Cage Protein Encapsulation

Although the systems described here have not been used for nanoencapsulated cascade reactions, or of course, for mutually incompatible catalysts, they offer an attractive possibility for the extension of this field, especially given the availability of a wide range of protein-based nanometer-sized cages, such as chaperonins, DNA binding proteins, and the extensive class of viruses [107]. 

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Douglas, T. and Young, M. (1998) Host-guest encapsulation of materials by assembled virus protein cages. Nature, 393, 152-155. 

T. Douglas, M Young Host-Guest Encapsulation of Materials by Assembled Vims Protein Cages Nature 393, 152 (1998). 

Several bioactive proteins retained their activity and conformation in sol-gel matrices. The sol-gel entrapped heme proteins such as cytochrome c and Mb showed good stability against pH and thermal perturbations compared to protein in solution [29, 55]. The sol-gel caged cytochrome c (cyt c) showed high thermal stability due to the exact fitting of the protein inside the cage, which was controlled by the protein size [56]. Sol-gel encapsulated acid phosphatase [57] and bovine carbonic anhydrase II (BCA II)... 

To test the dominance of electrostatic effects in the mineralization model, a mutant of CCMV was constructed (subE) in which all the basic residues on the N-terminus of the coat protein were substituted for glutamic acid (E), thus dramatically altering the electrostatic character of the interior of the assembled protein cage." This mutant was able to catalyze the oxidative hydrolysis of Fe(II) to form an iron oxide nanoparticle encapsulated within the protein cage of the modified virus. High-rcsolution spectral imaging allowed the elemental composition of a protein-mineral composite material to be resolved (1 nm spatial resolution, Fig. 3). This clearly showed that the mineral nanoparticle was completely encapsulated within the protein cage structure. This mutant is able to bind Fe(lT), facilitate its autoxidation... 

Aniagyei, S.E., Dufort, C., Kao, C.C., Dragnea, B., 2008. Self-assembly approaches to nanomaterial encapsulation in viral protein cages. J. Mater. Chem. 18, 3763—3774. 

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