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Kassinin
Kassinin is a peptide derived from the Kassina frog. It belongs to tachykinin family of neuropeptides. It is secreted as a defense response, and is involved in neuropeptide signalling. The amino acid sequence is H-Asp-Val-Pro-Lys-Ser-Asp-Gln-Phe-Val-Gly-Leu-Met-NH2 (DVPKSDQFVGLM-NH2). Ion transportation In frog skin, tachykinins are responsible for ion transportation. Kassinin is one of the tachykinin peptides, which interacts with NK2 receptor to increase short circuit current (SCC), resulting in an ion transportation in frog skin. Another peptide that belongs to tachykinin family is Eledoisin that interacts with NK3 receptor for stimulation of SCC, but can be reduced by either NK1 or NK2 antagonist, whereas kassinin can't be reduced by either of these NK1, NK2 or NK3 antagonists. Kassinin is very effective in increasing short circuit current to its maximum within 10 minutes with increase of 26.13 ± 1.53μΑ/cm2. There are some requirements that must be accomplished to gain ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kassina
''Kassina'' is a genus of hyperoliid frogs, commonly referred to as running frogs or kassinas. They are found throughout sub-Saharan Africa. They are characterized by preferring a distinctive "walking" with the back legs instead of the more traditional frog-hopping. Species The following species are recognized in the genus ''Kassina'': In captivity ''K. maculata'' is frequently exported from Tanzania for the exotic pet A pet, or companion animal, is an animal kept primarily for a person's company or entertainment rather than as a working animal, livestock, or a laboratory animal. Popular pets are often considered to have attractive appearances, intelligence ... trade. They require more horizontal space than vertical, being a terrestrial species. Their captive environment should include a substrate that accommodates burrowing, and provides high humidity. ''K. maculata'' will readily eat crickets and small mealworms, although insects should be dusted with a vitamin sup ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tachykinin Family
Tachykinin peptides are one of the largest families of neuropeptides, found from amphibians to mammals. They were so named due to their ability to rapidly induce contraction of gut tissue. The tachykinin family is characterized by a common C-terminal sequence, Phe-X-Gly- Leu- Met-NH2, where X is either an Aromatic or an Aliphatic amino acid. The genes that produce tachykinins encode precursor proteins called preprotachykinins, which are chopped apart into smaller peptides by posttranslational proteolytic processing. The genes also code for multiple splice forms that are made up of different sets of peptides. Tachykinins excite neurons, evoke behavioral responses, are potent vasodilators, and contract (directly or indirectly) many smooth muscles. Tachykinins are from ten to twelve residues long. The two human tachykinin genes are called TAC1 and TAC3 for historical reasons, and are equivalent to Tac1 and Tac2 of the mouse, respectively. TAC1 encodes neurokinin A (formerly know ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tachykinin Peptides
Tachykinin peptides are one of the largest families of neuropeptides, found from amphibians to mammals. They were so named due to their ability to rapidly induce contraction of gut tissue. The tachykinin family is characterized by a common C-terminal sequence, Phe-X-Gly- Leu- Met-NH2, where X is either an Aromatic or an Aliphatic amino acid. The genes that produce tachykinins encode precursor proteins called preprotachykinins, which are chopped apart into smaller peptides by posttranslational proteolytic processing. The genes also code for multiple splice forms that are made up of different sets of peptides. Tachykinins excite neurons, evoke behavioral responses, are potent vasodilators, and contract (directly or indirectly) many smooth muscles. Tachykinins are from ten to twelve residues long. The two human tachykinin genes are called TAC1 and TAC3 Tachykinin-3 is a protein that in humans is encoded by the ''TAC3'' gene. See also *Neurokinin B *Tachykinin receptor 3 Tach ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peptide
Peptides (, ) are short chains of amino acids linked by peptide bonds. Long chains of amino acids are called proteins. Chains of fewer than twenty amino acids are called oligopeptides, and include dipeptides, tripeptides, and tetrapeptides. A polypeptide is a longer, continuous, unbranched peptide chain. Hence, peptides fall under the broad chemical classes of biological polymers and oligomers, alongside nucleic acids, oligosaccharides, polysaccharides, and others. A polypeptide that contains more than approximately 50 amino acids is known as a protein. Proteins consist of one or more polypeptides arranged in a biologically functional way, often bound to ligands such as coenzymes and cofactors, or to another protein or other macromolecule such as DNA or RNA, or to complex macromolecular assemblies. Amino acids that have been incorporated into peptides are termed residues. A water molecule is released during formation of each amide bond.. All peptides except cyc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frog
A frog is any member of a diverse and largely carnivorous group of short-bodied, tailless amphibians composing the order Anura (ανοὐρά, literally ''without tail'' in Ancient Greek). The oldest fossil "proto-frog" ''Triadobatrachus'' is known from the Early Triassic of Madagascar, but molecular clock dating suggests their split from other amphibians may extend further back to the Permian, 265 million years ago. Frogs are widely distributed, ranging from the tropics to subarctic regions, but the greatest concentration of species diversity is in tropical rainforest. Frogs account for around 88% of extant amphibian species. They are also one of the five most diverse vertebrate orders. Warty frog species tend to be called toads, but the distinction between frogs and toads is informal, not from taxonomy or evolutionary history. An adult frog has a stout body, protruding eyes, anteriorly-attached tongue, limbs folded underneath, and no tail (the tail of tailed frogs is an ext ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neuropeptides
Neuropeptides are chemical messengers made up of small chains of amino acids that are synthesized and released by neurons. Neuropeptides typically bind to G protein-coupled receptors (GPCRs) to modulate neural activity and other tissues like the gut, muscles, and heart. There are over 100 known neuropeptides, representing the largest and most diverse class of signaling molecules in the nervous system. Neuropeptides are synthesized from large precursor proteins which are cleaved and post-translationally processed then packaged into dense core vesicles. Neuropeptides are often co-released with other neuropeptides and neurotransmitters in a single neuron, yielding a multitude of effects. Once released, neuropeptides can diffuse widely to affect a broad range of targets. Synthesis Neuropeptides are synthesized from large, inactive precursor proteins called prepropeptides. Prepropeptides contain sequences for a family of distinct peptides and often contain repeated copies of the sa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amino Acid
Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although hundreds of amino acids exist in nature, by far the most important are the alpha-amino acids, which comprise proteins. Only 22 alpha amino acids appear in the genetic code. Amino acids can be classified according to the locations of the core structural functional groups, as Alpha and beta carbon, alpha- , beta- , gamma- or delta- amino acids; other categories relate to Chemical polarity, polarity, ionization, and side chain group type (aliphatic, Open-chain compound, acyclic, aromatic, containing hydroxyl or sulfur, etc.). In the form of proteins, amino acid '' residues'' form the second-largest component (water being the largest) of human muscles and other tissues. Beyond their role as residues in proteins, amino acids participate in a number of processes such as neurotransmitter transport and biosynthesis. It is thought that they played a key role in enabling l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eledoisin
Eledoisin is an undecapeptide of mollusk origin, belonging to the tachykinin family of neuropeptides. It was first isolated from the posterior salivary glands of two mollusk species ''Eledone muschata'' and ''Eledone aldovandi'', which belong to the octopod order of Cephalopoda.De Marco, A., and G. Gatti, "1H- and 13C-NMR spectra of eledoisin and intermediate oligopeptides." ''Int. J. Pep. Pro. Res.'' 7:437–444, 1975. Other tachykinins from nonmammalian sources include kassinin and physalaemin. The mammalian tachykinins substance P, NKA, and NKB have similar effects as tachykinins of nonmammals and have been more widely studied and characterized. These peptides exhibit a wide and complex spectrum of pharmacological and physiological activities such as vasodilation, hypertension, and stimulation of extravascular smooth muscle.R. Christy Rani Grace, Indu R. Chandrashekar and Sudha M. Cowsik"Solution Structure of the Tachykinin Peptide Eledoisin", ''Biophysical Journal'' 84:6 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Substance P
Substance P (SP) is an undecapeptide (a peptide composed of a chain of 11 amino acid residues) and a member of the tachykinin neuropeptide family. It is a neuropeptide, acting as a neurotransmitter and as a neuromodulator. Substance P and its closely related neurokinin A (NKA) are produced from a polyprotein precursor after differential splicing of the preprotachykinin A gene. The deduced amino acid sequence of substance P is as follows: * Arg Pro Lys Pro Gln Gln Phe Phe Gly Leu Met (RPKPQQFFGLM) with an amidation at the C-terminus. Substance P is released from the terminals of specific sensory nerves. It is found in the brain and spinal cord and is associated with inflammatory processes and pain. Discovery The original discovery of Substance P (SP) was in 1931 by Ulf von Euler and John H. Gaddum as a tissue extract that caused intestinal contraction ''in vitro''. Its tissue distribution and biologic actions were further investigated over the following decades. The e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exposome
An environmental factor, ecological factor or eco factor is any factor, abiotic or biotic, that influences living organisms. Abiotic factors include ambient temperature, amount of sunlight, and pH of the water soil in which an organism lives. Biotic factors would include the availability of food organisms and the presence of biological specificity, competitors, predators, and parasites. Overview An organism's genotype (e.g., in the zygote) translated into the adult phenotype through development during an organism's ontogeny, and subject to influences by many environmental effects. In this context, a phenotype (or phenotypic trait) can be viewed as any definable and measurable characteristic of an organism, such as its body mass or skin color. Apart from the true monogenic genetic disorders, environmental factors may determine the development of disease in those genetically predisposed to a particular condition. Stress, physical and mental abuse, diet, exposure to toxins, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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