Transport of Molecular Cargo by Interaction with Virus-Like Particle RNA
Graphical Abstract
The binding of intercalating dyes such as thiazole orange (TO) to polynucleotides allows for a simple method to load RNA-rich virus-like particles with molecular cargo, and then to release that cargo by diffusion. TO-labeled molecules come out much slower than they go in because of the high RNA concentration inside the shell; the surprise is how much cargo these easily produced nanocontainers can carry.
Abstract
Virus-like particles (VLPs) derived from Leviviridae virions contain substantial amounts of cellular and plasmid-derived RNA. This encapsidated polynucleotide serves as a reservoir for the efficient binding of the intercalating dye thiazole orange (TO). Polyethylene glycol (PEG) molecules and oligopeptides of varying length, end-functionalized with TO, were loaded into VLPs up to approximately 50 % of the mass of the capsid protein (hundreds to thousands of cargo molecules per particle, depending on size). The kinetics of TO–PEG binding included a significant entropic cost for the reptation of long chains through the capsid pores. Cargo molecules were released over periods of 20–120 hours following simple reversible first-order kinetics in most cases. These observations define a simple general method for the noncovalent packaging, and subsequent release, of functional molecules inside nucleoprotein nanocages in a manner independent of modifications to the capsid protein.
Conflict of interest
The authors declare no conflict of interest.
