Effects of Co-Expression of Liver X Receptor beta-Ligand Binding Domain with its Partner, Retinoid X Receptor alpha-Ligand Binding Domain, on their Solubility and Biological Activity in Escherichia coli

摘要

In this presentation, I describe the expression and purification of the recombinant liver X receptor beta-ligand binding domain proteins in E. coli using a commercially available double cistronic vector, pACYCDuet-1, to express the receptor heterodimer in a single cell as the soluble form. I describe here the expression and characterization of a biologically active heterodimer composed of the liver X receptor beta-ligand binding domain and retinoid X receptor a-ligand binding domain. Although many of these proteins were previously seen to be produced in E. coli as insoluble aggregates or "inclusion bodies", I show here that as a form of heterodimer they can be made in soluble forms that are biologically active. This suggests that co-expression of the liver X receptor beta-ligand binding domain with its binding partner improves the solubility of the complex and probably assists in their correct folding, thereby functioning as a type of molecular chaperone.