Construct design, biophysical, and biochemical characterization of the fusion core from mouse hepatitis virus (a coronavirus) spike protein

March 27, 2020

Title

Construct design, biophysical, and biochemical characterization of the fusion core from mouse hepatitis virus (a coronavirus) spike protein

Author

Yanhui Xu, David K. Cole, Zhiyong Lou, Yiwei Liu, Lan Qin, Xu Li, Zhihong Bai, Fang Yuan, Zihe Rao, George F. Gao

Year

2004

Journal

Protein Expression and Purification

Abstract

Membrane fusion between virus and host cells is the key step for enveloped virus entry and is mediated by the viral envelope fusion protein. In murine coronavirus, mouse hepatitis virus (MHV), the spike (S) protein mediates this process. Recently, the formation of anti-parallel 6-helix bundle of the MHV S protein heptad repeat (HR) regions (HR1 and HR2) has been confirmed, implying coronavirus has a class I fusion protein. This bundle is also called fusion core. To facilitate the solution of the crystal structure of this fusion core, we deployed an Escherichia coli in vitro expression system to express the HR1 and HR2 regions linked together by a flexible linker as a single chain (named 2-helix). This 2-helix polypeptide subsequently assembled into a typical 6-helix bundle. This bundle has been analyzed by a series of biophysical and biochemical techniques and confirmed that the design technique can be used for coronavirus as we successfully used for members of paramyxoviruses.

Instrument

J-715

Keywords

Circular dichroism, Thermal stability, Secondary structure, Thermodynamics, Biochemistry