Reaction Process: Plant Reactome:R-VRA-1119384
NAD biosynthesis I (from aspartate) related metabolites
find 12 related metabolites which is associated with chemical reaction(pathway) NAD biosynthesis I (from aspartate)
L-Asp + Oxygen ⟶ H2O2 + iminoaspartate
Phosphoribosyl pyrophosphate
Phosphoribosyl pyrophosphate, also known as PRPP or PRib-PP, belongs to the class of organic compounds known as pentose phosphates. These are carbohydrate derivatives containing a pentose substituted by one or more phosphate groups. Phosphoribosyl pyrophosphate is an extremely weak basic (essentially neutral) compound (based on its pKa). Phosphoribosyl pyrophosphate exists in all living species, ranging from bacteria to humans. Within humans, phosphoribosyl pyrophosphate participates in a number of enzymatic reactions. In particular, guanine and phosphoribosyl pyrophosphate can be biosynthesized from guanosine monophosphate through its interaction with the enzyme adenine phosphoribosyltransferase. In addition, guanine and phosphoribosyl pyrophosphate can be biosynthesized from guanosine monophosphate; which is catalyzed by the enzyme hypoxanthine-guanine phosphoribosyltransferase. In humans, phosphoribosyl pyrophosphate is involved in adenosine deaminase deficiency. Phosphoribosyl pyrophosphate is a pentosephosphate and it is the key substance in the biosynthesis of histidine, tryptophan, and purine and pyrimidine nucleotides. It is formed from ribose 5-phosphate by the enzyme ribose-phosphate diphosphokinase. It plays a role in transferring phosphate groups in several reactions. Phosphoribosyl pyrophosphate (PRPP) is a pentosephosphate. The key substance in the biosynthesis of histidine, tryptophan, and purine and pyrimidine nucleotides. COVID info from COVID-19 Disease Map KEIO_ID P023 Corona-virus Coronavirus SARS-CoV-2 COVID-19 SARS-CoV COVID19 SARS2 SARS
Dihydroxyacetone phosphate
An important intermediate in lipid biosynthesis and in glycolysis.; Dihydroxyacetone phosphate (DHAP) is a biochemical compound involved in many reactions, from the Calvin cycle in plants to the ether-lipid biosynthesis process in Leishmania mexicana. Its major biochemical role is in the glycolysis metabolic pathway. DHAP may be referred to as glycerone phosphate in older texts.; Dihydroxyacetone phosphate lies in the glycolysis metabolic pathway, and is one of the two products of breakdown of fructose 1,6-phosphate, along with glyceraldehyde 3-phosphate. It is rapidly and reversibly isomerised to glyceraldehyde 3-phosphate.; In the Calvin cycle, DHAP is one of the products of the sixfold reduction of 1,3-bisphosphoglycerate by NADPH. It is also used in the synthesis of sedoheptulose 1,7-bisphosphate and fructose 1,6-bisphosphate which are both used to reform ribulose 5-phosphate, the key carbohydrate of the Calvin cycle. Dihydroxyacetone phosphate is found in many foods, some of which are sesame, mexican groundcherry, parsley, and common wheat. [Spectral] Glycerone phosphate (exact mass = 169.99802) and beta-D-Fructose 1,6-bisphosphate (exact mass = 339.99605) and NADP+ (exact mass = 743.07545) were not completely separated on HPLC under the present analytical conditions as described in AC$XXX. Additionally some of the peaks in this data contains dimers and other unidentified ions. Dihydroxyacetone phosphate is an important intermediate in lipid biosynthesis and in glycolysis. Dihydroxyacetone phosphate is found to be associated with transaldolase deficiency, which is an inborn error of metabolism. Dihydroxyacetone phosphate has been identified in the human placenta (PMID: 32033212). KEIO_ID D014
Nicotinic acid mononucleotide
Nicotinic acid mononucleotide, also known as nicotinate ribonucleotide, belongs to the class of organic compounds known as nicotinic acid nucleotides. These are pyridine nucleotides in which the pyridine base is nicotinic acid or a derivative thereof. Nicotinic acid mononucleotide is an extremely weak basic (essentially neutral) compound (based on its pKa). Nicotinic acid mononucleotide an intermediate in the cofactor biosynthesis and the nicotinate and nicotinamide metabolism pathways. It is a substrate for nicotinamide riboside kinase, ectonucleotide pyrophosphatase/phosphodiesterase, nicotinamide mononucleotide adenylyltransferase, 5-nucleotidase, nicotinate-nucleotide pyrophosphorylase, and 5(3)-deoxyribonucleotidase. Nicotinic acid mononucleotide is an intermediate in the metabolism of Nicotinate and nicotinamide. It is a substrate for Ectonucleotide pyrophosphatase/phosphodiesterase 2, Ectonucleotide pyrophosphatase/phosphodiesterase 1, Nicotinamide mononucleotide adenylyltransferase 3, Cytosolic 5-nucleotidase IA, Cytosolic 5-nucleotidase IB, Nicotinate-nucleotide pyrophosphorylase, 5(3)-deoxyribonucleotidase (cytosolic type), Cytosolic purine 5-nucleotidase, Nicotinamide mononucleotide adenylyltransferase 2, Ectonucleotide pyrophosphatase/phosphodiesterase 3, 5-nucleotidase, 5(3)-deoxyribonucleotidase (mitochondrial) and Nicotinamide mononucleotide adenylyltransferase 1. [HMDB] NaMN is the most common mononucleotide intermediate (a hub) in NAD biogenesis. For example, in E. coli all three pyridine precursors are converted into NaMN (Table 1 and Figure 3(a)). Qa produced by the de novo Asp–DHAP pathway (genes nadB and nadA) is converted into NaMN by QAPRT (gene nadC). Salvage of both forms of niacin proceeds via NAPRT (gene pncB) either directly upon or after deamidation by NMDSE (gene pncA). Overall, more than 90\% of approximately 680 analyzed bacterial genomes contain at least one of the pathways leading to the formation of NaMN. Most of them (∼480 genomes) have the entire set of nadBAC genes for NaMN de novo synthesis from Asp that are often clustered on the chromosome and/or are co-regulated by the same transcription factors (see Section 7.08.3.1.2). Among the examples provided in Table 1, F. tularensis (Figure 4(c)) has all three genes of this de novo pathway forming a single operon-like cluster and supporting the growth of this organism in the absence of any pyridine precursors in the medium. More than half the genomes with the Asp–DHAP pathway also contain a deamidating niacin salvage pathway (genes pncAB) as do many representatives of the α-, β-, and γ-Proteobacteria, Actinobacteria, and Bacillus/Clostridium group. As already emphasized, the genomic reconstruction approach provides an assessment of the metabolic potential of an organism, which may or may not be realized under given conditions. For example, E. coli and B. subtilis can utilize both de novo and PncAB Nm salvage pathways under the same growth conditions, whereas in M. tuberculosis (having the same gene pattern) the latter pathway was considered nonfunctional, so that the entire NAD pool is generated by the de novo NadABC route. However, a recent study demonstrated the functional activity of the Nm salvage pathway in vivo, under hypoxic conditions in infected macrophages.221 This study also implicated the two downstream enzymes of NAD synthesis (NAMNAT and NADSYN) as attractive chemotherapeutic targets to treat acute and latent forms of tuberculosis. In approximately 100 species, including many Cyanobacteria (e.g., Synechococcus spp.), Bacteroidetes (e.g., Chlorobium spp.) and Proteobacteria (e.g., Caulobacter crescentus, Zymomonas mobilis, Desulfovibrio spp., and Shewanella spp. representing α-, β-, δ-, and γ-groups, respectively) the Asp–DHAP pathway is the only route to NAD biogenesis. Among them, nearly all Helicobacter spp. (except H. hepaticus), contain only the two genes nadA and nadC but lack the first gene of the pathway (nadB), which is a likely subject of nonorthologous gene replacement. One case of NadB (ASPOX) replacement by the ASPDH enzyme in T. maritima (and methanogenic archaea) was discussed in Section 7.08.2.1. However, no orthologues of the established ASPDH could be identified in Helicobacter spp. as well as in approximately 15 other diverse bacterial species that have the nadAC but lack the nadB gene (e.g., all analyzed Corynebacterium spp. except for C. diphtheriae). Therefore, the identity of the ASPOX or ASPDH enzyme in these species is still unknown, representing one of the few remaining cases of ‘locally missing genes’220 in the NAD subsystem. All other bacterial species contain either both the nadA and nadB genes (plus nadC) or none. In a limited number of bacteria (∼20 species), mostly in the two distant groups of Xanthomonadales (within γ-Proteobacteria) and Flavobacteriales (within Bacteroidetes), the Asp–DHAP pathway of Qa synthesis is replaced by the Kyn pathway. As described in Section 7.08.2.1.2, four out of five enzymes (TRDOX, KYNOX, KYNSE, and HADOX) in the bacterial version of this pathway are close homologues of the respective eukaryotic enzymes, whereas the KYNFA gene is a subject of multiple nonorthologous replacements. Although the identity of one alternative form of KYNFA (gene kynB) was established in a group of bacteria that have a partial Kyn pathway for Trp degradation to anthranilate (e.g., in P. aeruginosa or B. cereus57), none of the known KYNFA homologues are present in Xanthomonadales or Flavobacteriales. In a few species (e.g., Salinispora spp.) a complete gene set of the Kyn pathway genes co-occurs with a complete Asp–DHAP pathway. Further experiments would be required to establish to what extent and under what conditions these two pathways contribute to Qa formation. As discussed, the QAPRT enzyme is shared by both de novo pathways, and a respective gene, nadC is always found in the genomes containing one or the other pathway. Similarly, gene nadC always co-occurs with Qa de novo biosynthetic genes with one notable exception of two groups of Streptococci, S. pneumonaie and S. pyogenes. Although all other members of the Lactobacillales group also lack the Qa de novo biosynthetic machinery and rely entirely on niacin salvage, only these two human pathogens contain a nadC gene. The functional significance of this ‘out of context’ gene is unknown, but it is tempting to speculate that it may be involved in a yet-unknown pathway of Qa salvage from the human host. Among approximately 150 bacterial species that lack de novo biosynthesis genes and rely on deamidating salvage of niacin (via NAPRT), the majority (∼100) are from the group of Firmicutes. Such a functional variant (illustrated for Staphylococcus aureus in Figure 4(b)) is characteristic of many bacterial pathogens, both Gram-positive and Gram-negative (e.g., Brucella, Bordetella, and Campylobacter spp. from α-, β-, and δ-Proteobacteria, Borrelia, and Treponema spp. from Spirochaetes). Most of the genomes in this group contain both pncA and pncB genes that are often clustered on the chromosome and/or are co-regulated (see Section 7.08.3.1.2). In some cases (e.g., within Mollicutes and Spirochaetales), only the pncB, but not the pncA gene, can be reliably identified, suggesting that either of these species can utilize only the deamidated form of niacin (Na) or that some of them contain an alternative (yet-unknown) NMASE. Although the nondeamidating conversion of Nm into NMN (via NMPRT) appears to be present in approximately 50 bacterial species (mostly in β- and γ-Proteobacteria), it is hardly ever the only route of NAD biogenesis in these organisms. The only possible exception is observed in Mycoplasma genitalium and M. pneumoniae that contain the nadV gene as the only component of pyridine mononucleotide biosynthetic machinery. In some species (e.g., in Synechocystes spp.), the NMPRT–NMNAT route is committed primarily to the recycling of endogenous Nm. On the other hand, in F. tularensis (Figure 4(c)), NMPRT (gene nadV) together with NMNAT (of the nadM family) constitute the functional nondeamidating Nm salvage pathway as it supports the growth of the nadE′-mutant on Nm but not on Na (L. Sorci et al., unpublished). A similar nondeamidating Nm salvage pathway implemented by NMPRT and NMNAT (of the nadR family) is present in some (but not all) species of Pasteurellaceae in addition to (but never instead of) the RNm salvage pathway (see below), as initially demonstrated for H. ducreyi.128 A two-step conversion of NaMN into NAD via a NaAD intermediate (Route I in Figure 2) is present in the overwhelming majority of bacteria. The signature enzyme of Route I, NAMNAT of the NadD family is present in nearly all approximately 650 bacterial species that are expected to generate NaMN via de novo or salvage pathways (as illustrated by Figures 3(a) and 3(b)). All these species, without a single exception, also contain NADSYN (encoded by either a short or a long form of the nadE gene), which is required for this route. The species that lack the NadD/NadE signature represent several relatively rare functional variants, including: 1. Route I of NAD synthesis (NaMN → NaAD → NAD) variant via a bifunctional NAMNAT/NMNAT enzyme of the NadM family is common for archaea (see Section 7.08.3.2), but it appears to be present in only a handful of bacteria, such as Acinetobacter, Deinococcus, and Thermus groups. Another unusual feature of the latter two groups is the absence of the classical NADKIN, a likely subject of a nonorthologous replacement that remains to be elucidated. 2. Route II of NAD synthesis (NaMN → NMN → NAD). This route is implemented by a combination of the NMNAT of either the NadM family (as in F. tularensis) or the NadR family (as in M. succinoproducens and A. succinogenes) with NMNSYN of the NadE′ family. The case of F. tularensis described in Section 7.08.2.4 is illustrated in Figure 3(b). The rest of the NAD biosynthetic machinery in both species from the Pasteurellaceae group, beyond the shared Route II, is remarkably different from that in F. tularensis. Instead of de novo biosynthesis, they harbor a Na salvage pathway via NAPRT encoded by a pncB gene that is present in a chromosomal cluster with nadE′. Neither of these two genes are present in other Pasteurellaceae that lack the pyridine carboxylate amidation machinery (see below). 3. Salvage of RNm (RNm → NMN → NAD). A genomic signature of this pathway, a combination of the PnuC-like transporter and a bifunctional NMNAT/RNMKIN of the NadR family, is present in many Enterobacteriaceae and in several other diverse species (e.g., in M. tuberculosis). However, in H. influenzae (Figure 3(d)) and related members of Pasteurellaceae, it is the only route of NAD biogenesis. As shown in Table 1, H. influenzae as well as many other members of this group have lost nearly all components of the rich NAD biosynthetic machinery that are present in their close phylogenetic neighbors (such as E. coli and many other Enterobacteriaceae). This pathway is an ultimate route for utilization of the so called V-factors (NADP, NAD, NMN, or RNm) that are required to support growth of H. influenzae. It was established that all other V-factors are degraded to RNm by a combination of periplasmic- and membrane-associated hydrolytic enzymes.222 Although PnuC was initially considered an NMN transporter,223 its recent detailed analysis in both H. influenzae and Salmonella confirmed that its actual physiological function is in the uptake of RNm coupled with the phosphorylation of RNM to NMN by RNMKIN.17,148,224 As already mentioned, H. ducreyi and several other V-factor-independent members of the Pasteurellaceae group (H. somnus, Actinobacillus pleuropneumoniae, and Actinomycetemcomitans) harbor the NMNAT enzyme (NadV) that allows them to grow in the presence of Nm (but not Na) in the medium (Section 7.08.2.2). 4. Uptake of the intact NAD. Several groups of phylogenetically distant intracellular endosymbionts with extremely truncated genomes contain only a single enzyme, NADKIN, from the entire subsystem. Among them are all analyzed species of the Wolbachia, Rickettsia, and Blochmannia groups. These species are expected to uptake and utilize the intact NAD from their host while retaining the ability to convert it into NADP. Among all analyzed bacteria, only the group of Chlamydia does not have NADKIN and depends on the salvage of both NAD and NADP via a unique uptake system.157 A comprehensive genomic reconstruction of the metabolic potential (gene annotations and asserted pathways) across approximately 680 diverse bacterial genomes sets the stage for the accurate cross-genome projection and prediction of regulatory mechanisms that control the realization of this potential in a variety of species and growth conditions. In the next section, we summarize the recent accomplishments in the genomic reconstruction of NAD-related regulons in bacteria. Nicotinic acid mononucleotide. CAS Common Chemistry. CAS, a division of the American Chemical Society, n.d. https://commonchemistry.cas.org/detail?cas_rn=321-02-8 (retrieved 2024-06-29) (CAS RN: 321-02-8). Licensed under the Attribution-Noncommercial 4.0 International License (CC BY-NC 4.0).
Water
Water is a chemical substance that is essential to all known forms of life. It appears colorless to the naked eye in small quantities, though it is actually slightly blue in color. It covers 71\\% of Earths surface. Current estimates suggest that there are 1.4 billion cubic kilometers (330 million m3) of it available on Earth, and it exists in many forms. It appears mostly in the oceans (saltwater) and polar ice caps, but it is also present as clouds, rain water, rivers, freshwater aquifers, lakes, and sea ice. Water in these bodies perpetually moves through a cycle of evaporation, precipitation, and runoff to the sea. Clean water is essential to human life. In many parts of the world, it is in short supply. From a biological standpoint, water has many distinct properties that are critical for the proliferation of life that set it apart from other substances. It carries out this role by allowing organic compounds to react in ways that ultimately allow replication. All known forms of life depend on water. Water is vital both as a solvent in which many of the bodys solutes dissolve and as an essential part of many metabolic processes within the body. Metabolism is the sum total of anabolism and catabolism. In anabolism, water is removed from molecules (through energy requiring enzymatic chemical reactions) in order to grow larger molecules (e.g. starches, triglycerides and proteins for storage of fuels and information). In catabolism, water is used to break bonds in order to generate smaller molecules (e.g. glucose, fatty acids and amino acids to be used for fuels for energy use or other purposes). Water is thus essential and central to these metabolic processes. Water is also central to photosynthesis and respiration. Photosynthetic cells use the suns energy to split off waters hydrogen from oxygen. Hydrogen is combined with CO2 (absorbed from air or water) to form glucose and release oxygen. All living cells use such fuels and oxidize the hydrogen and carbon to capture the suns energy and reform water and CO2 in the process (cellular respiration). Water is also central to acid-base neutrality and enzyme function. An acid, a hydrogen ion (H+, that is, a proton) donor, can be neutralized by a base, a proton acceptor such as hydroxide ion (OH-) to form water. Water is considered to be neutral, with a pH (the negative log of the hydrogen ion concentration) of 7. Acids have pH values less than 7 while bases have values greater than 7. Stomach acid (HCl) is useful to digestion. However, its corrosive effect on the esophagus during reflux can temporarily be neutralized by ingestion of a base such as aluminum hydroxide to produce the neutral molecules water and the salt aluminum chloride. Human biochemistry that involves enzymes usually performs optimally around a biologically neutral pH of 7.4. (Wikipedia). Water, also known as purified water or dihydrogen oxide, is a member of the class of compounds known as homogeneous other non-metal compounds. Homogeneous other non-metal compounds are inorganic non-metallic compounds in which the largest atom belongs to the class of other nonmetals. Water can be found in a number of food items such as caraway, oxheart cabbage, alaska wild rhubarb, and japanese walnut, which makes water a potential biomarker for the consumption of these food products. Water can be found primarily in most biofluids, including ascites Fluid, blood, cerebrospinal fluid (CSF), and lymph, as well as throughout all human tissues. Water exists in all living species, ranging from bacteria to humans. In humans, water is involved in several metabolic pathways, some of which include cardiolipin biosynthesis CL(20:4(5Z,8Z,11Z,14Z)/18:0/20:4(5Z,8Z,11Z,14Z)/18:2(9Z,12Z)), cardiolipin biosynthesis cl(i-13:0/i-15:0/i-20:0/i-24:0), cardiolipin biosynthesis CL(18:0/18:0/20:4(5Z,8Z,11Z,14Z)/22:5(7Z,10Z,13Z,16Z,19Z)), and cardiolipin biosynthesis cl(a-13:0/i-18:0/i-13:0/i-19:0). Water is also involved in several metabolic disorders, some of which include de novo triacylglycerol biosynthesis tg(i-21:0/i-13:0/21:0), de novo triacylglycerol biosynthesis tg(22:0/20:0/i-20:0), de novo triacylglycerol biosynthesis tg(a-21:0/i-20:0/i-14:0), and de novo triacylglycerol biosynthesis tg(i-21:0/a-17:0/i-12:0). Water is a drug which is used for diluting or dissolving drugs for intravenous, intramuscular or subcutaneous injection, according to instructions of the manufacturer of the drug to be administered [fda label]. Water plays an important role in the world economy. Approximately 70\\% of the freshwater used by humans goes to agriculture. Fishing in salt and fresh water bodies is a major source of food for many parts of the world. Much of long-distance trade of commodities (such as oil and natural gas) and manufactured products is transported by boats through seas, rivers, lakes, and canals. Large quantities of water, ice, and steam are used for cooling and heating, in industry and homes. Water is an excellent solvent for a wide variety of chemical substances; as such it is widely used in industrial processes, and in cooking and washing. Water is also central to many sports and other forms of entertainment, such as swimming, pleasure boating, boat racing, surfing, sport fishing, and diving .
Oxygen
Oxygen is the third most abundant element in the universe after hydrogen and helium and the most abundant element by mass in the Earths crust. Diatomic oxygen gas constitutes 20.9\\% of the volume of air. All major classes of structural molecules in living organisms, such as proteins, carbohydrates, and fats, contain oxygen, as do the major inorganic compounds that comprise animal shells, teeth, and bone. Oxygen in the form of O2 is produced from water by cyanobacteria, algae and plants during photosynthesis and is used in cellular respiration for all living organisms. Green algae and cyanobacteria in marine environments provide about 70\\% of the free oxygen produced on earth and the rest is produced by terrestrial plants. Oxygen is used in mitochondria to help generate adenosine triphosphate (ATP) during oxidative phosphorylation. For animals, a constant supply of oxygen is indispensable for cardiac viability and function. To meet this demand, an adult human, at rest, inhales 1.8 to 2.4 grams of oxygen per minute. This amounts to more than 6 billion tonnes of oxygen inhaled by humanity per year. At a resting pulse rate, the heart consumes approximately 8-15 ml O2/min/100 g tissue. This is significantly more than that consumed by the brain (approximately 3 ml O2/min/100 g tissue) and can increase to more than 70 ml O2/min/100 g myocardial tissue during vigorous exercise. As a general rule, mammalian heart muscle cannot produce enough energy under anaerobic conditions to maintain essential cellular processes; thus, a constant supply of oxygen is indispensable to sustain cardiac function and viability. However, the role of oxygen and oxygen-associated processes in living systems is complex, and they and can be either beneficial or contribute to cardiac dysfunction and death (through reactive oxygen species). Reactive oxygen species (ROS) are a family of oxygen-derived free radicals that are produced in mammalian cells under normal and pathologic conditions. Many ROS, such as the superoxide anion (O2-)and hydrogen peroxide (H2O2), act within blood vessels, altering mechanisms mediating mechanical signal transduction and autoregulation of cerebral blood flow. Reactive oxygen species are believed to be involved in cellular signaling in blood vessels in both normal and pathologic states. The major pathway for the production of ROS is by way of the one-electron reduction of molecular oxygen to form an oxygen radical, the superoxide anion (O2-). Within the vasculature there are several enzymatic sources of O2-, including xanthine oxidase, the mitochondrial electron transport chain, and nitric oxide (NO) synthases. Studies in recent years, however, suggest that the major contributor to O2- levels in vascular cells is the membrane-bound enzyme NADPH-oxidase. Produced O2- can react with other radicals, such as NO, or spontaneously dismutate to produce hydrogen peroxide (H2O2). In cells, the latter reaction is an important pathway for normal O2- breakdown and is usually catalyzed by the enzyme superoxide dismutase (SOD). Once formed, H2O2 can undergo various reactions, both enzymatic and nonenzymatic. The antioxidant enzymes catalase and glutathione peroxidase act to limit ROS accumulation within cells by breaking down H2O2 to H2O. Metabolism of H2O2 can also produce other, more damaging ROS. For example, the endogenous enzyme myeloperoxidase uses H2O2 as a substrate to form the highly reactive compound hypochlorous acid. Alternatively, H2O2 can undergo Fenton or Haber-Weiss chemistry, reacting with Fe2+/Fe3+ ions to form toxic hydroxyl radicals (-.OH). (PMID: 17027622, 15765131) [HMDB]. Oxygen is found in many foods, some of which are soy bean, watermelon, sweet basil, and spinach. Oxygen is the third most abundant element in the universe after hydrogen and helium and the most abundant element by mass in the Earths crust. Diatomic oxygen gas constitutes 20.9\\% of the volume of air. All major classes of structural molecules in living organisms, such as proteins, carbohydrates, and fats, contain oxygen, as do the major inorganic compounds that comprise animal shells, teeth, and bone. Oxygen in the form of O2 is produced from water by cyanobacteria, algae and plants during photosynthesis and is used in cellular respiration for all living organisms. Green algae and cyanobacteria in marine environments provide about 70\\% of the free oxygen produced on earth and the rest is produced by terrestrial plants. Oxygen is used in mitochondria to help generate adenosine triphosphate (ATP) during oxidative phosphorylation. For animals, a constant supply of oxygen is indispensable for cardiac viability and function. To meet this demand, an adult human, at rest, inhales 1.8 to 2.4 grams of oxygen per minute. This amounts to more than 6 billion tonnes of oxygen inhaled by humanity per year. At a resting pulse rate, the heart consumes approximately 8-15 ml O2/min/100 g tissue. This is significantly more than that consumed by the brain (approximately 3 ml O2/min/100 g tissue) and can increase to more than 70 ml O2/min/100 g myocardial tissue during vigorous exercise. As a general rule, mammalian heart muscle cannot produce enough energy under anaerobic conditions to maintain essential cellular processes; thus, a constant supply of oxygen is indispensable to sustain cardiac function and viability. However, the role of oxygen and oxygen-associated processes in living systems is complex, and they and can be either beneficial or contribute to cardiac dysfunction and death (through reactive oxygen species). Reactive oxygen species (ROS) are a family of oxygen-derived free radicals that are produced in mammalian cells under normal and pathologic conditions. Many ROS, such as the superoxide anion (O2-)and hydrogen peroxide (H2O2), act within blood vessels, altering mechanisms mediating mechanical signal transduction and autoregulation of cerebral blood flow. Reactive oxygen species are believed to be involved in cellular signaling in blood vessels in both normal and pathologic states. The major pathway for the production of ROS is by way of the one-electron reduction of molecular oxygen to form an oxygen radical, the superoxide anion (O2-). Within the vasculature there are several enzymatic sources of O2-, including xanthine oxidase, the mitochondrial electron transport chain, and nitric oxide (NO) synthases. Studies in recent years, however, suggest that the major contributor to O2- levels in vascular cells is the membrane-bound enzyme NADPH-oxidase. Produced O2- can react with other radicals, such as NO, or spontaneously dismutate to produce hydrogen peroxide (H2O2). In cells, the latter reaction is an important pathway for normal O2- breakdown and is usually catalyzed by the enzyme superoxide dismutase (SOD). Once formed, H2O2 can undergo various reactions, both enzymatic and nonenzymatic. The antioxidant enzymes catalase and glutathione peroxidase act to limit ROS accumulation within cells by breaking down H2O2 to H2O. Metabolism of H2O2 can also produce other, more damaging ROS. For example, the endogenous enzyme myeloperoxidase uses H2O2 as a substrate to form the highly reactive compound hypochlorous acid. Alternatively, H2O2 can undergo Fenton or Haber-Weiss chemistry, reacting with Fe2+/Fe3+ ions to form toxic hydroxyl radicals (-.OH). (PMID: 17027622, 15765131). V - Various > V03 - All other therapeutic products > V03A - All other therapeutic products > V03AN - Medical gases
Carbon dioxide
Carbon dioxide is a colorless, odorless gas that can be formed by the body and is necessary for the respiration cycle of plants and animals. Carbon dioxide is produced during respiration by all animals, fungi and microorganisms that depend on living and decaying plants for food, either directly or indirectly. It is, therefore, a major component of the carbon cycle. Additionally, carbon dioxide is used by plants during photosynthesis to make sugars which may either be consumed again in respiration or used as the raw material to produce polysaccharides such as starch and cellulose, proteins and the wide variety of other organic compounds required for plant growth and development. When inhaled at concentrations much higher than usual atmospheric levels, it can produce a sour taste in the mouth and a stinging sensation in the nose and throat. These effects result from the gas dissolving in the mucous membranes and saliva, forming a weak solution of carbonic acid. Carbon dioxide is used by the food industry, the oil industry, and the chemical industry. Carbon dioxide is used to produce carbonated soft drinks and soda water. Traditionally, the carbonation in beer and sparkling wine comes about through natural fermentation, but some manufacturers carbonate these drinks artificially. Leavening agent, propellant, aerating agent, preservative. Solvent for supercritical extraction e.g. of caffeine in manufacture of caffeine-free instant coffee. It is used in carbonation of beverages, in the frozen food industry and as a component of controlled atmosphere packaging (CAD) to inhibit bacterial growth. Especies effective against Gram-negative spoilage bacteria, e.g. Pseudomonas V - Various > V03 - All other therapeutic products > V03A - All other therapeutic products > V03AN - Medical gases
Pyrophosphate
The anion, the salts, and the esters of pyrophosphoric acid are called pyrophosphates. The pyrophosphate anion is abbreviated PPi and is formed by the hydrolysis of ATP into AMP in cells. This hydrolysis is called pyrophosphorolysis. The pyrophosphate anion has the structure P2O74-, and is an acid anhydride of phosphate. It is unstable in aqueous solution and rapidly hydrolyzes into inorganic phosphate. Pyrophosphate is an osteotoxin (arrests bone development) and an arthritogen (promotes arthritis). It is also a metabotoxin (an endogenously produced metabolite that causes adverse health affects at chronically high levels). Chronically high levels of pyrophosphate are associated with hypophosphatasia. Hypophosphatasia (also called deficiency of alkaline phosphatase or phosphoethanolaminuria) is a rare, and sometimes fatal, metabolic bone disease. Hypophosphatasia is associated with a molecular defect in the gene encoding tissue non-specific alkaline phosphatase (TNSALP). TNSALP is an enzyme that is tethered to the outer surface of osteoblasts and chondrocytes. TNSALP hydrolyzes several substances, including inorganic pyrophosphate (PPi) and pyridoxal 5-phosphate (PLP), a major form of vitamin B6. When TSNALP is low, inorganic pyrophosphate (PPi) accumulates outside of cells and inhibits the formation of hydroxyapatite, one of the main components of bone, causing rickets in infants and children and osteomalacia (soft bones) in adults. Vitamin B6 must be dephosphorylated by TNSALP before it can cross the cell membrane. Vitamin B6 deficiency in the brain impairs synthesis of neurotransmitters which can cause seizures. In some cases, a build-up of calcium pyrophosphate dihydrate crystals in the joints can cause pseudogout. COVID info from WikiPathways Corona-virus Coronavirus SARS-CoV-2 COVID-19 SARS-CoV COVID19 SARS2 SARS
Hydrogen peroxide
Hydrogen peroxide (H2O2) is a very pale blue liquid that appears colourless in a dilute solution. H2O2 is slightly more viscous than water and is a weak acid. H2O2 is unstable and slowly decomposes in the presence of light. It has strong oxidizing properties and is, therefore, a powerful bleaching agent that is mostly used for bleaching paper. H2O2 has also found use as a disinfectant and as an oxidizer. H2O2 in the form of carbamide peroxide is widely used for tooth whitening (bleaching), both in professionally- and in self-administered products. H2O2 is a well-documented component of living cells and is a normal metabolite of oxygen in the aerobic metabolism of cells and tissues. A total of 31 human cellular H2O2 generating enzymes has been identified so far (PMID: 25843657). H2O2 plays important roles in host defence and oxidative biosynthetic reactions. At high levels (>100 nM) H2O2 is toxic to most cells due to its ability to non-specifically oxidize proteins, membranes and DNA, leading to general cellular damage and dysfunction. However, at low levels (<10 nM), H2O2 functions as a signalling agent, particularly in higher organisms. In plants, H2O2 plays a role in signalling to cause cell shape changes such as stomatal closure and root growth. As a messenger molecule in vertebrates, H2O2 diffuses through cells and tissues to initiate cell shape changes, to drive vascular remodelling, and to activate cell proliferation and recruitment of immune cells. H2O2 also plays a role in redox sensing, signalling, and redox regulation (PMID: 28110218). This is normally done through molecular redox “switches” such as thiol-containing proteins. The production and decomposition of H2O2 are tightly regulated (PMID: 17434122). In humans, H2O2 can be generated in response to various stimuli, including cytokines and growth factors. H2O2 is degraded by several enzymes including catalase and superoxide dismutase (SOD), both of which play important roles in keeping the amount of H2O2 in the body below toxic levels. H2O2 also appears to play a role in vitiligo. Vitiligo is a skin pigment disorder leading to patchy skin colour, especially among dark-skinned individuals. Patients with vitiligo have low catalase levels in their skin, leading to higher levels of H2O2. High levels of H2O2 damage the epidermal melanocytes, leading to a loss of pigment (PMID: 10393521). Accumulating evidence suggests that hydrogen peroxide H2O2 plays an important role in cancer development. Experimental data have shown that cancer cells produce high amounts of H2O2. An increase in the cellular levels of H2O2 has been linked to several key alterations in cancer, including DNA changes, cell proliferation, apoptosis resistance, metastasis, angiogenesis and hypoxia-inducible factor 1 (HIF-1) activation (PMID: 17150302, 17335854, 16677071, 16607324, 16514169). H2O2 is found in most cells, tissues, and biofluids. H2O2 levels in the urine can be significantly increased with the consumption of coffee and other polyphenolic-containing beverages (wine, tea) (PMID: 12419961). In particular, roasted coffee has high levels of 1,2,4-benzenetriol which can, on its own, lead to the production of H2O2. Normal levels of urinary H2O2 in non-coffee drinkers or fasted subjects are between 0.5-3 uM/mM creatinine whereas, for those who drink coffee, the levels are between 3-10 uM/mM creatinine (PMID: 12419961). It is thought that H2O2 in urine could act as an antibacterial agent and that H2O2 is involved in the regulation of glomerular function (PMID: 10766414). A - Alimentary tract and metabolism > A01 - Stomatological preparations > A01A - Stomatological preparations > A01AB - Antiinfectives and antiseptics for local oral treatment D - Dermatologicals > D08 - Antiseptics and disinfectants > D08A - Antiseptics and disinfectants S - Sensory organs > S02 - Otologicals > S02A - Antiinfectives > S02AA - Antiinfectives It is used in foods as a bleaching agent, antimicrobial agent and oxidising agent C254 - Anti-Infective Agent > C28394 - Topical Anti-Infective Agent D009676 - Noxae > D016877 - Oxidants > D010545 - Peroxides D000890 - Anti-Infective Agents
Iminoaspartic acid
D018377 - Neurotransmitter Agents > D018846 - Excitatory Amino Acids Iminoaspartic acid is a substrate for D-aspartate oxidase. [HMDB] Iminoaspartic acid is a substrate for D-aspartate oxidase.
(2S)-2-ammoniobutanedioate
D018377 - Neurotransmitter Agents > D018846 - Excitatory Amino Acids
Hydrogen pyridine-2,3-dicarboxylate
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