| Popis: |
We describe genetic engineering of a novel protein-nanoparticle hybrid system with great potential for patterning of various types of nanoparticles and for biosensing applications. The hybrid system is based on a genetically-modified chaperonin protein from the hyperthermophilic archaeon Sulfolobus shibatae. This chaperonin is an 18-subunit double ring, which self-assembles in the presence of Mg ions and ATP. We describe a chaperonin mutant (His-β- loopless:HBLL), with increased access to the central cavity and His-tags on each subunit extending into the central cavity. This mutant binds water-soluble semiconductor quantum dots, creating a protein-encapsulated fluorescent nanoparticle. By adding selective binding sites to the solvent-exposed regions of the chaperonin, this proteinnanoparticle bioconjugate becomes a sensor for specific targets. Using a combination of biochemical and spectroscopic assays, we characterize the formation, stoichiometry, affinity and stability of these novel sensors. |
