The Discovery of Enzymes

The six main classes of enzymes and the reactions they catalyze. 

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Early basic research on viral infections of E. coli led to the discovery of enzyme systems that protect the bacterium against viral infection. These restriction systems, so-called because they restrict the growth of the virus, were found to be of two general types, differing in their enzymology. Type II systems are now used in recombinant DNA work. 

Enzyme kinetics is studied for two reasons (1) it is a practical concern to determine the activity of the enzyme under different conditions (2) frequently the analysis of enzyme kinetics gives information about the mechanism of enzyme action. Chapter 7, Enzyme Kinetics, begins with an introductory section on the discovery of enzymes, basic enzyme terminology and a description of the six main classes of enzymes and the reactions they catalyze. The remainder of the chapter deals with basic aspects of chemical kinetics, enzyme-catalyzed reactions and various factors that affect the kinetics. 

There are two approaches to the discovery of enzyme mimics, i.e., to identify molecules that are able to bind substrate (s) and then catalyze reactions (Rowan, 1997). The first approach, often inspired by enzymes themselves, utilizes chemical knowledge and experience to design the catalyst The other approach is to create a library and select the best host for a transition-state analog of the required reaction. The second approach, i.e., the combinatorial search, is covered in Chapter 11 the first one is discussed below. This first approach, the finding of enzyme mimics, has been reviewed by Kirby (1996) and Reichwein (1994), among others. 

Metabolomics has proven to be a useful and efficient approach for the discovery of enzyme-substrate interactions, metabolites, and protein-metabolite interactions. As a result, these metabolomics approaches have proven useful functional proteo-mics tools, especially when coupled to methods like ABPP. The continued use of these methods should result in improved methodology and validation of the efficiency of these approaches. 

The discovery of enzyme systems by which D-glucose could be isomerized directly to D-fructose was a key factor in the development of commercial-scale isomerization-processes. These direct systems were developed from fundamental studies of carbohydrate metabolism, in which was identified for the first time an enzyme that catalyzes the isomerization of an unsubstituted sugar, namely, the isomerization of D-erythrose to D-g/ycero-tetrulose.31... 

Comparative Profiling for the Discovery of Enzyme Activities Associated with Discrete Physiological and Pathological States... 

The discovery of enzymes that could selectively break down hyaluronan opened the door for the establishment of the polysaccharide molecule s chemical structure. In those days, a powerful tool for analysing the structure of polysaccharides such as nuclear magnetic resonance spectroscopy NMR was not known. At the present time, NMR makes it possible to determine the monosaccharide biopolymer residue s composition, centres for substitution reactions, sequence and three-dimensional structure. 

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