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Type II Topoisomerase
Type II topoisomerases are topoisomerases that cut both strands of the DNA helix simultaneously in order to manage DNA tangles and supercoils. They use the hydrolysis of ATP, unlike Type I topoisomerase. In this process, these enzymes change the linking number of circular DNA by ±2. Topoisomerases are ubiquitous enzymes, found in all living organisms. In animals, topoisomerase II is a chemotherapy target. In prokaryotes, gyrase is an antibacterial target. Indeed, these enzymes are of interest for a wide range of effects. Function Type II topoisomerases increase or decrease the linking number of a DNA loop by 2 units, and it promotes chromosome disentanglement. For example, DNA gyrase, a type II topoisomerase observed in '' E. coli'' and most other prokaryotes, introduces negative supercoils and decreases the linking number by 2. Gyrase is also able to remove knots from the bacterial chromosome. Along with gyrase, most prokaryotes also contain a second type IIA topoisomerase, t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Topoisomerases
DNA topoisomerases (or topoisomerases) are enzymes that catalyze changes in the topological state of DNA, interconverting relaxed and supercoiled forms, linked (catenated) and unlinked species, and knotted and unknotted DNA. Topological issues in DNA arise due to the intertwined nature of its double-helical structure, which, for example, can lead to overwinding of the DNA duplex during DNA replication and transcription. If left unchanged, this torsion would eventually stop the DNA or RNA polymerases involved in these processes from continuing along the DNA helix. A second topological challenge results from the linking or tangling of DNA during replication. Left unresolved, links between replicated DNA will impede cell division. The DNA topoisomerases prevent and correct these types of topological problems. They do this by binding to DNA and cutting the sugar-phosphate backbone of either one (type I topoisomerases) or both (type II topoisomerases) of the DNA strands. This transie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gepotidacin
Gepotidacin (INN) is an experimental antibiotic that acts as a topoisomerase type II inhibitor. It is being studied for the treatment of uncomplicated urinary tract infection (acute cystitis) and infection with ''Neisseria gonorrhoeae'' (gonorrhea Gonorrhea, colloquially known as the clap, is a sexually transmitted infection (STI) caused by the bacterium ''Neisseria gonorrhoeae''. Infection may involve the genitals, mouth, or rectum. Infected men may experience pain or burning with ur ...), including multidrug resistant strains. References Antibiotics {{Antiinfective-drug-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ciprofloxacin
Ciprofloxacin is a fluoroquinolone antibiotic used to treat a number of bacterial infections. This includes bone and joint infections, intra abdominal infections, certain types of infectious diarrhea, respiratory tract infections, skin infections, typhoid fever, and urinary tract infections, among others. For some infections it is used in addition to other antibiotics. It can be taken by mouth, as eye drops, as ear drops, or intravenously. Common side effects include nausea, vomiting, and diarrhea. Severe side effects include an increased risk of tendon rupture, hallucinations, and nerve damage. In people with myasthenia gravis, there is worsening muscle weakness. Rates of side effects appear to be higher than some groups of antibiotics such as cephalosporins but lower than others such as clindamycin. Studies in other animals raise concerns regarding use in pregnancy. No problems were identified, however, in the children of a small number of women who took the me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quinolones
Quinolone may refer to: * 2-Quinolone * 4-Quinolone 4-Quinolone is an organic compound derived from quinoline. It and 2-quinolone are the two most important parent (meaning simplified) quinolones. 4-Quinolone exists in equilibrium with a minor tautomer, 4-hydroxyquinoline (CAS#611-36-9). Aside ... * Quinolone antibiotics {{Short pages monitor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Novobiocin
Novobiocin, also known as albamycin or cathomycin, is an aminocoumarin antibiotic that is produced by the actinomycete '' Streptomyces niveus'', which has recently been identified as a subjective synonym for ''S. spheroides'' a member of the class Actinomycetia. Other aminocoumarin antibiotics include clorobiocin and coumermycin A1.Alessandra da Silva Eustáquio (2004) Biosynthesis of aminocoumarin antibiotics in Streptomyces: Generation of structural analogues by genetic engineering and insights into the regulation of antibiotic production. DISSERTATION Novobiocin was first reported in the mid-1950s (then called streptonivicin). Clinical use It is active against ''Staphylococcus epidermidis'' and may be used to differentiate it from the other coagulase-negative ''Staphylococcus saprophyticus'', which is resistant to novobiocin, in culture. Novobiocin was licensed for clinical use under the tradename Albamycin (Upjohn) in the 1960s. Its efficacy has been demonstrated in prec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Etoposide
Etoposide, sold under the brand name Vepesid among others, is a chemotherapy medication used for the treatments of a number of types of cancer including testicular cancer, lung cancer, lymphoma, leukemia, neuroblastoma, and ovarian cancer. It is also used for hemophagocytic lymphohistiocytosis. It is used by mouth or injection into a vein. Side effects are very common. They can include low blood cell counts, vomiting, loss of appetite, diarrhea, hair loss, and fever. Other severe side effects include allergic reactions and low blood pressure. Use during pregnancy will likely harm the fetus. Etoposide is in the topoisomerase inhibitor family of medication. It is believed to work by damaging DNA. Etoposide was approved for medical use in the United States in 1983. It is on the World Health Organization's List of Essential Medicines. Medical uses Etoposide is used as a form of chemotherapy for cancers such as Kaposi’s sarcoma, Ewing's sarcoma, lung cancer, testicular can ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Doxorubicin
Doxorubicin, sold under the brand name Adriamycin among others, is a chemotherapy medication used to treat cancer. This includes breast cancer, bladder cancer, Kaposi's sarcoma, lymphoma, and acute lymphocytic leukemia. It is often used together with other chemotherapy agents. Doxorubicin is given by injection into a vein. Common side effects include hair loss, bone marrow suppression, vomiting, rash, and inflammation of the mouth. Other serious side effects may include allergic reactions such as anaphylaxis, heart damage, tissue damage at the site of injection, radiation recall, and treatment-related leukemia. People often experience red discoloration of the urine for a few days. Doxorubicin is in the anthracycline and antitumor antibiotic family of medications. It works in part by interfering with the function of DNA. Doxorubicin was approved for medical use in the United States in 1974. It is on the World Health Organization's List of Essential Medicines. Versi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ICRF-193
ICRF 193 is a topoisomerase inhibitor Topoisomerase inhibitors are chemical compounds that block the action of topoisomerases, which are broken into two broad subtypes: type I topoisomerases (TopI) and type II topoisomerases (TopII). Topoisomerase plays important roles in cellular rep .... References Imides Diketopiperazines Topoisomerase inhibitors {{organic-compound-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HU-331
HU-331 is a quinone anticarcinogenic drug synthesized from cannabidiol, a cannabinoid in the ''Cannabis sativa'' plant. It showed a great efficacy against oncogenic human cells. HU-331 does not cause arrest in cell cycle, cell apoptosis or caspase activation. HU-331 inhibits DNA topoisomerase II even at nanomolar concentrations, but has shown a negligible effect on the action of DNA topoisomerase I. The cannabinoid quinone HU-331 is a very specific inhibitor of topoisomerase II, compared with most known anticancer quinones. One of the main objectives of these studies is the development of a new quinone derived compound that produces anti- neoplasm, neoplastic activity while maintaining low toxicity at therapeutic doses. Mechanism of action Inhibitors of topoisomerases can act at two different levels. First inhibiting topoisomerase, which stabilize the topoisomerase-DNA complex and thus introduce DNA breaks in the wires that lead to apoptosis, then inhibiting the catalytic activ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eukaryotes
Eukaryotes () are organisms whose cells have a nucleus. All animals, plants, fungi, and many unicellular organisms, are Eukaryotes. They belong to the group of organisms Eukaryota or Eukarya, which is one of the three domains of life. Bacteria and Archaea (both prokaryotes) make up the other two domains. The eukaryotes are usually now regarded as having emerged in the Archaea or as a sister of the Asgard archaea. This implies that there are only two domains of life, Bacteria and Archaea, with eukaryotes incorporated among archaea. Eukaryotes represent a small minority of the number of organisms, but, due to their generally much larger size, their collective global biomass is estimated to be about equal to that of prokaryotes. Eukaryotes emerged approximately 2.3–1.8 billion years ago, during the Proterozoic eon, likely as flagellated phagotrophs. Their name comes from the Greek εὖ (''eu'', "well" or "good") and κάρυον (''karyon'', "nut" or "kernel"). Euk ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
