L-homocysteine
362,296 routes · scope human · up to 3 steps · built 5 October 2026 · Reactions · API
512 compounds within 3 steps: 8 in 1, 58 in 2, 446 in 3
Three steps
- (6S)-5-methyl-5,6,7,8-tetrahydrofolate + L-homocysteine = (6S)-5,6,7,8-tetrahydrofolate + L-methionine
- (6R)-5,10-methylene-5,6,7,8-tetrahydrofolate + glycine + H2O = (6S)-5,6,7,8-tetrahydrofolate + L-serine
- succinyl-CoA:glycine C-succinyltransferase (decarboxylating)
Catalysed by MTR, SHMT1, SHMT2, ALAS1 and 2 moremitochondrial matrix
- (6S)-5-methyl-5,6,7,8-tetrahydrofolate + L-homocysteine = (6S)-5,6,7,8-tetrahydrofolate + L-methionine
- transport of methionine and tryptophan (cytosol to extracellular)
- L-tryptophan + O2 + H2O = indole-3-pyruvate + H2O2 + NH4(+)
Catalysed by MTR, SLC7A5, IL4I1extracellular space, cytosolOne of 3 routes
- (6S)-5-methyl-5,6,7,8-tetrahydrofolate + L-homocysteine = (6S)-5,6,7,8-tetrahydrofolate + L-methionine
- 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'-triiodo-L-thyronine sulfate + iodide + A + H(+) = L-thyroxine sulfate + AH2
- (6S)-5-methyl-5,6,7,8-tetrahydrofolate + L-homocysteine = (6S)-5,6,7,8-tetrahydrofolate + L-methionine
- 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'-diiodo-L-thyronine + iodide + A + H(+) = 3,3',5-triiodo-L-thyronine + AH2
- (6S)-5-methyl-5,6,7,8-tetrahydrofolate + L-homocysteine = (6S)-5,6,7,8-tetrahydrofolate + L-methionine
- 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'-diiodo-L-thyronine sulfate + iodide + A + H(+) = 3,3',5-triiodo-L-thyronine sulfate + AH2
- L-homocysteine + L-serine = L,L-cystathionine + H2O
- N-acetylglutamate synthase (N-acetyl-L-cystathionine)
- Fatty Acid Beta Oxidation (C18:3->C16:3), Mitochondrial
Catalysed by CBS, NAGS, HADHA, ACADVL and 1 moremitochondrial matrix
- (6S)-5-methyl-5,6,7,8-tetrahydrofolate + L-homocysteine = (6S)-5,6,7,8-tetrahydrofolate + L-methionine
- transport of chloride and methionine (cytosol to extracellular)
- transport of betaine and chloride (cytosol to extracellular)
Catalysed by MTR, SLC6A14, SLC6A12extracellular space, cytosolOne of 3 routes
- L-homocysteine + H2O = 2-oxobutanoate + hydrogen sulfide + NH4(+) + H(+)
- thiosulfate + 2 glutathione = glutathione disulfide + hydrogen sulfide + sulfite + 2 H(+)
- urate(out) + glutathione(in) = urate(in) + glutathione(out)
Catalysed by CTH, TSTD1, SLC22A13inner side of the membrane, outer side of the membrane
- (6S)-5-methyl-5,6,7,8-tetrahydrofolate + L-homocysteine = (6S)-5,6,7,8-tetrahydrofolate + L-methionine
- transport of methionine and tryptophan (cytosol to extracellular)
- (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin + L-tryptophan + O2 = 5-hydroxy-L-tryptophan + (4aS,6R)-4a-hydroxy-L-erythro-5,6,7,8-tetrahydrobiopterin
Catalysed by MTR, SLC7A5, TPH1, TPH2extracellular space, cytosol
- (6S)-5-methyl-5,6,7,8-tetrahydrofolate + L-homocysteine = (6S)-5,6,7,8-tetrahydrofolate + L-methionine
- transport of leucine and methionine (cytosol to extracellular)
- L-Leucine:2-oxoglutarate aminotransferase
Catalysed by MTR, SLC3A2, SLC7A5, BCAT2extracellular space, cytosol, mitochondrial matrixOne of 5 routes
- L-homocysteine + L-serine = L,L-cystathionine + H2O
- N-acetylglutamate synthase (N-acetyl-L-cystathionine)
- N1,N8-diacetylspermidine to N1-acetylspermidine conversion
Catalysed by CBS, NAGSmitochondrial matrix, cytosolOne of 2 routes
- (6S)-5-methyl-5,6,7,8-tetrahydrofolate + L-homocysteine = (6S)-5,6,7,8-tetrahydrofolate + L-methionine
- transport of methionine and phenylalanine (cytosol to extracellular)
- Phenylalanine Transaminase, Mitochondrial
Catalysed by MTR, SLC7A5, GOT2, TATextracellular space, cytosol, mitochondrial matrixOne of 6 routes
- L-homocysteine + H2O = 2-oxobutanoate + hydrogen sulfide + NH4(+) + H(+)
- thiosulfate + 2 glutathione = glutathione disulfide + hydrogen sulfide + sulfite + 2 H(+)
- transport of fumarate and thiosulfate (cytosol to mitochondria)
Catalysed by CTH, TSTD1, SLC25A10mitochondrial matrix, cytosolOne of 4 routes
- L-homocysteine + H2O = 2-oxobutanoate + hydrogen sulfide + NH4(+) + H(+)
- thiosulfate + 2 glutathione = glutathione disulfide + hydrogen sulfide + sulfite + 2 H(+)
- thiosulfate:cyanide sulfurtranserase
Catalysed by CTH, TSTD1, MPST, TSTmitochondrial matrixOne of 3 routes
- (6S)-5-methyl-5,6,7,8-tetrahydrofolate + L-homocysteine = (6S)-5,6,7,8-tetrahydrofolate + L-methionine
- transport of alanine and methionine (cytosol to extracellular)
- Transport of Hydroxy-Proline
Catalysed by MTR, SLC7A5, SLC1A4extracellular space, cytosolOne of 5 routes
- (6S)-5-methyl-5,6,7,8-tetrahydrofolate + L-homocysteine = (6S)-5,6,7,8-tetrahydrofolate + L-methionine
- transport of chloride and methionine (cytosol to extracellular)
- Transport of 3-Ureidopropionate
Catalysed by MTR, SLC6A14extracellular space, cytosolOne of 2 routes
- L-homocysteine + H2O = 2-oxobutanoate + hydrogen sulfide + NH4(+) + H(+)
- thiosulfate + 2 glutathione = glutathione disulfide + hydrogen sulfide + sulfite + 2 H(+)
- arsenic triglutathione + 3 [thioredoxin]-dithiol + 3 S-adenosyl-L-methionine = trimethylarsine + 3 [thioredoxin]-disulfide + 3 glutathione + 3 S-adenosyl-L-homocysteine + 3 H(+)
- (6S)-5-methyl-5,6,7,8-tetrahydrofolate + L-homocysteine = (6S)-5,6,7,8-tetrahydrofolate + L-methionine
- (6R)-5,10-methylene-5,6,7,8-tetrahydrofolate + glycine + H2O = (6S)-5,6,7,8-tetrahydrofolate + L-serine
- (6S)-5-methyl-5,6,7,8-tetrahydrofolate + NADP(+) = (6R)-5,10-methylene-5,6,7,8-tetrahydrofolate + NADPH + H(+)
- (6S)-5-methyl-5,6,7,8-tetrahydrofolate + L-homocysteine = (6S)-5,6,7,8-tetrahydrofolate + L-methionine
- transport of alanine and methionine (cytosol to extracellular)
- 2-aminoisobutanoate(out) + L-alanine(in) = 2-aminoisobutanoate(in) + L-alanine(out)
Catalysed by MTR, SLC7A5, SLC7A10extracellular space, cytosol, inner side of the membrane, outer side of the membraneOne of 2 routes
- L-homocysteine + H2O = 2-oxobutanoate + hydrogen sulfide + NH4(+) + H(+)
- thiosulfate + 2 glutathione = glutathione disulfide + hydrogen sulfide + sulfite + 2 H(+)
- (5S)-hydroperoxy-(6E,8Z,11Z,14Z,17Z)-eicosapentaenoate + 2 glutathione = (5S)-hydroxy-(6E,8Z,11Z,14Z,17Z)-eicosapentaenoate + glutathione disulfide + H2O
- L-homocysteine + H2O = 2-oxobutanoate + hydrogen sulfide + NH4(+) + H(+)
- thiosulfate + 2 glutathione = glutathione disulfide + hydrogen sulfide + sulfite + 2 H(+)
- (12S)-hydroperoxy-(5Z,8Z,10E,14Z,17Z)-eicosapentaenoate + 2 glutathione = (12S)-hydroxy-(5Z,8Z,10E,14Z,17Z)-eicosapentaenoate + glutathione disulfide + H2O
- L-homocysteine + H2O = 2-oxobutanoate + hydrogen sulfide + NH4(+) + H(+)
- thiosulfate + 2 glutathione = glutathione disulfide + hydrogen sulfide + sulfite + 2 H(+)
- (17S)-hydroperoxy-(4Z,7Z,10Z,13Z,15E,19Z)-docosahexaenoate + 2 glutathione = (17S)-hydroxy-(4Z,7Z,10Z,13Z,15E,19Z)-docosahexaenoate + glutathione disulfide + H2O
- L-homocysteine + H2O = 2-oxobutanoate + hydrogen sulfide + NH4(+) + H(+)
- thiosulfate + 2 glutathione = glutathione disulfide + hydrogen sulfide + sulfite + 2 H(+)
- a hydroperoxy-1,2-diacyl-glycero-3-phosphocholine + 2 glutathione = a hydroxy-1,2-diacyl-glycero-3-phosphocholine + glutathione disulfide + H2O
- (6S)-5-methyl-5,6,7,8-tetrahydrofolate + L-homocysteine = (6S)-5,6,7,8-tetrahydrofolate + L-methionine
- 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',5'-diiodo-L-thyronine + iodide + A + H(+) = 3,3',5'-triiodo-L-thyronine + AH2
- (6S)-5-methyl-5,6,7,8-tetrahydrofolate + L-homocysteine = (6S)-5,6,7,8-tetrahydrofolate + L-methionine
- (6R)-5,10-methylene-5,6,7,8-tetrahydrofolate + glycine + H2O = (6S)-5,6,7,8-tetrahydrofolate + L-serine
- N(omega),N('omega)-dimethyl-L-arginine + glyoxylate = 5-(3,3'-dimethylguanidino)-2-oxopentanoate + glycine
- L-homocysteine + L-serine = L,L-cystathionine + H2O
- N-acetylglutamate synthase (N-acetyl-L-cystathionine)
- acetyl-CoA C-acyltransferase (3-oxomyrist-7-enoyl-CoA)
Catalysed by CBS, NAGS, HADHA, ACAA2 and 1 moremitochondrial matrixOne of 2 routes
- (6S)-5-methyl-5,6,7,8-tetrahydrofolate + L-homocysteine = (6S)-5,6,7,8-tetrahydrofolate + L-methionine
- 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-iodothyronamine + iodide + A + H(+) = 3,5-diiodothyronamine + AH2
- L-homocysteine + L-serine = L,L-cystathionine + H2O
- N-acetylglutamate synthase (N-acetyl-L-cystathionine)
- long-chain-fatty-acid-CoA ligase (cis-cetoleic acid)
Catalysed by CBS, NAGS, SLC27A2, ACSL4 and 6 moremitochondrial matrix, cytosolOne of 5 routes
- (6S)-5-methyl-5,6,7,8-tetrahydrofolate + L-homocysteine = (6S)-5,6,7,8-tetrahydrofolate + L-methionine
- 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-iodo-L-thyronine + iodide + A + H(+) = 3,5-diiodo-L-thyronine + AH2
- L-homocysteine + L-serine = L,L-cystathionine + H2O
- N-acetylglutamate synthase (N-acetyl-L-cystathionine)
- long-chain-fatty-acid-CoA ligase ((7Z)-tetradecenoic acid)
Catalysed by CBS, NAGS, SLC27A2, ACSL4 and 6 moremitochondrial matrix, cytosolOne of 8 routes
- (6S)-5-methyl-5,6,7,8-tetrahydrofolate + L-homocysteine = (6S)-5,6,7,8-tetrahydrofolate + L-methionine
- 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'-iodo-L-thyronine + iodide + A + H(+) = 3',5'-diiodo-L-thyronine + AH2
- (6S)-5-methyl-5,6,7,8-tetrahydrofolate + L-homocysteine = (6S)-5,6,7,8-tetrahydrofolate + L-methionine
- 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(+)
- L-thyronine + iodide + A + H(+) = 3-iodo-L-thyronine + AH2
- (6S)-5-methyl-5,6,7,8-tetrahydrofolate + L-homocysteine = (6S)-5,6,7,8-tetrahydrofolate + L-methionine
- 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(+)
- thyronamine + iodide + A + H(+) = 3-iodothyronamine + AH2
- (6S)-5-methyl-5,6,7,8-tetrahydrofolate + L-homocysteine = (6S)-5,6,7,8-tetrahydrofolate + L-methionine
- 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'-iodothyronamine + iodide + A + H(+) = 3',5'-diiodothyronamine + AH2