Hiraga K, Koyata H
Department of Biochemistry, Toyama Medical and Pharmaceutical University, School of Medicine.
Nihon Rinsho. 1992 Jul;50(7):1575-80.
Glycine and serine are interconverted by serine hydroxymethyltransferase and hence share their metabolic pathways. In the rat the carbon skeleton of choline is derived from the alpha and beta carbons of serine through phosphatidylserine and is further converted to that of glycine through N-methylated molecules of glycine i.e. betaine, N-dimethylglycine, and sarcosine (N-methylglycine). Thus far, the production of a folate derivative of the active one carbon that is an essential material for purine nucleotides and thymidylate biosynthesis is the notable feature of this metabolic process. In the major degradative pathway for pyrimidine nucleotides, beta-alanine, one of omega-amino acids, is produced and further catabolized by beta-alanine: oxoglutarate transaminase which is suggested to be identical to that for gamma-aminobutyrate, another omega-amino acid. Disorders included in these metabolic pathways are succinctly reviewed.
甘氨酸和丝氨酸可通过丝氨酸羟甲基转移酶相互转化，因此共享其代谢途径。在大鼠中，胆碱的碳骨架通过磷脂酰丝氨酸源自丝氨酸的α和β碳原子，并通过甘氨酸的N-甲基化分子（即甜菜碱、N-二甲基甘氨酸和肌氨酸（N-甲基甘氨酸））进一步转化为甘氨酸的碳骨架。到目前为止，活性一碳叶酸衍生物的产生是该代谢过程的显著特征，该衍生物是嘌呤核苷酸和胸苷酸生物合成的必需物质。在嘧啶核苷酸的主要降解途径中，产生了ω-氨基酸之一的β-丙氨酸，并通过β-丙氨酸：氧代戊二酸转氨酶进一步分解代谢，该转氨酶被认为与另一种ω-氨基酸γ-氨基丁酸的转氨酶相同。对这些代谢途径中包含的疾病进行了简要综述。
