Self-assembly in biology

For examples of self-assembly in biological systems, see (a) Branden, C. Tooze, J. Introduction to Protein Structure Garland New York, 1991 (b) Fersht, A. Enzyme Structure arui Mechanism, 2nd ed. Freeman New York, 1985. See also ref. Ic. 

In summary, it is obvious that the attachment of dendron building blocks to common monomers leads to dramatic kinetic and structural consequences. Once more, it should be kept in mind that it is only the shape of the side groups attached that governs the conformation and structure of the resulting polymer chains, not hydrogen-bonding interactions, which are ubiquitous in self-assembly in biological processes. 

Proteins, Chemistry and Chemical Reactivity of Proteins, Structure, Function and Stabihty Self-Organization and Self-Assembly in Biology ... 

Start thinking about biological materials as soft matter and the importance of molecular self-assembly in biology. 

There are two levels of self-assembly in the formation of tetra-, penta-and hexa-nuclear products from the poly-bipyridyls (L) 20 and 21 and iron(II) salts FeCl2, FeBr2 or FeS04 - the products are anion-dependent. The coordination of three bpy units, from different ligand molecules, to the Fe2+ centers produces a helical structure interaction of these helical strands with anions results in further molecular organization to form the final toroidal product. The discussion draws parallels between the helical and toroidal structures here and secondary and tertiary structure in biological systems (482). Thermodynamic and kinetic intermediates have been characterized in the self-assembly of a di-iron triple stranded helicate with bis(2,2/-bipyridyl) ligands (483). 

Protein is an excellent natural nanomaterial for molecular machines. Protein-based molecular machines, often driven by an energy source such as ATP, are abundant in biology. Surfactant peptide molecules undergo self-assembly in solution to form a variety of supermolecular structures at the nanoscale such as micelles, vesicles, unilamellar membranes, and tubules (Maslov and Sneppen, 2002). These assemblies can be engineered to perform a broad spectrum of functions, including delivery systems for therapeutics and templates for nanoscale wires in the case of tubules, and to create and manipulate different structures from the same peptide for many different nanomaterials and nanoengineering applications. 

Lindsey JS. Self-assembly in synthetic routes to molecular devices—biological principles and chemical perspectives—a review. New J Chem 1991 15 153-180. 

Berti, D. (2006). Self assembly of biologically inspired amphiphiles. Current Opinion in Colloid and Interface Science, 11, 74-78. 

Finally, a discussion of surfactant self-assembly will not be complete without a mention of surfactant assemblies in biological systems. Although they are outside the scope of our book, we have already drawn attention to such biological applications of colloid science in Chapters 1 and 7 and above in this chapter. Some additional discussion is provided in the last section of this chapter (Section 8.11). 

Lindsey, J. S., Self-Assembly in synthetic routes to molecular devices biological principles and chemical perspectives - a review , New J. Chem. 1991,15, 153-180. 

Model systems have been developed for many of these ion-transport mechanisms in the context of bioorganic chemistry. Examples are the cyclic peptides, described by M. R. Ghadiri et al., that have antibiotic activity similar to that of ionophores, a property that is most probably caused by the ability of these peptides to self-assemble inside biological membranes into channels [1], Other compounds able to induce the formation of membrane pores are the bouquet-molecules introduced by J.-M. Lehn [2]. Artificial / -barrels have been developed by S. Matile s group [3]. Many host molecules used in bioorganic chemistry can serve as carriers for ions across membranes and have even made possible the development of systems with which active ion transport can be achieved [4]. 

Molecular Recognition and Chemistry in Restricted Reaction Spaces. Photophysics and Photoinduced Electron Transfer on the Surfaces of Micelles, Dendrimers and DNA [N. J. Turro, J. K. Barton, D. A. Tomalia, Acc. Chem. Res. 1991, 24, 332], Self-Assembly in Synthetic Routes to Molecular Devices. Biological Principles and Chemical Perspectives A Review [J. S. Lindsey, New J. Chem. 1991,15, 153], Amorphous molecular materials synthesis and properties of a novel starburst molecule, 4,4, 4 -tri(N-phenothiazinyl)triphenylamine [A. Higuchi, H. Inada, T. Kobata, Y. Shirota, Adv. Mat. (Weinheim, Ger.) 1991, 3(11), 549-550],... 

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