Hyperthermostable cube-shaped assembly in water

Abstract

Proteins in hyperthermophiles exhibit extremely high thermal stability unlike general proteins. These thermostable proteins are stabilized by weak molecular interactions such as hydrogen bonding, charge interactions and van der Waals (vdW) interactions, along with the hydrophobic effect. An in-depth understanding of the stabilization mechanisms will enable us to rationally design artificial molecules with very high thermal stability. Here we show thermally stable supramolecular assemblies composed of six identical amphiphilic molecules having an indented hydrophobic surface, held together by weak intermolecular interactions (vdW and cation-π interactions) and the hydrophobic effect in water. The disassembly temperature of one of the assemblies is over 150 °C, which is higher than that of the most hyperthermophilic protein reported to date (PhCutA1). Study of the relationship between the structure of the components and the stability of the assemblies indicates that the hyperthermostability is achieved only if all the weak interactions and the hydrophobic effect work cooperatively.