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Gephyronic Acid
Gephyronic acid is a polyketide that exists as an equilibrating mixture of structural isomers. In nature, gephyronic acid is produced by slow growing myxobacterium: Archangium gephyra strain Ar3895 and Cystobacter violaceus strain Cb vi76. It is the first antibiotic in myxobacteria that was reported to specifically inhibit eukaryotic protein synthesis. Biological properties Preliminary studies demonstrated that gephyronic acid inhibited growth of yeast and molds as well as elicited a cytostatic effect through the inhibition of eukaryotic protein synthesis in mammalian cell cultures. Feeding experiments done with radioactive precursors showed a drastic difference in incorporation of leucine by a human leukemic cell like K-562, but little difference in the incorporation of uridine and thymidine. This suggested that the primary target of gephyronic acid is protein synthesis. As such, it is a potential target for cancer chemotherapy Chemotherapy (often abbreviated to chemo and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyketide
Polyketides are a class of natural products derived from a precursor molecule consisting of a chain of alternating ketone (or reduced forms of a ketone) and methylene groups: (-CO-CH2-). First studied in the early 20th century, discovery, biosynthesis, and application of polyketides has evolved. It is a large and diverse group of secondary metabolites caused by its complex biosynthesis which resembles that of fatty acid synthesis. Because of this diversity, polyketides can have various medicinal, agricultural, and industrial applications. Many polyketides are medicinal or exhibit acute toxicity. Biotechnology has enabled discovery of more naturally-occurring polyketides and evolution of new polyketides with novel or improved bioactivity. History Naturally produced polyketides by various plants and organisms have been used by humans since before studies on them began in the 19th and 20th century. In 1893, J. Norman Collie synthesized detectable amounts of orcinol by heating de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Myxobacteria
The myxobacteria ("slime bacteria") are a group of bacteria that predominantly live in the soil and feed on insoluble organic substances. The myxobacteria have very large genomes relative to other bacteria, e.g. 9–10 million nucleotides except for '' Anaeromyxobacter'' and ''Vulgatibacter''. One species of myxobacteria, ''Minicystis rosea'', has the largest known bacterial genome with over 16 million nucleotides. The second largest is another myxobacteria '' Sorangium cellulosum''. Myxobacteria can move by gliding. They typically travel in ''swarms'' (also known as ''wolf packs''), containing many cells kept together by intercellular molecular signals. Individuals benefit from aggregation as it allows accumulation of the extracellular enzymes that are used to digest food; this in turn increases feeding efficiency. Myxobacteria produce a number of biomedically and industrially useful chemicals, such as antibiotics, and export those chemicals outside the cell. Myxobacteria ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytostasis
Cytostasis (cyto – cell; stasis – stoppage) is the inhibition of cell growth and multiplication. Cytostatic refers to a cellular component or medicine that inhibits cell division. Cytostasis is an important prerequisite for structured multicellular organisms. Without regulation of cell growth and division only unorganized heaps of cells would be possible. Chemotherapy of cancer, treatment of skin diseases and treatment of infections are common use cases of cytostatic drugs. Active hygienic products generally contain cytostatic substances. Cytostatic mechanisms and drugs generally occur together with cytotoxic ones. Activators Nitric oxide – activated macrophages produce large amounts of nitric oxide (NO), which induces both cytostasis and cytotoxicity to tumor cells both ''in vitro'' and ''in vivo''. Nitric oxide-induced cytostasis targets ribonucleotide reductase by rapid and reversible inhibition. However, other studies show there could be other targets that are respon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemotherapy
Chemotherapy (often abbreviated to chemo and sometimes CTX or CTx) is a type of cancer treatment that uses one or more anti-cancer drugs (chemotherapeutic agents or alkylating agents) as part of a standardized chemotherapy regimen. Chemotherapy may be given with a curative intent (which almost always involves combinations of drugs) or it may aim to prolong life or to reduce symptoms ( palliative chemotherapy). Chemotherapy is one of the major categories of the medical discipline specifically devoted to pharmacotherapy for cancer, which is called ''medical oncology''. The term ''chemotherapy'' has come to connote non-specific usage of intracellular poisons to inhibit mitosis (cell division) or induce DNA damage, which is why inhibition of DNA repair can augment chemotherapy. The connotation of the word chemotherapy excludes more selective agents that block extracellular signals (signal transduction). The development of therapies with specific molecular or genetic targets, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
P-bodies
P-bodies, or processing bodies are distinct foci formed by phase separation within the cytoplasm of the eukaryotic cell consisting of many enzymes involved in mRNA turnover. P-bodies are highly conserved structures and have been observed in somatic cells originating from vertebrates and invertebrates, plants and yeast. To date, P-bodies have been demonstrated to play fundamental roles in general mRNA decay, nonsense-mediated mRNA decay, adenylate-uridylate-rich element mediated mRNA decay, and microRNA (miRNA) induced mRNA silencing. Not all mRNAs which enter P-bodies are degraded, as it has been demonstrated that some mRNAs can exit P-bodies and re-initiate translation. Purification and sequencing of the mRNA from purified processing bodies showed that these mRNAs are largely translationally repressed upstream of translation initiation and are protected from 5' mRNA decay. P-bodies are involved in decapping and degradation of unwanted mRNAs, storing mRNA until needed for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
O-methyltransferase
An O-methyltransferase (OMT) is a type of methyltransferase enzyme transferring a methyl group on a molecule. Examples are : * Acetylserotonin O-methyltransferase * Apigenin 4'-O-methyltransferase * Caffeate O-methyltransferase * Caffeoyl-CoA O-methyltransferase * Catechol O-methyltransferase * Chlorophenol O-methyltransferase * Columbamine O-methyltransferase * Demethylmacrocin O-methyltransferase * 3'-demethylstaurosporine O-methyltransferase * Demethylsterigmatocystin 6-O-methyltransferase * 3-demethylubiquinone-9 3-O-methyltransferase * 3,7-dimethylquercetin 4'-O-methyltransferase * Fatty-acid O-methyltransferase * Glucuronoxylan 4-O-methyltransferase * 10-hydroxydihydrosanguinarine 10-O-methyltransferase * 12-hydroxydihydrochelirubine 12-O-methyltransferase * 6-hydroxymellein O-methyltransferase * 3'-hydroxy-N-methyl-(S)-coclaurine 4'-O-methyltransferase * 8-hydroxyquercetin 8-O-methyltransferase * Iodophenol O-methyltransferase * Isobutyraldoxime O-methyltransferase * (iso) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytochrome P450
Cytochromes P450 (CYPs) are a superfamily of enzymes containing heme as a cofactor that functions as monooxygenases. In mammals, these proteins oxidize steroids, fatty acids, and xenobiotics, and are important for the clearance of various compounds, as well as for hormone synthesis and breakdown. In 1963, Estabrook, Cooper, and Rosenthal described the role of CYP as a catalyst in steroid hormone synthesis and drug metabolism. In plants, these proteins are important for the biosynthesis of defensive compounds, fatty acids, and hormones. CYP enzymes have been identified in all kingdoms of life: animals, plants, fungi, protists, bacteria, and archaea, as well as in viruses. However, they are not omnipresent; for example, they have not been found in ''Escherichia coli''. , more than 300,000 distinct CYP proteins are known. CYPs are, in general, the terminal oxidase enzymes in electron transfer chains, broadly categorized as P450-containing systems. The term "P450" is derived fro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
N-acetyltransferase
N-acetyltransferase (NAT) is an enzyme that catalysis, catalyzes the transfer of acetyl groups from acetyl-CoA to arylamines, arylhydroxylamines and arylhydrazines. They have wide specificity for aromatic amines, particularly serotonin, and can also catalyze acetyl transfer between arylamines without CoA. N-acetyltransferases are cytosolic enzymes found in the liver and many tissues of most mammalian species, except the dog and fox, which cannot acetylate xenobiotics. Acetyl groups are important in the conjugation of metabolites from the liver, to allow excretion of the byproducts (phase II metabolism). This is especially important in the metabolism and excretion of drug products (drug metabolism). __TOC__ Enzyme Mechanism NAT enzymes are differentiated by the presence of a conserved catalytic triad that favors aromatic amine and hydrazine substrates. NATs catalyze the acetylation of small molecules through a double displacement reaction called the ping pong bi bi reaction. The Re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mechanism Of SAM O-methyltransferase
Mechanism may refer to: *Mechanism (engineering), rigid bodies connected by joints in order to accomplish a desired force and/or motion transmission *Mechanism (biology), explaining how a feature is created *Mechanism (philosophy), a theory that all natural phenomena can be explained by physical causes *Mechanism (sociology), a theory that all social phenomena can be explained by the existence of a deterministic mechanism * "The Mechanism", song by Disclosure * ''The Mechanism'' (TV series), a Netflix TV series See also * Machine *Machine (mechanical) *Linkage (mechanical) *Mechanism design, the art of designing rules of a game to achieve a specific outcome *Mechanism of action, the means by which a drug exerts its biological effects *Defence mechanism, unconscious mechanisms aimed at reducing anxiety *Reaction mechanism, the sequence of reactions by which overall chemical change occurs *Antikythera mechanism, an ancient Greek analog computer *Theory of operation A theory of o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytochrome P450
Cytochromes P450 (CYPs) are a superfamily of enzymes containing heme as a cofactor that functions as monooxygenases. In mammals, these proteins oxidize steroids, fatty acids, and xenobiotics, and are important for the clearance of various compounds, as well as for hormone synthesis and breakdown. In 1963, Estabrook, Cooper, and Rosenthal described the role of CYP as a catalyst in steroid hormone synthesis and drug metabolism. In plants, these proteins are important for the biosynthesis of defensive compounds, fatty acids, and hormones. CYP enzymes have been identified in all kingdoms of life: animals, plants, fungi, protists, bacteria, and archaea, as well as in viruses. However, they are not omnipresent; for example, they have not been found in ''Escherichia coli''. , more than 300,000 distinct CYP proteins are known. CYPs are, in general, the terminal oxidase enzymes in electron transfer chains, broadly categorized as P450-containing systems. The term "P450" is derived fro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
