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N-Octyl Beta-D-thioglucopyranoside
''n''-Octyl β--thioglucopyranoside (octylthioglucoside, OTG) is a mild nonionic detergent that is used for cell lysis or to solubilise membrane proteins without denaturing them. This is particularly of use in order to crystallise them or to reconstitute them into lipid bilayers. It has a critical micelle concentration of 9 mM. It is an analog of the commonly used detergent octyl glucoside, the presence of the thioether linkage making it resistant to degradation by beta-glucosidase enzymes. Preparation N-alkyl thioglycosides of the ''n''-octyl-β--thioglucopyranoside type are not naturally occurring. However, mustard oil glycosides are common natural S-glycosides. The synthesis of ''n''-octyl-β--thioglucopyranoside starts from D-glucose (I) which is prepared with acetic anhydride and concentrated sulfuric acid to give α--glucopyranose pentaacetate (pentaacetylglucose) (II). Pentaacetylglucose is reacted with hydrogen bromide to give 2,3,4,6-tetra-''O''-acetyl-α--glucopyran ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell Lysis
Lysis ( ) is the breaking down of the membrane of a cell, often by viral, enzymic, or osmotic (that is, "lytic" ) mechanisms that compromise its integrity. A fluid containing the contents of lysed cells is called a ''lysate''. In molecular biology, biochemistry, and cell biology laboratories, cell cultures may be subjected to lysis in the process of purifying their components, as in protein purification, DNA extraction, RNA extraction, or in purifying organelles. Many species of bacteria are subject to lysis by the enzyme lysozyme, found in animal saliva, egg white, and other secretions. Phage lytic enzymes (lysins) produced during bacteriophage infection are responsible for the ability of these viruses to lyse bacterial cells. Penicillin and related β-lactam antibiotics cause the death of bacteria through enzyme-mediated lysis that occurs after the drug causes the bacterium to form a defective cell wall. If the cell wall is completely lost and the penicillin was used on gr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boron Trifluoride Etherate
Boron trifluoride etherate, strictly boron trifluoride diethyl etherate, or boron trifluoride–ether complex, is the chemical compound with the formula BF3O(C2H5)2, often abbreviated BF3OEt2. It is a colorless liquid, although older samples can appear brown. The compound is used as a source of boron trifluoride in many chemical reactions that require a Lewis acid. The compound features tetrahedral boron coordinated to a diethylether ligand. Many analogues are known, including the methanol complex. Reactions Boron trifluoride etherate serves as a source of boron trifluoride Boron trifluoride is the inorganic compound with the formula BF3. This pungent, colourless, and toxic gas forms white fumes in moist air. It is a useful Lewis acid and a versatile building block for other boron compounds. Structure and bond ... according to the equilibrium: :BF3OEt2 BF3 + OEt2 The BF3 binds to even weak Lewis bases, inducing reactions of the resulting adducts with nucleophiles. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein Data Bank
The Protein Data Bank (PDB) is a database for the three-dimensional structural data of large biological molecules, such as proteins and nucleic acids. The data, typically obtained by X-ray crystallography, NMR spectroscopy, or, increasingly, cryo-electron microscopy, and submitted by biologists and biochemists from around the world, are freely accessible on the Internet via the websites of its member organisations (PDBe, PDBj, RCSB, and BMRB). The PDB is overseen by an organization called the Worldwide Protein Data Bank, wwPDB. The PDB is a key in areas of structural biology, such as structural genomics. Most major scientific journals and some funding agencies now require scientists to submit their structure data to the PDB. Many other databases use protein structures deposited in the PDB. For example, SCOP and CATH classify protein structures, while PDBsum provides a graphic overview of PDB entries using information from other sources, such as Gene ontology. History Two force ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Halobacteria
Haloarchaea (halophilic archaea, halophilic archaebacteria, halobacteria) are a class of the Euryarchaeota, found in water saturated or nearly saturated with salt. Halobacteria are now recognized as archaea rather than bacteria and are one of the largest groups. The name 'halobacteria' was assigned to this group of organisms before the existence of the domain Archaea was realized, and while valid according to taxonomic rules, should be updated. Halophilic archaea are generally referred to as haloarchaea to distinguish them from halophilic bacteria. These microorganisms are among the halophile organisms, that they require high salt concentrations to grow, with most species requiring more than 2.0M NaCl for growth and survival. They are a distinct evolutionary branch of the Archaea distinguished by the possession of ether-linked lipids and the absence of murein in their cell walls. Haloarchaea can grow aerobically or anaerobically. Parts of the membranes of haloarchaea are purpl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacteriorhodopsin
Bacteriorhodopsin is a protein used by Archaea, most notably by haloarchaea, a class of the Euryarchaeota. It acts as a proton pump; that is, it captures light energy and uses it to move protons across the membrane out of the cell. The resulting proton gradient is subsequently converted into chemical energy. Function Bacteriorhodopsin is a light-driven H+ ion transporter found in some haloarchaea, most notably '' Halobacterium salinarum'' (formerly known as syn. ''H. halobium''). The proton-motive force generated by the protein is used by ATP synthase to generate adenosine triphosphate (ATP). By expressing bacteriorhodopsin, the archaea cells are able to synthesise ATP in the absence of a carbon source. Structure Bacteriorhodopsin is a 27 kDa integral membrane protein usually found in two-dimensional crystalline patches known as "purple membrane", which can occupy almost 50% of the surface area of the archaeal cell. The repeating element of the hexagonal lattice is compos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proton Pump
A proton pump is an integral membrane protein pump that builds up a proton gradient across a biological membrane. Proton pumps catalyze the following reaction: : n one side of a biological membrane/sub> + energy n the other side of the membrane/sub> Mechanisms are based on energy-induced conformational changes of the protein structure or on the Q cycle. During evolution, proton pumps have arisen independently on multiple occasions. Thus, not only throughout nature but also within single cells, different proton pumps that are evolutionarily unrelated can be found. Proton pumps are divided into different major classes of pumps that use different sources of energy, have different polypeptide compositions and evolutionary origins. Function Transport of the positively charged proton is typically electrogenic, i.e. it generates an electric field across the membrane also called the membrane potential. Proton transport becomes electrogenic if not neutralized electrically by transp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell Membrane
The cell membrane (also known as the plasma membrane (PM) or cytoplasmic membrane, and historically referred to as the plasmalemma) is a biological membrane that separates and protects the interior of all cells from the outside environment (the extracellular space). The cell membrane consists of a lipid bilayer, made up of two layers of phospholipids with cholesterols (a lipid component) interspersed between them, maintaining appropriate membrane fluidity at various temperatures. The membrane also contains membrane proteins, including integral proteins that span the membrane and serve as membrane transporters, and peripheral proteins that loosely attach to the outer (peripheral) side of the cell membrane, acting as enzymes to facilitate interaction with the cell's environment. Glycolipids embedded in the outer lipid layer serve a similar purpose. The cell membrane controls the movement of substances in and out of cells and organelles, being selectively permeable to ions a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1-Octanol
1-Octanol, also known as octan-1-ol, is the organic compound with the molecular formula CH3(CH2)7OH. It is a fatty alcohol. Many other isomers are also known generically as octanols. 1-Octanol is manufactured for the synthesis of esters for use in perfumes and flavorings. It has a pungent odor. Esters of octanol, such as octyl acetate, occur as components of essential oils. It is used to evaluate the lipophilicity of pharmaceutical products. Preparation Octanol is mainly produced industrially by the oligomerization of ethylene using triethylaluminium followed by oxidation of the alkylaluminium products. This route is known as the Ziegler alcohol synthesis. An idealized synthesis is shown: :Al(C2H5)3 + 9 C2H4 → Al(C8H17)3 :Al(C8H17)3 + 3 O + 3 H2O → 3 HOC8H17 + Al(OH)3 The process generates a range of alcohols, which can be separated by distillation. The Kuraray process defines an alternative route to 1-octanol, but using C4 + C4 building strategy. 1,3-B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Critical Micelle Concentration
In colloidal and surface chemistry, the critical micelle concentration (CMC) is defined as the concentration of surfactants above which micelles form and all additional surfactants added to the system will form micelles. The CMC is an important characteristic of a surfactant. Before reaching the CMC, the surface tension changes strongly with the concentration of the surfactant. After reaching the CMC, the surface tension remains relatively constant or changes with a lower slope. The value of the CMC for a given dispersant in a given medium depends on temperature, pressure, and (sometimes strongly) on the presence and concentration of other surface active substances and electrolytes. Micelles only form above critical micelle temperature. For example, the value of CMC for sodium dodecyl sulfate in water (without other additives or salts) at 25 °C, atmospheric pressure, is 8x10−3 mol/L. Description Upon introducing surfactants (or any surface active materials) into a s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synthese Von N-Octyl-alpha-thioglucopyranosid
''Synthese'' () is a scholarly periodical specializing in papers in epistemology, methodology, and philosophy of science, and related issues. Its subject area is divided into four specialties, with a focus on the first three: (1) "epistemology, methodology, and philosophy of science, all broadly understood"; (2) "foundations of logic and mathematics, where 'logic', 'mathematics', and 'foundations' are all broadly understood"; (3) "formal methods in philosophy, including methods connecting philosophy to other academic fields"; and (4) "issues in ethics and the history and sociology of logic, mathematics, and science that contribute to the contemporary studies". As of 2022, according to Google Scholar's metrics ( h-5 index and h-5 index median), it is the top philosophy journal, but other metrics do not rank the journal as highly. Overview Published articles include specific treatment of methodological issues in science such as induction, probability, causation, statistics, symboli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbohydrate Research
''Carbohydrate Research'' is a peer-reviewed scientific journal covering research on the chemistry of carbohydrates. It is published by Elsevier and was established in 1965. The editor-in-chief is M. Carmen Galan (University of Bristol). According to the ''Journal Citation Reports'', the journal has a 2014 impact factor The impact factor (IF) or journal impact factor (JIF) of an academic journal is a scientometric index calculated by Clarivate that reflects the yearly mean number of citations of articles published in the last two years in a given journal, as i ... of 1.929. References External links * Biochemistry journals Elsevier academic journals Publications established in 1965 English-language journals Carbohydrate chemistry {{biochemistry-journal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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