title: Novel roles for well-known players: from tobacco mosaic virus pests to enzymatically active assemblies.
abstract: The rod-shaped nanoparticles of the widespread plant pathogen tobacco mosaic virus (TMV) have been a matter of intense debates and cutting-edge research for more than a hundred years. During the late 19th century, their behavior in filtration tests applied to the agent causing the 'plant mosaic disease' eventually led to the discrimination of viruses from bacteria. Thereafter, they promoted the development of biophysical cornerstone techniques such as electron microscopy and ultracentrifugation. Since the 1950s, the robust, helically arranged nucleoprotein complexes consisting of a single RNA and more than 2100 identical coat protein subunits have enabled molecular studies which have pioneered the understanding of viral replication and self-assembly, and elucidated major aspects of virus-host interplay, which can lead to agronomically relevant diseases. However, during the last decades, TMV has acquired a new reputation as a well-defined high-yield nanotemplate with multivalent protein surfaces, allowing for an ordered high-density presentation of multiple active molecules or synthetic compounds. Amino acid side chains exposed on the viral coat may be tailored genetically or biochemically to meet the demands for selective conjugation reactions, or to directly engineer novel functionality on TMV-derived nanosticks. The natural TMV size (length: 300 nm) in combination with functional ligands such as peptides, enzymes, dyes, drugs or inorganic materials is advantageous for applications ranging from biomedical imaging and therapy approaches over surface enlargement of battery electrodes to the immobilization of enzymes. TMV building blocks are also amenable to external control of in vitro assembly and re-organization into technically expedient new shapes or arrays, which bears a unique potential for the development of 'smart' functional 3D structures. Among those, materials designed for enzyme-based biodetection layouts, which are routinely applied, e.g., for monitoring blood sugar concentrations, might profit particularly from the presence of TMV rods: Their surfaces were recently shown to stabilize enzymatic activities upon repeated consecutive uses and over several weeks. This review gives the reader a ride through strikingly diverse achievements obtained with TMV-based particles, compares them to the progress with related viruses, and focuses on latest results revealing special advantages for enzyme-based biosensing formats, which might be of high interest for diagnostics employing 'systems-on-a-chip'.
authors.affiliation: Institute of Biomaterials and Biomolecular Systems, Department of Molecular Biology and Plant Virology, University of Stuttgart, Pfaffenwaldring 57, Stuttgart, D-70550, Germany.
authors.forename: Claudia
authors.initials: C
authors.lastname: Koch
authors.affiliation: Institute of Biomaterials and Biomolecular Systems, Department of Molecular Biology and Plant Virology, University of Stuttgart, Pfaffenwaldring 57, Stuttgart, D-70550, Germany.
authors.forename: Fabian J
authors.initials: FJ
authors.lastname: Eber
authors.affiliation: Institute of Functional Interfaces (IFG), Chemistry of Oxidic and Organic Interfaces, Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, Eggenstein-Leopoldshafen, Karlsruhe, D-76344, Germany.
authors.forename: Carlos
authors.initials: C
authors.lastname: Azucena
authors.affiliation: Institute of Nanotechnology (INT) and Karlsruhe Institute of Applied Physics (IAP) and Center for Functional Nanostructures (CFN), Karlsruhe Institute of Technology (KIT), INT: Hermann-von-Helmholtz-Platz 1, Eggenstein-Leopoldshafen, D-76344, Germany, and IAP/CFN: Wolfgang-Gaede-Straße 1, Karlsruhe, D-76131 Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Förste
authors.affiliation: Institute of Nanotechnology (INT) and Karlsruhe Institute of Applied Physics (IAP) and Center for Functional Nanostructures (CFN), Karlsruhe Institute of Technology (KIT), INT: Hermann-von-Helmholtz-Platz 1, Eggenstein-Leopoldshafen, D-76344, Germany, and IAP/CFN: Wolfgang-Gaede-Straße 1, Karlsruhe, D-76131 Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Walheim
authors.affiliation: Institute of Nanotechnology (INT) and Karlsruhe Institute of Applied Physics (IAP) and Center for Functional Nanostructures (CFN), Karlsruhe Institute of Technology (KIT), INT: Hermann-von-Helmholtz-Platz 1, Eggenstein-Leopoldshafen, D-76344, Germany, and IAP/CFN: Wolfgang-Gaede-Straße 1, Karlsruhe, D-76131 Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Schimmel
authors.affiliation: CIC Nanogune, Tolosa Hiribidea 76, E-20018 Donostia-San Sebastián, Spain, and Ikerbasque, Maria Díaz de Haro 3, E-48013 Bilbao, Spain.
authors.forename: Alexander M
authors.initials: AM
authors.lastname: Bittner
authors.affiliation: Institute of Biomaterials and Biomolecular Systems, Department of Molecular Biology and Plant Virology, University of Stuttgart, Pfaffenwaldring 57, Stuttgart, D-70550, Germany.
authors.forename: Holger
authors.initials: H
authors.lastname: Jeske
authors.affiliation: Institute of Functional Interfaces (IFG), Chemistry of Oxidic and Organic Interfaces, Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, Eggenstein-Leopoldshafen, Karlsruhe, D-76344, Germany.
authors.forename: Hartmut
authors.initials: H
authors.lastname: Gliemann
authors.affiliation: Institute of Biomaterials and Biomolecular Systems, Department of Molecular Biology and Plant Virology, University of Stuttgart, Pfaffenwaldring 57, Stuttgart, D-70550, Germany.
authors.forename: Sabine
authors.initials: S
authors.lastname: Eiben
authors.affiliation: Institute of Biomaterials and Biomolecular Systems, Department of Molecular Biology and Plant Virology, University of Stuttgart, Pfaffenwaldring 57, Stuttgart, D-70550, Germany.
authors.forename: Fania C
authors.initials: FC
authors.lastname: Geiger
authors.affiliation: Institute of Biomaterials and Biomolecular Systems, Department of Molecular Biology and Plant Virology, University of Stuttgart, Pfaffenwaldring 57, Stuttgart, D-70550, Germany.
authors.forename: Christina
authors.initials: C
authors.lastname: Wege
keywords: biotemplate; enzyme biosensor; nanotechnology; tobacco mosaic virus; virus-like particles