 channels from the extracellular membrane side. From the pore blocking mechanism, the pore mutations that change toxic affinity were identified. As a result, the four mutants decreased toxic affinity and several mutants increased it. Therefore, this was consistent with the scanned TM5-TM6 linker region being the outer vestibule of the channels and further confirming that AG489 is a pore blocker. See also * Agatoxin Ag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Venom
Venom or zootoxin is a type of toxin produced by an animal that is actively delivered through a wound by means of a bite, sting, or similar action. The toxin is delivered through a specially evolved ''venom apparatus'', such as fangs or a stinger, in a process called envenomation. Venom is often distinguished from poison, which is a toxin that is passively delivered by being ingested, inhaled, or absorbed through the skin, and toxungen, which is actively transferred to the external surface of another animal via a physical delivery mechanism. Venom has evolved in terrestrial and marine environments and in a wide variety of animals: both predators and prey, and both vertebrates and invertebrates. Venoms kill through the action of at least four major classes of toxin, namely necrotoxins and cytotoxins, which kill cells; neurotoxins, which affect nervous systems; myotoxins, which damage muscles; and haemotoxins, which disrupt blood clotting. Venomous animals cause tens ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Agelenopsis
''Agelenopsis'', commonly known as the American grass spiders, is a genus of funnel weavers first described by C.G. Giebel in 1869. They weave sheet webs that have a funnel shelter on one edge. The web is not sticky, but these spiders make up for that shortcoming by running very rapidly. The larger specimens (depending on species) can grow to about 19 mm in body length. They may be recognized by the arrangement of their eight eyes into three rows. The top row has two eyes, the middle row has four eyes, and the bottom row has two eyes (spaced wider than the ones on the top row). They have two prominent hind spinnerets, somewhat indistinct bands on their legs, and two dark bands running down either side of the cephalothorax. Name The genus name is a combination of '' Agelena'' (Eurasian grass spiders), a genus of similar spiders, and Greek ''-opsis'' "to look like". They are harmless spiders. Although most spiders use their webs to catch prey, the grass spider's web lacks adh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ligand Gated Ion Channel
Ligand-gated ion channels (LICs, LGIC), also commonly referred to as ionotropic receptors, are a group of transmembrane ion-channel proteins which open to allow ions such as Na+, K+, Ca2+, and/or Cl− to pass through the membrane in response to the binding of a chemical messenger (i.e. a ligand), such as a neurotransmitter. When a presynaptic neuron is excited, it releases a neurotransmitter from vesicles into the synaptic cleft. The neurotransmitter then binds to receptors located on the postsynaptic neuron. If these receptors are ligand-gated ion channels, a resulting conformational change opens the ion channels, which leads to a flow of ions across the cell membrane. This, in turn, results in either a depolarization, for an excitatory receptor response, or a hyperpolarization, for an inhibitory response. These receptor proteins are typically composed of at least two different domains: a transmembrane domain which includes the ion pore, and an extracellular dom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TRPV1
The transient receptor potential cation channel subfamily V member 1 (TrpV1), also known as the capsaicin receptor and the vanilloid receptor 1, is a protein that, in humans, is encoded by the ''TRPV1'' gene. It was the first isolated member of the transient receptor potential vanilloid receptor proteins that in turn are a sub-family of the transient receptor potential protein group. This protein is a member of the TRPV group of transient receptor potential family of ion channels. The function of TRPV1 is detection and regulation of body temperature. In addition, TRPV1 provides a sensation of scalding heat and pain (nociception). In primary afferent sensory neurons, it cooperates with TRPA1 (a chemical irritant receptor) to mediate the detection of noxious environmental stimuli. Function TRPV1 is an element of or mechanism used by the mammalian somatosensory system. It is a nonselective cation channel that may be activated by a wide variety of exogenous and endogenous physical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Agatoxin
Agatoxins are a class of chemically diverse polyamine and peptide toxins which are isolated from the venom of various spiders. Their mechanism of action includes blockade of glutamate -gated ion channels, voltage-gated sodium channels, or voltage-dependent calcium channels. Agatoxin is named after the funnel web spider ('' Agelenopsis aperta'') which produces a venom containing several agatoxins. There are different agatoxins. The ω-agatoxins are approximately 100 amino acids in length and are antagonists of voltage-sensitive calcium channels and also block the release of neurotransmitters. For instance, the ω-agatoxin 1A is a selective blocker and will block L-type calcium channels whereas the ω-agatoxin 4B will inhibit voltage sensitive P-type calcium channels. The μ-agatoxins only act on insect voltage-gated sodium channels. Isolation The venom of the ''Agelenopsis aperta'' is located in two glands, which are located in the two fang bases. Ejection of the veno ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
