Peptide-equipped tobacco mosaic virus templates for selective and controllable biomineral deposition

Abstract

SummaryThe coating of regular-shaped, readily available nanorod biotemplates with inorganic compounds has attracted increasing interest during recent years. The goal is an effective, bioinspired fabrication of fiber-reinforced composites and robust, miniaturized technical devices. Major challenges in the synthesis of applicable mineralized nanorods lie in selectivity and adjustability of the inorganic material deposited on the biological, rod-shaped backbones, with respect to thickness and surface profile of the resulting coating, as well as the avoidance of aggregation into extended superstructures. Nanotubular tobacco mosaic virus (TMV) templates have proved particularly suitable towards this goal: Their multivalent protein coating can be modified by high-surface-density conjugation of peptides, inducing and governing silica deposition from precursor solutions in vitro. In this study, TMV has been equipped with mineralization-directing peptides designed to yield silica coatings in a reliable and predictable manner via precipitation from tetraethoxysilane (TEOS) precursors. Three peptide groups were compared regarding their influence on silica polymerization: (i) two peptide variants with alternating basic and acidic residues, i.e. lysine–aspartic acid (KD)x motifs expected to act as charge-relay systems promoting TEOS hydrolysis and silica polymerization; (ii) a tetrahistidine-exposing polypeptide (CA4H4) known to induce silicification due to the positive charge of its clustered imidazole side chains; and (iii) two peptides with high ZnO binding affinity. Differential effects on the mineralization of the TMV surface were demonstrated, where a (KD)x charge-relay peptide (designed in this study) led to the most reproducible and selective silica deposition. A homogenous coating of the biotemplate and tight control of shell thickness were achieved.

Dual Functionalized Bacteriophage Qβ as a Photocaged Drug Carrier

“…Though transmission electron microscopy (TEM) micrographs show that both Qβ(1K)‐Dox and Qβ(2K)‐Dox continue to aggregate (Figure S8–S10, Supporting Information) when drop cast and dried onto a grid, they are more solution stable than Qβ‐Dox as shown by Zeta potential (Figure S4, Supporting Information) and dynamic light scattering (DLS) measurements (Figure S18–S20, Supporting Information) . The difference in aggregation behavior was further illustrated during confocal microscopy (Figure S22–S25, Supporting Information), which show significant fluorescent aggregates in the Qβ‐Dox experiments and yet little to no aggregates in the Qβ(MPEG)‐Dox studies.…”

Tobacco Mosaic Virus as a Versatile Platform for Molecular Assembly and Device Fabrication

“…A lysine inserted at the N‐terminus or C‐terminus similarly allows for bioconjugation to the exterior of TMV through a reaction with an N‐hydroxysuccinimide (NHS)‐ester‐labeled target. This enabled surface display of biotin or maleimide for the attachment of avidin‐/streptavidin‐linked immunogenic peptides and whole proteins such as GFP or cysteine‐containing peptides improving silica surface deposition …”

“…This enabled surface display of biotin or maleimide for the attachment of avidin-/streptavidin-linked immunogenic peptides and whole proteins such as GFP [10] or cysteine-containing peptides improving silica surface deposition. [30]…”

“…Fluorescent dye (Cy5 [20] ), PEG, [30] peptides [30] N-terminus proximal cysteine (S3C or S1_Y2insC)…”

Nanoscale device architectures derived from biological assemblies: The case of tobacco mosaic virus and (apo)ferritin

“…We recently published an advanced deposition method for SiO 2 that makes use of specific mineralizationdirecting peptides. 114) The peptides either contain varying numbers of histidines or alternating positively and negatively charged amino acids; the precursor is again Si(OC 2 H 5 ) 4 [Eq. (1a)].…”