Advances in understanding enzyme catalysis have made possible development of synthetic schemes and strategies to incorporate the essential functions of enzymes into artificial structures. Two of these functions, environmental effect inherent to the active site cavity defined by the protein conformation and cooperative effect of functional groups in the cavity, have been successfully introduced into artificial structures and examined. Illustrative examples of these studies are described, as well as remaining challenges and illustrative application potentials. (C) 2009 Elsevier B.V. All rights reserved.