Ball Rowena, Brindley John
Mathematical Sciences Institute, The Australian National University, , Canberra, Australian Capital Territory 0200, Australia.
J R Soc Interface. 2014 Mar 19;11(95):20131052. doi: 10.1098/rsif.2013.1052. Print 2014 Jun 6.
This paper presents and tests a previously unrecognized mechanism for driving a replicating molecular system on the prebiotic earth. It is proposed that cell-free RNA replication in the primordial soup may have been driven by self-sustained oscillatory thermochemical reactions. To test this hypothesis, a well-characterized hydrogen peroxide oscillator was chosen as the driver and complementary RNA strands with known association and melting kinetics were used as the substrate. An open flow system model for the self-consistent, coupled evolution of the temperature and concentrations in a simple autocatalytic scheme is solved numerically, and it is shown that thermochemical cycling drives replication of the RNA strands. For the (justifiably realistic) values of parameters chosen for the simulated example system, the mean amount of replicant produced at steady state is 6.56 times the input amount, given a constant supply of substrate species. The spontaneous onset of sustained thermochemical oscillations via slowly drifting parameters is demonstrated, and a scheme is given for prebiotic production of complementary RNA strands on rock surfaces.
本文提出并测试了一种此前未被认识到的、在生命起源前的地球上驱动复制分子系统的机制。有人提出,原始汤中的无细胞RNA复制可能是由自我维持的振荡热化学反应驱动的。为了验证这一假设,选择了一个特征明确的过氧化氢振荡器作为驱动因素,并使用具有已知缔合和解链动力学的互补RNA链作为底物。对一个简单自催化体系中温度和浓度的自洽耦合演化的开放流动系统模型进行了数值求解,结果表明热化学循环驱动了RNA链的复制。对于为模拟示例系统选择的(合理现实的)参数值,在底物物种持续供应的情况下,稳态时产生的复制体平均量是输入量的6.56倍。证明了通过缓慢漂移的参数自发产生持续的热化学振荡,并给出了在岩石表面进行益生元互补RNA链生产的方案。