METAPHOSPHATE SYNTHESIS BY AN ENZYME FROM ESCHERICHIA-COLI
METAPHOSPHATE SYNTHESIS BY AN ENZYME FROM ESCHERICHIA-COLI
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DOI：
10.1016/0006-3002(56)90280-3
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发表时间：
1956-01-01
期刊：
影响因子：
--
通讯作者：
SIMMS, ES
中科院分区：
文献类型：
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作者：
KORNBERG, A;KORNBERG, SR;SIMMS, ES
一种合成偏磷酸盐的酶从大肠杆菌提取物中纯化了 100 倍以上。该反应可用下式描述： [图片] 在聚合物中仅发现 ATP 的末端磷酸基团。由于该反应的另一种产物 ADP 被证明是一种非常有效的抑制剂，因此人们相信 ATP 再生系统通常与该反应偶联。无机焦磷酸盐（PP），但不是无机正磷酸盐或腺嘌呤核苷酸，被掺入偏磷酸盐中。然而，缺乏对 PP 的要求以及不存在 PP-ase 的任何抑制作用，使得真正的引物 (PO3)n 的性质受到怀疑。磷酸盐聚合物被称为长链偏磷酸盐，因为它（a）诱导异色性，（b）与蛋白质形成酸不溶性复合物，（c）不可透析，（d）对酸和碱不稳定，（e）与阴离子交换树脂牢固结合，并且（f）不受核酸酶攻击。
An enzyme that synthesizes metaphosphate was purified more than 100-fold from extracts of E. coli. The reaction may be described by the equation: [image] Only the terminal phosphate group of ATP was found in the polymer. Since ADP, the other product of the reaction, proved to be a very potent inhibitor, it is believed that an ATP-regen-erating system is generally coupled to the reaction. Inorganic pyrophosphate (PP), but not inorganic orthophosphate or adenine nucleotide, are incorporated into metaphosphate. However, lack of a requirement for PP and the absence of any inhibition by PP-ase leaves the nature of the true primer (PO3)n in doubt. The phosphate polymer is characterized as a long-chain metaphosphate because it (a) induces metachromasy, (b) forms an acid-insoluble complex with protein, (c) is nondialyzable, (d) is labile to acid and alkali, (e) binds tenaciously to anion exchange resins, and (f) is not attacked by nucleases.