Dunstan R H, Whatley F R, Greenaway W
Department of Plant Sciences, University of Oxford, U.K.
Proc R Soc Lond B Biol Sci. 1988 Feb 23;233(1270):1-15. doi: 10.1098/rspb.1988.0008.
The biosynthesis in vivo of a number of amino acids, sugars, and purines in Paracoccus denitrificans grown on either [2,3-13C]succinate or [1,4-13C]succinate was investigated by using gas chromatography-mass spectrometry. The distribution of label in the TCA-cycle-related amino acids indicated that carbon intermediates of energy metabolism were utilized as precursors for the biosynthesis of these amino acids in vivo. The biosynthesis of glycine, serine, phenylalanine and glycerol from labelled succinate in vivo were consistent with phosphoenol pyruvate as an intermediate. A mechanism for the formation of C4, C5 and C6 sugars without the use of fructose-1,6-bisphosphate aldolase (which has not been detected in P. denitrificans) is proposed. The 13C-enrichments of ribose in the bacterium indicate that there are at least three routes of ribose biosynthesis operating during growth on labelled succinate. The probability distribution of labelled purine molecules was successfully predicted for adenine, guanine and adenosine, thus confirming their generally accepted route of biosynthesis in vivo.
利用气相色谱 - 质谱法研究了在[2,3 - 13C]琥珀酸或[1,4 - 13C]琥珀酸上生长的反硝化副球菌体内多种氨基酸、糖类和嘌呤的生物合成。三羧酸循环相关氨基酸中的标记分布表明，能量代谢的碳中间体在体内被用作这些氨基酸生物合成的前体。体内由标记琥珀酸合成甘氨酸、丝氨酸、苯丙氨酸和甘油的过程与磷酸烯醇丙酮酸作为中间体一致。提出了一种不使用果糖 - 1,6 - 二磷酸醛缩酶（在反硝化副球菌中未检测到）形成C4、C5和C6糖类的机制。细菌中核糖的13C富集表明，在标记琥珀酸上生长期间，至少有三条核糖生物合成途径在运行。成功预测了腺嘌呤、鸟嘌呤和腺苷中标记嘌呤分子的概率分布，从而证实了它们在体内普遍接受的生物合成途径。
