title: In vivo encapsulation of nucleic acids using an engineered nonviral protein capsid.
abstract: In Nature, protein capsids function as molecular containers for a wide variety of molecular cargoes. Such containers have great potential for applications in nanotechnology, which often require encapsulation of non-native guest molecules. Charge complementarity represents a potentially powerful strategy for engineering novel encapsulation systems. In an effort to explore the generality of this approach, we engineered a nonviral, 60-subunit capsid, lumazine synthase from Aquifex aeolicus (AaLS), to act as a container for nucleic acid. Four mutations were introduced per subunit to increase the positive charge at the inner surface of the capsid. Characterization of the mutant (AaLS-pos) revealed that the positive charges lead to the uptake of cellular RNA during production and assembly of the capsid in vivo. Surprisingly, AaLS-pos capsids were found to be enriched with RNA molecules approximately 200-350 bases in length, suggesting that this simple charge complementarity approach to RNA encapsulation leads to both high affinity and a degree of selectivity. The ability to control loading of RNA by tuning the charge at the inner surface of a protein capsid could illuminate aspects of genome recognition by viruses and pave the way for the development of improved RNA delivery systems.
authors: Department of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112, USA.
authors: Seth
authors: S
authors: Lilavivat
authors: Debosmita
authors: D
authors: Sardar
authors: Subrata
authors: S
authors: Jana
authors: Geoffrey C
authors: GC
authors: Thomas
authors: Kenneth J
authors: KJ
authors: Woycechowsky
mesh_terms: D002213:Capsid / Q000737:chemistry*; D036022:Capsid Proteins / Q000138:chemical synthesis* / Q000235:genetics; D004587:Electrophoresis, Agar Gel; D046529:Microscopy, Electron, Transmission; D008954:Models, Biological; D008958:Models, Molecular; D009097:Multienzyme Complexes / Q000138:chemical synthesis* / Q000235:genetics; D019065:Virus Assembly
chemical_list: D036022:Capsid Proteins; D009097:Multienzyme Complexes; C044822:6,7-dimethyl-8-ribityllumazine synthase