RNA catalysis in model protocell vesicles.
RNA catalysis in model protocell vesicles.
复制标题
DOI：
10.1021/ja051784p
复制
发表时间：
2005-09-28
影响因子：
15
通讯作者：
Szostak, JW
中科院分区：
文献类型：
--
作者：
Chen, IA;Salehi-Ashtiani, K;Szostak, JW
我们正在进行一项长期的努力，以合成能够达尔文进化的化学系统，基于自我复制的核酸在自我复制的膜囊泡中的封装。在这里，我们解决这两个复制系统的兼容性问题。脂肪酸形成能够生长和分裂的囊泡，但是仅由脂肪酸组成的囊泡与大多数核酶的折叠和活性不相容，因为低浓度的二价阳离子（例如，Mg2+）导致脂肪酸沉淀。此外，生长和分裂的囊泡必须对内部代谢所需的阳离子和底物具有渗透性。我们使用肉豆蔻脑酸及其甘油单酯的混合物来构建耐受Mg 2+的囊泡，并发现Mg 2+阳离子可以渗透膜并在几分钟内平衡。在包裹锤头状核酶的囊泡中，外部Mg 2+的添加导致核酶分子的激活和自切割。由这些两亲物组成的囊泡自发地生长，通过atmosphically驱动囊泡之间的竞争，并进一步修改膜组合物允许混合胶束添加后的增长。我们的研究结果表明，由简单的两亲物制成的膜可以形成囊泡，这些囊泡在二价阳离子的存在下足够稳定以保留封装的RNA，但足够动态以自发生长并允许Mg2+和monoclitides在没有特定大分子转运蛋白的情况下通过。这种稳定性和动力学的结合对于在实验室中构建模型原始细胞至关重要，并且可能对早期细胞进化很重要。
We are engaged in a long-term effort to synthesize chemical systems capable of Darwinian evolution, based on the encapsulation of self-replicating nucleic acids in self-replicating membrane vesicles. Here, we address the issue of the compatibility of these two replicating systems. Fatty acids form vesicles that are able to grow and divide, but vesicles composed solely of fatty acids are incompatible with the folding and activity of most ribozymes, because low concentrations of divalent cations (e.g., Mg2+) cause fatty acids to precipitate. Furthermore, vesicles that grow and divide must be permeable to the cations and substrates required for internal metabolism. We used a mixture of myristoleic acid and its glycerol monoester to construct vesicles that were Mg2+-tolerant and found that Mg2+ cations can permeate the membrane and equilibrate within a few minutes. In vesicles encapsulating a hammerhead ribozyme, the addition of external Mg2+ led to the activation and self-cleavage of the ribozyme molecules. Vesicles composed of these amphiphiles grew spontaneously through osmotically driven competition between vesicles, and further modification of the membrane composition allowed growth following mixed micelle addition. Our results show that membranes made from simple amphiphiles can form vesicles that are stable enough to retain encapsulated RNAs in the presence of divalent cations, yet dynamic enough to grow spontaneously and allow the passage of Mg2+ and mononucleotides without specific macromolecular transporters. This combination of stability and dynamics is critical for building model protocells in the laboratory and may have been important for early cellular evolution.
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影响因子：
3.3
作者：
Berclaz, N;Müller, M;Luisi, PL
通讯作者：
Luisi, PL
影响因子：
56.9
作者：
Johnston, WK;Unrau, PJ;Bartel, DP
通讯作者：
Bartel, DP
DOI：
10.1038/2901
发表时间：
1998-11-01
期刊：
NATURE STRUCTURAL BIOLOGY
影响因子：
--
作者：
Draper, DE;Misra, VK
通讯作者：
Misra, VK
影响因子：
15
作者：
Li, YF;Breaker, RR
通讯作者：
Breaker, RR
DOI：
10.1073/pnas.0337743100
发表时间：
2003-02-18
影响因子：
11.1
作者：
Rangan, P;Masquida, B;Woodson, SA
通讯作者：
Woodson, SA