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GiTx1
GiTx1 (β/κ-theraphotoxin-Gi1a) is a peptide toxin present in the venom of ''Grammostola iheringi''. It reduces both inward and outward currents by blocking voltage-gated sodium and potassium channels, respectively. Etymology & Source GiTx1 is found in the venom of ''Grammostola iheringi'', a Brazilian tarantula of the family Theraphosidae. GiTx1 is an abbreviation of (G)rammostola (i)heringi (T)o(x)in 1, and its rational nomenclature name is β/κ-theraphotoxin-Gi1a. Chemistry GiTx1 is a positively charged protein that consists of 29 amino acids and has a molecular weight of 3585 Da. Its amino acid sequence is: SCQKWMWTCDQKRPCCEDMVCKLWCKIIK The protein contains three sulfide bridges and six cysteine residues. This pattern of disulfide bridges between cysteine amino acids creates a motif called an inhibitory cystine knot found in various other spider toxins. The structure of the toxin is further characterized by two short stranded antiparallel beta sheets and two polype ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GiTx1
GiTx1 (β/κ-theraphotoxin-Gi1a) is a peptide toxin present in the venom of ''Grammostola iheringi''. It reduces both inward and outward currents by blocking voltage-gated sodium and potassium channels, respectively. Etymology & Source GiTx1 is found in the venom of ''Grammostola iheringi'', a Brazilian tarantula of the family Theraphosidae. GiTx1 is an abbreviation of (G)rammostola (i)heringi (T)o(x)in 1, and its rational nomenclature name is β/κ-theraphotoxin-Gi1a. Chemistry GiTx1 is a positively charged protein that consists of 29 amino acids and has a molecular weight of 3585 Da. Its amino acid sequence is: SCQKWMWTCDQKRPCCEDMVCKLWCKIIK The protein contains three sulfide bridges and six cysteine residues. This pattern of disulfide bridges between cysteine amino acids creates a motif called an inhibitory cystine knot found in various other spider toxins. The structure of the toxin is further characterized by two short stranded antiparallel beta sheets and two polype ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grammostola Iheringi
''Grammostola iheringi'' also known as the Entre Rios tarantula, it was first described by Keyserling in 1891. They are found in Brazil, and is considered the biggest tarantula in the ''Grammostola'' genus. Description Females can live a bit over 20 years, and can grow to up to 23cm. They are leggier than most others in the ''Grammostola'' genus, and also differs from them by their behavior. They have velvety black legs, which have a slight blue tint. And a black carapace, which is bordered by an orange coloration. The opisthosoma is a dark red color. Venom As most New World Tarantulas, this species lacks potent venom. Although their venom has been analyzed, and the toxin A toxin is a naturally occurring organic poison produced by metabolic activities of living cells or organisms. Toxins occur especially as a protein or conjugated protein. The term toxin was first used by organic chemist Ludwig Brieger (1849– ... Gitx1 was found. The effects of this toxin in mice ra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drosophila Melanogaster
''Drosophila melanogaster'' is a species of fly (the taxonomic order Diptera) in the family Drosophilidae. The species is often referred to as the fruit fly or lesser fruit fly, or less commonly the "vinegar fly" or "pomace fly". Starting with Charles W. Woodworth's 1901 proposal of the use of this species as a model organism, ''D. melanogaster'' continues to be widely used for biological research in genetics, physiology, microbial pathogenesis, and life history evolution. As of 2017, five Nobel Prizes have been awarded to drosophilists for their work using the insect. ''D. melanogaster'' is typically used in research owing to its rapid life cycle, relatively simple genetics with only four pairs of chromosomes, and large number of offspring per generation. It was originally an African species, with all non-African lineages having a common origin. Its geographic range includes all continents, including islands. ''D. melanogaster'' is a common pest in homes, restaurants, and othe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Median Lethal Dose
In toxicology, the median lethal dose, LD50 (abbreviation for "lethal dose, 50%"), LC50 (lethal concentration, 50%) or LCt50 is a toxic unit that measures the lethal dose of a toxin, radiation, or pathogen. The value of LD50 for a substance is the dose required to kill half the members of a tested population after a specified test duration. LD50 figures are frequently used as a general indicator of a substance's acute toxicity. A lower LD50 is indicative of increased toxicity. The test was created by J.W. Trevan in 1927. The term semilethal dose is occasionally used in the same sense, in particular with translations of foreign language text, but can also refer to a sublethal dose. LD50 is usually determined by tests on animals such as laboratory mice. In 2011, the U.S. Food and Drug Administration approved alternative methods to LD50 for testing the cosmetic drug Botox without animal tests. Conventions The LD50 is usually expressed as the mass of substance administered per unit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyanosis
Cyanosis is the change of body tissue color to a bluish-purple hue as a result of having decreased amounts of oxygen bound to the hemoglobin in the red blood cells of the capillary bed. Body tissues that show cyanosis are usually in locations where the skin is thinner, including the mucous membranes, lips, nail beds, and ear lobes. Some medications containing amiodarone or silver, Mongolian spots, large birth marks, and the consumption of food products with blue or purple dyes can also result in the bluish skin tissue discoloration and may be mistaken for cyanosis. Cyanosis is further classified into central cyanosis vs. peripheral cyanosis. Pathophysiology The mechanism behind cyanosis is different depending on whether it is central or peripheral. Central cyanosis Central cyanosis is caused by a decrease in arterial oxygen saturation (SaO2) and begins to show once the concentration of deoxyhemoglobin in the blood reaches a concentration of ≥ 5.0 g/dL (≥ 3.1 mmol/L ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cerebrospinal Fluid
Cerebrospinal fluid (CSF) is a clear, colorless body fluid found within the tissue that surrounds the brain and spinal cord of all vertebrates. CSF is produced by specialised ependymal cells in the choroid plexus of the ventricles of the brain, and absorbed in the arachnoid granulations. There is about 125 mL of CSF at any one time, and about 500 mL is generated every day. CSF acts as a shock absorber, cushion or buffer, providing basic mechanical and immunological protection to the brain inside the skull. CSF also serves a vital function in the cerebral autoregulation of cerebral blood flow. CSF occupies the subarachnoid space (between the arachnoid mater and the pia mater) and the ventricular system around and inside the brain and spinal cord. It fills the ventricles of the brain, cisterns, and sulci, as well as the central canal of the spinal cord. There is also a connection from the subarachnoid space to the bony labyrinth of the inner ear via the perilymphat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intraperitoneal
The peritoneum is the serous membrane forming the lining of the abdominal cavity or coelom in amniotes and some invertebrates, such as annelids. It covers most of the intra-abdominal (or coelomic) organs, and is composed of a layer of mesothelium supported by a thin layer of connective tissue. This peritoneal lining of the cavity supports many of the abdominal organs and serves as a conduit for their blood vessels, lymphatic vessels, and nerves. The abdominal cavity (the space bounded by the vertebrae, abdominal muscles, diaphragm, and pelvic floor) is different from the intraperitoneal space (located within the abdominal cavity but wrapped in peritoneum). The structures within the intraperitoneal space are called "intraperitoneal" (e.g., the stomach and intestines), the structures in the abdominal cavity that are located behind the intraperitoneal space are called "retroperitoneal" (e.g., the kidneys), and those structures below the intraperitoneal space are called "subperito ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IC50
The half maximal inhibitory concentration (IC50) is a measure of the potency of a substance in inhibiting a specific biological or biochemical function. IC50 is a quantitative measure that indicates how much of a particular inhibitory substance (e.g. drug) is needed to inhibit, ''in vitro'', a given biological process or biological component by 50%. The biological component could be an enzyme, cell, cell receptor or microorganism. IC50 values are typically expressed as molar concentration. IC50 is commonly used as a measure of antagonist drug potency in pharmacological research. IC50 is comparable to other measures of potency, such as EC50 for excitatory drugs. EC50 represents the dose or plasma concentration required for obtaining 50% of a maximum effect ''in vivo''. IC50 can be determined with functional assays or with competition binding assays. Sometimes, IC50 values are converted to the pIC50 scale. :\ce = -\log_ \ce Due to the minus sign, higher values of pIC50 indica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dorsal Root Ganglion
A dorsal root ganglion (or spinal ganglion; also known as a posterior root ganglion) is a cluster of neurons (a ganglion) in a dorsal root of a spinal nerve. The cell bodies of sensory neurons known as first-order neurons are located in the dorsal root ganglia. The axons of dorsal root ganglion neurons are known as afferents. In the peripheral nervous system, afferents refer to the axons that relay sensory information into the central nervous system (i.e. the brain and the spinal cord). Structure The neurons comprising the dorsal root ganglion are of the pseudo-unipolar type, meaning they have a cell body (soma) with two branches that act as a single axon, often referred to as a ''distal process'' and a ''proximal process''. Unlike the majority of neurons found in the central nervous system, an action potential in posterior root ganglion neuron may initiate in the ''distal process'' in the periphery, bypass the cell body, and continue to propagate along the ''proximal process ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phrixotoxin
Phrixotoxins are peptide toxins derived from the venom of the Chilean copper tarantula ''Phrixotrichus auratus'', also named ''Paraphysa scrofa''. Phrixotoxin-1 and -2 block A-type voltage-gated potassium channels; phrixotoxin-3 blocks voltage-gated sodium channels. Similar toxins are found in other species, for instance the Chilean rose tarantula. Sources Phrixotoxins are purified from the venom of the spider ''Phrixotrichus auratus'' , but they can also be produced by chemical peptide synthesis . Structure There are three different phrixotoxins: *Phrixotoxin-1 (PaTx1) – which is composed of 29 amino acids *Phrixotoxin-2 (PaTx2) – which is composed of 31 amino acids *Phrixotoxin-3 (PaurTx3 or Beta-theraphotoxin-Ps1a) – which is composed of 34 amino acids PaTx1 is 83.3% identical to PATx2, differing only by two acidic residues. Phrixotoxin-1 and -2 are similar to heteropodatoxin, which also has a blocking activity on Kv4.2 channels . Phrixotoxin-1, -2 and -3 contain an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protoxin-II
Protoxin-II, also known as ProTx-II, PT-II or β/ω-TRTX-Tp2a, is a neurotoxin that inhibits certain voltage-gated calcium and voltage-gated sodium channels. This toxin is a 30-residue disulfide-rich peptide that has unusually high affinity and selectivity toward the human Nav1.7. channel. Sources Protoxin-II is a neurotoxin that is derived from the venom of the Peruvian green velvet tarantula (''Thrixopelma pruriens ''Thrixopelma pruriens'', known as the Peruvian green velvet tarantula, is a species of tarantula found in Chile and Perú in South America. Though docile, this species is rarely kept as a pet in part due to its tendency to fling urticating ha ...''). Chemistry ProTx-II is a 30-amino acid peptide with a molecular weight of 3826.65 Da. The structure of ProTx-II is amphipathic, with mostly hydrophobic residues on one face of the toxin. The toxin is formed by an inhibitor cystine knot (ICK) backbone region and a flexible C-terminal tail region. Target ProTx-II ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
