Construction Of Intelligent Supramolecular Structure Based On Fusion Protein

As an emerging field of supramolecular chemistry research in protein functions as building and research to build a primitive biological supramolecular structure has attracted the attention of scientists and research enthusiasm. As a class of protein macromolecular compound having a complicated higher-order structure, it plays a vital role in constituting the living tissue structure, catalytic materials and energy metabolism, leading immune processes. Analysis, simulation work on the structure of the native protein complex formed is extremely, enabling mankind from a more micro-level to understand the origin of life and formation, and the creation of more advanced technology to benefit human. With the vigorous development of protein crystallography, computer chemistry and other disciplines, resent years, researchers have been able to take advantage of a variety of natural proteins, modified proteins or even synthetic proteins as artificial building blocks to build a wide variety of unique supramolecular structure nanostructures. These light-trapping design, efficient artificial enzyme, the reaction of nano devices, controlled drug release and other fields have potential applications.Most existing protein assembly work is still focused on building a static structure, dynamic assemblies like the function and simulation of natural biological tissue structure reported less. Our research of this paper attempts to construct by combining computational chemistry and genetic engineering techniques, in response to environmental stimuli will have a series of functional domains of proteins as the introduction of new recombinant protein assembled into primitives, and through the design of different supramolecular self-assembly driving force formed nanoscale composite structure. Then we assembled structures were designed nanoscale characterization techniques, we have proved consistent with the composite assembly of structural design and experimental study of the regulation, determine the structure obtained in the assembly and design consistent expectations stimuli-responsive features.1. TMV-G7-SP1 fusion protein construct p H-responsive supramolecular nanocapsulesThe fusion protein construct a three-dimensional structure of the reports has been widespread concern in the field of protein assembly. Compared to static three-dimensional cage-like structure constructed to respond to environmental changes happening at work dynamic protein nanostructures supramolecular chemistry similar vesicle assembly and disassembly effects rarely reported. Therefore, we use recombinant protein technology, two kinds of different oligomeric protein assembly mechanism tobacco mosaic virus coat protein(TMV) and heat-stable protein SP1 fusion. Then, through the design of a flexible linker added some assembling structure TMV structural units have a good free space. Through different p H values to characterize the morphology of the assembly, we confirmed that the fusion protein under acidic conditions(p H = 5.5) assembled into closed nano-capsule structure, under alkaline conditions(p H = 7.5) to open the assembly type hollow nano-disk structure. Rhodamine B by regulating assembly environment p H value coated release experiment proved that this protein nanostructures with dynamic package of small molecules and controlled release function, is an excellent smart drug carriers.2. FGG-Recoverin-GST fusion protein construct Ca2 + response Supramolecular Nano springBy chemical synthesis molecules or thermal stable DNA, the researchers successfully constructed supramolecular structure having a spring sports properties. Use of protein as building artificial nano-spring body has not yet been reported. Therefore, we have designed a protein to restore the Ca2 + response as a fusion protein Recoverin allosteric core, fused at its N- terminus to identify CB [8] is formed 2: 1-phenylpropyl composite structure- Gly- Gly- tripeptide(the FGG) At the same time the opposite of its C- and N- terminal position terminal fusion dimeric protein glutathione S-transferase(GST), along with the formation of a stimulus response, host-guest recognition and binding protein dimer compound effect of recombinant proteins. The small protein molecule cucurbit [8] under the urea(the CB [8]) involvement, can form a tight Nanostructure linear structure. Spectrum by dynamic light scattering, electron microscopy, atomic force series of experiments confirmed the structural protein assembly in the presence, without the presence of Ca2 +, the length are formed, the flexible linear structure different nanometer. Through these experiments to characterize the different states of two kinds of nanowires conducted a detailed analysis, and confirmed that the regulation of ion response is stable and reversible. Through the analysis of experimental data, the protein nanowires dimensional changes in both forms of up to 50% is a sensitive response to the protein supramolecular nano-springs.3. AK-GST-143 FGG fusion protein construct ATP response twist-stretch allosteric nano-wiresAfter the successful design was to generate movement in the one-dimensional nanostructures axis, we try to build on a two-dimensional plane can be dynamically changed regularly protein assembly. Many researchers have already tried to use protein to build ring nanostructure morphology need to get this type of assembly follow in the process of forming an additional driving force and assembly angled unidirectional force, thus forming more difficult. Here we work through the introduction of a "V" shaped opening and closing movement of the ATP allosteric protein kinase(AK) as an allosteric center, still using the host-guest recognition and protein dimerization two kinds of forces as the driving force to build the formation of nanostructures protein assembly. Through the simulation of structural analysis, we find in the kinase ATP allosteric outside surface of a suitable location, the presence of hydrogen bonding interactions willing to be at the time of its proximity with the adjacent surface, thereby fixing the relative position between the proteins. We find a suitable site mutations in this position, and using a modified method has been successfully connected to the synthetic tripeptide GFF design position. The experimental results indicate that we have designed the modified fusion protein in CB [8] exist conditions capable of forming cyclic supramolecular structure, after the addition of specific substrates ATP, the cyclic structure can be opened and allosteric is linear assembly structure. Regulation by preliminary experiments, we have confirmed the ring- line morphological changes have a certain reversible. We collaborative genetic engineering, chemical modification, and a series of supramolecular assembly means, successfully prepared a two-dimensional plane can be in response to specific signals generated Superior structural changes Intelligent protein assembly.