title: Self-assembly and modular functionalization of three-dimensional crystals from oppositely charged proteins.
abstract: Multicomponent crystals and nanoparticle superlattices are a powerful approach to integrate different materials into ordered nanostructures. Well-developed, especially DNA-based, methods for their preparation exist, yet most techniques concentrate on molecular and synthetic nanoparticle systems in non-biocompatible environment. Here we describe the self-assembly and characterization of binary solids that consist of crystalline arrays of native biomacromolecules. We electrostatically assembled cowpea chlorotic mottle virus particles and avidin proteins into heterogeneous crystals, where the virus particles adopt a non-close-packed body-centred cubic arrangement held together by avidin. Importantly, the whole preparation process takes place at room temperature in a mild aqueous medium allowing the processing of delicate biological building blocks into ordered structures with lattice constants in the nanometre range. Furthermore, the use of avidin-biotin interaction allows highly selective pre- or post-functionalization of the protein crystals in a modular way with different types of functional units, such as fluorescent dyes, enzymes and plasmonic nanoparticles.
authors.affiliation: 1] Biohybrid Materials Group, Department of Biotechnology and Chemical Technology, Aalto University, 00076 Aalto, Finland [2] Molecular Materials Group, Department of Applied Physics, Aalto University, 00076 Aalto, Finland.
authors.forename: Ville
authors.initials: V
authors.lastname: Liljeström
authors.affiliation: 1] Biohybrid Materials Group, Department of Biotechnology and Chemical Technology, Aalto University, 00076 Aalto, Finland [2] Molecular Materials Group, Department of Applied Physics, Aalto University, 00076 Aalto, Finland.
authors.forename: Joona
authors.initials: J
authors.lastname: Mikkilä
authors.affiliation: Biohybrid Materials Group, Department of Biotechnology and Chemical Technology, Aalto University, 00076 Aalto, Finland.
authors.forename: Mauri A
authors.initials: MA
authors.lastname: Kostiainen
mesh_terms: D001360:Avidin / Q000737:chemistry; D001710:Biotin / Q000737:chemistry; D017795:Bromovirus / Q000737:chemistry* / Q000648:ultrastructure; D003460:Crystallization / Q000379:methods; D050091:Dendrimers / Q000737:chemistry; D005456:Fluorescent Dyes / Q000737:chemistry; D006046:Gold / Q000737:chemistry; D046529:Microscopy, Electron, Transmission; D049329:Nanostructures / Q000737:chemistry*; D011506:Proteins / Q000737:chemistry*; D053838:Scattering, Small Angle; D013056:Spectrophotometry, Ultraviolet; D055672:Static Electricity
chemical_list: D050091:Dendrimers; D005456:Fluorescent Dyes; D011506:Proteins; D001360:Avidin; D001710:Biotin; D006046:Gold