Functional mimicry of the active site of carboxypeptidase a by a molecular imprinting strategy: cooperativity of an amidinium and a copper ion in a transition-state imprinted cavity giving rise to high catalytic activity.
A model for the natural enzyme carboxypeptidase A was prepared by molecular imprinting in synthetic polymers. An unusually high activity and efficiency for carbonate hydrolysis could be obtained by imprinting with a stable transition-state analogue template and introducing an amidinium group and a Cu2+ ion-binding site in a defined orientation to each other into the active site. With substrates having a very similar structure to the template, extraordinarily high enhancements of rates of 110 000-fold were obtained of catalyzed to uncatalyzed reaction kcat/kuncat . The efficiency kcat/Km of the molecularly imprinted catalysts compared to that of the nonimprinted control polymers containing the same functional groups was 790-fold higher, a clear indication of a very efficient imprinting procedure.
Liu
Jun-Qiu
JQ
Institute of Organic and Macromolecular Chemistry, Heinrich Heine University, 40225 Düsseldorf, Germany.
Wulff
Günter
G
D000577:Amides / Q000737:chemistry*; D001665:Binding Sites / Q000502:physiology; D043422:Carboxypeptidases A / Q000737:chemistry* / Q000502:physiology*; D002384:Catalysis; D003300:Copper / Q000737:chemistry*; D007700:Kinetics; D008956:Models, Chemical; D018716:Molecular Mimicry; D015394:Molecular Structure; D010084:Oxidation-Reduction
D000577:Amides; D003300:Copper; D043422:Carboxypeptidases A