How did LUCA make a living? Chemiosmosis in the origin of life
How did LUCA make a living? Chemiosmosis in the origin of life
复制标题
DOI：
10.1002/bies.200900131
复制
发表时间：
2010-04-01
期刊：
影响因子：
4
通讯作者：
Martin, William
中科院分区：
文献类型：
--
作者：
Lane, Nick;Allen, John F.;Martin, William
尽管存在热力学、生物能量学和系统发育学上的缺陷，但有81年历史的原始汤概念仍然是关于生命起源的主流思想的核心。但汤液的pH值和氧化还原电位是均匀的，因此没有通过化学渗透作用进行能量耦合的能力。热力学的限制使得化学渗透对于所有自由生活的化学营养素和可能是第一个自由生活的细胞的碳和能量代谢来说是严格必要的。质子梯度在碱性热液喷口自然形成，被视为生命起源的中心。在这里，我们考虑最早的细胞如何利用地球化学产生的质子动力，然后学会制造自己的动力，这是它们逃离喷口所必需的过渡。现在用化学渗透法合成三磷酸腺苷涉及到通过从供体到受体的矢量电子转移来产生离子梯度。我们认为第一个施主是氢，第一个受主是二氧化碳。
Despite thermodynamic, bioenergetic and phylogenetic failings, the 81-year-old concept of primordial soup remains central to mainstream thinking on the origin of life. But soup is homogeneous in pH and redox potential, and so has no capacity for energy coupling by chemiosmosis. Thermodynamic constraints make chemiosmosis strictly necessary for carbon and energy metabolism in all free-living chemotrophs, and presumably the first free-living cells too. Proton gradients form naturally at alkaline hydrothermal vents and are viewed as central to the origin of life. Here we consider how the earliest cells might have harnessed a geochemically created proton-motive force and then learned to make their own, a transition that was necessary for their escape from the vents. Synthesis of ATP by chemiosmosis today involves generation of an ion gradient by means of vectorial electron transfer from a donor to an acceptor. We argue that the first donor was hydrogen and the first acceptor CO2.