Bioengineered Flagella Protein Nanotubes with Cysteine Loops:  Self-Assembly and Manipulation in an Optical Trap

Abstract

An E. coli flagellin protein, termed FliTrx, was investigated for use as a novel form of self-assembling protein nanotube. This protein was genetically engineered to display constrained peptide loops with a series of different thiol, cationic, anionic, and imidazole functional groups. "Cys-loop" thiol variants consisting of 6 and 12 cysteine residues were isolated in the form of disulfide-linked nanotube bundles, a novel nanomaterial. Bundles were characterized by fluorescence microscopy, transmission electron microscopy, and optical trapping.

Generation and Characterization of Inorganic and Organic Nanotubes on Bioengineered Flagella of Mesophilic Bacteria

“…122 123 Three of the FliTrx loop peptide variants used in this study were previously described. 122 To summarize, molecular biology procedures involved insertion of double-stranded synthetic oligonucleotide cassettes (i.e., "cassette mutagenesis") encoding desired peptides at a unique RsrII restriction site in a modified version of the pFliTrx plasmid. These procedures yielded modified FliTrx flagellin proteins that displayed peptide loops composed of one or more repeats of rationally designed peptide sequences on their outer surface.…”

A Deletion Variant Study of the Functional Role of the Salmonella Flagellin Hypervariable Domain Region in Motility

“…Structural information about functional deletion variants may be useful in developing rational design approaches for the insertion and display of fusion peptides and proteins on flagella fibers, which have potential applications as a bionanotube. 43 Here, we present the results of experimental and theoretical structure-function studies of the effects of internal deletions in the hypervariable region of S. typhimurium flagellin.…”

In vitro self-assembly of tailorable nanotubes from a simple protein building block

“…The bulk of research in this area makes use of naturally occurring protein scaffolds such as viral capsids (1-7), amyloid protein (8), actin (9), tubulin (10), pili (11), and flagella (12)(13)(14)(15). Two studies-the engineering of tobacco mosaic virus to form an artificial light harvesting apparatus (7) and the use of a self-assembling amyloid protein fiber from Saccharomyces cerevisiae to template the synthesis of conducting nanowires (8)-demonstrate the diversity of applications for which these systems have been adapted.…”