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Dihydropteroate Synthase Inhibitor
Dihydropteroate synthase inhibitors are drugs that inhibit the action of dihydropteroate synthase. They include Sulfonamide (medicine), sulfonamides, dapsone, and para-aminosalicylic acid. In bacterium, bacteria, antibacterial sulfonamides act as competitive inhibitors of the enzyme dihydropteroate synthase, DHPS. DHPS catalyses the conversion of PABA (para-Aminobenzoic acid, ''para''-aminobenzoate) to dihydropteroic acid, dihydropteroate, a key step in folate synthesis. Folate is necessary for the cell to synthesize nucleic acids (nucleic acids are essential building blocks of DNA and RNA), and in its absence cells will be unable to divide. Hence the sulfonamide antibacterials exhibit a bacteriostatic rather than bactericidal effect. Uses Folate is not synthesized in mammalian cells, but is instead a dietary requirement. This explains the selective toxicity to bacterial cells of these drugs. These antibiotics are used to treat ''Pneumocystis jirovecii'' pneumonia, urinary tract ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dihydropteroate Synthase
Dihydropteroate synthase is an enzyme classified under . It produces dihydropteroate in bacteria, but it is not expressed in most eukaryotes including humans. This makes it a useful target for sulfonamide In organic chemistry, the sulfonamide functional group (also spelled sulphonamide) is an organosulfur group with the structure . It consists of a sulfonyl group () connected to an amine group (). Relatively speaking this group is unreactive. ... antibiotics, which compete with the PABA precursor. * (2-amino-4-hydroxy-7,8-dihydropteridin-6-yl)methyl diphosphate + 4-aminobenzoate (PABA) \rightleftharpoons diphosphate + dihydropteroate. All organisms require reduced folate cofactors for the synthesis of a variety of metabolites. Most microorganisms must synthesize folate de novo because they lack the active transport system of higher vertebrate cells that allows these organisms to use dietary folates. Proteins containing this domain include dihydropteroate synthase ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfonamide (medicine)
Sulfonamide is a functional group (a part of a molecule) that is the basis of several groups of drugs, which are called sulphonamides, sulfa drugs or sulpha drugs. The original antibacterial sulfonamides are synthetic (nonantibiotic) antimicrobial agents that contain the sulfonamide group. Some sulfonamides are also devoid of antibacterial activity, e.g., the anticonvulsant sultiame. The sulfonylureas and thiazide diuretics are newer drug groups based upon the antibacterial sulfonamides. Allergies to sulfonamides are common. The overall incidence of adverse drug reactions to sulfa antibiotics is approximately 3%, close to penicillin; hence medications containing sulfonamides are prescribed carefully. Sulfonamide drugs were the first broadly effective antibacterials to be used systemically, and paved the way for the antibiotic revolution in medicine. Function In bacteria, antibacterial sulfonamides act as competitive inhibitors of the enzyme dihydropteroate synthas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dapsone
Dapsone, also known as 4,4'-sulfonyldianiline (SDA) or diaminodiphenyl sulfone (DDS), is an antibiotic commonly used in combination with rifampicin and clofazimine for the treatment of leprosy. It is a second-line medication for the treatment and prevention of pneumocystis pneumonia and for the prevention of toxoplasmosis in those who have poor immune function. Additionally, it has been used for acne, dermatitis herpetiformis, and various other skin conditions. Dapsone is available both topically and by mouth. Severe side effects may include a decrease in blood cells, red blood cell breakdown especially in those with glucose-6-phosphate dehydrogenase deficiency (G-6-PD), or hypersensitivity. Common side effects include nausea and loss of appetite. Other side effects include liver inflammation, methemoglobinemia, and a number of types of skin rashes. While the safety of use during pregnancy is not entirely clear some physicians recommend that it be continued in those with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacterium
Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among the first life forms to appear on Earth, and are present in most of its habitats. Bacteria inhabit soil, water, acidic hot springs, radioactive waste, and the deep biosphere of Earth's crust. Bacteria are vital in many stages of the nutrient cycle by recycling nutrients such as the fixation of nitrogen from the atmosphere. The nutrient cycle includes the decomposition of dead bodies; bacteria are responsible for the putrefaction stage in this process. In the biological communities surrounding hydrothermal vents and cold seeps, extremophile bacteria provide the nutrients needed to sustain life by converting dissolved compounds, such as hydrogen sulphide and methane, to energy. Bacteria also live in symbiotic and parasitic r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Competitive Inhibitor
Competitive inhibition is interruption of a chemical pathway owing to one chemical substance inhibiting the effect of another by competing with it for binding or bonding. Any metabolic or chemical messenger system can potentially be affected by this principle, but several classes of competitive inhibition are especially important in biochemistry and medicine, including the competitive form of enzyme inhibition, the competitive form of receptor antagonism, the competitive form of antimetabolite activity, and the competitive form of poisoning (which can include any of the aforementioned types). Enzyme inhibition type In competitive inhibition of enzyme catalysis, binding of an inhibitor prevents binding of the target molecule of the enzyme, also known as the substrate. This is accomplished by blocking the binding site of the substrate – the active site – by some means. The Vmax indicates the maximum velocity of the reaction, while the Km is the amount of substrate needed to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Para-Aminobenzoic Acid
4-Aminobenzoic acid (also known as ''para''-aminobenzoic acid or PABA because the two functional groups are attached to the benzene ring across from one another in the ''para'' position) is an organic compound with the formula H2NC6H4CO2H. PABA is a white solid, although commercial samples can appear gray. It is slightly soluble in water. It consists of a benzene ring substituted with amino and carboxyl groups. The compound occurs extensively in the natural world. Production and occurrence In industry, PABA is prepared mainly by two routes: * Reduction of 4-nitrobenzoic acid * Hoffman degradation of the monoamide derived from terephthalic acid. Food sources of PABA include liver, brewer's yeast (and unfiltered beer), kidney, molasses, mushrooms, and whole grains. A review on this compound. Biology Biochemistry PABA is an intermediate in the synthesis of folate by bacteria, plants, and fungi. Many bacteria, including those found in the human intestinal tract such a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dihydropteroic Acid
Dihydropteroate is an important intermediate in folate synthesis. It is a pterin created from ''para''-aminobenzoic acid (PABA) by the enzyme dihydropteroate synthase. Bacteriostatic agents such as sulfonamides target dihydropteroate synthetase. The effect of dihydropteroate synthetase inhibition is comparable to that of dihydrofolate reductase inhibition by trimethoprim, another bacteriostatic agent. Combinations of these two drug types, such as the combination trimethoprim/sulfamethoxazole (TMP-SMX]), are commonly used to treat recurrent urinary tract, ''Shigella'', ''Salmonella'', and ''Pneumocystis jivoreci'' infections. See also * Dihydrofolic acid Dihydrofolic acid (conjugate base dihydrofolate) (DHF) is a folic acid ( vitamin B9) derivative which is converted to tetrahydrofolic acid by dihydrofolate reductase. Since tetrahydrofolate is needed to make both purines and pyrimidines, which ar ... References {{reflist Benzoic acids Folates ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Folate
Folate, also known as vitamin B9 and folacin, is one of the B vitamins. Manufactured folic acid, which is converted into folate by the body, is used as a dietary supplement and in food fortification as it is more stable during processing and storage. Folate is required for the body to make DNA and RNA and metabolise amino acids necessary for cell division. As humans cannot make folate, it is required in the diet, making it an essential nutrient. It occurs naturally in many foods. The recommended adult daily intake of folate in the U.S. is 400 micrograms from foods or dietary supplements. Folate in the form of folic acid is used to treat anemia caused by folate deficiency. Folic acid is also used as a supplement by women during pregnancy to reduce the risk of neural tube defects (NTDs) in the baby. Low levels in early pregnancy are believed to be the cause of more than half of babies born with NTDs. More than 80 countries use either mandatory or voluntary fortification of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nucleic Acid
Nucleic acids are biopolymers, macromolecules, essential to all known forms of life. They are composed of nucleotides, which are the monomers made of three components: a 5-carbon sugar, a phosphate group and a nitrogenous base. The two main classes of nucleic acids are deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). If the sugar is ribose, the polymer is RNA; if the sugar is the ribose derivative deoxyribose, the polymer is DNA. Nucleic acids are naturally occurring chemical compounds that serve as the primary information-carrying molecules in cells and make up the genetic material. Nucleic acids are found in abundance in all living things, where they create, encode, and then store information of every living cell of every life-form on Earth. In turn, they function to transmit and express that information inside and outside the cell nucleus to the interior operations of the cell and ultimately to the next generation of each living organism. The encoded informatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacteriostatic
A bacteriostatic agent or bacteriostat, abbreviated Bstatic, is a biological or chemical agent that stops bacteria from reproducing, while not necessarily killing them otherwise. Depending on their application, bacteriostatic antibiotics, disinfectants, antiseptics and preservatives can be distinguished. When bacteriostatic antimicrobials are used, the duration of therapy must be sufficient to allow host defense mechanisms to eradicate the bacteria. Upon removal of the bacteriostat, the bacteria usually start to grow rapidly. This is in contrast to bactericides, which kill bacteria. Bacteriostats are often used in plastics to prevent growth of bacteria on surfaces. Bacteriostats commonly used in laboratory work include sodium azide (which is acutely toxic) and thiomersal. __TOC__ Bacteriostatic antibiotics Bacteriostatic antibiotics limit the growth of bacteria by interfering with bacterial protein production, DNA replication, or other aspects of bacterial cellular metabolism. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
