Enzyme analogues

Wulff G, Sarhan A, Zabrocki. K. Enzyme-analogue built polymers and their use for the resolution of racemates. Tetrahedron Lett 1973 44 4329-4332. 

Transition-metal-substituted POMs are oxidatively and hydrolytically stable compared with organometallic complexes, and their active sites can be controlled. These advantages have been applied to the development of biomimetic catalysis relating to enzyme analogues. To date, various kinds of transition-metal-substituted POMs have been synthesized and certain kinds of them can efficiently activate 02 and H202, as described below. 

J. Fraser Stoddart From carbohydrates to enzyme analogues... 

Zimmerman SC, Czarnik AW, Breslow R. Intramolecular general base-acid catalysis in transaminations catalyzed by pyridoxamine enzyme analogues. J. Am. Chem. Soc. 1983 105 1694-1695. 

Molecular imprinting in synthetic polymers was reported for the first time in 1972 [1--4]. The initial idea was to obtain in the polymer highly specific binding clefts with a predetermined size, shape and three-dimensional arrangement of functional groups. Later on, further experiments demonstrated that such functionalised cavities could be tailored to mimic the active sites of enzymes ( enzyme analogue built polymer ). 

In order to see whether or not these polymers display typical enzyme-analogue properties, we investigated the kinetics of the catalysed reaction in the presence... 

Macroheterocycles as enzyme analogues 80MI6, 80YGK361. Macroheterocycles as extractants 84MI9. 

Crown ethers as enzyme analogues 84ACR258 79CSR85. 

Numerous research groups have attempted to make use of the selectivity of MIPs to prepare enzyme analogues with a catalytic activity [71,155-170]. One strategy was to prepare a MIP around a template molecule with a structure similar to that of the substrate. The functional groups that play a catalytic role in the imprinted site are judiciously placed, by interaction with the functional groups on the guest molecule. An example of this strategy, represented in Fig. 19(2) [171, 172] concerns the catalysis of the dehydrofluorination of an... 

Essential characteristics of synthetic enzyme analogues are summarized in the Box on page 460. Many of these features are closely interrelated, such as complexation, saturation kinetics, and substrate selectivity, as well as competitive inhibition by stronger binding substrates, which are less reactive or completely unreactive. Regio- or stereoselectivity, if applicable, can change in comparison to the uncatalyzed process by a variation in structure or by disposition of the transition state, for example, from early to late or from an SN1 to an Sn2 mechanism. 

A Polycyclic Ammonium Salt as Host. Schmidtchen (52, 53) was the first to report examples of enzyme analogue catalysis of nucleophilic substitutions, mostly with aromatic compounds. He synthesized the two highly symmetrical cage compounds I and II (54) (Scheme II) and first examined their ability to form complexes with several anions (25). The smaller host with six methylene units as the spacer (cavity diameter of 4.5 A) showed, for example, association constants of 102 for chloride, 103 for bromide, and 102 for several biologically important anions such as adenosine triphosphate or nicotinamide dinucleotide diphosphate. Whereas the association of anions with I seems to be dominated by electrostatic interactions, the larger... 

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