Construction of three-dimensional interleaved protein hetero-superlattices in solution by cooperative electrostatic and aromatic stacking interactions

J Colloid Interface Sci. 2021 Jan 15;582(Pt A):1-11. doi: 10.1016/j.jcis.2020.08.016. Epub 2020 Aug 7.

Abstract

Hypothesis: Hierarchical assembly of naturally occurring assemblies is accurate and responsible for performing various cellular functions. However, Nature's wisdom in navigating the assembly process to desired protein assemblies by the cooperation of multiple noncovalent interactions has been underexploited for protein superstructures constructions. Owing to the chemical diversity of noncovalent interactions, it should be possible to fabricate protein assemblies with novel properties in high efficiency through the cooperation of different noncovalent interaction.

Experiments: Both charged residues and aromatic residues are introduced on the exterior surface of ferritin centered at their symmetry axes, mixing of complementary variants forms ordered assemblies through the cooperation of two kinds of chemical-diverse noncovalent interactions. The assemblies were further characterized in terms of their assembly behavior, structure, size, assembly kinetics, properties and stabilities.

Findings: We utilized both electrostatic and π-π stacking interactions between complementary nanocages to cooperatively trigger the self-assembly into predesigned interleaved hetero-superlattices which exhibit high electrolyte stability and thermal stability. The size of the hetero-superlattices can be well controlled with ranges from nanometers to micrometers in solution in response to external stimuli such as pH and salt concentration. The hetero-superlattice may have the potential applications in hybrid bio-templating, light-harvesting and compartmentalized encapsulation.

Keywords: Aromatic stacking interactions; Cooperative effect; Electrostatic interactions; Ferritin cage; Interleaved protein hetero-superlattices.