S-layer-streptavidin fusion proteins as template for nanopatterned molecular arrays

Abstract

Biomolecular self-assembly can be used as a powerful tool for nanoscale engineering. In this paper, we describe the development of building blocks for nanobiotechnology, which are based on the fusion of streptavidin to a crystalline bacterial cell surface layer (S-layer) protein with the inherent ability to self-assemble into a monomolecular protein lattice. The fusion proteins and streptavidin were produced independently in Escherichia coli, isolated, and mixed to refold and purify heterotetramers of 1:3 stoichiometry. Self-assembled chimeric S-layers could be formed in suspension, on liposomes, on silicon wafers, and on accessory cell wall polymer containing cell wall fragments. The two-dimensional protein crystals displayed streptavidin in defined repetitive spacing, and they were capable of binding D-biotin and biotinylated proteins. Therefore, the chimeric S-layer can be used as a self-assembling nanopatterned molecular affinity matrix to arrange biotinylated compounds on a surface. In addition, it has application potential as a functional coat of liposomes.

Assembly and molecular order of two-dimensional peptoid nanosheets through the oil–water interface

“…For experiments using hexane as the oil phase, 500 μL of aqueous nanosheet-forming solution (20 μM peptoid, 10 mM Tris, pH 8.0 buffer in Milli-Q water) was prepared from the 2-mM peptoid stock solution in the 4-mL glass vial, followed by gentle addition of hexane (4.2 mL) on top of the aqueous layer. For CCl 4 as the oil phase, 3 mL CCl 4 was added to a clean 4-mL glass vial, followed by gentle addition of ∼1.7 mL aqueous nanosheet-forming solution to completely fill the vial. All vials were tightly capped and slowly inverted to confirm the absence of any air bubbles.…”

“…Specifically, organic 2D nanomaterials hold promise as biocompatible materials that can be chemically tailored and built from the bottom up, through the self-assembly of small molecule, protein, or polymer building blocks (2)(3)(4)(5). Polymer-based 2D nanomaterials, in particular, hold promise as templates for bottom-up assembly of circuits, semiconductors, and organicinorganic composite materials (6)(7)(8) as well as high surface area membranes for filtration, catalysis, and sensing (9,10).…”

Immunoabsorbent nanoparticles based on a tobamovirus displaying protein A

“…Several potential biotechnological solutions have been described in the literature that propose fusing protein A (or other affinity ligands) to elements capable of polymerizing (bacteriophage capsid proteins [26][27][28]) or binding to structures of high molecular weight (bacterial S-layer proteins [29,30], oleosins recognizing oil bodies [31,32], cellulose-binding domains [33,34], starch-binding domains [35]). So far, only the process based on oleosin fusions (to protein A) has been advanced to the stage of a commercially viable platform (www.sembiosys.com).…”

Hierarchical Self‐Assembly of One‐Dimensional Streptavidin Bundles as a Collagen Mimetic for the Biomineralization of Calcite

“…[1][2][3][4][5][6] In parallel to these developments, surfaces and cavities spanned by protein higher-order aggregates have been exploited for molecular encapsulation and for templating nanoparticle synthesis. Typical examples include protein fibrils, [7,8] ferritin, [9,10] S-layers, [11][12][13] antibodies, [14] peptide amphiphiles, [15] capsids, [16][17][18][19] leucine zippers, [20] etc. [21][22][23][24][25][26] Controlled protein aggregation is a critical process in many areas, ranging from biomineralization [27] to neurodegenerative diseases.…”