Determining the chemical composition of biological materials is paramount to the study of natural phenomena. Here, we describe the composition of model gram-negative outer membranes, focusing on the predominant assembly, an asymmetrical bilayer of lipid molecules. We also give an overview of lipid biosynthetic pathways and molecular mechanisms that organize this material into the outer membrane bilayer. An emphasis is placed on the potential of these pathways as targets for antibiotic development. We discuss deviations in composition, through bacterial cell surface remodeling, and alternative modalities to the asymmetric lipid bilayer. Outer membrane lipid alterations of current microbiological interest, such as lipid structures found in commensal bacteria, are emphasized. Additionally, outer membrane components could potentially be engineered to develop vaccine platforms. Observations related to composition and assembly of gram-negative outer membranes will continue to generate novel discoveries, broaden biotechnologies, and reveal profound mysteries to compel future research.

中文翻译：

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不对称的力量：革兰氏阴性外膜脂双层的结构和组装

确定生物材料的化学组成对研究自然现象至关重要。在这里，我们描述模型革兰氏阴性外膜的组成，重点是主要的组装，脂质分子的不对称双层。我们还概述了脂质生物合成途径和分子机制，将这种物质组织到外膜双层中。重点放在这些途径作为抗生素开发目标的潜力上。我们讨论了通过细菌细胞表面重塑以及不对称脂质双层的替代方式在成分上的偏差。强调了当前微生物学感兴趣的外膜脂质改变，例如在共生细菌中发现的脂质结构。此外，外膜组件可能会被工程化以开发疫苗平台。与革兰氏阴性外膜的组成和组装有关的观察将继续产生新发现，拓宽生物技术，并揭示深刻的奥秘以推动未来的研究。