SP1 Protein-Based Nanostructures and Arrays

Abstract

Controlled formation of complex nanostructures is one of the main goals of nanoscience and nanotechnology. Stable Protein 1 (SP1) is a boiling-stable ring protein complex, 11 nm in diameter, which self-assembles from 12 identical monomers. SP1 can be utilized to form large ordered arrays; it can be easily modified by genetic engineering to produce various mutants; it is also capable of binding gold nanoparticles (GNPs) and thus forming protein-GNP chains made of alternating SP1s and GNPs. We report the formation and the protocols leading to the formation of those nanostructures and their characterization by transmission electron microscopy, atomic force microscopy, and electrostatic force microscopy. Further control over the GNP interdistances within the protein-GNP chains may lead to the formation of nanowires and structures that may be useful for nanoelectronics.

Constrained Synthesis and Organization of Catalytically Active Metal Nanoparticles by Self‐Assembled Protein Templates

“…By taking into account that the observed width depends on the preparation procedure for electron microscopy, that is, staining, drying, interaction with the TEM grid, and flattening on the grid, the observed distances are in agreement with the 4-5 nm width of the ring-like SP1 structure, and suggest stacking of protein rings mediated by residual his-tags and metal particles. Such a protein-particle chain formation has previously been observed with Ni-nitrilotriacetic acid (NTA)-functionalized Au nanoparticles and 6hisSP1, [7] whereas 6hisSP1 alone does not typically assemble into chain-like structures (see Supporting Information).…”

“…Protein Expression and Purification: 6hisSP1 was expressed in e.coli bacteria strain BL21 and purified as described previously [7].…”

“…[6] We have genetically fused a histidine tag to the N-terminus of SP1 (6hisSP1), thus obtaining a variant with 72 additional His residues facing the inner-pore of the ring structure. [7] Histidine is a typical metal-binding site in proteins due to the presence of the deprotonated N3 atom in the imidazole ring, analogous to the N7 atom of guanine or adenine. [8,9] When the 6hisSP1 mutant was treated with Na 2 PdCl 4 (typically 720 Pd atoms per dodecamer) for 2 h at room temperature, a homogenous pale-yellow solution resulted.…”

Protein nanorings organized by poly(styrene-block-ethylene oxide) self-assembled thin films

“…Previous work on creating protein assemblies has been largely centered around amyloid fibers [25][26][27][28][29] but has recently also involved native protein structures [30][31][32] with ring shaped proteins emerging as a commonly used self-assembling feature. [33][34][35][36][37] Recent work has established methods to post functionalize assembled structures, 38,39 an important step towards applications based on protein nanostructures. There is intense interest in "one-dimensional nanostructures".…”

Heat transport and thermal rectification in molecular junctions: A minimal model approach

“…1,2 In particular, the development of nanoscale electronics over the past years and the possibility to design hybrid devices, where biomolecules also could be integrated, 3,4 represent a strong motivation to investigate not only the mechanisms of heat flow in low dimensions as well as in biosystems, but also possible ways to control it. [5][6][7][8][9] Due to the structural complexity of such systems, the study of heat transport on a first-principle level becomes difficult, and thus, the development of minimal model approaches provides a very useful starting point.…”