1.
Fish
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A fish is any member of a group of animals that consist of all gill-bearing aquatic craniate animals that lack limbs with digits. They form a group to the tunicates, together forming the olfactores. Included in this definition are the living hagfish, lampreys, and cartilaginous, tetrapods emerged within lobe-finned fishes, so cladistically they are fish as well. However, traditionally fish are rendered obsolete or paraphyletic by excluding the tetrapods, because in this manner the term fish is defined negatively as a paraphyletic group, it is not considered a formal taxonomic grouping in systematic biology. The traditional term pisces is considered a typological, but not a phylogenetic classification, the earliest organisms that can be classified as fish were soft-bodied chordates that first appeared during the Cambrian period. Although they lacked a true spine, they possessed notochords which allowed them to be more agile than their invertebrate counterparts, fish would continue to evolve through the Paleozoic era, diversifying into a wide variety of forms. Many fish of the Paleozoic developed external armor that protected them from predators, the first fish with jaws appeared in the Silurian period, after which many became formidable marine predators rather than just the prey of arthropods. Fish are abundant in most bodies of water and they can be found in nearly all aquatic environments, from high mountain streams to the abyssal and even hadal depths of the deepest oceans. With 33,100 described species, fish exhibit greater species diversity than any group of vertebrates. Fish are an important resource for humans worldwide, especially as food, commercial and subsistence fishers hunt fish in wild fisheries or farm them in ponds or in cages in the ocean. They are also caught by fishers, kept as pets, raised by fishkeepers. Fish have had a role in culture through the ages, serving as deities, religious symbols, fish do not represent a monophyletic group, and therefore the evolution of fish is not studied as a single event. Early fish from the record are represented by a group of small, jawless. Jawless fish lineages are mostly extinct, an extant clade, the lampreys may approximate ancient pre-jawed fish. The first jaws are found in Placodermi fossils, the diversity of jawed vertebrates may indicate the evolutionary advantage of a jawed mouth. It is unclear if the advantage of a hinged jaw is greater biting force, improved respiration, fish may have evolved from a creature similar to a coral-like sea squirt, whose larvae resemble primitive fish in important ways. The first ancestors of fish may have kept the form into adulthood. Fish are a group, that is, any clade containing all fish also contains the tetrapods
2.
Polymerase chain reaction
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It is an easy, cheap, and reliable way to repeatedly replicate a focused segment of DNA, a concept which is applicable to numerous fields in modern biology and related sciences. Developed in 1983 by Kary Mullis, PCR is now a common and often indispensable technique used in clinical, in 1993, Mullis was awarded the Nobel Prize in Chemistry along with Michael Smith for his work on PCR. Primers containing sequences complementary to the region, along with a DNA polymerase, after which the method is named, enable selective. As PCR progresses, the DNA generated is used as a template for replication. The simplicity of the principle underlying PCR means it can be extensively modified to perform a wide array of genetic manipulations. PCR is not generally considered to be a recombinant DNA method, as it does not involve cutting and pasting DNA, almost all PCR applications employ a heat-stable DNA polymerase, such as Taq polymerase, an enzyme originally isolated from the thermophilic bacterium Thermus aquaticus. In the first step, the two strands of the DNA double helix are physically separated at a temperature in a process called DNA melting. In the second step, the temperature is lowered and the two DNA strands become templates for DNA polymerase to amplify the target DNA. The selectivity of PCR results from the use of primers that are complementary to the DNA region targeted for amplification under specific thermal cycling conditions, PCR amplifies a specific region of a DNA strand. Most PCR methods amplify DNA fragments of between 0.1 and 10 kilo base pairs, although some techniques allow for amplification of fragments up to 40 kbp in size. The amount of amplified product is determined by the available substrates in the reaction, the thermal cycler heats and cools the reaction tubes to achieve the temperatures required at each step of the reaction. Many modern thermal cyclers make use of the Peltier effect, which permits both heating and cooling of the holding the PCR tubes simply by reversing the electric current. Thin-walled reaction tubes permit favorable thermal conductivity to allow for rapid thermal equilibration, most thermal cyclers have heated lids to prevent condensation at the top of the reaction tube. Older thermal cyclers lacking a heated lid require a layer of oil on top of the mixture or a ball of wax inside the tube. Typically, PCR consists of a series of 20–40 repeated temperature changes, called cycles, the cycling is often preceded by a single temperature step at a very high temperature, and followed by one hold at the end for final product extension or brief storage. The individual steps common to most PCR methods are as follows, Initialization and it consists of heating the reaction chamber to a temperature of 94–96 °C, or 98 °C if extremely thermostable polymerases are used, which is then held for 1–10 minutes. Denaturation, This step is the first regular cycling event and consists of heating the reaction chamber to 94–98 °C for 20–30 seconds and this causes DNA melting, or denaturation, of the double-stranded DNA template by breaking the hydrogen bonds between complementary bases, yielding two single-stranded DNA molecules. Annealing, In the next step, the temperature is lowered to 50–65 °C for 20–40 seconds
3.
Jmol
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Jmol is computer software for molecular modelling chemical structures in 3-dimensions. Jmol returns a 3D representation of a molecule that may be used as a teaching tool and it is written in the programming language Java, so it can run on the operating systems Windows, macOS, Linux, and Unix, if Java is installed. It is free and open-source software released under a GNU Lesser General Public License version 2.0, a standalone application and a software development kit exist that can be integrated into other Java applications, such as Bioclipse and Taverna. A popular feature is an applet that can be integrated into web pages to display molecules in a variety of ways, for example, molecules can be displayed as ball-and-stick models, space-filling models, ribbon diagrams, etc. Jmol supports a range of chemical file formats, including Protein Data Bank, Crystallographic Information File, MDL Molfile. There is also a JavaScript-only version, JSmol, that can be used on computers with no Java, the Jmol applet, among other abilities, offers an alternative to the Chime plug-in, which is no longer under active development. While Jmol has many features that Chime lacks, it does not claim to reproduce all Chime functions, most notably, Chime requires plug-in installation and Internet Explorer 6.0 or Firefox 2.0 on Microsoft Windows, or Netscape Communicator 4.8 on Mac OS9. Jmol requires Java installation and operates on a variety of platforms. For example, Jmol is fully functional in Mozilla Firefox, Internet Explorer, Opera, Google Chrome, fast and Scriptable Molecular Graphics in Web Browsers without Java3D
4.
Amino acid
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Amino acids are organic compounds containing amine and carboxyl functional groups, along with a side chain specific to each amino acid. The key elements of an acid are carbon, hydrogen, oxygen. About 500 amino acids are known and can be classified in many ways, in the form of proteins, amino acids comprise the second-largest component of human muscles, cells and other tissues. Outside proteins, amino acids perform critical roles in such as neurotransmitter transport. In biochemistry, amino acids having both the amine and the acid groups attached to the first carbon atom have particular importance. They are known as 2-, alpha-, or α-amino acids and they include the 22 proteinogenic amino acids, which combine into peptide chains to form the building-blocks of a vast array of proteins. These are all L-stereoisomers, although a few D-amino acids occur in bacterial envelopes, as a neuromodulator, twenty of the proteinogenic amino acids are encoded directly by triplet codons in the genetic code and are known as standard amino acids. The other two are selenocysteine, and pyrrolysine, pyrrolysine and selenocysteine are encoded via variant codons, for example, selenocysteine is encoded by stop codon and SECIS element. N-formylmethionine is generally considered as a form of methionine rather than as a separate proteinogenic amino acid, codon–tRNA combinations not found in nature can also be used to expand the genetic code and create novel proteins known as alloproteins incorporating non-proteinogenic amino acids. Many important proteinogenic and non-proteinogenic amino acids also play critical roles within the body. Nine proteinogenic amino acids are called essential for humans because they cannot be created from other compounds by the human body, others may be conditionally essential for certain ages or medical conditions. Essential amino acids may also differ between species, because of their biological significance, amino acids are important in nutrition and are commonly used in nutritional supplements, fertilizers, and food technology. Industrial uses include the production of drugs, biodegradable plastics, the first few amino acids were discovered in the early 19th century. In 1806, French chemists Louis-Nicolas Vauquelin and Pierre Jean Robiquet isolated a compound in asparagus that was subsequently named asparagine, cystine was discovered in 1810, although its monomer, cysteine, remained undiscovered until 1884. Glycine and leucine were discovered in 1820, usage of the term amino acid in the English language is from 1898. Proteins were found to yield amino acids after enzymatic digestion or acid hydrolysis, in the structure shown at the top of the page, R represents a side chain specific to each amino acid. The carbon atom next to the group is called the α–carbon. Amino acids containing an amino group bonded directly to the alpha carbon are referred to as amino acids
5.
European Chemicals Agency
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ECHA is the driving force among regulatory authorities in implementing the EUs chemicals legislation. ECHA helps companies to comply with the legislation, advances the safe use of chemicals, provides information on chemicals and it is located in Helsinki, Finland. The Agency, headed by Executive Director Geert Dancet, started working on 1 June 2007, the REACH Regulation requires companies to provide information on the hazards, risks and safe use of chemical substances that they manufacture or import. Companies register this information with ECHA and it is freely available on their website. So far, thousands of the most hazardous and the most commonly used substances have been registered, the information is technical but gives detail on the impact of each chemical on people and the environment. This also gives European consumers the right to ask whether the goods they buy contain dangerous substances. The Classification, Labelling and Packaging Regulation introduces a globally harmonised system for classifying and labelling chemicals into the EU. This worldwide system makes it easier for workers and consumers to know the effects of chemicals, companies need to notify ECHA of the classification and labelling of their chemicals. So far, ECHA has received over 5 million notifications for more than 100000 substances, the information is freely available on their website. Consumers can check chemicals in the products they use, Biocidal products include, for example, insect repellents and disinfectants used in hospitals. The Biocidal Products Regulation ensures that there is information about these products so that consumers can use them safely. ECHA is responsible for implementing the regulation, the law on Prior Informed Consent sets guidelines for the export and import of hazardous chemicals. Through this mechanism, countries due to hazardous chemicals are informed in advance and have the possibility of rejecting their import. Substances that may have effects on human health and the environment are identified as Substances of Very High Concern 1. These are mainly substances which cause cancer, mutation or are toxic to reproduction as well as substances which persist in the body or the environment, other substances considered as SVHCs include, for example, endocrine disrupting chemicals. Companies manufacturing or importing articles containing these substances in a concentration above 0 and they are required to inform users about the presence of the substance and therefore how to use it safely. Consumers have the right to ask the retailer whether these substances are present in the products they buy, once a substance has been officially identified in the EU as being of very high concern, it will be added to a list. This list is available on ECHA’s website and shows consumers and industry which chemicals are identified as SVHCs, Substances placed on the Candidate List can then move to another list
6.
Glycosidic bond
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In chemistry, a glycosidic bond or glycosidic linkage is a type of covalent bond that joins a carbohydrate molecule to another group, which may or may not be another carbohydrate. A glycosidic bond is formed between the hemiacetal or hemiketal group of a saccharide and the group of some compound such as an alcohol. A substance containing a glycosidic bond is a glycoside, glycosidic bonds of the form discussed above are known as O-glycosidic bonds, in reference to the glycosidic oxygen that links the glycoside to the aglycone or reducing end sugar. In analogy, one also considers S-glycosidic bonds, where the oxygen of the bond is replaced with a sulfur atom. In the same way, N-glycosidic bonds, have the glycosidic oxygen replaced with nitrogen. Substances containing N-glycosidic bonds are known as glycosylamines. C-glycosyl bonds have the oxygen replaced by a carbon, the term C-glycoside is considered a misnomer by IUPAC and is discouraged. All of these modified glycosidic bonds have different susceptibility to hydrolysis, one distinguishes between α- and β-glycosidic bonds based on the relative stereochemistry of the anomeric position and the stereocenter furthest from C1 in the saccharide. An α-glycosidic bond is formed when both carbons have the same stereochemistry, whereas a β-glycosidic bond occurs when the two carbons have different stereochemistry. One complicating issue is that the alpha and beta conformations were originally defined based on the orientation of the major constituents in a Haworth projection. In this case, for D-sugars, a beta conformation would see the major constituent at each carbon drawn above the plane of the ring, for L-sugars, the definitions would then, necessarily, reverse. This is worth noting as these older definitions still permeate the literature, pharmacologists often join substances to glucuronic acid via glycosidic bonds in order to increase their water solubility, this is known as glucuronidation. Many other glycosides have important physiological functions, Nüchter et al. have shown a new approach to Fischer Glycosylation. Employing a microwave oven equipped with refluxing apparatus in a reactor with pressure bombs, Nüchter et al. were able to achieve 100% yield of α-. This method can be performed on a multi-kilogram scale, ondruschka, and W. Lautenschläger, Synthetic Communications 31,1277. Vishal Y Joshis method Joshi et al, d-glucose is first protected by forming the peracetate by addition of acetic anhydride in acetic acid, and then addition of hydrogen bromide which brominates at the 5-position. On addition of the alcohol ROH and lithium carbonate, the OR replaces the bromine and it was suggested by Joshi et al. that lithium acts as the nucleophile that attacks the carbon at the 5-position and through a transition state the alcohol is substituted for the bromine group. Glycoside hydrolases, are enzymes that break glycosidic bonds, glycoside hydrolases typically can act either on α- or on β-glycosidic bonds, but not on both
7.
Pharmacokinetics
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Pharmacokinetics, sometimes abbreviated as PK, is a branch of pharmacology dedicated to determining the fate of substances administered to a living organism. The substances of interest include any chemical xenobiotic such as, pharmaceutical drugs, pesticides, food additives, cosmetic ingredients, etc. It attempts to analyze chemical metabolism and to discover the fate of a chemical from the moment that it is administered up to the point at which it is eliminated from the body. Pharmacokinetics is the study of how an organism affects a drug, both together influence dosing, benefit, and adverse effects, as seen in PK/PD models. Pharmacokinetic properties of chemicals are affected by the route of administration and these may affect the absorption rate. Models have been developed to simplify conceptualization of the processes that take place in the interaction between an organism and a chemical substance. The various compartments that the model is divided into are commonly referred to as the ADME scheme, absorption - the process of a substance entering the blood circulation. Distribution - the dispersion or dissemination of substances throughout the fluids, metabolism – the recognition by the organism that a foreign substance is present and the irreversible transformation of parent compounds into daughter metabolites. Excretion - the removal of the substances from the body, in rare cases, some drugs irreversibly accumulate in body tissue. The two phases of metabolism and excretion can also be grouped together under the title elimination, the study of these distinct phases involves the use and manipulation of basic concepts in order to understand the process dynamics. All these concepts can be represented through mathematical formulas that have a graphical representation. The model outputs for a drug can be used in industry or in the application of pharmacokinetic concepts. Clinical pharmacokinetics provides many performance guidelines for effective and efficient use of drugs for human-health professionals, in practice, it is generally considered that steady state is reached when a time of 4 to 5 times the half-life for a drug after regular dosing is started. Noncompartmental methods estimate the exposure to a drug by estimating the area under the curve of a concentration-time graph, compartmental methods estimate the concentration-time graph using kinetic models. Noncompartmental methods are more versatile in that they do not assume any specific compartmental model. The final outcome of the transformations that a drug undergoes in an organism, a number of functional models have been developed in order to simplify the study of pharmacokinetics. These models are based on a consideration of an organism as a number of related compartments, the simplest idea is to think of an organism as only one homogenous compartment. However, these models do not always reflect the real situation within an organism
8.
Adenine
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It also has functions in protein synthesis and as a chemical component of DNA and RNA. The shape of adenine is complementary to either thymine in DNA or uracil in RNA, the image on the right shows pure adenine, as an independent molecule. When connected into DNA, a covalent bond is formed between deoxyribose sugar and the bottom left nitrogen, so removing the hydrogen, the remaining structure is called an adenine residue, as part of a larger molecule. Adenosine is adenine reacted with ribose as used in RNA and ATP, deoxyadenosine adenine attached to deoxyribose, adenine forms several tautomers, compounds that can be rapidly interconverted and are often considered equivalent. However, in isolated conditions, i. e. in an inert gas matrix and in the gas phase, purine metabolism involves the formation of adenine and guanine. Adenine is one of the two purine nucleobases used in forming nucleotides of the nucleic acids, in DNA, adenine binds to thymine via two hydrogen bonds to assist in stabilizing the nucleic acid structures. In RNA, which is used for synthesis, adenine binds to uracil. Adenine forms adenosine, a nucleoside, when attached to ribose and it forms adenosine triphosphate, a nucleoside triphosphate, when three phosphate groups are added to adenosine. Adenosine triphosphate is used in cellular metabolism as one of the methods of transferring chemical energy between chemical reactions. In older literature, adenine was sometimes called Vitamin B4 and it is no longer considered a true vitamin or part of the Vitamin B complex. However, two B vitamins, niacin and riboflavin, bind with adenine to form the essential cofactors nicotinamide adenine dinucleotide and flavin adenine dinucleotide, hermann Emil Fischer was one of the early scientists to study adenine. It was named in 1885 by Albrecht Kossel, in reference to the pancreas from which Kossels sample had been extracted. On August 8,2011, a report, based on NASA studies with meteorites found on Earth, was published suggesting building blocks of DNA and RNA may have been formed extraterrestrially in outer space
9.
Peroxynitrite
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Peroxynitrite is an ion with the formula ONOO−. It is a structural isomer of nitrate, NO−3. Although its conjugate acid is reactive, peroxynitrite is stable in basic solutions. It is prepared by the reaction of peroxide with nitrite, H2O2 + NO−2 → ONOO− + H2O Peroxynitrite is an oxidant. Because of its properties, peroxynitrite can damage a wide array of molecules in cells, including DNA. In the laboratory, a solution of peroxynitrite can be prepared by treating acidified hydrogen peroxide with a solution of sodium nitrite and its concentration is indicated by the absorbance at 302 nm. ONOO− reacts nucleophilically with carbon dioxide, in vivo, the concentration of carbon dioxide is about 1 mM, and its reaction with ONOO− occurs quickly. Thus, under conditions, the reaction of ONOO− with carbon dioxide to form nitrosoperoxycarbonate is by far the predominant pathway for ONOO−. ONOOCO−2 homolyzes to form carbonate radical and nitrogen dioxide, again as a pair of caged radicals, approximately 66% of the time, these two radicals recombine to form carbon dioxide and nitrate. The other 33% of the time, these two radicals escape the solvent cage and become free radicals and it is these radicals that are believed to cause peroxynitrite-related cellular damage
10.
Regulation of therapeutic goods
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The regulation of therapeutic goods, that is drugs and therapeutic devices, varies by jurisdiction. In some countries, such as the United States, they are regulated at the level by a single agency. In other jurisdictions they are regulated at the level, or at both state and national levels by various bodies, as is the case in Australia. The role of therapeutic goods regulation is designed mainly to protect the health, regulation is aimed at ensuring the safety, quality, and efficacy of the therapeutic goods which are covered under the scope of the regulation. In most jurisdictions, therapeutic goods must be registered before they are allowed to be marketed, there is usually some degree of restriction of the availability of certain therapeutic goods depending on their risk to consumers. Therapeutic goods in Australia are regulated by the Therapeutic Goods Administration, there are 5 main categories, Normal Medicines - Cough, cold and fever medicines, antiseptics, vitamins and others. Sold freely in pharmacies and some large supermarkets, red Stripe Medicines - These medicines are sold only with medical prescription. Antibiotics, Anti allergenics, Anti inflammatories, and other medicines, in Brazil, governmental control is loose on this type, it is not uncommon to buy this type of prescription medicine over the counter without a prescription. Red Stripe Psychoactive Medicines - These medicines are only with a Special Control white medical prescription with carbon copy. The original must be retained by the pharmacist after the sale, Drugs include anti-depressants, anti-convulsants, some sleep aids, anti-psychotics and other non-habit-inducing controlled medicines. Though some consider them habit inducing, anabolic steroids are also regulated under this category, black Stripe Medicines - These medicines are sold only with the Blue B Form medical prescription, which is valid for 30 days and must be retained by the pharmacist after the sale. Includes sedatives, some anorexic inducers and other habit-inducing controlled medicines, includes amphetamines and other stimulants, opioids and other strong habit-forming controlled medicines. In Canada, regulation of goods are governed by the Food and Drug Act. In addition, the Controlled Drugs and Substances Act requires additional regulatory requirements for controlled drugs, the regulation of drugs in Burma is governed by the Food and Drug Administration and Food and Drug Board of Authority. The regulation of drugs in China is governed by the China Food, Medicines for Human Use in the United Kingdom are regulated by the Medicines and Healthcare products Regulatory Agency. The availability of drugs is regulated by classification by the MHRA as part of marketing authorisation of a product, Medicines in the Republic of Ireland are regulated according to the Misuse of Drugs Regulations 1988. Controlled drugs are divided into five categories based on their potential for misuse, cD1, cannabis, lysergamide, coca leaf, etc. Use prohibited except in limited circumstances where a license has been granted, CD2, amphetamine, methadone, morphine, fentanyl, oxycodone, tapentadol, etc
11.
Over-the-counter drug
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In many countries, OTC drugs are selected by a regulatory agency to ensure that they are ingredients that are safe and effective when used without a physicians care. OTC drugs are regulated by active pharmaceutical ingredients, not final products. By regulating APIs instead of specific drug formulations, governments allow manufacturers freedom to formulate ingredients, or combinations of ingredients, into proprietary mixtures. The term over-the-counter may be somewhat counterintuitive, since, in many countries, in contrast, prescription drugs are almost always passed over a counter from the pharmacist to the customer. Some drugs may be classified as over-the-counter, but may only be dispensed by a pharmacist after an assessment of the patients needs or the provision of patient education. In many countries, a number of OTC drugs are available in establishments without a pharmacy, such as stores, supermarkets. Regulations detailing the establishments where drugs may be sold, who is authorized to dispense them, as of 2011, around a third of older adults in the U. S. reportedly use OTC drugs. In Canada, there are four drug schedules, Schedule 1, Schedule 2, Do not require a prescription, but require an assessment by a pharmacist prior to sale. These drugs are kept in an area of the pharmacy where there is no public access, Schedule 3, Do not require a prescription, but must be kept in an area under the supervision of a pharmacist. These drugs are kept in an area of the outlet where self-selection is possible. Unscheduled, Do not require a prescription and may be sold in any retail outlet, all medications outside of Schedule 1 may be considered an OTC drug, as they do not require prescriptions for sale. While the National Association of Pharmacy Regulatory Authorities provides recommendations on the scheduling of drugs for sale in Canada, due to this, the exact drugs found in each schedule may vary from province to province. The drug can be on the shelves like any other product, examples are domperidone,400 mg ibuprofen up to 50 tablets and dextromethorphan. The drugs are usually on the shelves and the store sells items like toys, gadgets, perfumes. The drugs in this category have limited risk and addiction potential, examples are naproxen and diclofenac in small amounts, cinnarizine,400 mg ibuprofen up to 20 tablets and also 500 mg paracetamol up to 50 tablets. In the United States, the manufacture and sale of OTC substances is regulated by the Food, the FDA requires that all new drugs obtain a New Drug Application before entering interstate commerce, but the act exempts any drugs generally recognized as safe and effective from this requirement. Thus, in the United States an OTC drug product is allowed to be marketed either pursuant to an FDA monograph, the Federal Trade Commission regulates advertising of OTC products. This is in contrast to prescription drug advertising, which is regulated by the FDA, the FDA requires that OTC products are labeled with an approved Drug Facts label to educate consumers about their medications
12.
IMP dehydrogenase
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IMP dehydrogenase is associated with cell proliferation and is a possible target for cancer chemotherapy. Mammalian and bacterial IMPDHs are tetramers of identical chains, there are two IMP dehydrogenase isozymes in humans. IMP dehydrogenase nearly always contains a long insertion that has two CBS domains within it, the structure of this enzyme is composed of a TIM barrel domain with two CBS domains inserted within a loop. It is inhibited by Mycophenolic acid, ribavirin, and 6TGMP, 6TGMP inhibition prevents purine interconversion and thus the synthesis of purine nucleotides. Humans express the following two IMP dehydrogenase isozymes, Purine metabolism This article incorporates text from the public domain Pfam and InterPro IPR001093
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