An Intrinsically Fluorescent Recognition Ligand Scaffold Based on Chaperonin Protein and Semiconductor Quantum-Dot Conjugates

作者：Xie Hongzhi; Li Yi Fen; Kagawa Hiromi K; Trent Jonathan D; Mudalige Kumara; Cotlet Mircea^*; Swanson Basil I

来源：Small, 2009, 5(9): 1036-1042.

DOI：10.1002/smll.200801106

• nanoparticles
• proteins
• quantum dots
• semiconductors

Genetic engineering of a novel protein-nanoparticle hybrid system with great potential for biosensing applications and for patterning of various types of nanoparticles is described. 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. Described here is a mutant chaperonin (His-beta-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. The new bioconjugate has high affinity, in the order of strong antibody-antigen interactions, a one-to-one protein-nanoparticle stoichiometry, and high stability. By adding selective binding sites to the solvent-exposed regions of the chaperonin, this protein-nanoparticle bioconjugate becomes a sensor for specific targets.

• 出版日期2009-5-4