Morowitz H J, Heinz B, Deamer D W
Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06511.
Orig Life Evol Biosph. 1988;18(3):281-7. doi: 10.1007/BF01804674.
Traditional schemes for the origin of cellular life on earth generally suppose that the chance assembly of polymer synthesis systems was the initial event, followed by incorporation into a membrane-enclosed volume to form the earliest cells. Here we discuss an alternative system consisting of replicating membrane vesicles, which we define as minimum protocells. These consist of vesicular bilayer membranes that self-assemble from relatively rare organic amphiphiles present in the prebiotic environment. If some of the amphiphiles are primitive pigment molecules asymmetrically oriented in the bilayer, light energy can be captured in the form of electrochemical ion gradients. This energy could then be used to convert relatively common precursor molecules into membrane amphiphiles, thereby providing an initial photosynthetic growth process, as well as an appropriate microenvironment for incorporation and evolution of polymer synthesis systems.
地球上细胞生命起源的传统观点一般认为，聚合物合成系统的偶然组装是起始事件，随后被纳入膜封闭的空间中形成最早的细胞。在此，我们讨论一种由复制性膜泡组成的替代系统，我们将其定义为最小原始细胞。这些最小原始细胞由囊泡双层膜构成，该双层膜由存在于前体生物环境中相对稀有的有机两亲分子自组装而成。如果某些两亲分子是在双层膜中不对称取向的原始色素分子，光能就可以以电化学离子梯度的形式被捕获。然后，这种能量可用于将相对常见的前体分子转化为膜两亲分子，从而提供一个初始的光合作用生长过程，以及一个适合聚合物合成系统纳入和进化的微环境。
