Figure 1.
Major pathways of sulphur-containing amino acid metabolism in the feline, involving the esstential amino acids, methionine, cysteine and taurine, and the B-vitamines, cobalamin, choline, folate and pyridoxine.5-CH3-THF: 5-methyl-tetrahydrofolate; 5,10-CH2-THF: 5,10-methylene-tetrahydrofolate; BHMT: betaine-homocysteine methyltransferase; CBS: cystathione β-synthase; CGL: cystathione γ-lyase; DMG: dimethyl glycine; MAT: methionine adenosyltransferase; MS: methionine synthase; MT: various methyltransferases; MTHFR: methylenetetrahydrofolate reductase; Pi: orthophosphate; Pii: pyrophosphate; SAHH: S-adenosylhomocysteine hydrolyase; SHMT: serine hodroxymethyltransferase; THF: tetrahydrolfolate.