Young Eric J, Kirst Henning, Dwyer Matthew E, Vermaas Josh V, Kerfeld Cheryl A
Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, California 94702, United States.
Departamento de Genética, Campus de Excelencia Internacional Agroalimentario ceiA3, Universidad de Córdoba, Córdoba 14071, Spain.
ACS Synth Biol. 2025 May 16;14(5):1405-1413. doi: 10.1021/acssynbio.4c00290. Epub 2025 Jan 14.
Naturally evolved and synthetically designed forms of compartmentalization benefit encapsulated function by increasing local concentrations of substrates and protecting cargo from destabilizing environments and inhibitors. Crucial to understanding the fundamental principles of compartmentalization are experimental systems enabling the measurement of the permeability rates of small molecules. Here, we report the experimental measurement of the small-molecule permeability of a 40 nm icosahedral bacterial microcompartment shell. This was accomplished by heterologous loading of light-producing luciferase enzymes and kinetic measurement of luminescence using stopped-flow spectrophotometry. Compared to free enzyme, the luminescence signal kinetics was slower when the luciferase was encapsulated in bacterial microcompartment shells. The results indicate that substrates and products can still exchange across the shell, and modeling of the experimental data suggest that a 50× permeability rate increase occurs when shell vertices were vacant. Overall, our results suggest design considerations for the construction of heterologous bacterial microcompartment shell systems and compartmentalized function at the nanoscale.
自然进化和人工合成设计的区室化形式通过提高底物的局部浓度以及保护货物免受不稳定环境和抑制剂的影响，从而使封装功能受益。对于理解区室化的基本原理至关重要的是能够测量小分子渗透率的实验系统。在此，我们报告了对40纳米二十面体细菌微区室外壳小分子渗透率的实验测量。这是通过异源加载发光荧光素酶并使用停流分光光度法对发光进行动力学测量来实现的。与游离酶相比，当荧光素酶封装在细菌微区室外壳中时，发光信号动力学较慢。结果表明底物和产物仍可跨外壳交换，并且对实验数据的建模表明，当外壳顶点为空时，渗透率提高50倍。总体而言，我们的结果为构建异源细菌微区室外壳系统和纳米级区室化功能提供了设计考量。
