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Isotuberculosinol
Isotuberculosinol, also called nosyberkol or edaxadiene is a diterpene molecule produced by the bacterium '' Mycobacterium tuberculosis'', the causative agent of TB, which aids in its pathogenesis. Isotuberculosinol functions by preventing maturation of the host-cell phagosome in which the bacterium lives. Maturation of the phagosome would enable it to kill the bacterium. Mutations in genes involved in the biosynthetic pathway of nosyberkol result in normal development of the phagosome and reduction of mycobacterial infection. These biosynthetic genes include isotuberculosinol synthase. Nosyberkol was originally isolated in 2004 from a marine sponge in the ocean near island of Nosy Be after which it was named. The molecule was characterised as a triterpene Triterpenes are a class of chemical compounds composed of three terpene units with the molecular formula C30H48; they may also be thought of as consisting of six isoprene units. Animals, plants and fungi all produce tri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isotuberculosinol Synthase
Isotuberculosinol synthase (, ''Rv3378c'') is an enzyme with systematic name ''tuberculosinyl diphosphate diphosphohydrolase (isotuberculosinol forming)''. This enzyme catalyses the following chemical reaction : tuberculosinyl diphosphate + H2O \rightleftharpoons (13S)-isotuberculosinol + diphosphate This enzyme is present in species of '' Mycobacterium'' that cause tuberculosis Tuberculosis (TB) is an infectious disease usually caused by '' Mycobacterium tuberculosis'' (MTB) bacteria. Tuberculosis generally affects the lungs, but it can also affect other parts of the body. Most infections show no symptoms, i .... References External links * {{Portal bar, Biology, border=no EC 3.1.7 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mycobacterium Tuberculosis
''Mycobacterium tuberculosis'' (M. tb) is a species of pathogenic bacteria in the family Mycobacteriaceae and the causative agent of tuberculosis. First discovered in 1882 by Robert Koch, ''M. tuberculosis'' has an unusual, waxy coating on its cell surface primarily due to the presence of mycolic acid. This coating makes the cells impervious to Gram staining, and as a result, ''M. tuberculosis'' can appear weakly Gram-positive. Acid-fastness, Acid-fast stains such as Ziehl–Neelsen stain, Ziehl–Neelsen, or Fluorescence, fluorescent stains such as Auramine O, auramine are used instead to identify ''M. tuberculosis'' with a microscope. The physiology of ''M. tuberculosis'' is highly aerobic organism, aerobic and requires high levels of oxygen. Primarily a pathogen of the mammalian respiratory system, it infects the lungs. The most frequently used diagnostic methods for tuberculosis are the Mantoux test, tuberculin skin test, Acid-Fast Stain, acid-fast stain, Microbiological cultu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diterpene
Diterpenes are a class of chemical compounds composed of four isoprene units, often with the molecular formula C20H32. They are biosynthesized by plants, animals and fungi via the HMG-CoA reductase pathway, with geranylgeranyl pyrophosphate being a primary intermediate. Diterpenes form the basis for biologically important compounds such as retinol, retinal, and phytol. They are known to be antimicrobial and antiinflammatory. Structures As with most terpenes a huge number of potential structures exists, which may be broadly divided according to the number of rings present. Biosynthesis Diterpenes are derived from the addition of one IPP unit to FPP to form geranylgeranyl-pyrophosphate (GGPP). From GGPP, structural diversity is achieved mainly by two classes of enzymes; the diterpene synthases and cytochromes P450. Several diterpenes are produced by plants and cyanobacteria. GGPP is also the precursor for the synthesis of the phytane by the action of the enzyme geranylger ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tuberculosis
Tuberculosis (TB) is an infectious disease usually caused by '' Mycobacterium tuberculosis'' (MTB) bacteria. Tuberculosis generally affects the lungs, but it can also affect other parts of the body. Most infections show no symptoms, in which case it is known as latent tuberculosis. Around 10% of latent infections progress to active disease which, if left untreated, kill about half of those affected. Typical symptoms of active TB are chronic cough with blood-containing mucus, fever, night sweats, and weight loss. It was historically referred to as consumption due to the weight loss associated with the disease. Infection of other organs can cause a wide range of symptoms. Tuberculosis is spread from one person to the next through the air when people who have active TB in their lungs cough, spit, speak, or sneeze. People with Latent TB do not spread the disease. Active infection occurs more often in people with HIV/AIDS and in those who smoke. Diagnosis of active TB is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phagosome
In cell biology, a phagosome is a vesicle formed around a particle engulfed by a phagocyte via phagocytosis. Professional phagocytes include macrophages, neutrophils, and dendritic cells (DCs). A phagosome is formed by the fusion of the cell membrane around a microorganism, a senescent cell or an apoptotic cell. Phagosomes have membrane-bound proteins to recruit and fuse with lysosomes to form mature phagolysosomes. The lysosomes contain hydrolytic enzymes and reactive oxygen species (ROS) which kill and digest the pathogens. Phagosomes can also form in non-professional phagocytes, but they can only engulf a smaller range of particles, and do not contain ROS. The useful materials (e.g. amino acids) from the digested particles are moved into the cytosol, and waste is removed by exocytosis. Phagosome formation is crucial for tissue homeostasis and both innate and adaptive host defense against pathogens. However, some bacteria can exploit phagocytosis as an invasion strategy. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sponge
Sponges, the members of the phylum Porifera (; meaning 'pore bearer'), are a basal animal clade as a sister of the diploblasts. They are multicellular organisms that have bodies full of pores and channels allowing water to circulate through them, consisting of jelly-like mesohyl sandwiched between two thin layers of cells. Sponges have unspecialized cells that can transform into other types and that often migrate between the main cell layers and the mesohyl in the process. Sponges do not have nervous, digestive or circulatory systems. Instead, most rely on maintaining a constant water flow through their bodies to obtain food and oxygen and to remove wastes. Sponges were first to branch off the evolutionary tree from the last common ancestor of all animals, making them the sister group of all other animals. Etymology The term ''sponge'' derives from the Ancient Greek word ( 'sponge'). Overview Sponges are similar to other animals in that they are multicellular, he ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nosy Be
Nosy Be (formerly Nossi-bé and Nosse Be) is an island off the northwest coast of Madagascar. Nosy Be is Madagascar's largest and busiest tourist resort. It has an area of , and its population was 109,465 according to the provisional results of the 2018 Census. ''Nosy Be'' means "big island" in the Malagasy language. The island was called Assada during the early colonial era of the 17th century. Nosy Be has been given several nicknames over the centuries, including "Nosy Manitra" (the scented island). History The first human inhabitants of Nosy Be were small bands of Antankarana and Zafinofotsy, before the Sakalava people migrated there and became the most numerous ethnic group on the island. These people were joined later by some Comorians, Indians or Antandroy. Nosy Be made first major appearance in Madagascar's history when King Radama I announced that he intended to conquer the whole west of Madagascar. That plan was eventually achieved in 1837 when the Sakalava Kingdom of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triterpene
Triterpenes are a class of chemical compounds composed of three terpene units with the molecular formula C30H48; they may also be thought of as consisting of six isoprene units. Animals, plants and fungi all produce triterpenes, including squalene, the precursor to all steroids. Structures Triterpenes exist in a great variety of structures. Nearly 200 different skeletons have been identified. These skeletons may be broadly divided according to the number of rings present. In general pentacyclic structures (5 rings) tend to dominate. Squalene is biosynthesized through the head-to-head condensation of two farnesyl pyrophosphate units. This coupling converts a pair of C15 components into a C30 product. Squalene serves as precursor for the formation of many triterpenoids, including bacterial hopanoids and eukaryotic sterols. Triterpenoids By definition triterpenoids are triterpenes that possess heteroatoms, usually oxygen. The terms ''triterpene'' and ''triterpenoid'' oft ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diterpenes
Diterpenes are a class of chemical compounds composed of four isoprene units, often with the molecular formula C20H32. They are biosynthesized by plants, animals and fungi via the HMG-CoA reductase pathway, with geranylgeranyl pyrophosphate being a primary intermediate. Diterpenes form the basis for biologically important compounds such as retinol, retinal, and phytol. They are known to be antimicrobial and antiinflammatory. Structures As with most terpenes a huge number of potential structures exists, which may be broadly divided according to the number of rings present. Biosynthesis Diterpenes are derived from the addition of one IPP unit to FPP to form geranylgeranyl-pyrophosphate (GGPP). From GGPP, structural diversity is achieved mainly by two classes of enzymes; the diterpene synthases and cytochromes P450. Several diterpenes are produced by plants and cyanobacteria. GGPP is also the precursor for the synthesis of the phytane by the action of the enzyme geranylger ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bicyclic Compounds
In chemistry, a bicyclic molecule () is a molecule that features two joined rings. Bicyclic structures occur widely, for example in many biologically important molecules like α-thujene and camphor. A bicyclic compound can be carbocyclic (all of the ring atoms are carbons), or heterocyclic (the rings' atoms consist of at least two elements), like DABCO. Moreover, the two rings can both be aliphatic (''e.g.'' decalin and norbornane), or can be aromatic (''e.g.'' naphthalene), or a combination of aliphatic and aromatic (''e.g.'' tetralin). Three modes of ring junction are possible for a bicyclic compound: * In spirocyclic compounds, the two rings share only one single atom, the spiro atom, which is usually a quaternary carbon. An example of a spirocyclic compound is the photochromic switch spiropyran. * In fused/condensed bicyclic compounds, two rings share two adjacent atoms. In other words, the rings share one covalent bond, ''i.e.'' the so-called bridgehead atoms are directly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
