L-homocysteine

Three steps

• glutarateReach 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) + glutarate(in) = kynurenate(in) + glutarate(out)

  Catalysed by CTH, AADAT, SLC22A6inner side of the membrane, outer side of the membraneOne of 2 routes

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

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

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

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

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

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

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

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

• L-lysineReach from here →
  1. (6S)-5-methyl-5,6,7,8-tetrahydrofolate + L-homocysteine = (6S)-5,6,7,8-tetrahydrofolate + L-methionine
  2. transport of leucine and methionine (cytosol to extracellular)
  3. L-lysine(in) + L-leucine(out) + Na(+)(out) = L-lysine(out) + L-leucine(in) + Na(+)(in)

  Catalysed by MTR, SLC3A2, SLC7A5, SLC7A7extracellular space, cytosol, inner side of the membrane, outer side of the membraneOne of 5 routes

• D-lysineReach 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 ornithine (cytosol to extracellular)
  3. D-lysine(in) + L-ornithine(out) = D-lysine(out) + L-ornithine(in)

  Catalysed by MTR, SLC7A6, SLC25A2extracellular space, cytosol, inner side of the membrane, outer side of the membraneOne of 2 routes

• putrescineReach from here →
  1. (6S)-5-methyl-5,6,7,8-tetrahydrofolate + L-homocysteine = (6S)-5,6,7,8-tetrahydrofolate + L-methionine
  2. transport of arginine and methionine (cytosol to extracellular)
  3. Putrescine Export via Putrescine/Arginine Antiporter

  Catalysed by MTR, SLC7A6, SLC3A2, SLC7A7extracellular space, cytosolOne of 4 routes

• D-arginineReach 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 ornithine (cytosol to extracellular)
  3. D-arginine(in) + L-ornithine(out) = D-arginine(out) + L-ornithine(in)

  Catalysed by MTR, SLC7A6, SLC25A2extracellular space, cytosol, inner side of the membrane, outer side of the membraneOne of 2 routes

• N-carbamoyl-L-aspartateReach 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. carbamoyl phosphate + L-aspartate = N-carbamoyl-L-aspartate + phosphate + H(+)

  Catalysed by MTR, SLC7A13, CADinner side of the membrane, outer side of the membrane

• 3-oxopropanoateReach from here →
  1. L-homocysteine + H2O = 2-oxobutanoate + hydrogen sulfide + NH4(+) + H(+)
  2. 2-oxobutanoate + L-alanine = (2S)-2-aminobutanoate + pyruvate
  3. 3-oxopropanoate + L-alanine = beta-alanine + pyruvate

  Catalysed by CTH, AGXT2

• di-mu-sulfido-diiron(2+)Reach from here →
  1. L-homocysteine + L-serine = L,L-cystathionine + H2O
  2. L-cystathionine cysteine-lyase (deaminating
  3. De novo synthesis of 2Fe2S

  Catalysed by CBS, CTH, NDUFAB1, FDXR and 5 morecytosol, mitochondrial matrix

• (S)-3-methyl-2-oxopentanoateReach 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 + 2-oxoglutarate = (S)-3-methyl-2-oxopentanoate + L-glutamate

  Catalysed by MTR, SLC7A5, BCAT2, BCAT1extracellular space, cytosol

• 2-oxohexanoateReach 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-oxohexanoate + N(omega),N(omega)-dimethyl-L-arginine = L-2-aminohexanoate + 5-(3,3-dimethylguanidino)-2-oxopentanoate

  Catalysed by CTH, AGXT2

• D-cysteineReach 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. D-cysteine(out) + L-alanine(in) = D-cysteine(in) + L-alanine(out)

  Catalysed by MTR, SLC7A5, SLC7A10extracellular space, cytosol, inner side of the membrane, outer side of the membraneOne of 2 routes

• D-serineReach 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. D-serine(out) + L-alanine(in) = D-serine(in) + L-alanine(out)

  Catalysed by MTR, SLC7A5, SLC7A10extracellular space, cytosol, inner side of the membrane, outer side of the membraneOne of 11 routes

• an organic disulfideReach from here →
  1. L-homocysteine + H2O = 2-oxobutanoate + hydrogen sulfide + NH4(+) + H(+)
  2. L-cysteinyl-[sulfatase] + 2 a thiol + O2 = an organic disulfide + 3-oxo-L-alanyl-[sulfatase] + hydrogen sulfide + H2O + H(+)
  3. L-cysteinyl-[sulfatase] + 2 a thiol + O2 = an organic disulfide + 3-oxo-L-alanyl-[sulfatase] + hydrogen sulfide + H2O + H(+)

  Catalysed by CTH, SUMF1

• 5-aminolevulinateReach 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. succinyl-CoA + glycine + H(+) = 5-aminolevulinate + CO2 + CoA

  Catalysed by MTR, SHMT1, SHMT2, ALAS1 and 1 more

• 3-methyl-2-oxovaleric 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 isoleucine and methionine (cytosol to extracellular)
  3. L-Leucine:2-oxoglutarate aminotransferase

  Catalysed by MTR, SLC7A5, BCAT1extracellular space, cytosolOne of 2 routes

• 3-(4-hydroxyphenyl)pyruvateReach 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 tyrosine (cytosol to extracellular)
  3. L-tyrosine:2-oxoglutarate aminotransferase

  Catalysed by MTR, SLC7A5, GOT2, GOT1 and 1 moreextracellular space, cytosolOne of 4 routes

• glycochenodeoxycholateReach 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. chenodeoxycholoyl-CoA + glycine = glycochenodeoxycholate + CoA + H(+)

  Catalysed by MTR, SHMT1, SHMT2, BAATOne of 2 routes

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

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

• glycochenodeoxycholic acidReach 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 3 routes

• glycolithocholic acidReach 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 (glycine)

  Catalysed by MTR, SHMT1, SHMT2, BAATcytosolOne of 2 routes

• L-2-amino-3-oxobutanoic acidReach 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. Acetyl-CoA:glycine C-acetyltransferase

  Catalysed by MTR, SHMT1, SHMT2, GCATmitochondrial matrix

• (R)-lactic acidReach from here →
  1. L-homocysteine + H2O = 2-oxobutanoate + hydrogen sulfide + NH4(+) + H(+)
  2. 2-oxobutanoate + L-alanine = (2S)-2-aminobutanoate + pyruvate
  3. (R)-Lactate:NAD+ oxidoreductase

  Catalysed by CTH, AGXT2, LDHDcytosol

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

  Catalysed by CTH, LDHB, LDHC, LDHAL6A and 8 morecytosol, extracellular spaceOne of 7 routes

• 25-hydroxycholesterolReach 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. cholesterol + AH2 + O2 = 25-hydroxycholesterol + A + H2O

  Catalysed by MTR, CDKAL1, CH25H

• 2-iminopropanoateReach from here →
  1. L-homocysteine + H2O = 2-oxobutanoate + hydrogen sulfide + NH4(+) + H(+)
  2. 2-oxobutanoate + L-alanine = (2S)-2-aminobutanoate + pyruvate
  3. 2-iminopropanoate + H2O = pyruvate + NH4(+)

  Catalysed by CTH, AGXT2, RIDA

• phosphoenolpyruvic acidReach from here →
  1. L-homocysteine + H2O = 2-oxobutanoate + hydrogen sulfide + NH4(+) + H(+)
  2. 2-oxobutanoate + L-alanine = (2S)-2-aminobutanoate + pyruvate
  3. pyruvate kinase (dTDP)

  Catalysed by CTH, AGXT2, PKM, PKLRcytosol

• N-acetyl-beta-neuraminic acidReach from here →
  1. L-homocysteine + H2O = 2-oxobutanoate + hydrogen sulfide + NH4(+) + H(+)
  2. 2-oxobutanoate + L-alanine = (2S)-2-aminobutanoate + pyruvate
  3. N-Acetylneuraminate pyruvate-lyase (N-acetyl-D-mannosamine-forming)

  Catalysed by CTH, AGXT2, NPLcytosol

• tert-butanolReach from here →
  1. L-homocysteine + H2O = 2-oxobutanoate + hydrogen sulfide + NH4(+) + H(+)
  2. thiosulfate + 2 glutathione = glutathione disulfide + hydrogen sulfide + sulfite + 2 H(+)
  3. tert-butyl hydroperoxide + 2 glutathione = tert-butanol + glutathione disulfide + H2O

  Catalysed by CTH, TSTD1, CLIC2, GPX1 and 3 more

• 1,2-dihydroxy-5-(methylsulfanyl)pent-1-en-3-oneReach from here →
  1. (6S)-5-methyl-5,6,7,8-tetrahydrofolate + L-homocysteine = (6S)-5,6,7,8-tetrahydrofolate + L-methionine
  2. glyoxylate + L-methionine = 4-methylsulfanyl-2-oxobutanoate + glycine
  3. 1,2-dihydroxy-5-(methylsulfanyl)pent-1-en-3-one + O2 = 4-methylsulfanyl-2-oxobutanoate + formate + 2 H(+)

  Catalysed by MTR, AADAT, ADI1

• gamma-Glu-AlaReach 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. gamma-glutamyltransferase (alanine)

  Catalysed by MTR, SLC7A5, GGT1, GGT5 and 4 moreextracellular space, cytosol

• S(8)-aminomethyldihydrolipoamideReach 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. dihydrolipoyl dehydrogenase ([protein]-N6-(lipoyl)lysine)

  Catalysed by MTR, SHMT1, SHMT2, GLDC and 1 moremitochondrial matrix

• taurineReach from here →
  1. L-homocysteine + L-serine = L,L-cystathionine + H2O
  2. N-acetylglutamate synthase (N-acetyl-L-cystathionine)
  3. bile acid-CoA:amino acid N-acyltransferase (taurodeoxycholate)

  Catalysed by CBS, NAGS, BAATmitochondrial matrix, cytosolOne of 4 routes

• a thioesterReach from here →
  1. L-homocysteine + H2O = 2-oxobutanoate + hydrogen sulfide + NH4(+) + H(+)
  2. L-cysteinyl-[sulfatase] + 2 a thiol + O2 = an organic disulfide + 3-oxo-L-alanyl-[sulfatase] + hydrogen sulfide + H2O + H(+)
  3. a thioester + H2O = a thiol + a carboxylate + H(+)

  Catalysed by CTH, SUMF1, PNKD

• all-trans-13,14-dihydroretinolReach 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. all-trans-13,14-dihydroretinol + A = all-trans-retinol + AH2

  Catalysed by MTR, CDKAL1, RETSAT

• 3,3',5-triiodo-L-thyronineReach 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-triiodo-L-thyronine + iodide + A + H(+) = L-thyroxine + AH2

  Catalysed by MTR, CDKAL1, DIO1, DIO2

• 1-(beta-D-ribofuranosyl)-1,4-dihydronicotinamideReach from here →
  1. L-homocysteine + H2O = 2-oxobutanoate + hydrogen sulfide + NH4(+) + H(+)
  2. a quinone + hydrogen sulfide + glutathione + H(+) = S-sulfanylglutathione + a quinol
  3. 1-(beta-D-ribofuranosyl)-1,4-dihydronicotinamide + a quinone + H(+) = beta-nicotinamide D-riboside + a quinol

  Catalysed by CTH, SQOR, NQO2

• 3,3',5'-triiodo-L-thyronineReach 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'-triiodo-L-thyronine + iodide + A + H(+) = L-thyroxine + AH2

  Catalysed by MTR, CDKAL1, DIO1, DIO3

• a 3-acylpyruvateReach from here →
  1. L-homocysteine + H2O = 2-oxobutanoate + hydrogen sulfide + NH4(+) + H(+)
  2. 2-oxobutanoate + L-alanine = (2S)-2-aminobutanoate + pyruvate
  3. a 3-acylpyruvate + H2O = a carboxylate + pyruvate + H(+)

  Catalysed by CTH, AGXT2, FAHD1

• (R)-methylmalonyl-CoAReach from here →
  1. L-homocysteine + L-serine = L,L-cystathionine + H2O
  2. N-acetylglutamate synthase (N-acetyl-L-cystathionine)
  3. aldehyde dehydrogenase (2-methyl-3-oxopropanoate)

  Catalysed by CBS, NAGS, ALDH6A1mitochondrial matrixOne of 2 routes

• (S)-methylmalonyl-CoAReach from here →
  1. L-homocysteine + L-serine = L,L-cystathionine + H2O
  2. N-acetylglutamate synthase (N-acetyl-L-cystathionine)
  3. (S)-methylmalonyl-CoA hydrolase

  Catalysed by CBS, NAGSmitochondrial matrixOne of 2 routes

• 3'-dephospho-CoAReach from here →
  1. L-homocysteine + L-serine = L,L-cystathionine + H2O
  2. N-acetylglutamate synthase (N-acetyl-L-cystathionine)
  3. acid phosphatase 2, lysosomal (CoA)

  Catalysed by CBS, NAGS, ACP2mitochondrial matrix, lysosomeOne of 2 routes

• (2E)-dodecenoyl-CoAReach from here →
  1. L-homocysteine + L-serine = L,L-cystathionine + H2O
  2. N-acetylglutamate synthase (N-acetyl-L-cystathionine)
  3. (2E)-dodecenoyl-CoA formation

  Catalysed by CBS, NAGSmitochondrial matrixOne of 3 routes

• 4,8,12-trimethyltridecanoyl-CoAReach from here →
  1. L-homocysteine + L-serine = L,L-cystathionine + H2O
  2. N-acetylglutamate synthase (N-acetyl-L-cystathionine)
  3. propanoyl-CoA C-acyltransferase (3-ketopristanoyl-CoA)

  Catalysed by CBS, NAGS, ACAA1, MYO5Bmitochondrial matrix, peroxisomeOne of 2 routes

• (6Z,9Z,12Z)-octadecatrienoyl-CoAReach 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 (gamma-linolenate)

  Catalysed by CBS, NAGS, SLC27A2, ACSL4 and 6 moremitochondrial matrix, cytosolOne of 7 routes

• acryloyl-CoAReach from here →
  1. L-homocysteine + H2O = 2-oxobutanoate + hydrogen sulfide + NH4(+) + H(+)
  2. 2-oxobutyrate oxidation
  3. medium-chain acyl-CoA dehydrogenase (propanoyl-CoA)

  Catalysed by CTH, ACADS, ACADSBcytosol, mitochondrial matrix

• butanoyl-CoAReach from here →
  1. L-homocysteine + L-serine = L,L-cystathionine + H2O
  2. N-acetylglutamate synthase (N-acetyl-L-cystathionine)
  3. Butanoate:CoA ligase (AMP-forming)

  Catalysed by CBS, NAGS, ACSM4, ACSM1 and 4 moremitochondrial matrix, cytosolOne of 9 routes