ATP‐Responsive Nanoparticles Covered with Biomolecular Machine “Chaperonin GroEL”

Abstract

<p>Herein, we report an ATP-responsive nanoparticle ((NP)-N-GroEL) whose surface is fully covered with the biomolecular machine "chaperonin protein GroEL". (NP)-N-GroEL was synthesized by DNA hybridization between a gold NP with DNA strands on its surface and GroEL carrying complementary DNA strands at its apical domains. The unique structure of (NP)-N-GroEL was visualized by transmission electron microscopy including under cryogenic conditions. The immobilized GroEL units retain their machine-like function and enable (NP)-N-GroEL to capture denatured green fluorescent protein and release it in response to ATP. Interestingly, the ATPase activity of (NP)-N-GroEL per GroEL was 4.8 and 4.0 times greater than those of precursor (cys)GroEL and its DNA-functionalized analogue, respectively. Finally, we confirmed that (NP)-N-GroEL could be iteratively extended to double-layered (GroEL)2 ${{<^>{({\rm GroEL}){_{2}}}}}$ NP.<br></p>