L-homocysteine

Three steps

• 3,3'-diiodothyronamineReach from here →
  1. (6S)-5-methyl-5,6,7,8-tetrahydrofolate + L-homocysteine = (6S)-5,6,7,8-tetrahydrofolate + L-methionine
  2. N(6)-L-threonylcarbamoyladenosine(37) in tRNA + (sulfur carrier)-SH + AH2 + 2 S-adenosyl-L-methionine = 2-methylsulfanyl-N(6)-L-threonylcarbamoyladenosine(37) in tRNA + (sulfur carrier)-H + 5'-deoxyadenosine + L-methionine + A + S-adenosyl-L-homocysteine + 2 H(+)
  3. 3,3'-diiodothyronamine + iodide + A + H(+) = 3,3',5'-triiodothyronamine + AH2

  Catalysed by MTR, CDKAL1, DIO1, DIO2One of 2 routes

• 3',5'-diiodothyronamineReach from here →
  1. (6S)-5-methyl-5,6,7,8-tetrahydrofolate + L-homocysteine = (6S)-5,6,7,8-tetrahydrofolate + L-methionine
  2. N(6)-L-threonylcarbamoyladenosine(37) in tRNA + (sulfur carrier)-SH + AH2 + 2 S-adenosyl-L-methionine = 2-methylsulfanyl-N(6)-L-threonylcarbamoyladenosine(37) in tRNA + (sulfur carrier)-H + 5'-deoxyadenosine + L-methionine + A + S-adenosyl-L-homocysteine + 2 H(+)
  3. 3',5'-diiodothyronamine + iodide + A + H(+) = 3,3',5'-triiodothyronamine + AH2

  Catalysed by MTR, CDKAL1, DIO3

• 3,3',5'-triiodothyronamineReach from here →
  1. (6S)-5-methyl-5,6,7,8-tetrahydrofolate + L-homocysteine = (6S)-5,6,7,8-tetrahydrofolate + L-methionine
  2. N(6)-L-threonylcarbamoyladenosine(37) in tRNA + (sulfur carrier)-SH + AH2 + 2 S-adenosyl-L-methionine = 2-methylsulfanyl-N(6)-L-threonylcarbamoyladenosine(37) in tRNA + (sulfur carrier)-H + 5'-deoxyadenosine + L-methionine + A + S-adenosyl-L-homocysteine + 2 H(+)
  3. 3,3',5'-triiodothyronamine + iodide + A + H(+) = 3,3',5,5'-tetraiodothyronamine + AH2

  Catalysed by MTR, CDKAL1, DIO3

• (4Z,7Z,10Z,13Z)-hexadecatetraenoyl-CoAReach from here →
  1. L-homocysteine + L-serine = L,L-cystathionine + H2O
  2. N-acetylglutamate synthase (N-acetyl-L-cystathionine)
  3. Fatty Acid Beta Oxidation (C18:4->C16:4), Mitochondrial

  Catalysed by CBS, NAGS, HADHA, ACADVL and 1 moremitochondrial matrixOne of 3 routes

• (7Z,10Z)-hexadecadienoyl-CoAReach from here →
  1. L-homocysteine + L-serine = L,L-cystathionine + H2O
  2. N-acetylglutamate synthase (N-acetyl-L-cystathionine)
  3. Fatty Acid Beta Oxidation Trans (C18:2->C16:2), Mitochondrial

  Catalysed by CBS, NAGS, HADHA, ACADVL and 1 moremitochondrial matrix

• (4Z,7Z)-decadienoyl-CoAReach from here →
  1. L-homocysteine + L-serine = L,L-cystathionine + H2O
  2. N-acetylglutamate synthase (N-acetyl-L-cystathionine)
  3. Fatty Acid Beta Oxidation (C12:3->C10:2), Mitochondrial

  Catalysed by CBS, NAGS, ECHS1, ACAA2 and 1 moremitochondrial matrixOne of 2 routes

• (5Z)-octenoyl-CoAReach from here →
  1. L-homocysteine + L-serine = L,L-cystathionine + H2O
  2. N-acetylglutamate synthase (N-acetyl-L-cystathionine)
  3. Fatty Acid Beta Oxidation (C10:2->C8:1), Mitochondrial

  Catalysed by CBS, NAGS, ECHS1, ACAA2 and 1 moremitochondrial matrixOne of 2 routes

• 3-(glutathion-S-yl)-4-hydroxynonanalReach from here →
  1. L-homocysteine + H2O = 2-oxobutanoate + hydrogen sulfide + NH4(+) + H(+)
  2. thiosulfate + 2 glutathione = glutathione disulfide + hydrogen sulfide + sulfite + 2 H(+)
  3. (E)-4-hydroxynon-2-enal + glutathione = 3-(glutathion-S-yl)-4-hydroxynonanal

  Catalysed by CTH, TSTD1, GSTP1

• CHEBI:240943Reach from here →
  1. (6S)-5-methyl-5,6,7,8-tetrahydrofolate + L-homocysteine = (6S)-5,6,7,8-tetrahydrofolate + L-methionine
  2. (6R)-5,10-methylene-5,6,7,8-tetrahydrofolate + glycine + H2O = (6S)-5,6,7,8-tetrahydrofolate + L-serine
  3. glycine N-acyltransferase (2-methylbutyryl-CoA)

  Catalysed by MTR, SHMT1, SHMT2, GLYAT and 2 moremitochondrial matrixOne of 3 routes

• hypochlorous acidReach from here →
  1. (6S)-5-methyl-5,6,7,8-tetrahydrofolate + L-homocysteine = (6S)-5,6,7,8-tetrahydrofolate + L-methionine
  2. transport of chloride and methionine (cytosol to extracellular)
  3. Peroxidase

  Catalysed by MTR, SLC6A14, LPOextracellular space, cytosolOne of 4 routes

• potassium atomReach from here →
  1. (6S)-5-methyl-5,6,7,8-tetrahydrofolate + L-homocysteine = (6S)-5,6,7,8-tetrahydrofolate + L-methionine
  2. transport of chloride and methionine (cytosol to extracellular)
  3. transport of chloride (cytosol to extracellular)

  Catalysed by MTR, SLC6A14, SLC12A2, SLC12A1extracellular space, cytosolOne of 3 routes

• folic acidReach from here →
  1. L-homocysteine + H2O = 2-oxobutanoate + hydrogen sulfide + NH4(+) + H(+)
  2. hydrogen sulfide + 2 O2 = sulfate + H(+)
  3. Folate Transport by Oats

  Catalysed by CTH, SOD1, SLC22A8, SLC22A7extracellular space, cytosolOne of 2 routes

• phenylacetylglycineReach from here →
  1. (6S)-5-methyl-5,6,7,8-tetrahydrofolate + L-homocysteine = (6S)-5,6,7,8-tetrahydrofolate + L-methionine
  2. (6R)-5,10-methylene-5,6,7,8-tetrahydrofolate + glycine + H2O = (6S)-5,6,7,8-tetrahydrofolate + L-serine
  3. phenylacetyl-CoA:glycine N-phenylacetyltransferase

  Catalysed by MTR, SHMT1, SHMT2, GLYATcytosolOne of 3 routes

• CHEBI:27540Reach from here →
  1. L-homocysteine + L-serine = L,L-cystathionine + H2O
  2. N-acetylglutamate synthase (N-acetyl-L-cystathionine)
  3. medium-chain acyl-CoA ligase (hexanoic acid)

  Catalysed by CBS, NAGS, ACSM4, ACSM1 and 4 moremitochondrial matrix, cytosolOne of 6 routes

• elaidic acidReach from here →
  1. L-homocysteine + L-serine = L,L-cystathionine + H2O
  2. N-acetylglutamate synthase (N-acetyl-L-cystathionine)
  3. long-chain-fatty-acid-CoA ligase (elaidate)

  Catalysed by CBS, NAGS, SLC27A2, ACSL4 and 6 moremitochondrial matrix, cytosolOne of 5 routes

• 5-hydroxytryptophanReach from here →
  1. (6S)-5-methyl-5,6,7,8-tetrahydrofolate + L-homocysteine = (6S)-5,6,7,8-tetrahydrofolate + L-methionine
  2. transport of methionine and tryptophan (cytosol to extracellular)
  3. L-Tryptophan, Tetrahydrobiopterin:Oxygen Oxidoreductase (5-Hydroxylating)

  Catalysed by MTR, SLC7A5, TPH1, TPH2extracellular space, cytosolOne of 2 routes

• 3-mercaptolactic acidReach from here →
  1. L-homocysteine + H2O = 2-oxobutanoate + hydrogen sulfide + NH4(+) + H(+)
  2. 2-oxo-3-sulfanylpropanoate + [thioredoxin]-dithiol = [thioredoxin]-disulfide + hydrogen sulfide + pyruvate + H(+)
  3. 3-Mercaptolactate:NAD+ oxidoreductase

  Catalysed by CTH, MPST, LDHB, LDHC and 2 morecytosol

• 2-oxopentanoateReach from here →
  1. L-homocysteine + H2O = 2-oxobutanoate + hydrogen sulfide + NH4(+) + H(+)
  2. N(omega),N(omega)-dimethyl-L-arginine + 2-oxobutanoate = 5-(3,3-dimethylguanidino)-2-oxopentanoate + (2S)-2-aminobutanoate
  3. 2-oxopentanoate + N(omega),N(omega)-dimethyl-L-arginine = 5-(3,3-dimethylguanidino)-2-oxopentanoate + L-2-aminopentanoate

  Catalysed by CTH, AGXT2

• CHEBI:28666Reach from here →
  1. (6S)-5-methyl-5,6,7,8-tetrahydrofolate + L-homocysteine = (6S)-5,6,7,8-tetrahydrofolate + L-methionine
  2. (6R)-5,10-methylene-5,6,7,8-tetrahydrofolate + glycine + H2O = (6S)-5,6,7,8-tetrahydrofolate + L-serine
  3. LTD4 hydrolysis

  Catalysed by MTR, SHMT1, SHMT2cytosol

• CHEBI:28701Reach from here →
  1. L-homocysteine + L-serine = L,L-cystathionine + H2O
  2. N-acetylglutamate synthase (N-acetyl-L-cystathionine)
  3. Propanoyl-CoA:acetyl-CoA C-acyltransferase

  Catalysed by CBS, NAGS, ACAA1, SCP2 and 1 moremitochondrial matrix, peroxisomeOne of 7 routes

• pyridoxine 5'-phosphateReach from here →
  1. (6S)-5-methyl-5,6,7,8-tetrahydrofolate + L-homocysteine = (6S)-5,6,7,8-tetrahydrofolate + L-methionine
  2. transport of alanine and methionine (cytosol to extracellular)
  3. L-selenocysteine selenide-lyase (L-alanine-forming)

  Catalysed by MTR, SLC7A5, SCLYextracellular space, cytosol

• N-acetyl-L-cysteineReach from here →
  1. L-homocysteine + L-serine = L,L-cystathionine + H2O
  2. L-cystathionine cysteine-lyase (deaminating
  3. N-acetylglutamate synthase (N-acetyl-L-cysteine)

  Catalysed by CBS, CTH, NAGScytosol, mitochondrial matrix

• a dicarboxylateReach from here →
  1. L-homocysteine + H2O = 2-oxobutanoate + hydrogen sulfide + NH4(+) + H(+)
  2. 2-oxobutanoate + L-kynurenine = (2S)-2-aminobutanoate + kynurenate + H2O
  3. kynurenate(out) + a dicarboxylate(in) = kynurenate(in) + a dicarboxylate(out)

  Catalysed by CTH, AADAT, SLC22A8inner side of the membrane, outer side of the membraneOne of 4 routes

• L-ascorbic acidReach from here →
  1. L-homocysteine + H2O = 2-oxobutanoate + hydrogen sulfide + NH4(+) + H(+)
  2. thiosulfate + 2 glutathione = glutathione disulfide + hydrogen sulfide + sulfite + 2 H(+)
  3. L-dehydroascorbate + 2 glutathione = glutathione disulfide + L-ascorbate

  Catalysed by CTH, TSTD1, CLIC1, GSTO1 and 1 more

• K(+)Reach from here →
  1. L-homocysteine + L-serine = L,L-cystathionine + H2O
  2. L-cystathionine cysteine-lyase (deaminating
  3. K(+)(in) + L-cysteine(out) + 3 Na(+)(out) + H(+)(out) = K(+)(out) + L-cysteine(in) + 3 Na(+)(in) + H(+)(in)

  Catalysed by CBS, CTH, SLC1A1cytosol, inner side of the membrane, outer side of the membraneOne of 4 routes

• Cys-tRNA(Cys)Reach from here →
  1. L-homocysteine + L-serine = L,L-cystathionine + H2O
  2. L-cystathionine cysteine-lyase (deaminating
  3. L-Cysteine:tRNA(Cys) ligase (AMP-forming)

  Catalysed by CBS, CTH, CARS1cytosol

• Phe-tRNA(Phe)Reach from here →
  1. (6S)-5-methyl-5,6,7,8-tetrahydrofolate + L-homocysteine = (6S)-5,6,7,8-tetrahydrofolate + L-methionine
  2. transport of methionine and phenylalanine (cytosol to extracellular)
  3. L-Phenylalanine:tRNA(Ala) ligase (AMP-forming)

  Catalysed by MTR, SLC7A5, FARSB, FARSAextracellular space, cytosol

• Gly-tRNA(Gly)Reach from here →
  1. (6S)-5-methyl-5,6,7,8-tetrahydrofolate + L-homocysteine = (6S)-5,6,7,8-tetrahydrofolate + L-methionine
  2. (6R)-5,10-methylene-5,6,7,8-tetrahydrofolate + glycine + H2O = (6S)-5,6,7,8-tetrahydrofolate + L-serine
  3. glycine:tRNA(Gly) ligase (AMP-forming)

  Catalysed by MTR, SHMT1, SHMT2, GARS1cytosol

• Asp-tRNA(Asp)Reach from here →
  1. (6S)-5-methyl-5,6,7,8-tetrahydrofolate + L-homocysteine = (6S)-5,6,7,8-tetrahydrofolate + L-methionine
  2. L-aspartate(in) + L-methionine(out) = L-aspartate(out) + L-methionine(in)
  3. L-Aspartate:tRNA(Asp) ligase (AMP-forming)

  Catalysed by MTR, SLC7A13, DARS1inner side of the membrane, outer side of the membrane, cytosol

• Trp-tRNA(Trp)Reach from here →
  1. (6S)-5-methyl-5,6,7,8-tetrahydrofolate + L-homocysteine = (6S)-5,6,7,8-tetrahydrofolate + L-methionine
  2. transport of methionine and tryptophan (cytosol to extracellular)
  3. L-Tryptophan -tRNA(Trp) ligase (AMP-forming)

  Catalysed by MTR, SLC7A5, WARS1extracellular space, cytosol

• Ile-tRNA(Ile)Reach from here →
  1. (6S)-5-methyl-5,6,7,8-tetrahydrofolate + L-homocysteine = (6S)-5,6,7,8-tetrahydrofolate + L-methionine
  2. transport of isoleucine and methionine (cytosol to extracellular)
  3. L-Isoleucine:tRNA(Ile) ligase (AMP-forming)

  Catalysed by MTR, SLC7A5, IARS1extracellular space, cytosol

• Gln-tRNA(Gln)Reach from here →
  1. (6S)-5-methyl-5,6,7,8-tetrahydrofolate + L-homocysteine = (6S)-5,6,7,8-tetrahydrofolate + L-methionine
  2. transport of glutamine and methionine (cytosol to extracellular)
  3. L-Glutamine:tRNA(Gln) ligase (AMP-forming)

  Catalysed by MTR, SLC7A5, QARS1extracellular space, cytosol

• isocyanateReach from here →
  1. (6S)-5-methyl-5,6,7,8-tetrahydrofolate + L-homocysteine = (6S)-5,6,7,8-tetrahydrofolate + L-methionine
  2. transport of citrulline and methionine (cytosol to extracellular)
  3. L-citrulline + H(+) = isocyanate + L-ornithine

  Catalysed by MTR, SLC7A6, LACC1extracellular space, cytosol

• Asn-tRNA(Asn)Reach from here →
  1. (6S)-5-methyl-5,6,7,8-tetrahydrofolate + L-homocysteine = (6S)-5,6,7,8-tetrahydrofolate + L-methionine
  2. transport of asparagine and methionine (cytosol to extracellular)
  3. L-Asparagine:tRNA(Asn) ligase (AMP-forming)

  Catalysed by MTR, SLC7A5, NARS1extracellular space, cytosol

• hydrogenselenideReach from here →
  1. (6S)-5-methyl-5,6,7,8-tetrahydrofolate + L-homocysteine = (6S)-5,6,7,8-tetrahydrofolate + L-methionine
  2. N(6)-L-threonylcarbamoyladenosine(37) in tRNA + (sulfur carrier)-SH + AH2 + 2 S-adenosyl-L-methionine = 2-methylsulfanyl-N(6)-L-threonylcarbamoyladenosine(37) in tRNA + (sulfur carrier)-H + 5'-deoxyadenosine + L-methionine + A + S-adenosyl-L-homocysteine + 2 H(+)
  3. L-selenocysteine + AH2 = hydrogenselenide + L-alanine + A + H(+)

  Catalysed by MTR, CDKAL1, SCLY

• glycocholateReach from here →
  1. (6S)-5-methyl-5,6,7,8-tetrahydrofolate + L-homocysteine = (6S)-5,6,7,8-tetrahydrofolate + L-methionine
  2. (6R)-5,10-methylene-5,6,7,8-tetrahydrofolate + glycine + H2O = (6S)-5,6,7,8-tetrahydrofolate + L-serine
  3. bile acid-CoA: amino acid N-acyltransferase

  Catalysed by MTR, SHMT1, SHMT2, BAATperoxisomeOne of 4 routes

• cholateReach from here →
  1. L-homocysteine + H2O = 2-oxobutanoate + hydrogen sulfide + NH4(+) + H(+)
  2. thiosulfate + 2 glutathione = glutathione disulfide + hydrogen sulfide + sulfite + 2 H(+)
  3. cholate(in) + glutathione(in) + ATP + H2O = cholate(out) + glutathione(out) + ADP + phosphate + H(+)

  Catalysed by CTH, TSTD1, ABCC4inner side of the membrane, outer side of the membrane

• glycolateReach from here →
  1. L-homocysteine + H2O = 2-oxobutanoate + hydrogen sulfide + NH4(+) + H(+)
  2. (2S)-2-aminobutanoate + glyoxylate = 2-oxobutanoate + glycine
  3. glycolate + NADP(+) = glyoxylate + NADPH + H(+)

  Catalysed by CTH, AGXT2, GRHPR

• D-aspartateReach from here →
  1. L-homocysteine + H2O = 2-oxobutanoate + hydrogen sulfide + NH4(+) + H(+)
  2. hydrogen sulfide + 2 O2 = sulfate + H(+)
  3. D-aspartate(in) + sulfate(out) = D-aspartate(out) + sulfate(in)

  Catalysed by CTH, SOD1, SLC25A14, SLC25A30inner side of the membrane, outer side of the membraneOne of 2 routes

• acetateReach from here →
  1. L-homocysteine + H2O = 2-oxobutanoate + hydrogen sulfide + NH4(+) + H(+)
  2. 2-hydroxybutyrate:NAD+ oxidoreductase
  3. transport of 2-hydroxybutyrate and acetate (cytosol to extracellular)

  Catalysed by CTH, LDHB, LDHC, LDHAL6A and 5 morecytosol, extracellular spaceOne of 4 routes

• CHEBI:30249Reach from here →
  1. (6S)-5-methyl-5,6,7,8-tetrahydrofolate + L-homocysteine = (6S)-5,6,7,8-tetrahydrofolate + L-methionine
  2. transport of methionine and tryptophan (cytosol to extracellular)
  3. L-tryptophan:oxygen 2,3-oxidoreductase (decyclizing)

  Catalysed by MTR, SLC7A5, IDO1, TDO2 and 1 moreextracellular space, cytosol

• oxalateReach from here →
  1. L-homocysteine + H2O = 2-oxobutanoate + hydrogen sulfide + NH4(+) + H(+)
  2. (2S)-2-aminobutanoate + glyoxylate = 2-oxobutanoate + glycine
  3. glyoxylate + O2 + H2O = oxalate + H2O2 + H(+)

  Catalysed by CTH, AGXT2, HAO1One of 3 routes

• formic acidReach from here →
  1. (6S)-5-methyl-5,6,7,8-tetrahydrofolate + L-homocysteine = (6S)-5,6,7,8-tetrahydrofolate + L-methionine
  2. transport of chloride and methionine (cytosol to extracellular)
  3. transport of chloride and formate (cytosol to extracellular)

  Catalysed by MTR, SLC6A14, SLC26A4extracellular space, cytosolOne of 6 routes

• propionic acidReach from here →
  1. L-homocysteine + H2O = 2-oxobutanoate + hydrogen sulfide + NH4(+) + H(+)
  2. 2-hydroxybutyrate:NAD+ oxidoreductase
  3. transport of 2-hydroxybutyrate and propanoate (cytosol to extracellular)

  Catalysed by CTH, LDHB, LDHC, LDHAL6A and 5 morecytosol, extracellular spaceOne of 7 routes

• butyric acidReach from here →
  1. L-homocysteine + H2O = 2-oxobutanoate + hydrogen sulfide + NH4(+) + H(+)
  2. 2-hydroxybutyrate:NAD+ oxidoreductase
  3. transport of 2-hydroxybutyrate and butyrate (cytosol to extracellular)

  Catalysed by CTH, LDHB, LDHC, LDHAL6A and 5 morecytosol, extracellular spaceOne of 4 routes

• maleateReach from here →
  1. L-homocysteine + H2O = 2-oxobutanoate + hydrogen sulfide + NH4(+) + H(+)
  2. hydrogen sulfide + 2 O2 = sulfate + H(+)
  3. maleate(in) + sulfate(out) = maleate(out) + sulfate(in)

  Catalysed by CTH, SOD1, SLC25A14, SLC25A30inner side of the membrane, outer side of the membraneOne of 2 routes

• malonic acidReach from here →
  1. (6S)-5-methyl-5,6,7,8-tetrahydrofolate + L-homocysteine = (6S)-5,6,7,8-tetrahydrofolate + L-methionine
  2. transport of chloride and methionine (cytosol to extracellular)
  3. Malonate Transport, Antiport with Chloride

  Catalysed by MTR, SLC6A14extracellular space, cytosolOne of 4 routes

• 3-hydroxypyruvic acidReach from here →
  1. L-homocysteine + H2O = 2-oxobutanoate + hydrogen sulfide + NH4(+) + H(+)
  2. 2-oxobutanoate + L-alanine = (2S)-2-aminobutanoate + pyruvate
  3. L-Serine:pyruvate aminotransferase

  Catalysed by CTH, AGXT2, AGXTcytosolOne of 2 routes

• (S)-dihydroorotateReach from here →
  1. L-homocysteine + H2O = 2-oxobutanoate + hydrogen sulfide + NH4(+) + H(+)
  2. a quinone + hydrogen sulfide + glutathione + H(+) = S-sulfanylglutathione + a quinol
  3. (S)-dihydroorotate + a quinone = orotate + a quinol

  Catalysed by CTH, SQOR, DHODH

• an alcoholReach from here →
  1. L-homocysteine + H2O = 2-oxobutanoate + hydrogen sulfide + NH4(+) + H(+)
  2. thiosulfate + 2 glutathione = glutathione disulfide + hydrogen sulfide + sulfite + 2 H(+)
  3. a hydroperoxide + 2 glutathione = an alcohol + glutathione disulfide + H2O

  Catalysed by CTH, TSTD1, CP, PRDX6