All known forms of life are composed of cells, whose boundaries are defined by lipid membranes that separate and protect cell contents from the environment. It is unknown how the earliest forms of life were compartmentalized. Several models have suggested a role for single-chain lipids such as fatty acids, but the membranes formed are often unstable, particularly when made from shorter alkyl chains (≤C₈) that were probably more prevalent on prebiotic Earth. Here we show that the amino acid cysteine can spontaneously react with two short-chain (C₈) thioesters to form diacyl lipids, generating protocell-like membrane vesicles. The three-component reaction takes place rapidly in water using low concentrations of reactants. Silica can catalyse the formation of protocells through a simple electrostatic mechanism. Several simple aminothiols react to form diacyl lipids, including short peptides. The protocells formed are compatible with functional ribozymes, suggesting that coupling of multiple short-chain precursors may have provided membrane building blocks during the early evolution of cells.

所有已知的生命形式都由细胞组成，其边界由脂质膜定义，脂质膜将细胞内容物与环境分离并保护。最早的生命形式是如何划分的尚不清楚。一些模型表明单链脂质（如脂肪酸）的作用，但形成的膜通常是不稳定的，特别是当由较短的烷基链 （≤C₈） 制成时，这可能在益生元地球上更为普遍。在这里，我们表明氨基酸半胱氨酸可以与两个短链 （C₈） 硫酯自发反应形成二酰基脂质，生成原生细胞样膜囊泡。三组分反应在水中使用低浓度的反应物迅速发生。二氧化硅可以通过简单的静电机制催化原细胞的形成。几种简单的氨基硫醇反应形成二酰基脂质，包括短肽。形成的原生细胞与功能性核酶相容，表明多个短链前体的偶联可能在细胞的早期进化过程中提供了膜构建单元。