Food Biochemistry and Food Processing (2 edition)

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154 Part 2: Biotechnology and Enzymology

Figure 7.22.Principal scheme of using CAAX-tagged proteins for covalent modification with prenyl transferases.

ENZYME UTILISATION IN INDUSTRY

Enzymes offer potential for many exciting applications in in-

dustry. Some important industrial enzymes and their sources are

listed in Table 7.9. In addition to the industrial enzymes listed

above, a number of enzyme products have been approved for

therapeutic use. Examples include tissue plasminogen activator

and streptokinase for cardiovascular disease, adenosine deami-

nase for the rare severe combined immunodeficiency disease,β-

glucocerebrosidase for Type 1 Gaucher disease,l-asparaginase

for the treatment of acute lymphoblastic leukemia, DNAse for

the treatment of cystic fibrosis and neuraminidase which is being

targeted for the treatment of influenza (Cutler 2003).

There are also thousands of enzyme products used in small

amounts for research and development in routine laboratory

practice and others that are used in clinical laboratory assays.

This group also includes a number of DNA- and RNA-modifying

enzymes (DNA and RNA polymerase, DNA ligase, restriction

endonucleases, reverse transcriptase, etc.), which led to the de-

velopment of molecular biology methods and were a foundation

for the biotechnology industry (Yeo et al. 2004). The clever ap-

plication of one thermostable DNA polymerase led to the PCR

and this has since blossomed into numerous clinical, forensic and

academic embodiments. Along with the commercial success of

these enzyme products, other enzyme products are currently in

commercial development.

Another important field of application of enzymes is in

metabolic engineering. Metabolic engineering is a new ap-

proach involving the targeted and purposeful manipulation of

the metabolic pathways of an organism, aiming at improving

the quality and yields of commercially important compounds.

It typically involves alteration of cellular activities by manipu-

lation of the enzymatic functions of the cell using recombinant

DNA and other genetic techniques. For example, the combina-

tion of rational pathway engineering and directed evolution has

been successfully applied to optimise the pathways for the pro-

duction of isoprenoids such as carotenoids (Schmidt-Dannert

et al. 2000, Umeno and Arnold 2004).