SYNTHETIC-POLYMERS AS MODELS FOR ENZYME CATALYSIS - REVIEW

Cyclodextrins, crown ethers, cyclophanes, oligopeptides, homopolymers, modified homopolymers, ion exchange resins and various copolymers are considered as models of enzyme catalysis. The importance of hydrophobic, electrostatic and hydrogen-bonding interactions is discussed. Factors, such as complex formation, that contribute to specific binding and catalysis are examined in terms of binding constants and rate enhancement factors. The effectiveness of the various model catalysts is compared with that of natural enzymes. The nature and evolution of enzyme catalytic power is discussed in terms of the relative importance of induced fit, angular relationships, rotational restriction, transition-state binding, strain, coupled group motions, entropy reduction on complex formation and diffusional limitation. It is concluded that much further effort will be required in order to realise model catalyst that are fully characteristic of natural enzymes although impressive progress has been made in recent years. Criteria for future effort are outlined together with some tactical considerations. The potential usefulness and applications of model-enzyme catalysts are discussed briefly. © 1979.