Functionalization of thioctic acid-capped gold nanoparticles for specific immobilization of histidine-tagged proteins
Abad, JM × Mertens, SFL Pita, M Fernandez, VM Schiffrin, DJ #
American Chemical Society
Journal of the American Chemical Society vol:127 issue:15 pages:5689-5694
This paper presents an efficient strategy for the specific immobilization of fully functional proteins onto the surface of nanoparticles. Thioctic acid-derivatized gold clusters are used as a scaffold for further stepwise modification, leading to a cobalt(II)-terminated ligand shell. A histidine tag introduced by genetic engineering into a protein is coordinated to this transition metal ion. The specific immobilization has been demonstrated for the cases of a genetically engineered horseradish peroxidase and ferredoxin-NADP+ reductase, confirming the attachment of the fully functional proteins to the Co(II)-terminated nanointerface. The absence of nonspecific protein adsorption and the specificity of the binding site have been verified using several analogues of the enzymes without the histidine tag.