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Conantokin
Conantokins are a small family of helical peptides that are derived from the venom of predatory marine snails of the genus ''Conus''. Conantokins act as potent and specific NMDA receptor antagonist, antagonists of the N-methyl-D-aspartate receptor (NMDAR). They are the only naturally-derived peptides to do so. The subtypes of conantokins exhibit a surprising variability of selectivity across the NMDAR subunits, and are therefore uniquely useful in developing subunit-specific pharmacological probes. Chemically, conantokins are unique in that they possess a number (generally 4 or 5) of carboxyglutamic acid, gamma-carboxyglutamyl (Gla) residues, generated by the post-translational modification of glutamyl (Glu) residues. These Gla residues induce a conformational change from a 3 10 helix to an alpha helix on binding to Calcium. In the broader scheme of genetic conotoxin classification, Conanotokins are also known as "Conotoxin Superfamily B." The word "conantokin" is derived from the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conus Rolani
''Conus rolani'', common name Rolan's cone, is a species of sea snail, a marine gastropod mollusk in the family (biology), family Conidae, the Conus, cone snails and their allies. Like all species within the genus ''Conus'', these snails are predatory and venomous. They are capable of "stinging" humans, therefore live ones should be handled carefully or not at all. Description The size of the shell varies between 37 mm and 70 mm. Conantokin-R1-A is a toxin derived from the venom of Conus rolani. This sea snail harecently been studiedregarding its venom's toxic compounds that can replace the pain-killing effect of morphine. Distribution This marine species occurs off Taiwan and Papua New Guinea. File:Conus rolani 1.jpg, ''Conus rolani'' Röckel, D., 1986 File:Conus rolani 2.jpg, ''Conus rolani'' Röckel, D., 1986 References * Tucker J.K. & Tenorio M.J. (2009) ''Systematic classification of Recent and fossil conoidean gastropods.'' Hackenheim: Conchbooks. 296 p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conus Radiatus
''Conus radiatus'', common name the rayed cone, is a species of sea snail, a marine gastropod mollusk in the family Conidae, the cone snails and their allies. Like all species within the genus ''Conus'', these snails are predatory and venomous. They are capable of "stinging" humans, therefore live ones should be handled carefully or not at all. Description The size of the shell varies between 30 mm and 109 mm. The color of the shell is pale yellowish to pale chestnut, often longitudinally indistinctly marked with deeper coloring. The spire is striate. The lower part of body whorl is distantly sulcate. The white variety is frequently covered by a smooth olivaceous epidermis. Conantokin-C is a toxin derived from the venom of ''Conus radiatus''. Distribution This marine species occurs off the Philippines, New Guinea and Fiji Fiji ( , ,; fj, Viti, ; Fiji Hindi: फ़िजी, ''Fijī''), officially the Republic of Fiji, is an island country in Melanesia, pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
N-methyl-D-aspartate Receptor
The ''N''-methyl-D-aspartate receptor (also known as the NMDA receptor or NMDAR), is a glutamate receptor and ion channel found in neurons. The NMDA receptor is one of three types of ionotropic glutamate receptors, the other two being AMPA and kainate receptors. Depending on its subunit composition, its ligands are glutamate and glycine (or D-serine). However, the binding of the ligands is typically not sufficient to open the channel as it may be blocked by Mg2+ ions which are only removed when the neuron is sufficiently depolarized. Thus, the channel acts as a “coincidence detector” and only once both of these conditions are met, the channel opens and it allows positively charged ions (cations) to flow through the cell membrane. The NMDA receptor is thought to be very important for controlling synaptic plasticity and mediating learning and memory functions. The NMDA receptor is ionotropic, meaning it is a protein which allows the passage of ions through the cell memb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conus Tulipa
''Conus tulipa'', common name the tulip cone, is a species of sea snail, a marine gastropod mollusk in the family Conidae, the cone snails and their allies. Like all species within the genus ''Conus'', these snails are predatory and venomous. They are capable of "stinging" humans, therefore live ones should be handled carefully. A class of conopeptides named rho-TIA was discovered in ''Conus tulipa'' in 2001. This class of conopetides targets (react with) alpha1- adrenergic receptors. Description The size of the shell varies between 45 mm and 95 mm. The shell is variegated with violet and white, clouded with chestnut, with numerous revolving rows of minute chestnut and white articulations. The interior of the aperture is violaceous. Conantokin-T is a toxin derived from the venom of ''Conus tulipa''. Distribution The marine species occurs in the Indo-Western Pacific. * Madagascar * Mauritius * Tanzania * India * the Philippines * Queensland (Australia) Feeding ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conus Ermineus
''Conus ermineus'', common name the turtle cone, is a species of sea snail, a marine gastropod mollusk in the family Conidae, the cone snails and their allies. Like all species within the genus ''Conus'', these snails are predatory and venomous. They are capable of "stinging" humans, therefore live ones should be handled carefully or not at all. Distribution This species occurs in the Caribbean Sea and the Gulf of Mexico to South America; in the Atlantic Ocean off West Africa and the Cape Verdes; in the Indian Ocean off Tanzania. Description The maximum recorded shell Shell may refer to: Architecture and design * Shell (structure), a thin structure ** Concrete shell, a thin shell of concrete, usually with no interior columns or exterior buttresses ** Thin-shell structure Science Biology * Seashell, a hard o ... length is 103 mm.Welch J. J. (2010). "The "Island Rule" and Deep-Sea Gastropods: Re-Examining the Evidence". '' PLoS ONE'' 5(1): e8776. . Conantokin-E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conus Purpurascens
''Conus purpurascens'', common name the purple cone, is a species of sea snail, a marine gastropod mollusk in the family Conidae, the cone snails and their allies. Like all species within the genus ''Conus'', these snails are predatory and venomous. They are capable of "stinging" humans, therefore live ones should be handled carefully or not at all. Conantokin-P is a toxin derived from the venom of ''Conus purpurascens''. Description The size of the shell varies between 33 mm and 80 mm. The shell is broad-shouldered, with a rude, striate spire. It is striate below, and the string sometimes is slightly granular. The shell is clouded with white or violaceous and brown or olive, with close lines of chestnut and white minute articulations. Sometimes it is irregularly white-banded in the middle. The color variations of this handsome species are dazzling, but the general habit of the shell is quite constant. (Original description of ''Conus purpurascens'' var. ''rejectus'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conotoxin
A conotoxin is one of a group of neurotoxic peptides isolated from the venom of the marine cone snail, genus ''Conus''. Conotoxins, which are peptides consisting of 10 to 30 amino acid residues, typically have one or more disulfide bonds. Conotoxins have a variety of mechanisms of actions, most of which have not been determined. However, it appears that many of these peptides modulate the activity of ion channels. Over the last few decades conotoxins have been the subject of pharmacological interest. The LD50 of conotoxin ranges from 5-25 μg/kg. Hypervariability Conotoxins are hypervariable even within the same species. They do not act within a body where they are produced (endogenously) but act on other organisms. Therefore, conotoxin genes experience less selection against mutations (like gene duplication and nonsynonymous substitution), and mutations remain in the genome longer, allowing more time for potentially beneficial novel functions to arise. Variability in c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conus Parius
''Conus parius'', common name the Parian cone, is a species of sea snail, a marine gastropod mollusk in the family Conidae, the cone snails and their allies. Like all species within the genus ''Conus'', these snails are predatory and venomous. They are capable of "stinging" humans, therefore live ones should be handled carefully or not at all. Description The size of the shell varies between 25 mm and 46 mm. The color of the shell is white to pale yellowish, often longitudinally indistinctly marked with deeper coloring. The spire is striate. The lower part of the body whorl is distantly sulcate. Conantokin-Pr1, -Pr2 and -Pr3 are toxins derived from the venom of Conus parius. These small neurotoxic peptides have been found to act as NMDA antagonists ''in vitro'', and stimulate production of the transcription factor CREB in the brain. Distribution This marine species occurs off the Philippines and Indonesia; off Papua New Guinea, the Solomon Islands and Vanuatu Va ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conus Lynceus
''Conus lynceus'' , the lynceus cone, is a species of predatory sea snail, a marine gastropod mollusk in the family Conidae, the cone snails, cone shells or cones. Like all species within the genus Conus, these snails are predatory and venomous. They are capable of "stinging" humans, therefore live ones should be handled carefully or not at all. Description Conantokin-L is a toxin derived from the venom of Conus lynceus. Distribution This is an Indo-Pacific species found along Taiwan, the Philippines, Java, Solomon Islands, Queensland, Australia. Shell description The size of an adult shell varies between 50 mm and 89 mm. The shell is somewhat swollen, distantly sulcate below, otherwise smooth. The shell is white with encircled by chestnut spots, clouds, and oblique and triangular markings. It has a very pointed, maculated spire.George Washington Tryon, Manual of Conchology vol. VI, p. 56; 1879 (described as ''Conus nisus'' Chemn.) References * Hinton, A. 197 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conus Geographus
''Conus geographus'', popularly called the geography cone or the geographer cone, is a species of predatory cone snail. It lives in reefs of the tropical Indo-Pacific, and hunts small fish. While all cone snails hunt and kill prey using venom, the venom of conus geographus is potent enough to kill humans.WoRMS (2010). Conus geographus Linnaeus, 1758. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=215499 on 2011-07-24 The variety ''Conus geographus'' var. ''rosea'' G. B. Sowerby I, 1833 is a synonym of '' Conus eldredi'' Morrison, 1955. This species is the type species of : * ''Gastridium'' Modeer, 1793 * ''Rollus'' Montfort, 1810 * ''Utriculus'' Schumacher, 1817 Shell description ''C. geographus'' has a broad, thin shell, cylindrically inflated. Geography cones grow to about in length. The size of an adult shell varies between . The ground color of the shell is pink or violaceous white, occasionally reddish. It has ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allodynia
Allodynia is a condition in which pain is caused by a stimulus that does not normally elicit pain. For example, bad sunburn can cause temporary allodynia, and touching sunburned skin, or running cold or warm water over it, can be very painful. It is different from hyperalgesia, an exaggerated response from a normally painful stimulus. The term is from Ancient Greek '' άλλος'' ''állos'' "other" and '' οδύνη'' ''odúnē'' "pain". Types There are different kinds or types of allodynia: * Mechanical allodynia (also known as tactile allodynia) ** Static mechanical allodynia – pain in response when touched ** Dynamic mechanical allodynia – pain in response to stroking lightly * Thermal (hot or cold) allodynia – pain from normally mild skin temperatures in the affected area * Movement allodynia – pain triggered by normal movement of joints or muscles Causes Allodynia is a clinical feature of many painful conditions, such as neuropathies,Landerholm, A. (2010). Neuropathic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anticonvulsant
Anticonvulsants (also known as antiepileptic drugs or recently as antiseizure drugs) are a diverse group of pharmacological agents used in the treatment of epileptic seizures. Anticonvulsants are also increasingly being used in the treatment of bipolar disorder and borderline personality disorder, since many seem to act as mood stabilizers, and for the treatment of neuropathic pain. Anticonvulsants suppress the excessive rapid firing of neurons during seizures. Anticonvulsants also prevent the spread of the seizure within the brain. Conventional antiepileptic drugs may block sodium channels or enhance γ-aminobutyric acid ( GABA) function. Several antiepileptic drugs have multiple or uncertain mechanisms of action. Next to the voltage-gated sodium channels and components of the GABA system, their targets include GABAA receptors, the GAT-1 GABA transporter, and GABA transaminase. Additional targets include voltage-gated calcium channels, SV2A, and α2δ. By blocking sodium or ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
