Tamura T, Wada M, Esaki N, Soda K
Institute for Chemical Research, Kyoto University, Japan.
J Bacteriol. 1995 May;177(9):2265-9. doi: 10.1128/jb.177.9.2265-2269.1995.
Streptomyces cattleya produces fluoroacetate and 4-fluorothreonine from inorganic fluoride added to the culture broth. We have shown by 19F nuclear magnetic resonance (NMR) spectrometry that fluoroacetate is accumulated first in the culture broth and that accumulation of 4-fluorothreonine is next. To show precursors of the carbon skeleton of fluoroacetate, we carried out tracer experiments with various 14C- and 13C-labeled compounds. Radioactivity of [U-14C]glucose, [U-14C]glycerol, [U-14C]serine, and [U-14C]beta-hydroxypyruvate was incorporated into fluoroacetate to an extent of 0.2 to 0.4%, whereas [3-14C]pyruvate, [2,3-14C]succinate, and [U-14C]aspartate were less efficiently incorporated (0.04 to 0.08%). The addition of [2-13C]glycerol to the mycelium suspension of Streptomyces cattleya caused exclusive enrichment of the carboxyl carbon of fluoroacetate with 13C; about 40% of carboxyl carbon of fluoroacetate was labeled with 13C. We studied the radioactivity incorporation of [3-14C]-, [U-14C]-, and [1-14C]beta-hydroxypyruvates to show that C-2 and C-3 of beta-hydroxypyruvate are exclusively converted to the carbon skeleton of fluoroacetate. These results suggest that the carbon skeleton of fluoroacetate derives from C-1 and C-2 of glycerol through beta-hydroxypyruvate, whose hydroxyl group is eventually replaced by fluoride.
卡特利链霉菌能利用添加到培养液中的无机氟化物产生氟乙酸盐和4-氟苏氨酸。我们通过19F核磁共振（NMR）光谱法表明，氟乙酸盐首先在培养液中积累，随后是4-氟苏氨酸的积累。为了揭示氟乙酸盐碳骨架的前体，我们用各种14C和13C标记的化合物进行了示踪实验。[U-14C]葡萄糖、[U-14C]甘油、[U-14C]丝氨酸和[U-14C]β-羟基丙酮酸的放射性以0.2%至0.4%的程度掺入氟乙酸盐中，而[3-14C]丙酮酸、[2,3-14C]琥珀酸和[U-14C]天冬氨酸的掺入效率较低（0.04%至0.08%）。向卡特利链霉菌的菌丝体悬浮液中添加[2-13C]甘油导致氟乙酸盐的羧基碳仅被13C富集；约40%的氟乙酸盐羧基碳被13C标记。我们研究了[3-14C]-、[U-14C]-和[1-14C]β-羟基丙酮酸的放射性掺入情况，以表明β-羟基丙酮酸的C-2和C-3仅转化为氟乙酸盐的碳骨架。这些结果表明，氟乙酸盐的碳骨架通过β-羟基丙酮酸源自甘油的C-1和C-2，其羟基最终被氟取代。
