Evolution of Oxygen Isotopologues in Phosphate and Pyrophosphate during Enzyme-Catalyzed Isotopic Exchange Reactions
Evolution of Oxygen Isotopologues in Phosphate and Pyrophosphate during Enzyme-Catalyzed Isotopic Exchange Reactions
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酶催化同位素交换反应过程中磷酸盐和焦磷酸盐中氧同位素异构体的演化
DOI：
10.1021/acsearthspacechem.2c00050
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发表时间：
2022
影响因子：
3.4
通讯作者：
Jaisi, Deb P.
中科院分区：
文献类型：
--
作者：
Moller, Spencer R.;Sakhno, Yuriy;Aristilde, Ludmilla;Blake, Ruth E.;Jaisi, Deb P.
无机焦磷酸酶（PPase）是一种催化焦磷酸盐（PPi）中磷酸酐键水解释放无机磷酸盐（Pi）并同时在磷酸和水之间交换氧同位素的酶。本文采用拉曼光谱和31p核磁共振（NMR）技术，定量分析了ppase在Pi-water和PPi-water体系中催化的18o - 16o同位素交换反应过程中，5种pi同位素物（P18O4、P18O316O、P18O216O2、P18O16O3和P16O4）与水的氧同位素交换动力学。在PPi高浓度（300 mM）时，PPi酶的水解作用占主导地位，只有一小部分PPi（≪1%）参与了可逆的水解-冷凝反应（PPi↔Pi），导致了PPi和水之间的氧同位素交换。我们证明了拉曼和核磁共振方法可以同样应用于监测氧同位素物与水之间的交换动力学。发现用光谱法测定的同位素交换可检测到低至0.2%的18O丰度，但低于1%的可靠性要低得多。考虑到这些方法需要高磷浓度（≥1 mM），这些方法的环境应用仅限于工程和农业环境中罕见的高磷条件。
Inorganic pyrophosphatase (PPase) is an enzyme that catalyzes the hydrolysis of the phosphoanhydride bond in pyrophosphate (PPi) to release inorganic phosphate (Pi) and simultaneously exchange oxygen isotopes between Piand water. Here, we quantified the exchange kinetics of oxygen isotopes between five Piisotopologues (P18O4, P18O316O, P18O216O2, P18O16O3, and P16O4) and water using Raman spectroscopy and31P nuclear magnetic resonance (NMR) during the PPase-catalyzed18O–16O isotope exchange reaction in Pi-water and PPi-water systems. At a high PPiconcentration (300 mM), hydrolysis of PPiby PPase was predominant, and only a small fraction of PPi(≪1%) took part in the reversible hydrolysis–condensation reaction (PPi↔ Pi), leading to the oxygen isotope exchange between Piand water. We demonstrated that Raman and NMR methods can be equally applied for monitoring the kinetics of the oxygen exchange between the Piisotopologue and water. It was found that the isotope exchange determined by the spectroscopic methods was detectable as low as 0.2%18O abundance, but the reliability below 1% was much lower. Given that high P concentrations (≥1 mM) are required in these methods, environmental application of these methods is limited to rare high P conditions in engineered and agricultural environments.
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交换反应动力学
影响因子：
64.8
作者：
H. Mckay
通讯作者：
H. Mckay
影响因子：
5
作者：
R. Zeebe
通讯作者：
R. Zeebe
影响因子：
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作者：
Antler, Gilad;Turchyn, Alexandra V.;Sivan, Orit
通讯作者：
Sivan, Orit
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DOI：
--
发表时间：
2017
期刊：
影响因子：
--
作者：
C. Sperber;H. Lewandowski;F. Tamburini;S. Bernasconi;W. Amelung;E. Frossard
通讯作者：
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大鼠肝胞质和线粒体无机焦磷酸酶双向催化的基本步骤的速率。
影响因子：
3.9
作者：
I. Smirnova;V. Kasho;S. Volk;A. Ivanov;A. Baykov
通讯作者：
A. Baykov