Specific recognition functions

Enzyme Substrate Interaction Specific Recognition, Function and Domain Formation of Phosphoiipase A2 at Lecithin Monolayers... 

By analogy, a great many of other functionalized styrenes, including carboxyHc acids, amino acids, Schiff bases, or specific compounds, eg, l-DOPA, have successfully been appHed as print templates. Moreover, it has also been shown that siUca gel can be imprinted with similar templates, and that the resulting gel has specific recognition sites determined by the print molecule (162—164). 

Cells contain thousands of different proteins. A major problem for protein chemists is to purify a chosen protein so that they can study its specific properties in the absence of other proteins. Proteins have been separated and purified on the basis of their two prominent physical properties size and electrical charge. A more direct approach is to employ affinity purification strategies that take advantage of the biological function or similar specific recognition properties of a protein (see Table 5.5 and Chapter Appendix). 

Built-in functional specific recognition and binding, e.g., antigen binding by antibodies or hybridization of nucleic acids ... 

Another hypothesis was provided by Mikio Shimitso (1982) on the basis of studies of steric effects in molecular models. It had been noted years previously that the fourth nucleotide at the 3 end of the tRNA molecules (referred to as the discrimination base) might have a recognition function. In the case of certain amino acids (i.e., their tRNA-amino acid complexes) this base pair, in combination with the anticodon of the tRNA molecule, can select the amino acid corresponding to the tRNA species in question this is done on the basis of the stereochemical properties of the molecule. Since the anticodon of a tRNA molecule and the fourth nucleotide of the acceptor stem are far apart in space, two tRNA molecules must complex in a head-to-tail manner. The pocket thus formed can then fit specifically to the corresponding amino acid. 

L. Haussling, H. Ringsdorf, F.J. Schimitt, and W. Knoll, Biotin-functionalized self-assembled monolayers on gold-surface-plasmon optical studies of specific recognition reactions. Langmuir 7, 1837-184 (1991). 

The potential binding sites for various SH2 domain proteins on cytoplasmic receptor domains as well as on soluble proteins have been precisely mapped for several pTyr-containing target proteins. Apart from the impressive diversity of SH2 domain function, the fundamental property of all SH2 domains refers to the specific recognition of pTyr epitopes. 

Another beautiful example of multiple recognition by the use of multi-functionalized cyclodextrin is symmetrical triamino-O-permethyl-a-cyclo-dextrin (16), which is designed for the specific recognition for the phosphate group (Fig. 23) (55). As is expected, 16 shows a higher affinity toward benzyl phosphate (Kass = 3.2 x 104) than does the corresponding monoammonium derivative (Kaas = 3.3 x 101). 

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