Pote M S, Viswanathan G, Kesavan V
Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai 400 085.
Indian J Biochem Biophys. 2003 Jun;40(3):175-9.
Various folate coenzymes and their polyglutamyl derivatives involved in 1-carbon metabolism are modulated as a result of altered physiological states and also vary with respect to growth conditions. We studied the metabolic changes in folic acid and their conjugated polyglutamyl derivatives in Lactobacillus casei cells grown in the presence of D20. A 40% decrease in methyltetrahydrofolyl polyglutamate derivatives was observed in the cells grown in media prepared with D20-depleted water (D20 content, 8-10 ppm). Chromatographic analysis of folates showed significant alterations in the formyl- and methyltetrahydrofolate derivatives and their polyglutamylation profiles. Higher amounts of oxidized folates were also present in the cells grown in D20-depleted conditions. No significant changes were observed in folates and their polyglutamate derivatives when the cells were grown in the presence of 300, 450 and 600 ppm D20. The altered folate homoestasis is attributed to changes in the metabolic adaptation of cells to D20-depleted environment.
参与一碳代谢的各种叶酸辅酶及其多聚谷氨酰衍生物会因生理状态的改变而受到调节，并且在生长条件方面也有所不同。我们研究了在D20存在下生长的干酪乳杆菌细胞中叶酸及其共轭多聚谷氨酰衍生物的代谢变化。在用贫D20水（D20含量为8 - 10 ppm）制备的培养基中生长的细胞中，观察到甲基四氢叶酸多聚谷氨酸衍生物减少了40%。叶酸的色谱分析表明，甲酰基和甲基四氢叶酸衍生物及其多聚谷氨酰化谱有显著变化。在贫D20条件下生长的细胞中也存在较高含量的氧化叶酸。当细胞在300、450和600 ppm D20存在下生长时，叶酸及其多聚谷氨酸衍生物未观察到显著变化。叶酸内稳态的改变归因于细胞对贫D20环境的代谢适应性变化。
