L'invention concerne de nouvelles proteines homo-oligomeriques, resistant aux proteases et st... more L'invention concerne de nouvelles proteines homo-oligomeriques, resistant aux proteases et stables face aux denaturants, egalement appelees proteines stables (PS) et dont l'activite est semblable a celle des chaperons. Cette invention concerne egalement des procedes de fabrication et de purification des PS ; des acides nucleiques codant les PS ; des procedes d'isolation d'acides nucleiques codant les PS ; des anticorps reconnaissant les PS ; l'utilisation des PS pour stabiliser, replier, reparer, empecher l'agregation et la desagregation de macromolecules telles que les proteines ; des proteines de fusion comprenant des PS ; des constructions d'acide nucleique codant les proteines de fusion ; ainsi que leurs utilisations dans une variete de procedes et d'applications.
Polyacrylonitrile–phenolic composites display excellent in-plane properties but perform poorly wh... more Polyacrylonitrile–phenolic composites display excellent in-plane properties but perform poorly when out-of-plane, through-thickness properties are considered. Composite architectures with carbon nanotubes, either dispersed within the matrix or bound to a fabric, in traditional composites have the potential to alleviate this weakness. However, effective reinforcement of composites using carbon nanotubes is difficult, due to poor dispersion and interfacial stress transfer and has thus far been met with limited success and at high costs. This paper describes an innovative and cost-effective technology to improve these inferior mechanical properties by using an exceptionally stable protein, SP1, for CNT attachment to PAN fabric, forming a three-dimensional nano-reinforced structure. This work confirms remarkable improvements in interlaminar shear strength and through-thickness tensile strength of SP1/CNT-reinforced polyacrylonitrile composites.
Controlled formation of complex nanostructures is one of the main goals of nanoscience and nanote... more 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.
Carbon nanotubes (CNT) have stimulated research due to their wide range of applications. However,... more Carbon nanotubes (CNT) have stimulated research due to their wide range of applications. However, their existence as aggregates and the difficulty in debundling and dispersion limits the improvement of properties when used as fillers. Many techniques have been employed to obtain such dispersions including mechanical, ultrasonic, and solution mixing, resulting in limited effect. Attaching a protein moiety such as SP1
Stable protein 1 (SP1) is a homo-oligomeric protein isolated from aspen (Populus tremula aspen) p... more Stable protein 1 (SP1) is a homo-oligomeric protein isolated from aspen (Populus tremula aspen) plants which forms a ring-shape dodecameric particle with a central cavity. The oligomeric form of SP1 is an exceptionally stable structure that is resistant to proteases (e.g., trypsin, V8, and proteinase K), high temperatures, organic solvents, and high levels of ionic detergent. Analytical ultra-centrifugation, chemical cross-linking, matrix-assisted laser-desorption time-of-flight mass spectrometry (MALDI-TOF-MS), and transmission electron microscopy were used to further characterize the SP1 dodecamer. Introduction of a single cysteine at the N-terminus of SP1 enabled the formation of disulfide bridges within the SP1 dodecamer, concurrent with increased melting point. A six-histidine tag was introduced at the N-terminus of SP1 to generate 6HSP1, and the DeltaNSP1 mutant was generated by a deletion of amino acids 2-6 at the N-terminus. Both 6HSP1 and DeltaNSP1 maintained their ability to assemble a stable dodecamer. Remarkably, these SP1 homo-dodecamers were able to re-assemble into stable hetero-dodecamers following co-electro-elution from SDS-PAGE. The exceptional stability of the SP1-nano ring and its ability to self-assemble hetero-complexes paves the way to further research in utilizing this unique protein in nano-biotechnology.
L'invention concerne de nouvelles proteines homo-oligomeriques, resistant aux proteases et st... more L'invention concerne de nouvelles proteines homo-oligomeriques, resistant aux proteases et stables face aux denaturants, egalement appelees proteines stables (PS) et dont l'activite est semblable a celle des chaperons. Cette invention concerne egalement des procedes de fabrication et de purification des PS ; des acides nucleiques codant les PS ; des procedes d'isolation d'acides nucleiques codant les PS ; des anticorps reconnaissant les PS ; l'utilisation des PS pour stabiliser, replier, reparer, empecher l'agregation et la desagregation de macromolecules telles que les proteines ; des proteines de fusion comprenant des PS ; des constructions d'acide nucleique codant les proteines de fusion ; ainsi que leurs utilisations dans une variete de procedes et d'applications.
Polyacrylonitrile–phenolic composites display excellent in-plane properties but perform poorly wh... more Polyacrylonitrile–phenolic composites display excellent in-plane properties but perform poorly when out-of-plane, through-thickness properties are considered. Composite architectures with carbon nanotubes, either dispersed within the matrix or bound to a fabric, in traditional composites have the potential to alleviate this weakness. However, effective reinforcement of composites using carbon nanotubes is difficult, due to poor dispersion and interfacial stress transfer and has thus far been met with limited success and at high costs. This paper describes an innovative and cost-effective technology to improve these inferior mechanical properties by using an exceptionally stable protein, SP1, for CNT attachment to PAN fabric, forming a three-dimensional nano-reinforced structure. This work confirms remarkable improvements in interlaminar shear strength and through-thickness tensile strength of SP1/CNT-reinforced polyacrylonitrile composites.
Controlled formation of complex nanostructures is one of the main goals of nanoscience and nanote... more 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.
Carbon nanotubes (CNT) have stimulated research due to their wide range of applications. However,... more Carbon nanotubes (CNT) have stimulated research due to their wide range of applications. However, their existence as aggregates and the difficulty in debundling and dispersion limits the improvement of properties when used as fillers. Many techniques have been employed to obtain such dispersions including mechanical, ultrasonic, and solution mixing, resulting in limited effect. Attaching a protein moiety such as SP1
Stable protein 1 (SP1) is a homo-oligomeric protein isolated from aspen (Populus tremula aspen) p... more Stable protein 1 (SP1) is a homo-oligomeric protein isolated from aspen (Populus tremula aspen) plants which forms a ring-shape dodecameric particle with a central cavity. The oligomeric form of SP1 is an exceptionally stable structure that is resistant to proteases (e.g., trypsin, V8, and proteinase K), high temperatures, organic solvents, and high levels of ionic detergent. Analytical ultra-centrifugation, chemical cross-linking, matrix-assisted laser-desorption time-of-flight mass spectrometry (MALDI-TOF-MS), and transmission electron microscopy were used to further characterize the SP1 dodecamer. Introduction of a single cysteine at the N-terminus of SP1 enabled the formation of disulfide bridges within the SP1 dodecamer, concurrent with increased melting point. A six-histidine tag was introduced at the N-terminus of SP1 to generate 6HSP1, and the DeltaNSP1 mutant was generated by a deletion of amino acids 2-6 at the N-terminus. Both 6HSP1 and DeltaNSP1 maintained their ability to assemble a stable dodecamer. Remarkably, these SP1 homo-dodecamers were able to re-assemble into stable hetero-dodecamers following co-electro-elution from SDS-PAGE. The exceptional stability of the SP1-nano ring and its ability to self-assemble hetero-complexes paves the way to further research in utilizing this unique protein in nano-biotechnology.
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