Synzymes Synthetic enzymes

Although polyethyleneimine possesses moderate catalytic effects on several hydrolysis reactions, the polymer modified with long allQrl chains show mudi enhanced reactivity toward hydrophobic substrates. Remaikable catalytic effects were observed in the hydrolysis of phenyl esters and a sulfate ester catalyzed by the methylene-imidazole-modified polymer. These results were explained as arising from the hi y brandied, compact stmcture of the polyediyleneimine derivative. Klotz called the imidazole-containing polyethyleneimine synzyme (synthetic enzyme), on the basis of its stmctural characteristics and catalytic activity which are comparable to hydrolytic enzymes. 

This rigid macromolecular matrix possessing catalytic imidazole groups and micellar hydrophobic regions is the closest enzyme-like synthetic polymer made to date. It has been called synzyme (synthetic enzyme) by Klotz since its reactivity is purported to be of the same order of magnitude as that of an enzyme (171). 

I would like to return to the original theme of synthetic enzymes. I think that Dr. Klotz is being too modest in calling his synzymes mere catalysts. Surely his work is aimed at producing a catalyst as similar as... 

Based on these mechanisms a new frontier in the application of enzymes to biotechnology, including the development of synthetic enzymes (synzymes)82,83 will be exploited. Research on structure-function relationships between ribozymes and abzymes will lead to the development of a number of sequence specific catalysts, which will control expression of a specific gene or its products, and eventually to application as pathogen controls in agriculture and to clinical use. Sequence specific abzymes may also facilitate research on the primary structure determination of protein. 

An edited volume entitled Molecular Movements and Chemical Reactivity as Conditioned by Membranes, Enzymes, and Other Macromolecules includes sections on synzymes (synthetic polymers with enzyme-like catalytic activities), diffusion-reaction in structured media and membranes bearing enzymes, and structures and energetics of proteins and their active sites. ... 

From the practical viewpoint, enzyme-like synthetic catalysts, or syn-zymes, need not be specific for a given reactant structure. In nature enzymes distinguish among closely related molecules and transform only the substrate for which it is specific. Mixtures of molecules may not be involved in the industrial reaction to be catalyzed. Reaction specificity is, of course, a requirement. A synthetic hydrolase should not catalyze other reactions such as decarboxylation. Enzymes bring about rate enhancements of 10 -lO. A synzyme could be of great practical importance with far less efficiency than the natural enzyme if it is cheap and stable. In other words, a near miss in an attempt to mimic enzymes could be a fabulous success. 

Enzyme-like Synthetic Catalysts (Synzymes) G. P. Royer... 

Electrocatalytic groups such as porphyrins and phthalocyanines that act as supramolecular hosts for different metals and mimic the active sites of various proteins are commonly used in amperometric sensors [66,67]. A biomimetic sensor based on an artificial enzyme or synzyme has been demonstrated [68]. The artificial enzyme used in this study was a synthetic polymer (quaternised polyethyleneimine containing 10% primary amines) which decarboxylated oxaloacetate. The product carbon dioxide was detected potentiometrically via a gas membrane electrode. 

Synzymes are synthetic polymers with catalytic activity mimicing that of enzymes. Numerous investigations in search of synzymes have been reported " The main approach for the design of mzyn shas been to modify polymers and mold their conformation to maricedly increase their affinity for small molecules. 

Synzymes, enzyme analogs synthetic macromolecules with enzymatic activity. S. may be prepared by polymerization of amino acids or their derivatives, or by the attachment of catalytic groups to nonprotein materials. Examples of amino acid-derived S. are a glutamic acid-phenylalanine copolymer (Glu ... 

---