A Self‐Assembled Protein Nanotube with High Aspect Ratio

Miranda, Frederico F.; Iwasaki, Katsunori; Akashi, Satoko; Sumitomo, Koji; Kobayashi, Mime; Yamashita, Ichiro; Tame, J.R.H.; Heddle, Jonathan G.

doi:10.1002/smll.200900667

Cited by 75 publications

(76 citation statements)

References 28 publications

(30 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…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".…”

Section: Introductionmentioning

confidence: 99%

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

et al. 2015

View full text Add to dashboard Cite

This study explores the use of block copolymer self-assembly to organize Lsmα, a protein which forms stable doughnut-shaped heptameric structures. Here, we have explored the idea that 2-D crystalline arrays of protein filaments can be prepared by stacking doughnut shaped Lsmα protein into the poly(ethylene oxide) blocks of a hexagonal microphase-separated polystyrene-b-polyethylene oxide (PS-b-PEO) block copolymer. We were able to demonstrate the coordinated assembly of such a complex hierarchical nanostructure. The key to success was the choice of solvent systems and protein functionalization that achieved sufficient compatibility whilst still promoting assembly. Unambiguous characterisation of these structures is difficult; however AFM and TEM measurements confirmed that the protein was sequestered into the PEO blocks. The use of a protein that assembles into stackable doughnuts offers the possibility of assembling nanoscale optical, magnetic and electronic structures. This study explores the use of block copolymer self-assembly to organize Lsmα, a protein which forms stable doughnut-shaped heptameric structures. Here, we have explored the idea that 2-D crystalline arrays of protein filaments can be prepared by stacking doughnut shaped Lsmα protein into the poly(ethylene oxide) blocks of a hexagonal microphase-separated polystyrene-b-polyethylene oxide (PSb-PEO) block copolymer. We were able to demonstrate the coordinated assembly of such a complex hierarchical nanostructure. The key to success was the choice of solvent systems and protein functionalization that achieved sufficient compatibility whilst still promoting assembly. Unambiguous characterisation of these structures is difficult; however AFM and TEM measurements confirmed that the protein was sequestered into the PEO blocks. The use of a protein that assembles into stackable doughnuts offers the possibility of assembling nanoscale optical, magnetic and electronic structures.

show abstract

Section: Introductionmentioning

confidence: 99%

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

et al. 2015

View full text Add to dashboard Cite

show abstract

“…To date TRAP has already alluded to its value in bionanotechnology, showing that mutations to residues protruding into the central cavity allow gold nanoparticle binding [11]. Nanotubes consisting of stacked TRAP rings linked by disulfide bonds have also been shown to self-assemble, in response to the introduction of cysteine residues on the ring-faces orthogonal to the principal axis [12].…”

Section: Introductionmentioning

confidence: 99%

Trp RNA-Binding Attenuation Protein: Modifying Symmetry and Stability of a Circular Oligomer

et al. 2012

View full text Add to dashboard Cite

BackgroundSubunit number is amongst the most important structural parameters that determine size, symmetry and geometry of a circular protein oligomer. The L-tryptophan biosynthesis regulator, TRAP, present in several Bacilli, is a good model system for investigating determinants of the oligomeric state. A short segment of C-terminal residues defines whether TRAP forms an 11-mer or 12-mer assembly. To understand which oligomeric state is more stable, we examine the stability of several wild type and mutant TRAP proteins.Methodology/Principal FindingsAmong the wild type B. stearothermophilus, B. halodurans and B. subtilis TRAP, we find that the former is the most stable whilst the latter is the least. Thermal stability of all TRAP is shown to increase with L-tryptophan concentration. We also find that mutant TRAP molecules that are truncated at the C-terminus - and hence induced to form 12-mers, distinct from their 11-mer wild type counterparts - have increased melting temperatures. We show that the same effect can be achieved by a point mutation S72N at a subunit interface, which leads to exclusion of C-terminal residues from the interface. Our findings are supported by dye-based scanning fluorimetry, CD spectroscopy, and by crystal structure and mass spectrometry analysis of the B. subtilis S72N TRAP.Conclusions/SignificanceWe conclude that the oligomeric state of a circular protein can be changed by introducing a point mutation at a subunit interface. Exclusion (or deletion) of the C-terminus from the subunit interface has a major impact on properties of TRAP oligomers, making them more stable, and we argue that the cause of these changes is the altered oligomeric state. The more stable TRAP oligomers could be used in potential applications of TRAP in bionanotechnology.

show abstract

“…However, this task is complicated by the fact that proteins are complex macromolecules that do not possess many canonical interaction motifs with which to program their organization. A number of strategies have been devised toward this end, including computational design of associative surfaces (8), the construction of chimeric protein assemblies with preprogrammed symmetries (9,10), and those that use specific ligand-protein interactions (11)(12)(13)(14), metal coordination (15)(16)(17), disulfide bonds (18)(19)(20), or a combination of these strategies (21,22) to connect protein building blocks. These approaches have produced supramolecular architectures with increasing structural sophistication or improved functions.…”

mentioning

confidence: 99%

Exceptionally stable, redox-active supramolecular protein assemblies with emergent properties

Brodin

Carr

Sontz

et al. 2014

Proc. Natl. Acad. Sci. U.S.A.

104

107

View full text Add to dashboard Cite

The designed assembly of proteins into well-defined supramolecular architectures not only tests our understanding of proteinprotein interactions, but it also provides an opportunity to tailor materials with new physical and chemical properties. Previously, we described that RIDC3, a designed variant of the monomeric electron transfer protein cytochrome cb 562 , could self-assemble through Zn 2+ coordination into uniform 1D nanotubes or 2D arrays with crystalline order. Here we show that these 1D and 2D RIDC3 assemblies display very high chemical stabilities owing to their metal-mediated frameworks, maintaining their structural order in ≥90% (vol/vol) of several polar organic solvents including tetrahydrofuran (THF) and isopropanol (iPrOH). In contrast, the unassembled RIDC3 monomers denature in ∼30% THF and 50% iPrOH, indicating that metal-mediated self-assembly also leads to considerable stabilization of the individual building blocks. The 1D and 2D RIDC3 assemblies are highly thermostable as well, remaining intact at up to ∼70°C and ∼90°C, respectively. The 1D nanotubes cleanly convert into the 2D arrays on heating above 70°C, a rare example of a thermal crystalline-to-crystalline conversion in a biomolecular assembly. Finally, we demonstrate that the Zn-directed RIDC3 assemblies can be used to spatiotemporally control the templated growth of small Pt 0 nanocrystals. This emergent function is enabled by and absolutely dependent on both the supramolecular assembly of RIDC3 molecules (to form a periodically organized structural template) and their innate redox activities (to direct Pt 2+ reduction).protein self-assembly | supramolecular coordination chemistry | nanomaterials | biomaterials | inorganic nanoparticles T he enormous structural and chemical diversity of proteins makes them highly attractive building blocks for functional materials. Supramolecular protein assemblies constitute the major components of cellular machinery, and many of them [e.g., 0D ferritin (1), 1D silicatein filaments (2, 3), 2D S-layers (4)] have also found a number of applications in nano-and biotechnology (2, 4, 5). Such protein assemblies are typically highly ordered, yet they possess dynamic structures that respond to external stimuli (6). Distinctively, protein assemblies are innately functional: the individual building blocks of these assemblies often perform specific chemical functions. For instance, the monomeric components of silicatein filaments or ferritin cages each have catalytic sites that process the precursors (SiO 2 or Fe 2+ ) for the downstream biomineralization processes (1, 3). On self-assembly, these individual components can be significantly stabilized (allowing them to withstand the extracellular environment and perform their functions) (7), and their chemical function takes on an entirely different context within the supramolecular architecture (acting as the template for biomineralization in the cases of silicatein and ferritin). Thus, they display emergent properties, both structurally and functionally.Such a...

show abstract

A Self‐Assembled Protein Nanotube with High Aspect Ratio

Cited by 75 publications

References 28 publications

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

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

Trp RNA-Binding Attenuation Protein: Modifying Symmetry and Stability of a Circular Oligomer

Exceptionally stable, redox-active supramolecular protein assemblies with emergent properties

Contact Info

Product

Resources

About