Enzymes in Biocatalysis: Characteristics, Kinetic Approach, Production, and Uses

Enzymes are proteins that efficiently catalyze chemical reactions of specific substrates; they are highly specific for one reaction or a class of reactions, based on the structure of their active sites. This chapter presents the classification according to the nature of the reactions where enzymes are involved as biocatalysts and shows examples of biocatalyzed chemical processes. Kinetic aspects are discussed, and the relevance of the kinetic parameters is highlighted. Inhibitors of enzyme-mediated reactions are also described and classified; their kinetic implications are revealed; besides, examples of enzyme inhibition, examples of pharmacological drug-inhibition are presented. The roles of enzyme cofactors and cosubstrates are described taking examples of biological systems. Enzymes are also used in bioremediation processes and examples are mentioned. Enzyme production strategies developed to enable industrial application are presented, taking lactase as a model example; enzyme preparation, purification, recovery, and stabilization are the key steps in their utilization. Nowadays, with the development of genomics and proteomics, it is possible to access new enzyme activities as well as manipulate, design and improve new and traditional enzyme activities. Biocatalysis is a multidisciplinary area of science that is gaining increasing interest both from a scientific point of view and for its growing industrial applications due to its high specificity in the conversion of substrates into specific products, the reduced volume of waste generated and the non-aggressive operating conditions. Specifically, the enzymes’ use in pharmacological drugs synthesis is remarkably interesting, since they allow to improve both the performance and the stereoselectivity of the active principles.

Keywords: Active-site, Biocatalysis, Chromatography, Classification, Cofactor, Competitive inhibitors, Downstream processing, Enzymes, Immobilization, Inhibitors, Intermolecular Union, Irreversible Union, Isolation, Kinetic aspects, Michaelis- Menten, Non-competitive inhibitors, Purification, Recovery, Reversible Union.