L-homocysteine

Three steps

• 5-oxo-L-prolineReach from here →
  1. L-homocysteine + H2O = 2-oxobutanoate + hydrogen sulfide + NH4(+) + H(+)
  2. thiosulfate + 2 glutathione = glutathione disulfide + hydrogen sulfide + sulfite + 2 H(+)
  3. glutathione = L-cysteinylglycine + 5-oxo-L-proline

  Catalysed by CTH, TSTD1, CHAC2, CHAC1

• histamineReach from here →
  1. (6S)-5-methyl-5,6,7,8-tetrahydrofolate + L-homocysteine = (6S)-5,6,7,8-tetrahydrofolate + L-methionine
  2. transport of histidine and methionine (cytosol to extracellular)
  3. L-histidine carboxy-lyase (histamine-forming)

  Catalysed by MTR, SLC7A6, HDCextracellular space, cytosol

• (2S)-2-[5-amino-1-(5-phospho-beta-D-ribosyl)imidazole-4-carboxamido]succinateReach 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. 1-(5-Phosphoribosyl)-5-amino-4-carboxyimidazole:L-aspartate ligase (ADP-forming)

  Catalysed by MTR, SLC7A13, PAICSinner side of the membrane, outer side of the membrane, cytosolOne of 2 routes

• 5-formamido-1-(5-phospho-D-ribosyl)imidazole-4-carboxamideReach from here →
  1. (6S)-5-methyl-5,6,7,8-tetrahydrofolate + L-homocysteine = (6S)-5,6,7,8-tetrahydrofolate + L-methionine
  2. (6S)-5,6,7,8-tetrahydrofolate + formate + ATP = (6R)-10-formyltetrahydrofolate + ADP + phosphate
  3. (6R)-10-formyltetrahydrofolate + 5-amino-1-(5-phospho-beta-D-ribosyl)imidazole-4-carboxamide = 5-formamido-1-(5-phospho-D-ribosyl)imidazole-4-carboxamide + (6S)-5,6,7,8-tetrahydrofolate

  Catalysed by MTR, MTHFD1, MTHFD1L, ATIC

• 5-guanidino-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 arginine and methionine (cytosol to extracellular)
  3. L-arginine + O2 + H2O = 5-guanidino-2-oxopentanoate + H2O2 + NH4(+)

  Catalysed by MTR, SLC7A6, IL4I1extracellular space, cytosol

• (3Z)-dodecenoyl-CoAReach from here →
  1. L-homocysteine + L-serine = L,L-cystathionine + H2O
  2. N-acetylglutamate synthase (N-acetyl-L-cystathionine)
  3. acetyl-CoA C-acyltransferase (3-oxomyrist-5-enoyl-CoA)

  Catalysed by CBS, NAGS, HADHA, ACAA2 and 1 moremitochondrial matrixOne of 3 routes

• S-sulfanyl-L-cysteineReach from here →
  1. L-homocysteine + L-serine = L,L-cystathionine + H2O
  2. L-cystathionine cysteine-lyase (deaminating
  3. 2 L-cysteine = S-sulfanyl-L-cysteine + L-alanine

  Catalysed by CBS, CTH, CARS2cytosol

• N-formyl-L-kynurenineReach 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 + O2 = N-formyl-L-kynurenine

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

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

  Catalysed by CTH, AGXT2, CLYBL

• (25R)-3alpha,7alpha,12alpha-trihydroxy-5beta-cholestan-26-oyl-CoAReach from here →
  1. L-homocysteine + L-serine = L,L-cystathionine + H2O
  2. N-acetylglutamate synthase (N-acetyl-L-cystathionine)
  3. 3alpha,7alpha,12alpha-trihydroxy-5beta-cholestanoate:CoA ligase (AMP-forming)

  Catalysed by CBS, NAGS, SLC27A2, SLC27A5mitochondrial matrix, endoplasmic reticulumOne of 3 routes

• 5-phospho-beta-D-ribosylamineReach 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. phosphoribosyl pyrophosphate amidotransferase (glutamine)

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

• D-glucosamine 6-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 glutamine and methionine (cytosol to extracellular)
  3. D-fructose 6-phosphate + L-glutamine = D-glucosamine 6-phosphate + L-glutamate

  Catalysed by MTR, SLC7A5, GFPT2, GFPT1extracellular space, cytosol

• 5-amino-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 methionine and ornithine (cytosol to extracellular)
  3. L-ornithine + pyruvate = 5-amino-2-oxopentanoate + L-alanine

  Catalysed by MTR, SLC7A6, AGXT2extracellular space, cytosolOne of 4 routes

• deoxycholoyl-CoAReach from here →
  1. L-homocysteine + L-serine = L,L-cystathionine + H2O
  2. N-acetylglutamate synthase (N-acetyl-L-cystathionine)
  3. cholate-CoA ligase (3alpha,12alpha-dihydroxy-5beta-cholanate)

  Catalysed by CBS, NAGS, SLC27A2, SLC27A5mitochondrial matrix, cytosolOne of 4 routes

• N-formimidoyl-L-glutamateReach from here →
  1. (6S)-5-methyl-5,6,7,8-tetrahydrofolate + L-homocysteine = (6S)-5,6,7,8-tetrahydrofolate + L-methionine
  2. 5-formimidoyltetrahydrofolate + L-glutamate = N-formimidoyl-L-glutamate + (6S)-5,6,7,8-tetrahydrofolate
  3. 5-Formiminotetrahydrofolate:L-glutamate N-formiminotransferase

  Catalysed by MTR, FTCDcytosol

• N-(5Z,8Z,11Z,14Z)-eicosatetraenoyl-glycineReach 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. (5Z,8Z,11Z,14Z)-eicosatetraenoyl-CoA + glycine = N-(5Z,8Z,11Z,14Z)-eicosatetraenoyl-glycine + CoA + H(+)

  Catalysed by MTR, SHMT1, SHMT2, GLYATL2One of 2 routes

• N-[(R)-4-phosphopantothenoyl]-L-cysteineReach from here →
  1. L-homocysteine + L-serine = L,L-cystathionine + H2O
  2. L-cystathionine cysteine-lyase (deaminating
  3. (R)-4'-phosphopantothenate:L-cysteine ligase

  Catalysed by CBS, CTH, PPCScytosolOne of 4 routes

• 4-aminobutanoateReach 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 4-aminobutyrate and chloride (cytosol to extracellular)

  Catalysed by MTR, SLC6A14, SLC6A12extracellular space, cytosolOne of 4 routes

• 3-iodo-L-tyrosineReach 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. thyroid peroxidase (iodine)

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

• L-prolineReach 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-proline(out) + L-alanine(in) + Na(+)(out) = L-proline(in) + L-alanine(out) + Na(+)(in)

  Catalysed by MTR, SLC7A5, SLC1A4extracellular space, cytosol, inner side of the membrane, outer side of the membraneOne of 3 routes

• estrone 3-sulfateReach from here →
  1. L-homocysteine + H2O = 2-oxobutanoate + hydrogen sulfide + NH4(+) + H(+)
  2. hydrogen sulfide + 2 O2 = sulfate + H(+)
  3. estrone 3-sulfate + H2O = estrone + sulfate + H(+)

  Catalysed by CTH, SOD1, STS

• N-benzoylglycineReach 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. Hippurate (Benzoylglycinate) Formation

  Catalysed by MTR, SHMT1, SHMT2mitochondrial matrixOne of 2 routes

• 3-sulfino-L-alanineReach from here →
  1. L-homocysteine + L-serine = L,L-cystathionine + H2O
  2. L-cystathionine cysteine-lyase (deaminating
  3. L-Cysteine:oxygen oxidoreductase

  Catalysed by CBS, CTH, CDO1cytosolOne of 6 routes

• decanoyl-CoAReach 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 (decanoic acid)

  Catalysed by CBS, NAGS, ACSM4, ACSM1 and 4 moremitochondrial matrix, cytosolOne of 7 routes

• (2E)-hexadecenoyl-CoAReach from here →
  1. L-homocysteine + L-serine = L,L-cystathionine + H2O
  2. N-acetylglutamate synthase (N-acetyl-L-cystathionine)
  3. Carnitine O-Palmitoyltransferase

  Catalysed by CBS, NAGS, CPT1A, CPT1C and 1 moremitochondrial matrix, cytosolOne of 4 routes

• (9Z)-hexadecenoyl-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 (palmitolate)

  Catalysed by CBS, NAGS, SLC27A2, ACSL4 and 6 moremitochondrial matrix, cytosolOne of 11 routes

• L-cysteinylglycineReach 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, GGTLC3, GGT1 and 4 moreextracellular space, cytosolOne of 4 routes

• (4R)-4-hydroxy-2-oxoglutarateReach from here →
  1. L-homocysteine + H2O = 2-oxobutanoate + hydrogen sulfide + NH4(+) + H(+)
  2. (2S)-2-aminobutanoate + glyoxylate = 2-oxobutanoate + glycine
  3. (4R)-4-hydroxy-2-oxoglutarate = glyoxylate + pyruvate

  Catalysed by CTH, AGXT2, HOGA1One of 2 routes

• 3-hydroxyisovaleryl-CoAReach from here →
  1. L-homocysteine + L-serine = L,L-cystathionine + H2O
  2. N-acetylglutamate synthase (N-acetyl-L-cystathionine)
  3. (3-Hydroxyisovalerylcoa->3-Hydroxyisovalerylcarnitine)

  Catalysed by CBS, NAGS, CPT1A, CPT1Bmitochondrial matrix, cytosol

• (5-hydroxyindol-3-yl)acetateReach from here →
  1. L-homocysteine + H2O = 2-oxobutanoate + hydrogen sulfide + NH4(+) + H(+)
  2. hydrogen sulfide + 2 O2 = sulfate + H(+)
  3. Transport of 5-Hydroxyindoleacetate

  Catalysed by CTH, SOD1, SLC4A1extracellular space, cytosolOne of 2 routes

• dTMPReach 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. dUMP + (6R)-5,10-methylene-5,6,7,8-tetrahydrofolate = 7,8-dihydrofolate + dTMP

  Catalysed by MTR, SHMT1, SHMT2, TYMS

• CHEBI:63544Reach 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 (adrenic acid)

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

• 3-demethylubiquinol-10Reach from here →
  1. L-homocysteine + H2O = 2-oxobutanoate + hydrogen sulfide + NH4(+) + H(+)
  2. ubiquinone-10 + hydrogen sulfide + sulfite + 2 H(+) = ubiquinol-10 + thiosulfate
  3. 3-demethylubiquinol-10 + S-adenosyl-L-methionine = ubiquinol-10 + S-adenosyl-L-homocysteine + H(+)

  Catalysed by CTH, SQOR, COQ3

• hexacosanoyl-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 (cerotic acid)

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

• tetracosanoyl-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 (lignocerate)

  Catalysed by CBS, NAGS, SLC27A2, ACSL4 and 6 moremitochondrial matrix, cytosolOne of 10 routes

• docosanoyl-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 (behenic acid)

  Catalysed by CBS, NAGS, SLC27A2, ACSL4 and 6 moremitochondrial matrix, cytosolOne of 9 routes

• a 2,3-saturated acyl-CoAReach 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. a 2,3-saturated acyl-CoA + A = a 2,3-dehydroacyl-CoA + AH2

  Catalysed by MTR, CDKAL1, ACAD10

• N(5)-[(Z)-amino(hydroxyimino)methyl]ornithineReach 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. L-arginine,NADPH:oxygen oxidoreductase (N-(omega)-hydroxyarginine-forming)

  Catalysed by MTR, SLC7A6, NOS3, NOS1 and 1 moreextracellular space, cytosol

• xanthurenateReach from here →
  1. L-homocysteine + H2O = 2-oxobutanoate + hydrogen sulfide + NH4(+) + H(+)
  2. (2S)-2-aminobutanoate + glyoxylate = 2-oxobutanoate + glycine
  3. 3-hydroxy-L-kynurenine + glyoxylate = xanthurenate + glycine + H2O

  Catalysed by CTH, AGXT2, KYAT3, AADAT

• Mo-molybdopterinReach 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. Mo-molybdopterin + L-cysteine + AH2 = thio-Mo-molybdopterin + L-alanine + A + H2O

  Catalysed by MTR, SLC7A5, MOCOSextracellular space, cytosol

• (2E)-octadecenoyl-CoAReach from here →
  1. L-homocysteine + L-serine = L,L-cystathionine + H2O
  2. N-acetylglutamate synthase (N-acetyl-L-cystathionine)
  3. Carnitine O-Palmitoyltransferase

  Catalysed by CBS, NAGS, CPT1A, CPT1C and 1 moremitochondrial matrix, cytosolOne of 3 routes

• (6Z,9Z,12Z,15Z)-octadecatetraenoyl-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 (stearidonic acid)

  Catalysed by CBS, NAGS, SLC27A2, ACSL4 and 6 moremitochondrial matrix, cytosolOne of 8 routes

• (4S)-4-hydroxy-2-oxoglutarateReach from here →
  1. L-homocysteine + H2O = 2-oxobutanoate + hydrogen sulfide + NH4(+) + H(+)
  2. (2S)-2-aminobutanoate + glyoxylate = 2-oxobutanoate + glycine
  3. (4S)-4-hydroxy-2-oxoglutarate = glyoxylate + pyruvate

  Catalysed by CTH, AGXT2, HOGA1One of 2 routes

• L-threonylcarbamoyladenylateReach from here →
  1. L-homocysteine + H2O = 2-oxobutanoate + hydrogen sulfide + NH4(+) + H(+)
  2. L-threonine = 2-oxobutanoate + NH4(+)
  3. L-threonine + hydrogencarbonate + ATP = L-threonylcarbamoyladenylate + diphosphate + H2O

  Catalysed by CTH, SDS, SDSL, YRDC

• (5Z,8Z,11Z,14Z,17Z)-eicosapentaenoyl-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 (EPA)

  Catalysed by CBS, NAGS, SLC27A2, ACSL4 and 6 moremitochondrial matrix, cytosolOne of 9 routes

• (7Z,10Z,13Z,16Z,19Z)-docosapentaenoyl-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 (DPA)

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

• (9Z,12Z,15Z)-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 (linolenate)

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

• (13Z)-docosenoyl-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 (cis-erucic acid)

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

• (11Z)-eicosenoyl-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 (cis-gondoic acid)

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

• (9Z,12Z,15Z,18Z,21Z)-tetracosapentaenoyl-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 ((9Z,12Z,15Z,18Z,21Z)-TPA)

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