L-homocysteine

Three steps

• (5S,15R)-dihydroxy-(6E,8Z,11Z,13E)-eicosatetraenoateReach 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. (5S)-hydroxy-(6E,8Z,11Z,14Z)-eicosatetraenoate + AH2 + O2 = (5S,15R)-dihydroxy-(6E,8Z,11Z,13E)-eicosatetraenoate + A + H2O

  Catalysed by MTR, CDKAL1, PTGS2

• (5S,15S)-dihydroxy-(6E,8Z,11Z,13E)-eicosatetraenoateReach 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. (5S)-hydroxy-(6E,8Z,11Z,14Z)-eicosatetraenoate + AH2 + O2 = (5S,15S)-dihydroxy-(6E,8Z,11Z,13E)-eicosatetraenoate + A + H2O

  Catalysed by MTR, CDKAL1, PTGS2

• 17R-hydroxy-(4Z,7Z,10Z,13Z,15E,19Z)-docosahexaenoateReach 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. (4Z,7Z,10Z,13Z,16Z,19Z)-docosahexaenoate + AH2 + O2 = 17R-hydroxy-(4Z,7Z,10Z,13Z,15E,19Z)-docosahexaenoate + A + H2O

  Catalysed by MTR, CDKAL1, PTGS2

• 13-hydroxy-(4Z,7Z,10Z,14E,16Z,19Z)-docosahexaenoateReach 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. (4Z,7Z,10Z,13Z,16Z,19Z)-docosahexaenoate + AH2 + O2 = 13-hydroxy-(4Z,7Z,10Z,14E,16Z,19Z)-docosahexaenoate + A + H2O

  Catalysed by MTR, CDKAL1, PTGS2

• (18R)-hydroxy-(5Z,8Z,11Z,14Z,16E)-eicosapentaenoateReach 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. (5Z,8Z,11Z,14Z,17Z)-eicosapentaenoate + AH2 + O2 = (18R)-hydroxy-(5Z,8Z,11Z,14Z,16E)-eicosapentaenoate + A + H2O

  Catalysed by MTR, CDKAL1, PTGS2

• (15R)-hydroxy-(5Z,8Z,11Z,13E,17Z)-eicosapentaenoateReach 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. (5Z,8Z,11Z,14Z,17Z)-eicosapentaenoate + AH2 + O2 = (15R)-hydroxy-(5Z,8Z,11Z,13E,17Z)-eicosapentaenoate + A + H2O

  Catalysed by MTR, CDKAL1, PTGS2

• (11R)-hydroxy-(5Z,8Z,12E,14Z,17Z)-eicosapentaenoateReach 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. (5Z,8Z,11Z,14Z,17Z)-eicosapentaenoate + AH2 + O2 = (11R)-hydroxy-(5Z,8Z,12E,14Z,17Z)-eicosapentaenoate + A + H2O

  Catalysed by MTR, CDKAL1, PTGS2

• 13R-hydroxy-(7Z,10Z,14E,16Z,19Z)-docosapentaenoateReach 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. (7Z,10Z,13Z,16Z,19Z)-docosapentaenoate + AH2 + O2 = 13R-hydroxy-(7Z,10Z,14E,16Z,19Z)-docosapentaenoate + A + H2O

  Catalysed by MTR, CDKAL1, PTGS2

• (13S)-hydroxy-(9Z,11E)-octadecadienoateReach 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. (9Z,12Z)-octadecadienoate + AH2 + O2 = (13S)-hydroxy-(9Z,11E)-octadecadienoate + A + H2O

  Catalysed by MTR, CDKAL1, PTGS1, PTGS2One of 2 routes

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

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

• thiamine(1+) diphosphateReach from here →
  1. L-homocysteine + H2O = 2-oxobutanoate + hydrogen sulfide + NH4(+) + H(+)
  2. branched chain keto acid dehydrogenase E1 (2-oxobutyrate)
  3. lipoamide to thiamin-PP conversion

  Catalysed by CTH, BCKDHA, BCKDHB, DBTmitochondrial matrix

• 2-(1-hydroxyethyl)thiamine diphosphateReach from here →
  1. L-homocysteine + H2O = 2-oxobutanoate + hydrogen sulfide + NH4(+) + H(+)
  2. 2-oxobutanoate + L-alanine = (2S)-2-aminobutanoate + pyruvate
  3. pyruvate:thiamin diphosphate acetaldehydetransferase (decarboxylating)

  Catalysed by CTH, AGXT2, PDHA1, PDHB and 1 moremitochondrial matrix