Experimental results from host–guest complexes for the design of effectors in biological systems and of enzyme analogous catalysts
✍ Scribed by Hans-Jörg Schneider; Frank Eblinger; Joachim Sartorius; Jörg Rammo
- Publisher
- John Wiley and Sons
- Year
- 1996
- Tongue
- English
- Weight
- 613 KB
- Volume
- 9
- Category
- Article
- ISSN
- 0952-3499
No coin nor oath required. For personal study only.
✦ Synopsis
Strategies and results for the extraction of biologically important non-covalent binding increments from studies of synthetic host-guest complexes are described with selected examples. Systematic analyses of association constants and the corresponding complex conformations in solution allows us to assign specific values to different pairwise interactions, including salt bridges, amide-type hydrogen bonds, van der Waals effects, and metal ion interactions. A comparison of association constants between selected flexible and rigid ion pairs shows few differences, indicating that different entropy contributions either are small, or cancel with corresponding enthalpy changes, at least in weakly bound complexes. The supramolecular design of enzyme-analogous catalysts is illustrated with complexes containing, e.g. strongly bound yet still active Ln" ions, e.g. in an azacrown ether, and groups which support association with nucleic acids and can serve as nucleophiles. The experimentally observed hydrolysis rate enhancements with such artificial nucleases amount to lo6 and more, both with phenyl phosphates and with ds-DNA.