Adsorption of globular proteins at liquid–liquid interface results in compromised structures and functionalities to maintain a thermodynamically favorable state. However, the structural behavior of highly symmetrical supramolecular protein assemblies, adsorbed at the liquid–liquid interface, is not well understood. In this study, a model supramolecular protein assembly, E2 protein nanocage, a dodecahedral cage‐structured protein, is studied upon adsorption at the oil–water interface by both theoretical and experimental analyses. Molecular dynamics simulations and force estimation reveal that noncovalent interactions between E2 subunits dominate over the tangential force experienced by E2 at the interface allowing it to retain its structural integrity. Experimental analyses confirm the adsorption of E2 on the liquid–liquid interface with negligible penetration depth. Molecular structural analyses further suggest the structural integrity of the caged structure of E2 at the oil–water interface with minimal change in the tertiary and secondary structures. In conclusion, this study brings new insights into the behavior of highly symmetrical supramolecular protein assemblies at liquid–liquid interface which is important in preserving their functionalities.

中文翻译：

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超分子蛋白质组装体在液-液界面处保持其结构完整性

液-液界面上的球状蛋白吸附会导致结构和功能受损，无法维持热力学上有利的状态。但是，人们对高度对称的超分子蛋白质组装体在液-液界面处吸附的结构行为还不甚了解。在这项研究中，通过理论和实验分析，研究了模型超分子蛋白组装体E2蛋白nanocage（十二面体笼状结构蛋白）在油水界面上的吸附情况。分子动力学模拟和力估计表明，E2亚基之间的非共价相互作用主导着E2在界面处经历的切向力，从而使其保持了结构完整性。实验分析证实，E2在液-液界面上的吸附深度可忽略不计。分子结构分析进一步表明，E2笼状结构在油-水界面处的结构完整性，其三级和二级结构变化很小。总而言之，这项研究为高度对称的超分子蛋白质组装体在液-液界面的行为提供了新见解，这对于保持其功能至关重要。