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α-cobratoxin
α-Cobratoxin is a substance of the venom of certain ''Naja'' cobras. It is a nicotinic acetylcholine receptor (nAChR) antagonist which causes paralysis by preventing the binding of acetylcholine to the nAChR. Sources α-Cobratoxin is a neurotoxin from the venom of certain ''Naja genus'', including the Thailand cobra, the Indochinese spitting cobra (''Naja siamensis'') and the Chinese cobra (''Naja atra''). The cobras that produce the toxin live in tropical and subtropical regions of Africa and Asia. The venom, produced by these snakes, is a mixture of proteins, carbohydrates, and other substances. The venom is only used when the snake needs it for survival, because it costs a lot of effort to produce. If poisoning a subject is not necessary, it can bite without excreting the venom. When the snake does use it, it mostly tries to immobilize or kill its prey. Structure α-Cobratoxin forms three hairpin type loops with its polypeptide chain. The two minor loops are loop I (amino ac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ribbon Diagram
Ribbon diagrams, also known as Richardson diagrams, are three-dimensional space, 3D schematic representations of protein structure and are one of the most common methods of protein depiction used today. The ribbon depicts the general course and organization of the protein backbone in 3D and serves as a visual framework for hanging details of the entire atomic structure, such as the balls for the oxygen atoms attached to myoglobin's active site in the adjacent figure. Ribbon diagrams are generated by interpolating a smooth curve through the polypeptide backbone. Alpha helix, α-helices are shown as coiled ribbons or thick tubes, Beta sheet, β-sheets as arrows, and non-repetitive coils or loops as lines or thin tubes. The direction of the Peptide, polypeptide chain is shown locally by the arrows, and may be indicated overall by a colour ramp along the length of the ribbon. Ribbon diagrams are simple yet powerful, expressing the visual basics of a molecular structure (twist, fold an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Naja
''Naja'' is a genus of venomous elapid snakes commonly known as cobras (or "true cobras"). Various species occur throughout Africa, Southwest Asia, South Asia, and Southeast Asia. Several other elapid species are often called "cobras", such as the king cobra and the rinkhals, but they are not "true cobras", in that they do not belong to the genus ''Naja''. Until recently, the genus ''Naja'' had 20 to 22 species, but it has undergone several Taxonomy (biology), taxonomic revisions in recent years, so sources vary greatly. Wide support exists, though, for a 2009 revision that synonymised the genera ''Boulengerina'' and ''Paranaja multifasciata, Paranaja'' with ''Naja''. According to that revision, the genus ''Naja'' now includes 38 species. Etymology The origin of the Genus, generic name, ''Naja'', is from the Sanskrit ''nāga'' (with a hard "g") meaning "snake". Some hold that the Sanskrit word is Cognate (etymology), cognate with English "snake", Germanic: ''*snēk-a-'', Pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cobra
COBRA or Cobra, often stylized as CoBrA, was a European avant-garde art group active from 1948 to 1951. The name was coined in 1948 by Christian Dotremont from the initials of the members' home countries' capital cities: Copenhagen (Co), Brussels (Br), Amsterdam (A). History During the time of occupation of World War II, the Netherlands had been disconnected from the art world beyond its borders. CoBrA was formed shortly thereafter. This international movement of artists who worked experimentally evolved from the criticisms of Western society and a common desire to break away from existing art movements, including the "detested" naturalism and the "sterile" abstraction. Experimentation was the symbol of an unfettered freedom, which, according to Constant, was ultimately embodied by children and the expressions of children. CoBrA was formed by Karel Appel, Constant, Corneille, Christian Dotremont, Asger Jorn, and Joseph Noiret on 8 November 1948 in the Café Notre-Dame, Pari ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nicotinic Acetylcholine Receptor
Nicotinic acetylcholine receptors, or nAChRs, are Receptor (biochemistry), receptor polypeptides that respond to the neurotransmitter acetylcholine. Nicotinic receptors also respond to drugs such as the agonist nicotine. They are found in the central and peripheral nervous system, muscle, and many other tissues of many organisms. At the neuromuscular junction they are the primary receptor in muscle for motor nerve-muscle communication that controls muscle contraction. In the peripheral nervous system: (1) they transmit outgoing signals from the presynaptic to the postsynaptic cells within the Sympathetic nervous system, sympathetic and parasympathetic nervous system, and (2) they are the receptors found on skeletal muscle that receive acetylcholine released to signal for muscular contraction. In the immune system, nAChRs regulate inflammatory processes and signal through distinct intracellular pathways. In insects, the cholinergic system is limited to the central nervous system. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Receptor Antagonist
A receptor antagonist is a type of receptor ligand or drug that blocks or dampens a biological response by binding to and blocking a receptor rather than activating it like an agonist. Antagonist drugs interfere in the natural operation of receptor proteins.Pharmacology Guide: In vitro pharmacology: concentration-response curves ." '' GlaxoWellcome.'' Retrieved on December 6, 2007. They are sometimes called blockers; examples include alpha blockers, beta b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acetylcholine
Acetylcholine (ACh) is an organic compound that functions in the brain and body of many types of animals (including humans) as a neurotransmitter. Its name is derived from its chemical structure: it is an ester of acetic acid and choline. Parts in the body that use or are affected by acetylcholine are referred to as cholinergic. Acetylcholine is the neurotransmitter used at the neuromuscular junction. In other words, it is the chemical that motor neurons of the nervous system release in order to activate muscles. This property means that drugs that affect cholinergic systems can have very dangerous effects ranging from paralysis to convulsions. Acetylcholine is also a neurotransmitter in the autonomic nervous system, both as an internal transmitter for both the sympathetic nervous system, sympathetic and the parasympathetic nervous system, and as the final product released by the parasympathetic nervous system. Acetylcholine is the primary neurotransmitter of the parasympathet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indochinese Spitting Cobra
The Siamese spitting cobra (''Naja siamensis'') (, pronounced: nguu hao) also called the Indochinese spitting cobra, Thai spitting cobra and black and white spitting cobra is a species of spitting cobra found in Southeast Asia. Description This is a medium-sized elapid, with a more slender build compared to most other cobras within the genus ''Naja''. The body colour of this species is variable from grey to brown to black, with white spots or stripes. The white patterning can be so prolific that it covers the majority of the snake. The highly distinctive black and white colour phase is common in central Thailand, specimens from western Thailand are mostly black, whereas individuals from elsewhere are usually brown. The hood mark can be spectacle-shaped, irregular or missing altogether, especially in adults. Adults average between in length, and can potentially reach lengths of , although this is considered rare. Body mass for adults can be tends to be around 1,600 grams. This s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chinese Cobra
The Chinese cobra (''Naja atra''), also called the Taiwan cobra, is a species of cobra in the family Elapidae, found mostly in southern China and a couple of neighboring nations and islands. It is one of the most prevalent venomous snakes in China, which has caused many snakebite incidents to humans. Etymology and names ''Naja atra'' was first described by Danish physician, zoologist, and botanist Theodore Edward Cantor in 1842. The generic name ''naja'' is a Latinisation of the Sanskrit word () meaning "cobra". The specific epithet ''atra'' comes from the Latin term ''ater'', which means "dark", "black", or "gloomy". In Mandarin Chinese, the snake is known as ''Zhōnghuá yǎnjìngshé'' ( simplified: 中华眼镜蛇, traditional: 中華眼鏡蛇, lit. "Chinese spectacled snake", i.e. Chinese cobra), ''Zhōushān yǎnjìngshé'' (舟山眼鏡蛇, lit. "Zhoushan spectacled snake", i.e. Zhoushan cobra) or, in Cantonese, ''faahnchaántàuh'' (飯鏟頭, lit. "rice paddle hea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neurotoxin
Neurotoxins are toxins that are destructive to nervous tissue, nerve tissue (causing neurotoxicity). Neurotoxins are an extensive class of exogenous chemical neurological insult (medical), insultsSpencer 2000 that can adversely affect function in both developing and mature nervous tissue.Olney 2002 The term can also be used to classify endogenous compounds, which, when abnormally contacted, can prove neurologically toxic. Though neurotoxins are often neurologically destructive, their ability to specifically target neural components is important in the study of nervous systems. Common examples of neurotoxins include lead, ethanol (drinking alcohol), glutamate,Choi 1987 nitric oxide, botulinum toxin (e.g. Botox), tetanus toxin,Simpson 1986 and tetrodotoxin. Some substances such as nitric oxide and glutamate are in fact essential for proper function of the body and only exert neurotoxic effects at excessive concentrations. Neurotoxins inhibit neuron control over ion concentrations ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Central Nervous System
The central nervous system (CNS) is the part of the nervous system consisting primarily of the brain, spinal cord and retina. The CNS is so named because the brain integrates the received information and coordinates and influences the activity of all parts of the bodies of bilateria, bilaterally symmetric and triploblastic animals—that is, all multicellular animals except sponges and Coelenterata, diploblasts. It is a structure composed of nervous tissue positioned along the Anatomical_terms_of_location#Rostral,_cranial,_and_caudal, rostral (nose end) to caudal (tail end) axis of the body and may have an enlarged section at the rostral end which is a brain. Only arthropods, cephalopods and vertebrates have a true brain, though precursor structures exist in onychophorans, gastropods and lancelets. The rest of this article exclusively discusses the vertebrate central nervous system, which is radically distinct from all other animals. Overview In vertebrates, the brain and spinal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ophthalmoparesis
Ophthalmoparesis refers to weakness (-paresis) or paralysis (-plegia) of one or more extraocular muscles which are responsible for eye movements. It is a physical finding in certain neurologic, ophthalmologic, and endocrine disease. Internal ophthalmoplegia means involvement limited to the pupillary sphincter and ciliary muscle. External ophthalmoplegia refers to involvement of only the extraocular muscles. Complete ophthalmoplegia indicates involvement of both. Presentation Causes Ophthalmoparesis can result from disorders of various parts of the eye and nervous system: * Infection around the eye. Ophthalmoplegia is an important finding in orbital cellulitis. * The orbit of the eye, including mechanical restrictions of eye movement, as in Graves' disease. * The muscle, as in progressive external ophthalmoplegia or Kearns–Sayre syndrome. * The neuromuscular junction, as in myasthenia gravis. * The relevant cranial nerves (specifically the oculomotor, trochlear, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genetic Vaccine
A genetic vaccine (also ''gene-based vaccine'') is a vaccine that contains nucleic acids such as DNA or RNA that lead to protein biosynthesis of antigens within a cell. Genetic vaccines thus include DNA vaccines, RNA vaccines and viral vector vaccines. Properties Most vaccines other than live attenuated vaccines and genetic vaccines are not taken up by MHC-I-presenting cells, but act outside of these cells, producing only a strong humoral immune response via antibodies. In the case of intracellular pathogens, an exclusive humoral immune response is ineffective.Eckhart Buddecke: ''Molekulare Medizin.'' ecomed-Storck GmbH, 2002, ISBN 3609160918. S. 162. Genetic vaccines are based on the principle of uptake of a nucleic acid into cells, whereupon a protein is produced according to the nucleic acid template. This protein is usually the immunodominant antigen of the pathogen or a surface protein that enables the formation of neutralizing antibodies that inhibit the infection of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
