Hyperthermostable cube-shaped assembly in water

Yi-Yang Zhan,Takako Mashiko,Masanori Tachikawa,Susumu Uchiyama,Kentaro Ishii,Kazuho Ogata,Takuya Koide,Shuichi Hiraoka,Tatsuo Kojima

doi:10.1038/s42004-018-0014-2

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.

Highlights

Proteins in hyperthermophiles exhibit extremely high thermal stability unlike general proteins
Their stabilization mechanism has attracted much attention[1,2,3,4,5,6,7,8,9], as these proteins are mainly composed of general amino acids, indicating that the same weak molecular interactions seen in general proteins, such as hydrogen bonding, charge interactions, van der Waals interactions and the hydrophobic effect contribute to their high thermal stability
Comparing the thermodynamic parameters in the gear-shaped amphiphilic molecules (GSAs) library enabled to evaluate the contribution of each molecular interaction to the stability, which emphasized that extremely high thermal stability is realized only when all the molecular interactions and the hydrophobic effect efficiently work together

Summary

Introduction

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. Unlike the proteins that we generally encounter, which are denaturated by gentle heating, proteins in hyperthermophiles, microorganisms able to survive in temperatures above 80 °C, exhibit extremely high thermal stability Their stabilization mechanism has attracted much attention[1,2,3,4,5,6,7,8,9], as these proteins are mainly composed of general amino acids, indicating that the same weak molecular interactions seen in general proteins, such as hydrogen bonding, charge interactions, van der Waals (vdW) interactions and the hydrophobic effect contribute to their high thermal stability. Comparing the thermodynamic parameters in the GSA library enabled to evaluate the contribution of each molecular interaction to the stability, which emphasized that extremely high thermal stability is realized only when all the molecular interactions and the hydrophobic effect efficiently work together

Methods

Results

Conclusion