Virus Materials
“More recently, biomaterials (such as bionanoparticles) have been explored as building blocks for nanomaterial development. Bionanoparticles, including, but not limited to, virus and viral like particles, ferritins, and other self-assembled protein cages, are highly ordered nano-scale biological structures generated by nature. For example, viruses are generally composed of genetic material contained within a protective protein shell, sometimes referred to as the capsid. A capsid is composed of proteins encoded by the viral genome and its shape serves as the basis for morphological distinction.”
“Many viruses can be classified according to their structure as either a rod-like virus or an icosahedral virus. Rod-like viruses appear 1-dimensional on the nanometer scale, but are actually tubular in shape, usually with a hollow center. Most rod-like viruses have helical capsids composed of a single type of protomer stacked around a central circumference to form an enclosed tube resembling a spiral staircase. This arrangement results in rod-shaped virions which can be short and rigid, or long and flexible. Long helical particles must be flexible in order to prevent forces snapping the structure. The genetic material is housed and protected in the inside of the tube. Overall, the length of a helical capsid is related to the length of the nucleic acid contained within it, while the diameter is dependent on the overall length and arrangement of protomer”
“One example of a well known rod-like virus is the tobacco mosaic virus (TMV). Each viral particle of TMV has 2130 identical protein subunits arranged in a helical motif around a single stand of RNA to produce a hollow protein tube. The internal and external surfaces of the protein have repeated patterns of charged amino acid residues, such as glutamate, aspartate, arginine, and lysine. The rod-like TMV is about 300 nm long and about 18 nm in diameter. When the RNA and the coat protein of the virus are taken apart, the protein molecules aggregate into a 20S structure under physiological conditions.”
“TMV is a remarkably stable virion, remaining intact at temperatures up to 60.degree. C. and at pH values between 2 and 10. The known structures of TMV, as well as the ability to reverse engineer this virus, make it a particularly versatile biotemplate for the production of nanocomposites. The highly polar exterior surface of TMV can be used for surface binding and in situ reduction of iron oxyhydroxides, CdS, PbS, gold, nickel, cobalt, silver, iron oxides and silica. Furthermore, genetically modified TMV can improve the metal binding properties.”
Recent US Patents
10/26/2010
US Patent 7,820,426
Bionanomaterials and their synthesis
Wang and Zhongwei of University of South Carolina, South Carolina, used biomaterials, such as viruses and virus-like particles, to form nanostructures. Rod-like viruses are used to form composite nanofibers that are fixed together in a head-to-tail assembly by a polymer. 2-dimensional nanostructures formed from crosslinked viruses assembled in a single, film-like layer. Porous gels having controllable pore size through the use of virus particles were formed. (RDC 3/25/2011)