Protein Cages as Containers for Gold Nanoparticles

Abstract

Abundant and highly diverse, viruses offer new scaffolds in nanotechnology for the encapsulation, organization, or even synthesis of novel materials. In this work the coat protein of the cowpea chlorotic mottle virus (CCMV) is used to encapsulate gold nanoparticles with different sizes and stabilizing ligands yielding stable particles in buffered solutions at neutral pH. The sizes of the virus-like particles correspond to T = 1, 2, and 3 Caspar-Klug icosahedral triangulation numbers. We developed a simple one-step process enabling the encapsulation of commercially available gold nanoparticles without prior modification with up to 97% efficiency. The encapsulation efficiency is further increased using bis-p-(sufonatophenyl)phenyl phosphine surfactants up to 99%. Our work provides a simplified procedure for the preparation of metallic particles stabilized in CCMV protein cages. The presented results are expected to enable the preparation of a variety of similar virus-based colloids for current focus areas.

Oligonucleotide Length‐Dependent Formation of Virus‐Like Particles

“…Apart from VLP formation at pH 5, there are also reports in the literature proving that CCMV can form defined VLPs at neutral pH, at which CP–cargo interactions dominate, in the presence of a sufficiently negative template . However, the required strength of this interaction and the exact mechanism of assembly under these conditions are currently not yet fully understood.…”

“…Isolated CP can be reassembled into empty capsids at low pH and high ionic strength. Furthermore, CPs can assemble around non‐native polyanionic species, for example, polymers, nanoparticles, or genomic material, forming virus‐like particles (VLPs) with T =1, 2, or 3 icosahedral symmetry and diameters of 18, 23, and 28 nm, respectively, depending on the cargo . Thus, CCMV can be used in a wide array of applications.…”

“…[7,8] In vitro studies show that CCMV can easily be disassembled into its RNA and free CP dimers upon raising the pH and increasing the ionic strength.I solated CP can be reassembled into empty capsids at low pH and high ionic strength. Furthermore,C Ps can assemble around non-native polyanionic species, for example, polymers, [9][10][11][12] nanoparticles, [13,14] or genomic material, [15][16][17] forming virus-like particles (VLPs) with T = 1, 2, or 3i cosahedral symmetry and diameters of 18, 23, and 28 nm, respectively,depending on the cargo. [18] Thus, CCMV can be used in aw ide array of applications.…”

“…[23,24] Apart from VLP formation at pH 5, there are also reports in the literature proving that CCMV can form defined VLPs at neutralp H, at whichC P-cargo interactions dominate, in the presenceo fas ufficiently negative template. [9,14,25] However, the required strength of this interaction and the exact mechanism of assembly under these conditions are currently not yet fully understood. Therefore, herein,w es eek to determine the minimal number of charges, that is, the number of nucleotides (nt), neededt oi nduce virus assembly around oligonucleotides.…”

A 3‐D bonding perspective of the factors influencing the relative stability of the S1/S0 conical intersections of the penta‐2,4‐dieniminium cation (PSB3)

“…Now we will undertake a comparison of the results of the SSR-ωPBEh/cc-pVDZ calculations with the results of other calculations available in the literature. [4,10,[41][42][43][44] The SA-CASSCF calculations [44] from the literature yield the occurrence of the S 1 minimum for torsion θ around the C6 C7 bond at the BLA value of −0.012 Ǻ . This indicates an inversion of the lengths of the former double and single bonds; the bonds, which were double in the S 0 state, become longer than the former single bonds.…”