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Teichoic Acid
Teichoic acids (''cf.'' Greek τεῖχος, ''teīkhos'', "wall", to be specific a fortification wall, as opposed to τοῖχος, ''toīkhos'', a regular wall) are bacterial copolymers of glycerol phosphate or ribitol phosphate and carbohydrates linked via phosphodiester bonds. Teichoic acids are found within the cell wall of most Gram-positive bacteria such as species in the genera ''Staphylococcus'', ''Streptococcus'', ''Bacillus'', ''Clostridium'', ''Corynebacterium'', and ''Listeria'', and appear to extend to the surface of the peptidoglycan layer. They can be covalently linked to ''N''-acetylmuramic acid or a terminal D-alanine in the tetrapeptide crosslinkage between ''N''-acetylmuramic acid units of the peptidoglycan layer, or they can be anchored in the cytoplasmic membrane with a lipid anchor. Teichoic acid's chemical signal is CH17P4O29NOH. Teichoic acids that are anchored to the lipid membrane are referred to as lipoteichoic acids (LTAs), whereas teichoic acids ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Listeria
''Listeria'' is a genus of bacteria that acts as an intracellular parasite in mammals. As of 2024, 28 species have been identified. The genus is named in honour of the British pioneer of sterile surgery Joseph Lister. ''Listeria'' species are Gram-positive, rod-shaped, and facultatively anaerobic, and do not produce endospores. The major human pathogen in the genus is '' L. monocytogenes''. Although ''L. monocytogenes'' has low infectivity, it is hardy and can grow in a refrigerator temperature of 4 °C (39.2 °F) up to the human body temperature of 37 °C (98.6 °F). [No longer accessible. Archived version availablhere] It is the usual cause of the relatively rare bacterial disease listeriosis, an infection caused by eating foodborne illness, food contaminated with the bacteria. The overt form of the disease has a case-fatality rate of around 20–30%. Listeriosis can cause serious illness in pregnant women, newborns, adults with weakened immune ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
EC 2
EC or ec may refer to: Arts and entertainment * EC Comics, an American publisher of comic books * '' Electric Circus'', a Canadian television program * Eric Clapton Stratocaster, signature model guitars by Fender Businesses and organisations Government * Environment and Climate Change Canada, a Canadian federal government department * European Commission, the executive body of the European Union * European Council, the European Union institution comprising the college of heads of state of government * European Communities, one of the three pillars of the EU * European Community, a significant component of the European Union from 1993 to 2009, renamed European Economic Community Transportation * EuroCity, a train service of the European inter-city rail network * EasyJet Europe (IATA code: EC) * Avialeasing (former IATA code: EC), a cargo airline * East Coast (train operating company), a train operating company in the UK * EC, the aircraft registration prefix for Spain Educ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autolysins
Autolysins are endogenous lytic enzymes that break down the peptidoglycan components of biological cells which enables the separation of daughter cells following cell division. They are involved in cell growth, cell wall metabolism, cell division and separation, as well as peptidoglycan turnover and have similar functions to lysozymes. Autolysin is formed from the precursor gene, Atl. Amidases (EC 3.5.1.28), gametolysin (EC 3.4.24.38), and glucosaminidase are considered as types of autolysins. Function and mechanisms Autolysins exist in all bacteria containing peptidoglycan and are potentially considered as lethal enzymes when uncontrolled. They target the glycosidic bonds as well as the cross-linked peptides of the peptidoglycan matrix. The peptidoglycan matrix functions for cell wall stability to protect from turgor changes and carries out function for immunological defense. These enzymes break down the peptidoglycan matrix in small sections to allow for peptidoglycan biosynt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Toll-like Receptor
Toll-like receptors (TLRs) are a class of proteins that play a key role in the innate immune system. They are single-pass membrane protein, single-spanning receptor (biochemistry), receptors usually expressed on sentinel cells such as macrophages and dendritic cells, that recognize structurally conserved molecules derived from Microorganism, microbes. Once these microbes have reached physical barriers such as the skin or intestinal tract mucosa, they are recognized by TLRs, which activate immune cell responses. The TLRs include TLR1, TLR2, TLR3, TLR4, TLR5, TLR6, TLR7, TLR8, TLR9, TLR10, TLR11, TLR12, and TLR13. Humans lack genes for TLR11, TLR12 and TLR13 and mice lack a functional gene for TLR10. The receptors TLR1, TLR2, TLR4, TLR5, TLR6, and TLR10 are located on the cell membrane, whereas TLR3, TLR7, TLR8, and TLR9 are located in Intracellular receptor, intracellular Vesicle (biology and chemistry), vesicles (because they are sensors of nucleic acids). TLRs received their name ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zwitterion
In chemistry, a zwitterion ( ; ), also called an inner salt or dipolar ion, is a molecule that contains an equal number of positively and negatively charged functional groups. : (1,2- dipolar compounds, such as ylides, are sometimes excluded from the definition.) Some zwitterions, such as amino acid zwitterions, are in chemical equilibrium with an uncharged "parent" molecule. Betaines are zwitterions that cannot isomerize to an all-neutral form, such as when the positive charge is located on a quaternary ammonium group. Similarly, a molecule containing a phosphonium group and a carboxylate group cannot isomerize. Amino acids Tautomerism of amino acids follows this stoichiometry: : The ratio of the concentrations of the two species in solution is independent of pH. It has been suggested, on the basis of theoretical analysis, that the zwitterion is stabilized in aqueous solution by hydrogen bonding with solvent water molecules. Analysis of neutron diffraction data for g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glucosamine
Glucosamine (C6H13NO5) is an amino sugar and a prominent precursor in the biochemical synthesis of glycosylated proteins and lipids. Glucosamine is part of the structure of two polysaccharides, chitosan and chitin. Glucosamine is one of the most abundant monosaccharides. Produced commercially by the hydrolysis of shellfish exoskeletons or, less commonly, by fermentation of a grain such as corn or wheat, glucosamine has many names depending on country. Although a common dietary supplement, there is little evidence that it is effective for relief of arthritis or pain, and is not an approved prescription drug in the United States. Dietary supplement Oral glucosamine is a dietary supplement and is not a prescription drug in the United States. Glucosamine is marketed as a supplement to support the structure and function of joints, and the marketing is targeted to people with osteoarthritis. Commonly sold forms of glucosamine are glucosamine sulfate, glucosamine chondroitin, glu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LCP Family
The LCP family or TagU family of proteins is a conserved family of phosphotransferases that are involved in the attachment of teichoic acid (TA) molecules to gram-positive cell wall or cell membrane. It was initially thought as the LytR (lytic repressor) component of a LytABC operon encoding autolysin Autolysins are endogenous lytic enzymes that break down the peptidoglycan components of biological cells which enables the separation of daughter cells following cell division. They are involved in cell growth, cell wall metabolism, cell division ...s, but the mechanism of regulation was later realized to be the production of TA molecules. It was accordingly renamed TagU. The "LCP" acronym derives from three proteins initially identified to contain this domain, LytR (now TagU, ), cpsA ("Capsular polysaccharide expression regulator"), and psr ("PBP 5 synthesis repressor"). These proteins were mistaken as transcriptional regulators via different reasons, but all three of them are n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lipoteichoic Acid
Lipoteichoic acid (LTA) is a major constituent of the cell wall of gram-positive bacteria. These organisms have an inner (or cytoplasmic) membrane and, external to it, a thick (up to 80 nanometer) peptidoglycan layer. The structure of LTA varies between the different species of gram-positive bacteria and may contain long chains of ribitol or glycerol phosphate. LTA is anchored to the cell membrane via a diacylglycerol. It acts as regulator of autolytic wall enzymes ( muramidases). It has antigenic properties being able to stimulate specific immune response. LTA may bind to target cells non-specifically through membrane phospholipids, or specifically to CD14 and to Toll-like receptors. Binding to TLR-2 has shown to induce NF-κB expression(a central transcription factor In molecular biology, a transcription factor (TF) (or sequence-specific DNA-binding factor) is a protein that controls the rate of transcription (genetics), transcription of genetics, genetic informat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lipid
Lipids are a broad group of organic compounds which include fats, waxes, sterols, fat-soluble vitamins (such as vitamins A, D, E and K), monoglycerides, diglycerides, phospholipids, and others. The functions of lipids include storing energy, signaling, and acting as structural components of cell membranes. Lipids have applications in the cosmetic and food industries, and in nanotechnology. Lipids are broadly defined as hydrophobic or amphiphilic small molecules; the amphiphilic nature of some lipids allows them to form structures such as vesicles, multilamellar/ unilamellar liposomes, or membranes in an aqueous environment. Biological lipids originate entirely or in part from two distinct types of biochemical subunits or "building-blocks": ketoacyl and isoprene groups. Using this approach, lipids may be divided into eight categories: fatty acyls, glycerolipids, glycerophospholipids, sphingolipids, saccharolipids, and polyketides (derived from condensatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytoplasmic Membrane
The cell membrane (also known as the plasma membrane or cytoplasmic membrane, and historically referred to as the plasmalemma) is a biological membrane that separates and protects the cytoplasm, interior of a Cell (biology), cell from the extracellular space, 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 Membrane fluidity, 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 membrane transport, controls the movement of substances in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetrapeptide
A tetrapeptide is a peptide, classified as an oligopeptide, since it only consists of four amino acids joined by peptide bonds. Many tetrapeptides are pharmacologically active, often showing affinity and specificity for a variety of receptors in protein-protein signaling. Present in nature are both linear and cyclic tetrapeptides (CTPs), the latter of which mimics protein reverse turns which are often present on the surface of proteins and druggable targets. Tetrapeptides may be cyclized by a fourth peptide bond or other covalent bonds. Examples of tetrapeptides are: * Tuftsin (L-threonyl-L-lysyl-L-prolyl-L-arginine) is a peptide related primarily to the immune system function. * Rigin (glycyl-L-glutaminyl-L-prolyl-L-arginine) is a tetrapeptide with functions similar to those of tuftsin. * Postin (Lys-Pro-Pro-Arg) is the N-terminal tetrapeptide of cystatin C and an antagonist of tuftsin. * Endomorphin-1 (H-Tyr-Pro-Trp-Phe-NH2) and endomorphin-2 (H-Tyr-Pro-Phe-Phe-NH2) a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
