Phosphate Activation via Reduced Oxidation State Phosphorus (P). Mild Routes to Condensed-P Energy Currency Molecules.
Phosphate Activation via Reduced Oxidation State Phosphorus (P). Mild Routes to Condensed-P Energy Currency Molecules.
复制标题
DOI：
10.3390/life3030386
复制
发表时间：
2013-07-19
期刊：
影响因子：
--
通讯作者：
Cousins CR
中科院分区：
文献类型：
--
作者：
Kee TP;Bryant DE;Herschy B;Marriott KE;Cosgrove NE;Pasek MA;Atlas ZD;Cousins CR
有机和无机分子磷酸化机制的出现是通往最早生命系统的关键一步。在所有现代生化系统的核心都有活性磷分子(如三磷酸腺苷)作为能量流通分子来驱动能量代谢过程，有人提出这种分子的前身可能是焦磷酸盐[P2O74−；ppi(V)]。可以说，获得PPI(V)的最合理的地质途径是正磷酸盐PI(V)的脱水，在缺乏激活PI(V)的机制的情况下，这通常是一个高度放热的过程。这一问题的一个可能的解决方案是认识到陨石中存在含有活性磷的矿物相，如施雷伯石[(Fe，Ni)3P]，它们在早期地球上的丰度很可能在推测的海德-太古宙强烈轰击期间显著增加。在这里，我们认为，还原的氧化态对氧酸，H-亚磷酸[HPO32−；PI(III)]可以激活PI(V)通过缩合的含氧酸焦亚磷酸[H_2P_2O_52−；PPI(III)]的中间体进行缩合。我们提供了PPI(III)的地质来源，以及它在温和的水条件(80°C)下激活PI(V)形成PPI(V)的能力的证据。
The emergence of mechanisms for phosphorylating organic and inorganic molecules is a key step en route to the earliest living systems. At the heart of all contemporary biochemical systems reside reactive phosphorus (P) molecules (such as adenosine triphosphate, ATP) as energy currency molecules to drive endergonic metabolic processes and it has been proposed that a predecessor of such molecules could have been pyrophosphate [P2O74−; PPi(V)]. Arguably the most geologically plausible route to PPi(V) is dehydration of orthophosphate, Pi(V), normally a highly endergonic process in the absence of mechanisms for activating Pi(V). One possible solution to this problem recognizes the presence of reactive-P containing mineral phases, such as schreibersite [(Fe,Ni)3P] within meteorites whose abundance on the early Earth would likely have been significant during a putative Hadean-Archean heavy bombardment. Here, we propose that the reduced oxidation state P-oxyacid, H-phosphite [HPO32−; Pi(III)] could have activated Pi(V) towards condensation via the intermediacy of the condensed oxyacid pyrophosphite [H2P2O52−; PPi(III)]. We provide geologically plausible provenance for PPi(III) along with evidence of its ability to activate Pi(V) towards PPi(V) formation under mild conditions (80 °C) in water.