Recognition units

Peptides as Molecular Recognition Units for Receptor Binding. 268... 

In addition to utilizing natural ODNs in block copolymers, ODN mimics have also been studied using polymers with the capability of forming hydrogen bonds. Bazzi and colleagues (Bazzi and Sleiman 2002 Bazzi et al. 2003) have reported diblock and triblock amphiphilic polymers with diamidopyridine (DAP) and dicarboximide moieties as molecular recognition units and studied their micelle formation properties (Chart 2.4). 

Self-Associative Polymer Network. In self-associative polymer networks (often called one component systems), the hydrogen bonding recognition units that are covalently attached to the polymer backbone have an appreciable tendency for self-association, that is, self-dimerize, which leads to interchain cross-linking of the polymers. As a result, the system is inherently cross-linked and does not require any external cross-linking agents for network formation (Fig. 5.11a). Because the cross-linking is based on dimerization phenomena, to achieve effective... 

Gong B, Yan YF, Zeng HQ, Skrzypczak-Jankunn E, Kim YW, Zhu J, Ickes H. A new approach for the design of supramolecular recognition units hydrogen-bonded molecular duplexes. J Am Chem Soc 1999 121 5607-5608. 

Despite the dominance of the a-helical motif as a recognition unit, the /3-sheet motif has been used in a limited number of cases. In these cases (three are known) two chains in the anti-parallel orientation interact with half-sites in adjacent large grooves of the DNA (see fig. 30.28 for an example). (The /3-sheet motif obviously works in these cases de-... 

Supermolecular metallocatalysts, by combining a substrate recognition unit with a catalytic metallic site, offer powerful entries to catalysts presenting shape, regio-and stereoselectivity. 

Endowing these polymolecular entities with recognition units and reactive functional groups may lead to systems performing molecular recognition or supramolecular catalysis on external or internal surfaces of organic (molecular layers, membranes, vesicles, polymers, etc.) [7.1-7.13, A.41] or inorganic (zeolites, clays, sol-gel preparations, etc.) [7.14-7.20] materials. 

Organic supramolecular materials may be devised on the basis of molecular components of various structures bearing recognition units [9.149, 9.235]. As shown above, liquid crystals and liquid crystalline polymers of supramolecular nature presenting various supramolecular textures are generated by the self-assembly of complementary subunits. 

Perisic, O., Xiao, H. Lis, J.T. (1989). Stable binding of Drosophila heat shock factor to head-to-head and tail-to-tail repeats of a conserved 5 bp recognition unit. Cell 59, 797-806. 

This concept could be used for self-organised generation-wise growth of dendri-mers by controlled shell-by-shell construction around the core utilising various recognition units. However, the poor solubility of the multiple amide and urea structural elements has so far made isolation of pure oligomeric products difficult. 

All sensors of the array were exposed simultaneously to the test gases. Dry air was used as a carrier gas. In Fig. 9 the sensor responses of Iipodex E to both enantiomers of halodiether B in a concentration range from 0 to 140 xgl-1 is shown. The interaction between the cyclodextrin-recognition units and the S-enantiomer is stronger than that with the R-enantiomer. 

This problem was overcome by anchoring the recognition unit - zinc cyclene - onto a polymer. [2] Cyclene bearing a vinylbenzyl group was co-polymerised with an ethylene glycol dimethacrylate cross-linker, yielding a solid material (Scheme 2). 

It was found that the polymer exhibited selectivity towards phosphomonoester dianions. Less polar compounds were found to bind non-specifically to the polymer. The polymer was then used as a stationary phase for a HPLC column. A mixture containing dA, 5 -dAMP and 3, 5 -cAMP was thus separated. As expected, the retention time of 5 -AMP was larger than those for dA and 3, 5 -cAMP. The same was tme for other nucleotides compared to the corresponding nucleosides. When the Zn2+-free control polymer was used, all compounds were immediately eluted. The possibility to use polymer-anchored recognition units to separate biologically important phosphates was thus proved. 

A different redox system model - the model for NADH - was also described by our group. [16] As electron transfer mediators, FMN and FAD accept two electrons from NAD(P)H and transfer one electron to metal centres in heme-containing proteins, nonheme iron, or molybdenum sites. However, the transfer of electrons between reduced pyridine - dinucleotide cofactors is slow under physiological conditions and must be catalysed by enzymes. Function of these enzymes was mimicked by a modification of the cofactor by a recognition site for its counterpart and, thus, efficient electron transfer was enabled directly. Functionalised 1,4-dihydronicotinamides bearing a recognition unit for flavins were synthesised (Scheme 18). 

A4] Kim, Daniel Daehoon, et al., Ms identification system and method of identifying a person through Ms recognition, United States Patent 6.247.813, June 19, 2001... 

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