ABSTRACT
References ........................................................................................................................... 20
Nitrilase and nitrile hydratase (NHase) are two classes of enzymes that are finding increasing
use as catalysts for the conversion of nitriles to carboxylic acids and amides, respectively; in
addition, NHases are often used in combination with amidases to produce carboxylic acids.
These reactions can be enantioselective, chemoselective, and/or regioselective, and there are
often no equivalent chemical catalysts that can produce the desired product with the same
selectivity afforded by the enzyme-catalyzed reactions. A large number of publications, patent
applications, and patents describe the preparation and use of these enzyme catalysts, and
numerous reviews of nitrilase-and NHase-catalyzed reactions have been published. The most
recent work in this area has been summarized here, with a focus on the application of these
enzymes as catalysts in synthesis, as well as in process development or in commercial processes.
Nitrilases have been the subject of a number of recent reviews [1-7]. All known nitrilases share a
highly conserved region of amino acid sequence which includes a cysteine that is responsible for
the catalytic activity of the enzyme [1,8]. Themechanism that has been proposed for conversion
2 Biocatalysis in the Pharmaceutical and Biotechnology Industries
