|
Apamin
Apamin is an 18 amino acid globular peptide neurotoxin found in apitoxin (bee venom). Dry bee venom consists of 2–3% of apamin. Apamin selectively blocks SK channels, a type of Ca2+-activated K+ channel expressed in the central nervous system. Toxicity is caused by only a few amino acids, in particular cysteine1, lysine4, arginine13, arginine14 and histidine18. These amino acids are involved in the binding of apamin to the Ca2+-activated K+ channel. Due to its specificity for SK channels, apamin is used as a drug in biomedical research to study the electrical properties of SK channels and their role in the afterhyperpolarizations occurring immediately following an action potential. Origin The first symptoms of apitoxin (bee venom), that are now thought to be caused by apamin, were described back in 1936 by Hahn and Leditschke. Apamin was first isolated by Habermann in 1965 from ''Apis mellifera'', the Western honey bee. Apamin was named after this bee. Bee venom contains many o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tamapin
Tamapin is a toxin from the Indian Red Scorpion (''Hottentotta tamulus''), which is a selective and potent blocker of SK2 channels. Etymology Tamapin is named after the scorpion from which it was isolated. Sources Tamapin has been isolated from ''hottentotta tamulus'', the Indian red scorpion. Chemical structure and methods of isolation Tamapin belongs to short-chain scorpion toxin subfamily 5, together with PO5 and Scyllatoxin. Its sequence similarity to other toxins that can compete with the binding site of apamin is much lower. It is 31 amino acids long and its weight is 3458 Daltons. Its amino acid sequence is AFCNLRRCELSCRSLGLLGKCIGEECKCVPY, with disulfide bonds between Cys3-Cys21, Cys8-Cys26, and Cys12-Cys28 (chemical formula C146H234N42O42S6). Tamapin has been isolated via detection of the apamin-competing fraction of the venom from the scorpion via a Sephadex G-50 size exclusion chromatography, followed by high performance liquid chromatography (HPLC). An isoform ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MCD Peptide
Mast cell degranulating (MCD) peptide is a cationic 22-amino acid residue peptide, which is a component of the venom of the bumblebee (''Megabombus pennsylvanicus''). At low concentrations, MCD peptide can stimulate mast cell degranulation. At higher concentrations, it has anti-inflammatory properties. In addition, it is a potent blocker of voltage-sensitive potassium channels. Sources MCD peptide is a component of bumblebee (''Megabombus pennsylvanicus'') venom. In addition to MCD peptide, melittin and apamin have also been identified in this venom and are also described as voltage-dependent channel blockers. MCD peptide is also present in the venom of the honey bee ''Apis mellifera''. Chemistry MCD peptide is a cationic 22-amino acid residue peptide with two disulfide bridges. Although the MCD peptide sequence shows similarity with apamin, they have different toxic properties. MCD peptide belongs to a large family composed of numerous derivatives detecting specific targets a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PubChem
PubChem is a database of chemical molecules and their activities against biological assays. The system is maintained by the National Center for Biotechnology Information (NCBI), a component of the National Library of Medicine, which is part of the United States National Institutes of Health (NIH). PubChem can be accessed for free through a web user interface. Millions of compound structures and descriptive datasets can be freely downloaded via FTP. PubChem contains multiple substance descriptions and small molecules with fewer than 100 atoms and 1,000 bonds. More than 80 database vendors contribute to the growing PubChem database. History PubChem was released in 2004 as a component of the Molecular Libraries Program (MLP) of the NIH. As of November 2015, PubChem contains more than 150 million depositor-provided substance descriptions, 60 million unique chemical structures, and 225 million biological activity test results (from over 1 million assay experiments performed on mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HNMR
Proton nuclear magnetic resonance (proton NMR, hydrogen-1 NMR, or 1H NMR) is the application of nuclear magnetic resonance in NMR spectroscopy with respect to hydrogen-1 nuclei within the molecules of a substance, in order to determine the structure of its molecules. In samples where natural hydrogen (H) is used, practically all the hydrogen consists of the isotope 1H (hydrogen-1; i.e. having a proton for a nucleus). Simple NMR spectra are recorded in solution, and solvent protons must not be allowed to interfere. Deuterated (deuterium = 2H, often symbolized as D) solvents especially for use in NMR are preferred, e.g. deuterated water, D2O, deuterated acetone, (CD3)2CO, deuterated methanol, CD3OD, deuterated dimethyl sulfoxide, (CD3)2SO, and deuterated chloroform, CDCl3. However, a solvent without hydrogen, such as carbon tetrachloride, CCl4 or carbon disulfide, CS2, may also be used. Historically, deuterated solvents were supplied with a small amount (typically 0.1%) of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pain
Pain is a distressing feeling often caused by intense or damaging stimuli. The International Association for the Study of Pain defines pain as "an unpleasant sensory and emotional experience associated with, or resembling that associated with, actual or potential tissue damage." In medical diagnosis, pain is regarded as a symptom of an underlying condition. Pain motivates the individual to withdraw from damaging situations, to protect a damaged body part while it heals, and to avoid similar experiences in the future. Most pain resolves once the noxious stimulus is removed and the body has healed, but it may persist despite removal of the stimulus and apparent healing of the body. Sometimes pain arises in the absence of any detectable stimulus, damage or disease. Pain is the most common reason for physician consultation in most developed countries. It is a major symptom in many medical conditions, and can interfere with a person's quality of life and general functioning. Simp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spinal Cord
The spinal cord is a long, thin, tubular structure made up of nervous tissue, which extends from the medulla oblongata in the brainstem to the lumbar region of the vertebral column (backbone). The backbone encloses the central canal of the spinal cord, which contains cerebrospinal fluid. The brain and spinal cord together make up the central nervous system (CNS). In humans, the spinal cord begins at the occipital bone, passing through the foramen magnum and then enters the spinal canal at the beginning of the cervical vertebrae. The spinal cord extends down to between the first and second lumbar vertebrae, where it ends. The enclosing bony vertebral column protects the relatively shorter spinal cord. It is around long in adult men and around long in adult women. The diameter of the spinal cord ranges from in the cervical and lumbar regions to in the thoracic area. The spinal cord functions primarily in the transmission of nerve signals from the motor cortex to the b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glomerular , a hemorrhage of the bladder
{{SIA ...
''Glomerulus'' () is a common term used in anatomy to describe globular structures of entwined vessels, fibers, or neurons. ''Glomerulus'' is the diminutive of the Latin ''glomus'', meaning "ball of yarn". ''Glomerulus'' may refer to: * the filtering unit of the kidney; see Glomerulus (kidney). * a structure in the olfactory bulb; see Glomerulus (olfaction). * the contact between specific cells in the cerebellum; see Glomerulus (cerebellum). See also *Glomerulation Glomerulation refers to bladder hemorrhages which are thought to be associated with some types of interstitial cystitis (IC). The presence of glomerulations, also known as petechial hemorrhages, in the bladder suggests that the bladder wall has bee ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kidney
The kidneys are two reddish-brown bean-shaped organs found in vertebrates. They are located on the left and right in the retroperitoneal space, and in adult humans are about in length. They receive blood from the paired renal arteries; blood exits into the paired renal veins. Each kidney is attached to a ureter, a tube that carries excreted urine to the bladder. The kidney participates in the control of the volume of various body fluids, fluid osmolality, acid–base balance, various electrolyte concentrations, and removal of toxins. Filtration occurs in the glomerulus: one-fifth of the blood volume that enters the kidneys is filtered. Examples of substances reabsorbed are solute-free water, sodium, bicarbonate, glucose, and amino acids. Examples of substances secreted are hydrogen, ammonium, potassium and uric acid. The nephron is the structural and functional unit of the kidney. Each adult human kidney contains around 1 million nephrons, while a mouse kidney ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scyllatoxin
Scyllatoxin (also leiurotoxin I) is a toxin, from the scorpion '' Leiurus quinquestriatus hebraeus'', which blocks small-conductance Ca2+-activated K+ channels. It is named after Scylla, a sea monster from Greek mythology. Charybdotoxin is also found in the venom from the same species of scorpion, and is named after the sea monster Charybdis. In Greek mythology, Scylla and Charybdis lived on rocks on opposing sides of a narrow strait of water. Sources Scyllatoxin is one of the components of the venom of the Israeli scorpion ''‘Leiurus quinquestriatus hebraeus’''. It consists of only 0.02% of the total protein in crude venom. Chemistry Leiurotoxin I is a 31-residue peptide (sequence AFCNLRMCQLSCRSLGLLGKCIGDKCECVKH-NH2), with a helix and a short antiparallel β-sheet. This toxin is stabilized by disulfide bonds: Cys8-Cys26 and Cys12-Cys28 is bound to the β-sheet, while Cys3-Cys21 is bound to an N-terminal segment preceding the helix. Leiurotoxin adopts the ά/β motif ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calmodulin
Calmodulin (CaM) (an abbreviation for calcium-modulated protein) is a multifunctional intermediate calcium-binding messenger protein expressed in all eukaryotic cells. It is an intracellular target of the secondary messenger Ca2+, and the binding of Ca2+ is required for the activation of calmodulin. Once bound to Ca2+, calmodulin acts as part of a calcium signal transduction pathway by modifying its interactions with various target proteins such as kinases or phosphatases. Structure Calmodulin is a small, highly conserved protein that is 148 amino acids long (16.7 kDa). The protein has two approximately symmetrical globular domains (the N- and C- domains) each containing a pair of EF hand motifs separated by a flexible linker region for a total of four Ca2+ binding sites, two in each globular domain. In the Ca2+-free state, the helices that form the four EF-hands are collapsed in a compact orientation, and the central linker is disordered; in the Ca2+-saturated state, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trypsin
Trypsin is an enzyme in the first section of the small intestine that starts the digestion of protein molecules by cutting these long chains of amino acids into smaller pieces. It is a serine protease from the PA clan superfamily, found in the digestive system of many vertebrates, where it hydrolyzes proteins. Trypsin is formed in the small intestine when its proenzyme form, the trypsinogen produced by the pancreas, is activated. Trypsin cuts peptide chains mainly at the carboxyl side of the amino acids lysine or arginine. It is used for numerous biotechnological processes. The process is commonly referred to as trypsin proteolysis or trypsinization, and proteins that have been digested/treated with trypsin are said to have been trypsinized. Trypsin was discovered in 1876 by Wilhelm Kühne and was named from the Ancient Greek word for rubbing since it was first isolated by rubbing the pancreas with glycerin. Function In the duodenum, trypsin catalyzes the hydro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1,2-Cyclohexanedione
1,2-Cyclohexanedione is an organic compound with the formula (CH)(CO). It is one of three isomeric cyclohexanediones. It is a colorless compound that is soluble in a variety of organic solvents. It can be prepared by oxidation of cyclohexanone by selenium dioxide. The enol is about 1 kcal/mol more stable than the diketo form. Numerous diimine and dioxime ligands have been prepared from this diketone. It condenses with 1,2-diamine A diamine is an amine with exactly two amino groups. Diamines are used as monomers to prepare polyamides, polyimides, and polyureas. The term ''diamine'' refers mostly to primary diamines, as those are the most reactive. In terms of quantiti ...s to give diaza heterocycles. References {{DEFAULTSORT:Cyclohexanedione, 1, 2- Diketones Cyclic ketones ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
