High-level expression, one-step purification of soluble Ad5-knob protein and its activity assay

This report describes a simple, highly efficient, and reproducible method for obtaining large quantities of highly pure recombinant Ad5-knob protein, which can be used for gene-delivery application. The Ad5- knob protein expressed in Escherichia coli contained a His tag at the N-terminus that allowed one-step isolation by immobilized metal affinity chromatography (IMAC). The activity of the recombinant protein was tested by receptor-binding assay in Hela cells for potential application in gene delivery.