Dendrimer globular

The field of synthetic enzyme models encompasses attempts to prepare enzymelike functional macromolecules by chemical synthesis [30]. One particularly relevant approach to such enzyme mimics concerns dendrimers, which are treelike synthetic macromolecules with a globular shape similar to a folded protein, and useful in a range of applications including catalysis [31]. Peptide dendrimers, which, like proteins, are composed of amino acids, are particularly well suited as mimics for proteins and enzymes [32]. These dendrimers can be prepared using combinatorial chemistry methods on solid support [33], similar to those used in the context of catalyst and ligand discovery programs in chemistry [34]. Peptide dendrimers used multivalency effects at the dendrimer surface to trigger cooperativity between amino acids, as has been observed in various esterase enzyme models [35]. 

Figure 28 A dendrimer-based approach for the design of globular protein mimic using glutamic (Glu) and aspartic (Asp) acids as the building blocks and adamantyl as the core [151].

Dendrimers are attractive nanosize model compounds because of their globular architecture and their highly functionalized surface. These hyperbranched compounds are synthesized in a repetitive reaction sequence of nearly quantitative reactions. The synthetic route can either be divergent, starting from the nucleus toward the surface, or convergent, where dendrons or wedges are covalently linked to a polyfunctional nucleus. The number of metallodendrimers is still limited.493-506... 

Due to their well defined geometrical sizes, globular shapes, and uniform multiple surface functional groups, dendrimers are promising candidates for the construction of mono- or multi-layer films. 

K. Aoi, K. Itoh, and M. Okada, Globular carbohydrate macromolecules sugar balls Synthesis of novel sugar-persubstituted poly(amido amine) dendrimers, Macromolecules, 28 (1995) 5391-5393. 

Rouhi, M. (2004) High-yield path to dendrimers. Copper-catalyzed reaction offers easy, efficient route to globular molecules. Chem. Eng. News 82(28), 5. 

In the AFM images of Figure 12.15, one can see many separated and randomly deposited globular particles on the mica surface. In each image, the particles appear to be substantially uniform in size, i.e. they are essentially monodisperse. This is not surprising if each bright spot represents a single dendrimer molecule. 

Their results are indicative of a low-density region inside the dendrimer with a considerable end-group interaction in the shell. Similar results were obtained from CHARMm molecular mechanics calculations on the dendritic box (Figure 16.12b), which indicated a globular architecture in which the dendritic interior is... 

The fact that the dendritic shell can produce localized microenvironments has been used by Diederich et al. who developed water-soluble dendritic cyclophanes (dendrophanes) as models for globular proteins (Figure 16.13) [5, 170, 171], These dendrimers contain well-defined cyclophane recognition sites as initiator cores for the complexation of small aromatic guests [172-174] and steroids [174-176], Enlargement of the cyclophane core could be used as a tool to complex larger steroid molecules. 

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