2.02012-07-30 14:55:03 -06002015-09-13 12:56:15 -0600ECMDB21232M2MDB001640Hydrogen peroxideHydrogen peroxide (H2O2) is the simplest peroxide (a compound with an oxygen-oxygen single bond). It is also a strong oxidizer. Hydrogen peroxide is a clear liquid, slightly more viscous than water. The oxidizing capacity of hydrogen peroxide is so strong that it is considered a highly reactive oxygen species. Organisms also naturally produce hydrogen peroxide as a by-product of oxidative metabolism. Consequently, nearly all living things (specifically, all obligate and facultative aerobes) possess enzymes known as catalase peroxidases, which harmlessly and catalytically decompose low concentrations of hydrogen peroxide to water and oxygen. (Wikipedia) Hydrogen peroxide (H2O2) is a very pale blue liquid which appears colourless in a dilute solution, slightly more viscous than water. It is a weak acid. It has strong oxidizing properties and has also found use as a disinfectant and as an oxidizer. Hydrogen peroxide (H2O2) is a well-documented component of living cells. It plays important roles in host defense and oxidative biosynthetic reactions. In addition, there is growing evidence that at low levels, H2O2 also functions as a signaling agent, particularly in higher organisms. (HMDB) In E. coli, H2O2 is used in the aerobic degradation of L-ascorbate, and produced as a byproduct in many reactions involving oxygen as an oxidizing agent. (EcoCyc) In E. coli glyoxylate metabolism, H2O2 is produced as a byproduct of the conversion of glycolate to glyoxylate by the enzyme glycolate oxidase (EC 1.1.3.15), and H2O2 is then converted to harmless O2 by the enzyme catalase (EC 1.11.1.6). (KEGG)Adeka Super ELAlboneAlbone 35Albone DSAnti-Keim 50AsepticperBaquashockBis(hydridooxygen)(OO)CIXClarigel GoldCrestal WhitestripsCrystacideDentaseptDeslime LPDihydrogen dioxideDihydrogen peroxideDihydrogen(peroxide)DioxidaneElawoxH2O2H<SUB>2</SUB>O<SUB>2</SUB>HioxylHipoxHOOHHybriteHydrogen dioxideHydrogen dioxide solutionHydrogen oxideHydrogen peroxideHydrogen peroxide (H2O2)Hydrogen peroxide solution (DOT)Hydrogen peroxide, 90%Hydrogen peroxide, solutionHydroperoxideInhibineLase PeroxideLensan ALenseptMagic BleachingMetrokurMiraseptNite White Excel 2Odosat DOpalescence XtraOxigenalOxydolOxyfullOxyseptOxysept IPegasylPerhydrolPeronePeroxaanPeroxcleanPeroxideQuasar BriteSelect BleachSuperoxolT-StuffWhiteness HPWhitespeedXtra White[OH(OH)]H2O234.014734.005479308peroxolhydrogen peroxide7722-84-1OOInChI=1S/H2O2/c1-2/h1-2HMHAJPDPJQMAIIY-UHFFFAOYSA-NLiquidCytosolExtra-organismPeriplasmmelting_point-0.43 oClogp-0.45pka_strongest_acidic11.52pka_strongest_basic-4.2iupacperoxolaverage_mass34.0147mono_mass34.005479308smilesOOformulaH2O2inchiInChI=1S/H2O2/c1-2/h1-2HinchikeyMHAJPDPJQMAIIY-UHFFFAOYSA-Npolar_surface_area40.46refractivity5.13polarizability2.29rotatable_bond_count0acceptor_count2donor_count2physiological_charge0formal_charge0Glutathione metabolismThe biosynthesis of glutathione starts with the introduction of L-glutamic acid through either a glutamate:sodium symporter, glutamate / aspartate : H+ symporter GltP or a
glutamate / aspartate ABC transporter. Once in the cytoplasm, L-glutamice acid reacts with L-cysteine through an ATP glutamate-cysteine ligase resulting in gamma-glutamylcysteine. This compound reacts which Glycine through an ATP driven glutathione synthetase thus catabolizing Glutathione.
This compound is metabolized through a spontaneous reaction with an oxidized glutaredoxin resulting in a reduced glutaredoxin and an oxidized glutathione. This compound is reduced by a NADPH glutathione reductase resulting in a glutathione.
PW000833ec00480MetabolicAlanine, aspartate and glutamate metabolismec00250Tyrosine metabolismec00350Phenylalanine metabolismThe pathways of the metabolism of phenylalaline begins with the conversion of chorismate to prephenate through a P-protein (chorismate mutase:pheA). Prephenate then interacts with a hydrogen ion through the same previous enzyme resulting in a release of carbon dioxide, water and a phenolpyruvic acid. Three enzymes those enconde by tyrB, aspC and ilvE are involved in catalyzing the third step of these pathways, all three can contribute to the synthesis of phenylalanine: only tyrB and aspC contribute to biosynthesis of tyrosine.
Phenolpyruvic acid can also be obtained from a reversivle reaction with ammonia, a reduced acceptor and a D-amino acid dehydrogenase, resulting in a water, an acceptor and a D-phenylalanine, which can be then transported into the periplasmic space by aromatic amino acid exporter.
L-phenylalanine also interacts in two reversible reactions, one involved with oxygen through a catalase peroxidase resulting in a carbon dioxide and 2-phenylacetamide. The other reaction involved an interaction with oxygen through a phenylalanine aminotransferase resulting in a oxoglutaric acid and phenylpyruvic acid.
L-phenylalanine can be imported into the cytoplasm through an aromatic amino acid:H+ symporter AroP.
The compound can also be imported into the periplasmic space through a transporter: L-amino acid efflux transporter.PW000921ec00360MetabolicIsoquinoline alkaloid biosynthesisec00950Tropane, piperidine and pyridine alkaloid biosynthesisec00960Glycine, serine and threonine metabolismec00260Methane metabolismec00680Vitamin B6 metabolismec00750Tryptophan metabolismThe biosynthesis of L-tryptophan begins with L-glutamine interacting with a chorismate through a anthranilate synthase which results in a L-glutamic acid, a pyruvic acid, a hydrogen ion and a 2-aminobenzoic acid. The aminobenzoic acid interacts with a phosphoribosyl pyrophosphate through an anthranilate synthase component II resulting in a pyrophosphate and a N-(5-phosphoribosyl)-anthranilate. The latter compound is then metabolized by an indole-3-glycerol phosphate synthase / phosphoribosylanthranilate isomerase resulting in a 1-(o-carboxyphenylamino)-1-deoxyribulose 5'-phosphate. This compound then interacts with a hydrogen ion through a indole-3-glycerol phosphate synthase / phosphoribosylanthranilate isomerase resulting in the release of carbon dioxide, a water molecule and a (1S,2R)-1-C-(indol-3-yl)glycerol 3-phosphate. The latter compound then interacts with a D-glyceraldehyde 3-phosphate and an Indole. The indole interacts with an L-serine through a tryptophan synthase, β subunit dimer resulting in a water molecule and an L-tryptophan.
The metabolism of L-tryptophan starts with L-tryptophan being dehydrogenated by a tryptophanase / L-cysteine desulfhydrase resulting in the release of a hydrogen ion, an Indole and a 2-aminoacrylic acid. The latter compound is isomerized into a 2-iminopropanoate. This compound then interacts with a water molecule and a hydrogen ion spontaneously resulting in the release of an Ammonium and a pyruvic acid. The pyruvic acid then interacts with a coenzyme A through a NAD driven pyruvate dehydrogenase complex resulting in the release of a NADH, a carbon dioxide and an Acetyl-CoA
PW000815ec00380MetabolicPorphyrin and chlorophyll metabolismec00860Glyoxylate and dicarboxylate metabolismec00630Nicotinate and nicotinamide metabolismec00760beta-Alanine metabolismThe Beta-Alanine Metabolism starts with a product of Aspartate metabolism. Aspartate is decarboxylated by aspartate 1-decarboxylase, releasing carbon dioxide and Beta-alanine. Beta alanine is then metabolized through a pantothenate synthetase resulting in Pantothenic acid undergoes phosphorylation through a ATP driven pantothenate kinase, resulting in D-4-phosphopantothenate.
Pantothenate (vitamin B5) is the universal precursor for the synthesis of the 4'-phosphopantetheine moiety of coenzyme A and acyl carrier protein. Only plants and microorganismscan synthesize pantothenate de novo - animals require a dietary supplement. The enzymes of this pathway are therefore considered to be antimicrobial drug targets.PW000896ec00410MetabolicPhenylpropanoid biosynthesisec00940Arachidonic acid metabolismDelete Pathway
Arachidonate (arachidonic acid) is a polyunsaturated ω-6 fatty acid with a 20-carbon chain and four cis-double bonds. It is produced at high levels by mosses, some plants, and by some marine bacteria.
Mammals cannot synthesize arachidonate de novo, but most mammals are able to synthesize it from simpler unsaturated fatty acids.
In addition to being involved in cellular signaling as a lipid second messenger, arachidonate is also a key inflammatory intermediate and can also act as a vasodilator.
Like other fatty acids, arachidonate is rarely found in its free form. It is usually found either as arachidonoyl-CoA or incorporated into a lipid.
It is produced from phosphatidylcholine through a phospholipase A1PW000759ec00590MetabolicMicrobial metabolism in diverse environmentsec01120Metabolic pathwayseco01100Ascorbate metabolismE. coli is able to utilize L-ascorbate (vitamin C) as the sole source of carbon under anaerobic and aerobic conditions.
Ascorbic acid in the cytoplasm is processed through a spontaneous reaction with a hydrogen ion and hydrogen peroxide, producing water, dehydroascorbic acid and ascorbic acid. Dehydroascorbic acid reacts with water spontaneously producing an isomer, dehydroascorbate (bicyclic form). The compound then loses a hydrogen ion resulting in a 2,3-Diketo-L-gulonate. This compound is then reduced through a NADH dependent 2,3 diketo-L-gulonate reductase, releasing a NAD and 3-Dehydro-L-gulonate.This compound is phosphorylated through an ATP mediated L-xylulose/3-keto-L-gulonate kinase resulting in an ADP, hydrogen ion and a 3-Keto-L-gulonate 6 phosphate.
L-ascorbate can also be imported and converted to L-ascorbate-6-phosphate by the L-ascorbate PTS transporter. L-ascorbate-6-phosphate reacts with a probable L-ascorbate-6-phosphate lactonase ulaG, resulting in a 3-keto-L-gulonate 6-phosphate.
The compound 3-keto-L-gulonate 6-phosphate can be processed aerobically or anaerobically.
Aerobic:
3-keto-L-gulonate 6-phosphate is decarboxylated by a 3-keto-L-gulonate-6-phosphate decarboxylase ulaD, releasing carbon dioxide and L-xylulose-5-phosphate. This compound in turn is changed into an isomer by L-ribulose-5-phosphate 3-epimerase ulaE, resulting in L-ribulose 5-phosphate. This compound again changes into a different isomer through a L-ribulose-5-phosphate 4-epimerase ulaF resulting in Xylulose 5-phosphate. This compound can then be part of the pentose phosphate pathway.
Anaerobic:
3-keto-L-gulonate 6-phosphate is decarboxylated by 3-keto-L-gulonate 6-phosphate decarboxylase sgbH, releasing carbon dioxide and L-xylulose-5-phosphate. This compound in turn is changed into an isomer by predicted L-xylulose 5-phosphate 3-epimerase, resulting in L-ribulose 5-phosphate. This compound again changes into a different isomer through a L-ribulose-5-phosphate 4-epimerase resulting in Xylulose 5-phosphate. This compound can then be part of the pentose phosphate pathway.
Expression of the ula regulon is regulated by the L-ascorbate 6-phosphate-binding repressor UlaR and by cAMP-CRP.
Under aerobic conditions, metabolism of L-ascorbate is hindered by the special reactivity and toxicity of this compound in the presence of oxygen.PW000793MetabolicAspartate metabolismAspartate (seen in the center) is synthesized from and degraded to oxaloacetate , an intermediate of the TCA cycle, by a reversible transamination reaction with glutamate. As shown here, AspC is the principal transaminase that catalyzes this reaction, but TyrB also catalyzes it. Null mutations in aspC do not confer aspartate auxotrophy; null mutations in both aspC and tyrB do.
Aspartate is a constituent of proteins and participates in several other biosyntheses as shown here( NAD biosynthesis and Beta-Alanine Metabolism . Approximately 27 percent of the cell's nitrogen flows through aspartate
Aspartate can be synthesized from fumaric acid through a aspartate ammonia lyase. Aspartate also participates in the synthesis of L-asparagine through two different methods, either through aspartate ammonia ligase or asparagine synthetase B.
Aspartate is also a precursor of fumaric acid. Again it has two possible ways of synthesizing it. First set of reactions follows an adenylo succinate synthetase that yields adenylsuccinic acid and then adenylosuccinate lyase in turns leads to fumaric acid. The second way is through argininosuccinate synthase that yields argininosuccinic acid and then argininosuccinate lyase in turns leads to fumaric acid
PW000787MetabolicNAD biosynthesisNicotinamide adenine dinucleotide (NAD) can be biosynthesized from L-aspartic acid.This amino acid reacts with oxygen through an L-aspartate oxidase resulting in a hydrogen ion, hydrogen peroxide and an iminoaspartic acid. The latter compound interacts with dihydroxyacetone phosphate through a quinolinate synthase A, resulting in a phosphate, water, and a quinolic acid. Quinolic acid interacts with phosphoribosyl pyrophosphate and hydrogen ion through a quinolinate phosphoribosyltransferase resulting in pyrophosphate, carbon dioxide and nicotinate beta-D-ribonucleotide. This last compound is adenylated through an ATP driven nicotinate-mononucleotide adenylyltransferase releasing a pyrophosphate and resulting in a nicotinic acid adenine dinucleotide.
Nicotinic acid adenine dinucleotide is processed through an NAD synthetase, NH3-dependent in two different manners.
In the first case, Nicotinic acid adenine dinucleotide interacts with ATP, L-glutamine and water through the enzyme and results in hydrogen ion, AMP, pyrophosphate, L-glutamic acid and NAD.
In the second case, Nicotinic acid adenine dinucleotide interacts with ATP and ammonium through the enzyme resulting in a pyrophosphate, AMP, hydrogen ion and NAD.
NAD then proceeds to regulate its own pathway by repressing L-aspartate oxidase.
As a general rule, most prokaryotes utilize the aspartate de novo pathway, in which the nicotinate moiety of NAD is synthesized from aspartate , while in eukaryotes, the de novo pathway starts with tryptophan.
PW000829MetabolicPorphyrin metabolismThe metabolism of porphyrin begins with with glutamic acid being processed by an ATP-driven glutamyl-tRNA synthetase by interacting with hydrogen ion and tRNA(Glu), resulting in amo, pyrophosphate and L-glutamyl-tRNA(Glu) Glutamic acid. Glutamic acid can be obtained as a result of L-glutamate metabolism pathway, glutamate / aspartate : H+ symporter GltP, glutamate:sodium symporter or a glutamate / aspartate ABC transporter .
L-glutamyl-tRNA(Glu) Glutamic acid interacts with a NADPH glutamyl-tRNA reductase resulting in a NADP, a tRNA(Glu) and a (S)-4-amino-5-oxopentanoate.
This compound interacts with a glutamate-1-semialdehyde aminotransferase resulting a 5-aminolevulinic acid. This compound interacts with a porphobilinogen synthase resulting in a hydrogen ion, water and porphobilinogen. The latter compound interacts with water resulting in hydroxymethylbilane synthase resulting in ammonium, and hydroxymethylbilane.
Hydroxymethylbilane can either be dehydrated to produce uroporphyrinogen I or interact with a uroporphyrinogen III synthase resulting in a water molecule and a uroporphyrinogen III.
Uroporphyrinogen I interacts with hydrogen ion through a uroporphyrinogen decarboxylase resulting in a carbon dioxide and a coproporphyrinogen I
Uroporphyrinogen III can be metabolized into precorrin by interacting with a S-adenosylmethionine through a siroheme synthase resulting in hydrogen ion, an s-adenosylhomocysteine and a precorrin-1. On the other hand, Uroporphyrinogen III interacts with hydrogen ion through a uroporphyrinogen decarboxylase resulting in a carbon dioxide and a Coproporphyrinogen III.
Precorrin-1 reacts with a S-adenosylmethionine through a siroheme synthase resulting in a S-adenosylhomocysteine and a Precorrin-2. The latter compound is processed by a NAD dependent uroporphyrin III C-methyltransferase [multifunctional] resulting in a NADH and a sirohydrochlorin. This compound then interacts with Fe 2+
uroporphyrin III C-methyltransferase [multifunctional] resulting in a hydrogen ion and a siroheme. The siroheme is then processed in sulfur metabolism pathway.
Uroporphyrinogen III can be processed in anaerobic or aerobic condition.
Anaerobic:
Uroporphyrinogen III interacts with an oxygen molecule, a hydrogen ion through a coproporphyrinogen III oxidase resulting in water, carbon dioxide and protoporphyrinogen IX. The latter compound then interacts with an 3 oxygen molecule through a protoporphyrinogen oxidase resulting in 3 hydrogen peroxide and a Protoporphyrin IX
Aerobic:
Uroporphyrinogen III reacts with S-adenosylmethionine through a coproporphyrinogen III dehydrogenase resulting in carbon dioxide, 5-deoxyadenosine, L-methionine and protoporphyrinogen IX. The latter compound interacts with a meanquinone through a protoporphyrinogen oxidase resulting in protoporphyrin IX.
The protoporphyrin IX interacts with Fe 2+ through a ferrochelatase resulting in a hydrogen ion and a ferroheme b. The ferroheme b can either be incorporated into the oxidative phosphorylation as a cofactor of the enzymes involved in that pathway or it can interact with hydrogen peroxide through a catalase HPII resulting in a heme D. Heme D can then be incorporated into the oxidative phosphyrlation pathway as a cofactor of the enzymes involved in that pathway. Ferroheme b can also interact with water and a farnesyl pyrophosphate through a heme O synthase resulting in a release of pyrophosphate and heme O. Heme O is then incorporated into the Oxidative phosphorylation pathway.
PW000936MetabolicVitamin B6 1430936196PW000891Metabolicarginine metabolismThe metabolism of L-arginine starts with the acetylation of L-glutamic acid resulting in a N-acetylglutamic acid while releasing a coenzyme A and a hydrogen ion. N-acetylglutamic acid is then phosphorylated via an ATP driven acetylglutamate kinase which yields a N-acetyl-L-glutamyl 5-phosphate. This compound undergoes a NDPH dependent reduction resulting in N-acetyl-L-glutamate 5-semialdehyde. This compound reacts with L-glutamic acid through a acetylornithine aminotransferase / N-succinyldiaminopimelate aminotransferase to produce a N-acetylornithine which is then deacetylated through a acetylornithine deacetylase which yield an ornithine.
L-glutamine is used to synthesize carbamoyl phosphate through the interaction of L-glutamine, water, ATP, and hydrogen carbonate. This reaction yields ADP, L-glutamic acid, phosphate, and hydrogen ion.
Carbamoyl phosphate and ornithine are used to catalyze the production of citrulline through an ornithine carbamoyltransferase. Citrulline reacts with L-aspartic acid through an ATP dependent enzyme, argininosuccinate synthase to produce pyrophosphate, AMP and argininosuccinic acid. Argininosussinic acid is then lyase to produce L-arginine and fumaric acid.
L-arginine can be metabolized into succinic acid by two different sets of reactions:
1. Arginine reacts with succinyl-CoA through a arginine N-succinyltransferase resulting in N2-succinyl-L-arginine while releasing CoA and Hydrogen Ion. N2-succinyl-L-arginine is then dihydrolase to produce a N2-succinyl-L-ornithine through a N-succinylarginine dihydrolase. This compound in turn reacts with oxoglutaric acid through succinylornithine transaminase resulting in L-glutamic acid and N2-succinyl-L-glutamic acid 5-semialdehyde. This compoud in turn reacts with a NAD dependent dehydrogenase resulting in N2-succinylglutamate while releasing NADH and hydrogen ion. N2-succinylglutamate reacts with water through a succinylglutamate desuccinylase resulting in L-glutamic acid and
a succinic acid. The succinic acid is then incorporated in the TCA cycle
2.Argine reacts with carbon dioxide and a hydrogen ion through a biodegradative arginine decarboxylase, resulting in Agmatine. This compound is then transformed into putrescine by reacting with water and an agmatinase, and releasing urea. Putrescine can be metabolized by reaction with either l-glutamic acid or oxoglutaric acid. If putrescine reacts with L-glutamic acid, it reacts through an ATP mediated gamma-glutamylputrescine producing a hydrogen ion, ADP, phosphate and gamma-glutamyl-L-putrescine. This compound is reduced by interacting with oxygen, water and a gamma-glutamylputrescine oxidoreductase resulting in ammonium, hydrogen peroxide and 4-gamma-glutamylamino butanal. This compound is dehydrogenated through a NADP mediated reaction lead by gamma-glutamyl-gamma-aminobutaryaldehyde dehydrogenase resulting in hydrogen ion, NADPH and 4-glutamylamino butanoate. In turn, the latter compound reacts with water through a gamma-glutamyl-gamma-aminobutyrate hydrolase resulting in L-glutamic acid and Gamma aminobutyric acid. On the other hand, if putrescine reacts with oxoglutaric acid through a putrescine aminotransferase, it results in L-glutamic acid, and a 4-aminobutyraldehyde. This compound reacts with water through a NAD dependent gamma aminobutyraldehyde dehydrogenase resulting in hydrogen ion, NADH and gamma-aminobutyric acid.
Gamma Aaminobutyric acid reacts with oxoglutaric acid through 4-aminobutyrate aminotransferase resulting in L-glutamic acid and succinic acid semialdehyde. This compound in turn can react with with either NADP or NAD to result in the production of succinic acid through succinate-semialdehyde dehydrogenase or aldehyde dehydrogenase-like protein yneI respectively. Succinic acid can then be integrated in the TCA cycle.
L-arginine is eventua lly metabolized into succinic acid which then goes to the TCA cyclePW000790Metabolicornithine metabolism
In the ornithine biosynthesis pathway of E. coli, L-glutamate is acetylated to N-acetylglutamate by the enzyme N-acetylglutamate synthase, encoded by the argA gene. The acetyl donor for this reaction is acetyl-CoA. N-acetylglutamic acid is then phosphorylated via an ATP driven acetylglutamate kinase which yields a N-acetyl-L-glutamyl 5-phosphate. This compound undergoes a NADPH dependent reduction resulting in N-acetyl-L-glutamate 5-semialdehyde. This compound reacts with L-glutamic acid through a acetylornithine aminotransferase / N-succinyldiaminopimelate aminotransferase to produce a N-acetylornithine which is then deacetylated through a acetylornithine deacetylase which yield an ornithine. Ornithine interacts with hydrogen ion through a Ornithine decarboxylase resulting in a carbon dioxide release and a putrescine
Putrescine can be metabolized by reaction with either l-glutamic acid or oxoglutaric acid. If putrescine reacts with L-glutamic acid, it reacts through an ATP mediated gamma-glutamylputrescine producing a hydrogen ion, ADP, phosphate and gamma-glutamyl-L-putrescine. This compound is reduced by interacting with oxygen, water and a gamma-glutamylputrescine oxidoreductase resulting in ammonium, hydrogen peroxide and 4-gamma-glutamylamino butanal. This compound is dehydrogenated through a NADP mediated reaction lead by gamma-glutamyl-gamma-aminobutaryaldehyde dehydrogenase resulting in hydrogen ion, NADPH and 4-glutamylamino butanoate. In turn, the latter compound reacts with water through a gamma-glutamyl-gamma-aminobutyrate hydrolase resulting in L-glutamic acid and Gamma aminobutyric acid. On the other hand, if putrescine reacts with oxoglutaric acid through a putrescine aminotransferase, it results in L-glutamic acid, and a 4-aminobutyraldehyde. This compound reacts with water through a NAD dependent gamma aminobutyraldehyde dehydrogenase resulting in hydrogen ion, NADH and gamma-aminobutyric acid.
Gamma Aaminobutyric acid reacts with oxoglutaric acid through 4-aminobutyrate aminotransferase resulting in L-glutamic acid and succinic acid semialdehyde. This compound in turn can react with with either NADP or NAD to result in the production of succinic acid through succinate-semialdehyde dehydrogenase or aldehyde dehydrogenase-like protein yneI respectively. Succinic acid can then be integrated in the TCA cycle.
PW000791MetabolicPhenylethylamine metabolismThe process of phenylethylamine metabolism starts with 2-phenylethylamine interacting with an oxygen molecule and a water molecule in the periplasmic space through a phenylethylamine oxidase. This reaction results in the release of a hydrogen peroxide, ammonium and phenylacetaldehyde.
Phenylacetaldehyde is introduced into the cytosol and degraded into phenylacetate by reaction with a phenylacetaldehyde dehydrogenase. This reaction involves phenylacetaldehyde interacting with NAD, and a water molecule and then resulting in the release of NADH, and 2 hydrogen ion.
Phenylacetate is then degraded. The first step involves phenylacetate interacting with an coenzyme A and an ATP driven phenylacetate-CoA ligase resulting in the release of a AMP, a diphosphate and a phenylacetyl-CoA. This resulting compound the interacts with a hydrogen ion, NADPH, and oxygen molecule through a ring 1,2-phenylacetyl-CoA epoxidase protein complex resulting in the release of a water molecule, an NADP and a 2-(1,2-epoxy-1,2-dihydrophenyl)acetyl-CoA. This compound is then metabolized by a ring 1,2 epoxyphenylacetyl-CoA isomerase resulting in a 2-oxepin-2(3H)-ylideneacetyl-CoA. This compound is then hydrolated through a oxepin-CoA hydrolase resulting in a 3-oxo-5,6-didehydrosuberyl-CoA semialdehyde. This commpound then interacts with a water molecule and NADP driven 3-oxo-5,6-dehydrosuberyl-CoA semialadehyde dehydrogenase resulting in 2 hydrogen ions, a NADPH and a 3-oxo-5,6-didehydrosuberyl-CoA. The resulting compound interacts with a coenzyme A and a 3-oxo-5,6 dehydrosuberyl-CoA thiolase resulting in an acetyl-CoA and a 2,3-didehydroadipyl-CoA. This resulting compound is the hydrated by a 2,3-dehydroadipyl-CoA hydratas resulting in a 3-hydroxyadipyl-CoA whuch is dehydrogenated through an NAD driven 3-hydroxyadipyl-CoA dehydrogenase resulting in a NADH, a hydrogen ion and a 3-oxoadipyl-CoA. The latter compound then interacts with conezyme A through a beta-ketoadipyl-CoA thiolase resulting in an acetyl-CoA and a succinyl-CoA. The succinyl-CoA is then integrated into the TCA cycle.PW002027MetabolicPutrescine Degradation IISeveral metabolic pathways for putrescine degradation as a source of nitrogen for E. coli K-12 are known. The first putrescine degradation pathway was found in in 1985. That pathway is dedicated to the degradation of intracellular putrescine. A second pathway was found in E. coli K-12 twenty years later. This pathway seems to be dedicated to the degradation of extracellular putrescine.
The pathway was discovered following the discovery of a cluster of seven unassigned genes on the E. coli K-12 chromosome. In addition to a putrescine transporter, encoded by the puuP gene, the cluster contains four genes that encode the enzymes involved in this pathway, and two additional genes (puuE and puuR) that encode an enzyme involved in the catabolism of GABA (see superpathway of 4-aminobutanoate degradation) and a regulator.
In this pathway, putrescine is γ-glutamylated at the expense of an ATP molecule. The resulting γ-glutamyl-putrescine is oxidized to γ-glutamyl-γ-aminobutyraldehyde, which is then dehydrogenated into 4-(glutamylamino) butanoate. In the last step, the γ-glutamyl group is removed by hydrolysis, generating 4-aminobutyrate.
The key difference between this pathway and putrescine degradation I is the γ-glutamylation of putrescine. In the other pathway, putrescine is degraded directly to 4-amino-butanal.
Wild type E. coli cells are unable to utilize putrescine as the sole source of carbon at temperatures above 30°C. It is possible to select for mutants that possess this ability; these mutants contain elevated levels of the enzymes in this pathway. (EcoCyc)PW002054MetabolicSuperoxide Radicals DegradationGram-negative bacteria commonly synthesize both cytoplasmic and periplasmic isozymes of SOD as their frontline defense against superoxide anion (O2-). E. coli contains two cytoplasmic SOD isozymes, one each of the manganese- and iron-cofactored types (MnSOD and FeSOD), and secretes a copper, zinc-cofactored enzyme (CuZnSOD) to the periplasm. Periplasmic superoxide may be generated by autooxidation of dihydromenaquinone in the cytoplasmic membrane.
In E. coli, the MnSOD and FeSOD enzymes (encoded by sodA and sodB, respectively) are structurally and kinetically similar. Unlike MnSOD and FeSOD, CuZnSOD is monomeric. Regulation of the three enzymes is complex. Under anaerobic conditions, FeSOD is the only superoxide dismutase enzyme present in E. coli. MnSOD is induced by aerobic growth and a variety of environmental stress conditions. CuZnSOD constitutes only a small fraction of superoxide dismutase activity in the cell; its expression is induced in stationary phase.
In E. coli, with rising H2O2 concentration, catalase is strongly induced and becomes the primary scavenging enzyme. E. coli expresses two catalases, known as HPI and HPII, that are encoded by katG and katE, respectively. While katG katE mutants could not degrade millimolar concentrations of H2O2, they were subsequently found to retain the ability to degrade H2O2 when it was present at low micromolar concentrations. This residual activity is due to an enzyme known as alkylhydroperoxide reductase (Ahp). This two-component enzyme had originally been identified as a scavenger of organic hydroperoxides.
SOD mutants of E. coli are unable to perform normal sulfur metabolism. Both SOD and catalase/peroxidase mutants of E. coli are incapable of synthesizing aromatic products, including amino acids.
SoxRS regulon is turned on by any condition that increases superoxide radical production in E. coli. One of its products is Mn-SOD. Another independent regulon turned on in response to H2O2 is referred to as the OxyR regulon. (EcoCyc)PW002053MetabolicL-threonine degradation to methylglyoxalL-threonine is degrade into methylglyoxal (pyruvaldehyde) by first reacting with a NDA dependent threonine dehydrogenase resulting in the release of a hydrogen ion, an NADH and a 2-amino-3-oxobutanoate. The latter compound reacts spontaneously with a hydrogen ion resulting in the release of a carbon dioxide and a aminoacetone. The aminoacetone in turn reacts with an oxygen and a water molecule through an aminoacetone oxidase resulting in the release of a hydrogen peroxide, ammonium and a methylglyoxal which can then be incorporated in the methylglyoxal degradation pathways.PW002106MetabolicL-ascorbate degradation II (bacterial, aerobic)PWY-6961NAD biosynthesis I (from aspartate)PYRIDNUCSYN-PWYthreonine degradation III (to methylglyoxal)THRDLCTCAT-PWYphenylethylamine degradation I2PHENDEG-PWYpyridoxal 5'-phosphate salvage pathwayPLPSAL-PWYpyridoxal 5'-phosphate biosynthesis IPYRIDOXSYN-PWYputrescine degradation IIPWY0-1221heme biosynthesis from uroporphyrinogen-III IHEME-BIOSYNTHESIS-IIsuperpathway of heme biosynthesis from uroporphyrinogen-IIIPWY0-1415superoxide radicals degradationDETOX1-PWYSpecdb::CMs3384Specdb::CMs132497Specdb::CMs140231Specdb::MsMs28757Specdb::MsMs28758Specdb::MsMs28759Specdb::MsMs35315Specdb::MsMs35316Specdb::MsMs35317Specdb::MsMs2413402Specdb::MsMs2413403Specdb::MsMs2413404Specdb::MsMs2552306Specdb::MsMs2552307Specdb::MsMs2552308HMDB03125784763C0002716240HYDROGEN-PEROXIDEPERHydrogen_peroxideKeseler, I. M., Collado-Vides, J., Santos-Zavaleta, A., Peralta-Gil, M., Gama-Castro, S., Muniz-Rascado, L., Bonavides-Martinez, C., Paley, S., Krummenacker, M., Altman, T., Kaipa, P., Spaulding, A., Pacheco, J., Latendresse, M., Fulcher, C., Sarker, M., Shearer, A. G., Mackie, A., Paulsen, I., Gunsalus, R. P., Karp, P. D. (2011). "EcoCyc: a comprehensive database of Escherichia coli biology." Nucleic Acids Res 39:D583-D590.21097882Gonzalez-Flecha, B., Demple, B. (1997). "Homeostatic regulation of intracellular hydrogen peroxide concentration in aerobically growing Escherichia coli." J Bacteriol 179:382-388.8990289Lopez-Lazaro M: Dual role of hydrogen peroxide in cancer: possible relevance to cancer chemoprevention and therapy. Cancer Lett. 2007 Jul 8;252(1):1-8. Epub 2006 Dec 5.17150302Schallreuter KU, Elwary S: Hydrogen peroxide regulates the cholinergic signal in a concentration dependent manner. Life Sci. 2007 May 30;80(24-25):2221-6. Epub 2007 Jan 25.17335854Stone JR, Yang S: Hydrogen peroxide: a signaling messenger. Antioxid Redox Signal. 2006 Mar-Apr;8(3-4):243-70.16677071Tredwin CJ, Naik S, Lewis NJ, Scully C: Hydrogen peroxide tooth-whitening (bleaching) products: review of adverse effects and safety issues. Br Dent J. 2006 Apr 8;200(7):371-6.16607324Ardanaz N, Pagano PJ: Hydrogen peroxide as a paracrine vascular mediator: regulation and signaling leading to dysfunction. Exp Biol Med (Maywood). 2006 Mar;231(3):237-51.16514169http://hmdb.ca/system/metabolites/msds/000/002/708/original/HMDB03125.pdf?1358461854Superoxide dismutase [Mn]P00448SODM_ECOLIsodAhttp://ecmdb.ca/proteins/P00448.xmlVitamin B12 transport periplasmic protein BtuEP06610BTUE_ECOLIbtuEhttp://ecmdb.ca/proteins/P06610.xmlProtoporphyrinogen oxidaseP0ACB4HEMG_ECOLIhemGhttp://ecmdb.ca/proteins/P0ACB4.xmlPutative peroxiredoxin bcpP0AE52BCP_ECOLIbcphttp://ecmdb.ca/proteins/P0AE52.xmlGlycolate oxidase subunit glcDP0AEP9GLCD_ECOLIglcDhttp://ecmdb.ca/proteins/P0AEP9.xmlSuperoxide dismutase [Cu-Zn]P0AGD1SODC_ECOLIsodChttp://ecmdb.ca/proteins/P0AGD1.xmlSuperoxide dismutase [Fe]P0AGD3SODF_ECOLIsodBhttp://ecmdb.ca/proteins/P0AGD3.xmlThioredoxin-2P0AGG4THIO2_ECOLItrxChttp://ecmdb.ca/proteins/P0AGG4.xmlL-aspartate oxidaseP10902NADB_ECOLInadBhttp://ecmdb.ca/proteins/P10902.xmlCatalase-peroxidaseP13029KATG_ECOLIkatGhttp://ecmdb.ca/proteins/P13029.xmlCatalase HPIIP21179CATE_ECOLIkatEhttp://ecmdb.ca/proteins/P21179.xmlAdenine deaminaseP31441ADEC_ECOLIadehttp://ecmdb.ca/proteins/P31441.xmlMalate:quinone oxidoreductaseP33940MQO_ECOLImqohttp://ecmdb.ca/proteins/P33940.xmlProbable cytochrome c peroxidaseP37197YHJA_ECOLIyhjAhttp://ecmdb.ca/proteins/P37197.xmlGamma-glutamylputrescine oxidoreductaseP37906PUUB_ECOLIpuuBhttp://ecmdb.ca/proteins/P37906.xmlPrimary amine oxidaseP46883AMO_ECOLItynAhttp://ecmdb.ca/proteins/P46883.xmlGlycolate oxidase iron-sulfur subunitP52074GLCF_ECOLIglcFhttp://ecmdb.ca/proteins/P52074.xmlGlycolate oxidase subunit glcEP52073GLCE_ECOLIglcEhttp://ecmdb.ca/proteins/P52073.xmlN-methyl-L-tryptophan oxidaseP40874MTOX_ECOLIsolAhttp://ecmdb.ca/proteins/P40874.xmlThioredoxin-1P0AA25THIO_ECOLItrxAhttp://ecmdb.ca/proteins/P0AA25.xmlPyridoxine/pyridoxamine 5'-phosphate oxidaseP0AFI7PDXH_ECOLIpdxHhttp://ecmdb.ca/proteins/P0AFI7.xmlOuter membrane protein NP77747OMPN_ECOLIompNhttp://ecmdb.ca/proteins/P77747.xmlOuter membrane pore protein EP02932PHOE_ECOLIphoEhttp://ecmdb.ca/proteins/P02932.xmlOuter membrane protein FP02931OMPF_ECOLIompFhttp://ecmdb.ca/proteins/P02931.xmlOuter membrane protein CP06996OMPC_ECOLIompChttp://ecmdb.ca/proteins/P06996.xmlHydrogen peroxide + Reduced Thioredoxin >2 Water + Oxidized Thioredoxin2 Hydrogen peroxide <>2 Water + OxygenR00009CATAL-RXN2 Hydrogen ion + 2 Superoxide anion > Hydrogen peroxide + OxygenSUPEROX-DISMUT-RXNWater + Oxygen + Sarcosine > Formaldehyde + Glycine + Hydrogen peroxideN-Methyltryptophan + Water + Oxygen > Formaldehyde + Hydrogen peroxide + L-TryptophanRXN0-301gamma-Glutamyl-L-putrescine + Water + Oxygen > gamma-Glutamyl-gamma-butyraldehyde + Hydrogen peroxide + AmmoniumRXN0-3921Dopamine + Water + Oxygen > 3,4-Dihydroxyphenylacetaldehyde + Hydrogen peroxide + AmmoniumWater + Oxygen + Tyramine > 4-Hydroxyphenylacetaldehyde + Hydrogen peroxide + AmmoniumWater + Oxygen + Phenylethylamine > Hydrogen peroxide + Ammonium + PhenylacetaldehydeWater + Oxygen + Pyridoxamine 5'-phosphate > Hydrogen peroxide + Ammonium + Pyridoxal 5'-phosphateOxygen + Pyridoxine 5'-phosphate > Hydrogen peroxide + Pyridoxal 5'-phosphateR00278PNPOXI-RXN2 Glutathione + Hydrogen peroxide <> Glutathione disulfide +2 WaterR00274GLUTATHIONE-PEROXIDASE-RXNL-Aspartic acid + Oxygen <> Hydrogen ion + Hydrogen peroxide + Iminoaspartic acidR00481L-ASPARTATE-OXID-RXNHydrogen peroxide + L-Methionine > Water + Methionine sulfoxide2 [4Fe-4S] iron-sulfur cluster + 2 Hydrogen ion + Hydrogen peroxide >2 [3Fe-4S] damaged iron-sulfur cluster +2 Fe3+ +2 WaterPyridoxamine 5'-phosphate + Water + Oxygen <> Pyridoxal 5'-phosphate + Ammonia + Hydrogen peroxideR00277PMPOXI-RXNPyridoxine 5'-phosphate + Oxygen <> Hydrogen peroxide + Pyridoxal 5'-phosphateR00278L-Aspartic acid + Water + Oxygen <> Oxalacetic acid + Ammonia + Hydrogen peroxideR00357Glycolic acid + Oxygen <> Glyoxylic acid + Hydrogen peroxideR00475L-Aspartic acid + Oxygen <> Iminoaspartic acid + Hydrogen peroxideR00481L-ASPARTATE-OXID-RXNMethanol + Hydrogen peroxide <> Formaldehyde +2 WaterR00602Pyridoxamine + Water + Oxygen <> Pyridoxal + Ammonia + Hydrogen peroxideR01710Pyridoxine + Oxygen <> Pyridoxal + Hydrogen peroxideR01711Tyramine + Water + Oxygen <> 4-Hydroxyphenylacetaldehyde + Ammonia + Hydrogen peroxideR02382Aminoacetone + Water + Oxygen <> Pyruvaldehyde + Ammonia + Hydrogen peroxideR02529Phenylethylamine + Oxygen + Water <> Phenylacetaldehyde + Ammonia + Hydrogen peroxideR026132 3-Hydroxyanthranilic acid + 4 Oxygen <> Cinnavalininate +2 Superoxide anion +2 Hydrogen peroxide +2 Hydrogen ionR026701,3-Diaminopropane + Oxygen + Water <> 3-Aminopropionaldehyde + Ammonia + Hydrogen peroxideR03139N-Methylputrescine + Oxygen + Hydrogen ion <> 1-Methylpyrrolinium + Hydrogen peroxide + AmmoniaR04027Dopamine + Water + Oxygen <> 3,4-Dihydroxyphenylacetaldehyde + Ammonia + Hydrogen peroxideR04300Methylamine + Oxygen + Water <> Formaldehyde + Ammonia + Hydrogen peroxideR06154Cadaverine + Water + Oxygen <> 5-Aminopentanal + Ammonia + Hydrogen peroxideR06740gamma-Glutamyl-L-putrescine + Water + Oxygen <> gamma-Glutamyl-gamma-butyraldehyde + Ammonia + Hydrogen peroxideR07415Hydrogen ion + Hydrogen peroxide + Iron > hydroxyl radical + OH<SUP>-</SUP> + Fe<SUP>3+</SUP>RXN-12540dehydroascorbate (bicyclic form) + Hydrogen peroxide > L-threonate + Oxalic acid + Hydrogen ionRXN-12863Ascorbic acid + Hydrogen peroxide > monodehydroascorbate + WaterRXN-3521Heme + Hydrogen peroxide Heme DRXN-8073NAD(P)H + Cr<sup>6+</sup> + Oxygen > NAD(P)<sup>+</sup> + Cr<sup>3+</sup> + Hydrogen peroxideRXN0-3381L-Methionine + Hydrogen peroxide > L-methionine <i>S</i>-oxide + WaterRXN0-6721Aminoacetone + Water + Oxygen > Hydrogen ion + Pyruvaldehyde + Ammonia + Hydrogen peroxideR02529AMACETOXID-RXNan aliphatic amine + Water + Oxygen > an aldehyde + Ammonia + Hydrogen peroxide + Hydrogen ionAMINEOXID-RXNWater + Oxygen + Phenylethylamine > Hydrogen ion + Hydrogen peroxide + Ammonia + PhenylacetaldehydeR02613AMINEPHEN-RXNHydrogen peroxide > Water + OxygenCATAL-RXNHydrogen peroxide + Glutathione > Glutathione disulfide + WaterGLUTATHIONE-PEROXIDASE-RXNOxygen + L-Aspartic acid > Hydrogen ion + Hydrogen peroxide + Iminoaspartic acidL-ASPARTATE-OXID-RXNL-Malic acid + Oxygen <> Oxalacetic acid + Hydrogen peroxideMALOX-RXNa phenolic donor + Hydrogen peroxide a phenoxyl radical of a phenolic donor + WaterPEROXID-RXNOxygen + Water + Pyridoxamine 5'-phosphate > Hydrogen ion + Hydrogen peroxide + Ammonia + Pyridoxal 5'-phosphatePMPOXI-RXNProtoporphyrinogen IX + Oxygen > Protoporphyrin IX + Hydrogen peroxidePROTOPORGENOXI-RXNa reduced electron acceptor + Hydrogen peroxide > an oxidized electron acceptor + WaterRXN-12120Hydrogen peroxide > Water + OxygenRXN-12121Ascorbic acid + Hydrogen peroxide + Hydrogen ion > Ascorbic acid + L-dehydro-ascorbate + WaterRXN-12440a primary amine + Water + Oxygen > an aldehyde + Ammonia + Hydrogen peroxideRXN-9597L-2-Hydroxyglutaric acid + Oxygen > Oxoglutaric acid + Hydrogen peroxideRXN0-5364Hydrogen ion + Superoxide anion > Hydrogen peroxide + OxygenSUPEROX-DISMUT-RXNRCH(2)NH(2) + Water + Oxygen > RCHO + Ammonia + Hydrogen peroxidePhenylethylamine + Water + Oxygen > Phenylacetaldehyde + Ammonia + Hydrogen peroxide2 Hydrogen peroxide > Oxygen +2 Water2 Iron + Hydrogen peroxide + 2 Hydrogen ion >2 Fe3+ +2 WaterDonor + Hydrogen peroxide > oxidized donor +2 Water(S)-2-hydroxy acid + Oxygen > 2-oxo acid + Hydrogen peroxideN-methyl-L-tryptophan + Water + Oxygen > L-Tryptophan + Formaldehyde + Hydrogen peroxideL-Aspartic acid + Oxygen > Iminoaspartic acid + Hydrogen peroxidePyridoxamine 5'-phosphate + Water + Oxygen > Pyridoxal 5'-phosphate + Ammonia + Hydrogen peroxidegamma-Glutamyl-L-putrescine + Water + Oxygen > Gamma-glutamyl-gamma-aminobutyraldehyde + Ammonia + Hydrogen peroxide2 superoxide + 2 Hydrogen ion > Oxygen + Hydrogen peroxide2 Ferrocytochrome c + Hydrogen peroxide >2 Ferricytochrome c +2 Water2 Hydrogen ion + 2 superoxide <> Oxygen + Hydrogen peroxideR00275 Reduced acceptor + Hydrogen peroxide <> Acceptor + Water + OxygenR03532 Primary amine + Water + Oxygen <> Aldehyde + Ammonia + Hydrogen peroxideR01853 Pyridoxamine 5'-phosphate + Water + Oxygen + Pyridoxine 5'-phosphate <> Pyridoxal 5'-phosphate + Ammonia + Hydrogen peroxideR00277 (S)-2-Hydroxyacid + Oxygen <> 2-Oxo acid + Hydrogen peroxideR01341 Ferrocytochrome c + Hydrogen peroxide <> Ferricytochrome c + WaterR00017 Protoporphyrinogen IX + 3 Oxygen <> Protoporphyrin IX +3 Hydrogen peroxideR03222 L-Aspartic acid + Water + Oxygen + L-Aspartic acid > Oxalacetic acid + Ammonia + Hydrogen peroxidePW_R002645L-Aspartic acid + Oxygen + L-Aspartic acid > Hydrogen peroxide + Hydrogen ion + Iminoaspartic acidPW_R003007gamma-Glutamyl-L-putrescine + Oxygen + Water > 4-(γ-glutamylamino)butanal + Ammonium + Hydrogen peroxidePW_R002686Protoporphyrinogen IX + 3 Oxygen > Protoporphyrin IX +3 Hydrogen peroxidePW_R003484ferroheme b + Hydrogen peroxide > Heme DPW_R003488gamma-Glutamyl-L-putrescine + Oxygen + Hydrogen ion > gamma-Glutamyl-gamma-butyraldehyde + Hydrogen peroxide + AmmoniumPW_R005998Aminoacetone + Oxygen + Water > Hydrogen peroxide + Ammonium + PyruvaldehydePW_R006139L-Aspartic acid + Oxygen <> Hydrogen ion + Hydrogen peroxide + Iminoaspartic acidOxygen + Pyridoxine 5'-phosphate > Hydrogen peroxide + Pyridoxal 5'-phosphate2 Hydrogen peroxide <>2 Water + Oxygengamma-Glutamyl-L-putrescine + Water + Oxygen <> gamma-Glutamyl-gamma-butyraldehyde + Ammonia + Hydrogen peroxide2 Hydrogen ion + 2 superoxide <> Oxygen + Hydrogen peroxideGlycolic acid + Oxygen <> Glyoxylic acid + Hydrogen peroxideL-Aspartic acid + Oxygen <> Hydrogen ion + Hydrogen peroxide + Iminoaspartic acidOxygen + Pyridoxine 5'-phosphate > Hydrogen peroxide + Pyridoxal 5'-phosphate2 Hydrogen ion + 2 superoxide <> Oxygen + Hydrogen peroxideGlycolic acid + Oxygen <> Glyoxylic acid + Hydrogen peroxideGlycolic acid + Oxygen <> Glyoxylic acid + Hydrogen peroxideLuria-Bertani BrothShake flask0.25uM0.0337 oCAB1157/K12Mid-Log Phase1000120Gonzalez-Flecha, B., Demple, B. (1997). "Homeostatic regulation of intracellular hydrogen peroxide concentration in aerobically growing Escherichia coli." J Bacteriol 179:382-388.8990289Luria-Bertani BrothShake flask0.18uM0.0237 oCAB1157/K12Stationary Phase72080Gonzalez-Flecha, B., Demple, B. (1997). "Homeostatic regulation of intracellular hydrogen peroxide concentration in aerobically growing Escherichia coli." J Bacteriol 179:382-388.8990289