Enzyme-catalyzed reactions stereochemistry

Before leaving this biosynthetic scheme notice that PGE2 has four chirality cen ters Even though arachidomc acid is achiral only the stereoisomer shown m the equa tion IS formed Moreover it is formed as a single enantiomer The stereochemistry is controlled by the interaction of the substrate with the enzymes that act on it Enzymes offer a chiral environment m which biochemical transformations occur and enzyme catalyzed reactions almost always lead to a single stereoisomer Many more examples will be seen m this chapter... 

Vladimir Prelog and John W. Comforth (V. P.) stereochemistry of organic molecules and reactions, (J. C.) stereochemistry of enzyme-catalyzed reactions... 

Williams, G.J., Domann, S., Nelson, A. and Berry, A. (2003) Modifying the stereochemistry of an enzyme-catalyzed reaction by directed evolution. Proceedings of the National Academy of Sciences of the United States of America, 100, 3143-3148. 

NADH. These experiments were pioneering with respect to contemporary enzymology, especially with regard to early recognition that coenzymes are held within enzyme active sites in stereochemically preferred ways. One typically utilizes NADH that contains a tritium or deuterium atom in the 4R or 45 position, and the success or failure of substrate deuteration/tritiation indicates the stereochemistry. Westheimer has tabulated the known examples of dehydrogenases that exhibit specificity for a particular face of NADH. Creighton and Murthy have reproduced this tabulation in their comprehensive review on the stereochemistry of enzyme-catalyzed reactions at carbon. 

John Warcup Cornforth (1917-), Australian-English chemist, receives the Nobel Prize for his work on the stereochemistry of enzyme-catalyzed reaction. Vladimir Prelog (1906- ), Croatian-Swiss chemist, also receives the Nobel Prize in chemistry for his research into the stereochemistry of organic molecules and reactions. 

Williams GJ, Domann S, Nelson A, Berry A. Modifying die stereochemistry of an enzyme-catalyzed reaction by directed evolution. Proc. Natl. Acad. Sci. U.S.A. 2003 100 3143-3148. 

The enzyme-catalyzed reactions involving a proprochiral phosphorus center can be categorized into the following types based on the stereochemistry involved ... 

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