Proteins molecular self-assembly

In Nature, there are many examples of protein and peptide molecular self-assembly. Of the genetically engineered fibrous proteins, collagen, spider silks, and elastin have received attention due to their mechanical and biological properties which can be used for biomaterials and tissue engineering. 

In this study, we report a very effective and widely applicable method for fabricating of nanostructures of an inert material for the biomolecular nanoarrays. The stable nanostructures of the PEG and PVA hydrogels were directly fabricated on gold substrates by UV-NIL (Fig. la). The site-selective nanoarray of various biomolecules such as protein and tethered lipid bilayer raft membrane (tLBRM) was constructed from a nanoimprinted inert materials by stepwise molecular self-assembly (Fig. lb and Ic). 

Site-specific affinity binding of proteins to self-assembled molecular architectures... 

There are a large number of methods (Table 2) to prepare nanoparticulate systems. These depend to a large extent on the material (polymer, protein, metal, ceramic) that will form the basis of the carrier. One can, in essence, consider three approaches to their production (0 by comminution (in the case of solids, milling, and in the case of liquids, high pressure emulsification) (ii) molecular self-assembly, such as that occurs with polymeric surfactants to form polymeric micelles or with dendrons to form dendrimeric aggregates and (iii) precipitation from a good solvent as shown in Figure 6. 

Hydrophobic attraction is also very important in understanding molecular self-assembly, micelle-formation, biological membrane structure and protein conformations, which will be discussed in Chapters 5, 7, 9 and 10. 

Electron transport systems perform important functions concerning respiration and energy metabolism in eucaryotes [22, 23], The electron transport reactions occur at the mitochondria inner membrane formed by electron transport proteins [24] and the lipid bilayer built up by the self-assembly of phospholipids as vital smfactants [25, 26]. The electron transport proteins include redox catalysts such as nicotinamide, iron [27, 28], and quinones [29]. The electrons produced by these redox reactions transfer through the lipid bilayer. While the relationship between the electron transport mechanisms and the molecular self-assembly in vivo has been clarified, control of the self-assembly by electron transport has been applied for an artificial polymeric surfactant. 

Ben-Naim, A. 2011. Molecular Theory of Water and Aqueous Solutions. Part 2 The Role of Water in Protein Folding, Self-Assembly and Molecular Recognition. Singapore World Scientific Pubhshing Co. 

In this exercise, you will react a thiol (R-SH) with a gold surface to form a self-assembled monolayer (SAM) of thiol molecules on the gold. The thickness of this layer is about 2 nm (nanometer). A molecular system like this with dimensions at the nanometer level is an example of nanotechnology. Molecular self-assembly is also the key mechanism used in nature for the creation of complex structures such as the DNA double helix, proteins, enzymes, and the lipid bilayer of cell walls. 

Thickness. The thickness of polymersome bilayers is several times greater than that of typical phospholipid bilayers in natural membranes. Lipid bilayers have a hydrophobic core thickness that is in a very narrow range of rf 3-4 nm to be compatible with integral membrane proteins. For self-assembled bilayers of PEE-PEO vesicles, the hydrophobic core thickness increases with increasing molecular weight from d 8-21 nm (see Fig. 18) to more than 100 nm (53,151-153). The observed d scaling is t5q)ical for random coil polymers and agrees... 

Popular approaches to molecular self-assembly, which can give structures in the nanometer to millimeter range, are based on SAMs and LBL deposition of electrolytes. Self-assembly leads to equilibrium structures that are close to the thermodynamic minimum and result from multiple weak, reversible interactious betweeu subuuits which include hydrogen bonds, ionic bonds, and van der Waals forces. As information is already coded in the building blocks, this is a means to avoid defect formation in aggregate formation. SAMs are molecular assemblies of long chain alkanes that chemisorb on the patterned and unpat-temed surfaces of appropriate solid materials. The structures of SAMs, effectively 2D-crystals with controllable chemical functionality, make them a means to modify substrates to direct protein adsorption and cell attachment, surface passivation, ultrathin resists and masks and sensor development. 

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