Multienzyme reactions

A one-pot three-enzyme system for the production of a valuable chiral building block has been developed to a 70 g scale leading to 89% isolated yield [(R)-enantiomer]. 

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Guatelli, J. C et al. (1990). Isothermal in vitro amplification of nucleic acids by multienzyme reaction modeled after retroviral replication. Proc. Natl. Acad. Sci. USA 87,1874-1878. 

In summary, the concept of multienzyme reactions with integrated cofactor regeneration has been shown to be useful for sequential synthesis of rather complicated heterooligosaccharides. This conception opens up new perspectives for the synthesis of glycosides having up to three or four different glycosyl units in one-pot reactions. 

GuateUi JC, Whitfield KM, Kwoh DY, Barringer KJ, Richman DD, Gingeras TR. Isothermal, in vitro amphfication of nucleic acids by a multienzyme reaction modeled after retroviral replication. Proc Natl Acad Sci U S A 1990 87 1874-8. 

High catalyst concentration possible No side reaction Simple product recovery No transport limitation Multienzyme reactions possible Cofactor regeneration needed... 

This chapter deals with three important classes of biotransformations. Firstly, those enzymes that catalyse the stereoselective formation of carbon-carbon bonds will be examined. These enzymes, whose natural functions often are to degrade carbohydrate-like molecules, have proved to be versatile catalysts for C—C bond synthesis. Secondly, we shall look at those enzymes that mediate the formation of C—X bonds, where X = O, N, S, Hal (halogen). These enzymes are termed lyases (see Table 2.1) and often carry out very simple reactions (e.g. the addition of water to a double bond) with very high stereoselectivity and regioselectivity. Finally, the application of a range of enzymes (including C—C bond formation) to carbohydrate synthesis will be examined. This chapter will conclude with some examples of the ways in which multienzyme reactions can be constructed to enable highly complex molecules to be assembled in an efficient manner. 

The term control is used here to include the wide variety of factors which may influence the rate of multienzyme reaction sequences. 

A biosynthetic multienzyme reaction of particular interest involves carbon dioxide fixation with the production of methanol [373, 374]. FDH catalyzes the reduction of carbon dioxide to formate, and methanol dehydrogenase (M DH) catalyzes the reduction of formate to methanol. Both of these enzymes require NAD+/NADH-cofactor, and in the presence of the reduced dimethyl viologen mediator (MV +), they can drive a sequence of enzymatic reactions. The cascade of biocatalytic reactions results in the reduction of GO2 to formate catalyzed by FDH, followed by the reduction of formate to methanol catalyzed by MDH. A more complex system composed of immobilized cells of Parococcus deni-trijicans has been demonstrated for the reduction of nitrate and nitrite [375]. 

L-Lactic acid may be produced from carbon dioxide and ethanol by using a multienzyme reaction system, with a designed internal cofactor regeneration loop [1]. 

In multienzyme reactions similar to other cascades the product of one reaction serves as the substrate for the next. 

Many multienzyme reactions function simultaneously in microbial cells and thus analysis of multi-enzyme reactions is essential for understanding processing happening in nature. 

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