Usefulness of bacterial thermostable enzymes in clinical chemical analysis

Abstract

Since enzymes have many excellent characteristics, e.g., high substrate and reaction specificities, they have become popular in clinical chemical analysis. However, many of the usual enzymes tend to lose their activities on storage, especially in a solution state, even at rather low temperature, which limits their uses remarkably. On the other hand, enzymes from thermophiles are known to be superior to usual enzymes in thermal and storage stabilities. The author et al. [1] have successfully prepared many thermostable enzymes from a thermophilic bacterium, Bacillus stearothermophilus (BS). Moreover, we have obtained several enzymes from a mesophilic bacterium, Zymomonas mobilis (ZM), and found they also have good thermal stability[2]. In this paper, we show their usefulness as tools in clinical chemical analysis, with focusing the application of two kinds of them, i.e., glucokinase (GlcK, EC 2.7.1.2) and alanine dehydrogenase (AlaDH, EC 1.4.1.1), to the determination of some components in a serum.