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Sea Anemone Neurotoxin
Sea anemone neurotoxin is the name given to neurotoxins produced by sea anemones with related structure and function. Sea anemone neurotoxins can be divided in two functional groups that either specifically target the sodium channel or the potassium channel. A number of proteins belong to the sodium channel toxin family, including ''calitoxin'' and '' anthopleurin''. The neurotoxins bind specifically to the sodium channel, thereby delaying its inactivation during signal transduction, resulting in strong stimulation of mammalian cardiac muscle contraction. Calitoxin 1 has been found in neuromuscular preparations of crustaceans, where it increases transmitter release, causing firing of the axons. Three disulfide bonds are present in this protein. This family also includes the antihypertensive and antiviral proteins BDS-I () and BDS-II () expressed by '' Anemonia viridis'' (previously '' Anemonia sulcata)''. BDS-I is organised into a triple-stranded antiparallel beta-sheet, with a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neurotoxin
Neurotoxins are toxins that are destructive to nerve tissue (causing neurotoxicity). Neurotoxins are an extensive class of exogenous chemical neurological 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 across the cell membrane, or com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anemonia Sulcata
''Anemonia sulcata'', or Mediterranean snakelocks sea anemone, is a species of sea anemone in the family Actiniidae from the Mediterranean Sea. Whether ''A. sulcata'' should be recognized as a synonym of '' A. viridis'' remains a matter of dispute. Description This sea anemone has two ecotypes; one has a basal disk up to in diameter and has fewer than 192 tentacles (usually 142 to 148); the other has a disk up to in diameter and 192 tentacles or more, up to 348. The tentacles are long, slender and tapering, arranged in six whorls round the central mouth on the oral disk. They vary in colour but are usually some shade of green, grey or light brown. A knob on the tip of each tentacle, where the stinging cells are concentrated, may be violet. Distribution and habitat This sea anemone is native to the Mediterranean Sea and the eastern Atlantic Ocean as far south as Western Sahara. It is found in the intertidal zone and the sublittoral zone, on rocky ledges, in crevices and on b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sea Anemone Toxins
The sea, connected as the world ocean or simply the ocean, is the body of salty water that covers approximately 71% of the Earth's surface. The word sea is also used to denote second-order sections of the sea, such as the Mediterranean Sea, as well as certain large, entirely landlocked, saltwater lakes, such as the Caspian Sea. The sea moderates Earth's climate and has important roles in the water, carbon, and nitrogen cycles. Humans harnessing and studying the sea have been recorded since ancient times, and evidenced well into prehistory, while its modern scientific study is called oceanography. The most abundant solid dissolved in seawater is sodium chloride. The water also contains salts of magnesium, calcium, potassium, and mercury, amongst many other elements, some in minute concentrations. Salinity varies widely, being lower near the surface and the mouths of large rivers and higher in the depths of the ocean; however, the relative proportions of dissolved salts vary li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein Domains
In molecular biology, a protein domain is a region of a protein's polypeptide chain that is self-stabilizing and that folds independently from the rest. Each domain forms a compact folded three-dimensional structure. Many proteins consist of several domains, and a domain may appear in a variety of different proteins. Molecular evolution uses domains as building blocks and these may be recombined in different arrangements to create proteins with different functions. In general, domains vary in length from between about 50 amino acids up to 250 amino acids in length. The shortest domains, such as zinc fingers, are stabilized by metal ions or disulfide bridges. Domains often form functional units, such as the calcium-binding EF hand domain of calmodulin. Because they are independently stable, domains can be "swapped" by genetic engineering between one protein and another to make chimeric proteins. Background The concept of the domain was first proposed in 1973 by Wetlaufer after ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cangitoxin
Cangitoxin, also known as CGTX or CGX, is a toxin purified from the venom of the sea anemone ''Bunodosoma cangicum'', which most likely acts by prolonging the inactivation of voltage-gated sodium channels (NaV channels). Sources Cangitoxin is a polypeptide isolated from the venom of ''Bunodosoma cangicum'', a common sea anemone species found in the intertidal zone during low tides on the coastal reefs of the Brazilian seashore. Chemistry Structure Cangitoxin belongs to the type 1 class sea anemone toxins, consisting of long polypeptides with short anti-parallel β–sheets and three disulfide bonds. Cangitoxin is a 4958 Da peptide, with the primary structure GVACRCDSDGPTVRGNSLSGTLWLTGGCPSGWHNCRGSGPFIGYCCKK and disulfide bonds Cys4-Cys45, Cys6-Cys35, and Cys28-Cys46. It contains 48 amino acid residues. Substitution of the 16th amino acid, asparagine (N), into an aspartic acid (D) is named cangitoxin-II (CGTX-II). Cangitoxin-III (CGTX-III) contains in addition to the previous subst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Halcurin
Halcurin is a polypeptide neurotoxin from the sea anemone '' Halcurias'' sp. Based on sequence homology to type 1 and type 2 sea anemone toxins it is thought to delay channel inactivation by binding to the extracellular site 3 on the voltage gated sodium channels in a membrane potential-dependent manner. Source and etymology The polypeptide toxin halcurin is named after its source: the sea anemone genus ''Halcurias'', which are ocean dwelling solitary invertebrates. Chemistry The amino acid sequence of halcurin is: VACRCESDGP DVRSATFTGT VDLWNCNTGW HKCIATYTAV ASCCKKD; it consists of 47 amino acids and has a molecular weight of 5,086 Da General information A classification of sea anemone polypeptide neurotoxins has been proposed based on their amino acid sequence, dividing the group into three classes of sodium channel toxins. Halcurin is structurally homologous with type 2 toxins, but also has sequence homology to type 1 toxins. Type 1 and 2 toxins are composed of 46 t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AETX
AETX refers to a group of polypeptide neurotoxins isolated from the sea anemone ''Anemonia erythraea'' that target ion channels, altering their function. Four subtypes have been identified: AETX I, II, III and K, which vary in their structure and target. Etymology and Source The four subtypes of AETX (''Anemonia erythraea'' toxins) are produced by the sea anemone ''Anemonia erythraea''. Chemistry AETX I AETX I consists of 47 amino acids. The determined molecular mass appears to be approximately 5 kDa. It is classified into Type I voltage-gated sodium channel neurotoxins. As reported by Norton ''et al.'', this group consists of polypeptide neurotoxins with an average of 46-49 amino acids and 27 residues that are highly conserved. AETX I shares 21 of the 27 conserved residues with the representatives of Type I polypeptide toxins from sea anemone. AETX II & III AETX II and AETX III have not yet been categorized since their structure does not correspond to any known polypeptide neur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kaliseptine
Kaliseptine (AsKS) is a neurotoxin which can be found in the snakelocks anemone ''Anemonia viridis''. It belongs to a class of sea anemone neurotoxins that inhibits voltage-gated potassium channels. Etymology “Kali” is derived from the Latin word alium which means potassium. The suffix “septine” is derived from the Greek word “sepsis” ῆψις which means “decay” or “putrefaction”. This suffix was added to distinguish it from the related toxin kalicludine. Kaliseptine was first isolated from the snakelocks anemone, which at the time was called ''Anemonia sulcata''. Kaliseptine is abbreviated as AsKS, which stands for Anemonia sulcata KaliSeptine. The rational nomenclature of kaliseptine is kappa-actitoxin-Avd6a. The first letter Kappa indicates its molecular target, namely a voltage-gated potassium channel. Actitoxin is a neurotoxin derived from the Actiniidae. Avd denotes that it is extracted from '' Anemonia viridis''. Finally, 6a specifies that this was t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Snakelocks Anemone
The snakelocks anemone (''Anemonia viridis'') is a sea anemone found in the eastern Atlantic Ocean and the Mediterranean Sea. The latter population is however sometimes considered a separate species, the Mediterranean snakelocks anemone (''Anemonia sulcata''). The tentacles are usually a deep green colour with purple tips, the green colour is often attributed to the presence of symbiotic algae within the tentacles but is actually the result of the presence of Green Fluorescent Protein which is present in corals, sea anemones, and some other cnidarians. The anemone tissue contains a symbiotic algae called zooxanthellae, which is necessary for the long-term survival of the sea anemone. When the numbers of algae diminish the anemone may appear dull grey in colour. The algae need light to flourish, so Snakelocks Anemones will be found in the sunniest pools. On average the snakelock anemone is 8 cm wide. Reproduction Unlike other cnidarians, anemones (and other Anthozoa) entire ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sea Anemone
Sea anemones are a group of predation, predatory marine invertebrates of the order (biology), order Actiniaria. Because of their colourful appearance, they are named after the ''Anemone'', a terrestrial flowering plant. Sea anemones are classified in the phylum Cnidaria, class Anthozoa, subclass Hexacorallia. As cnidarians, sea anemones are related to corals, jellyfish, tube-dwelling anemones, and ''hydra (genus), Hydra''. Unlike jellyfish, sea anemones do not have a Jellyfish#Life history and behavior, medusa stage in their life cycle. A typical sea anemone is a single polyp (zoology), polyp attached to a hard surface by its base, but some species live in soft sediment, and a few float near the surface of the water. The polyp has a columnar trunk topped by an oral disc with a ring of tentacles and a central mouth. The tentacles can be retracted inside the body cavity or expanded to catch passing prey. They are armed with cnidocytes (stinging cells). In many species, additional n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antiviral Protein
Antiviral proteins are proteins that are induced by human or animal cells to interfere with viral replication. These proteins are isolated to inhibit the virus from replicating in a host's cells and stop it from spreading to other cells. The Pokeweed antiviral protein and the Zinc-Finger antiviral protein are two major antiviral proteins that have undergone several tests for viruses, including HIV and influenza. Pokeweed antiviral protein Pokeweed antiviral protein (PAP) is a ribosome inactivating protein that provides pokeweed plants protection against both viral and fungal infections. It also protects other types of plants that have genetically engineered to express RAP that do not normally do so. Recombinant PAP has also been proposed as a treatment of human diseases such as AIDS and cancer. ZC3HAV1 ZAP (Zinc finger Antiviral Protein) is encoded by the ZC3HAV1 gene whose expression is induced by interferon and helps fight a number of viral infections including influenza. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antihypertensive
Antihypertensives are a class of drugs that are used to treat hypertension (high blood pressure). Antihypertensive therapy seeks to prevent the complications of high blood pressure, such as stroke and myocardial infarction. Evidence suggests that reduction of the blood pressure by 5 mmHg can decrease the risk of stroke by 34% and of ischaemic heart disease by 21%, and can reduce the likelihood of dementia, heart failure, and mortality from cardiovascular disease. There are many classes of antihypertensives, which lower blood pressure by different means. Among the most important and most widely used medications are thiazide diuretics, calcium channel blockers, ACE inhibitors, angiotensin II receptor antagonists (ARBs), and beta blockers. Which type of medication to use initially for hypertension has been the subject of several large studies and resulting national guidelines. The fundamental goal of treatment should be the prevention of the important endpoints of hypert ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
