l-Alanine Determination with Alanine Dehydrogenase

Publisher Summary This chapter discusses the method of the determination of l -alanine using l -alanine dehydrogenase. This method is applied in biochemistry, clinical biochemistry, and microbiology. It has only been tested on pure solutions and on extracts of liver tissue. The chapter also reviews the specificity, accuracy, and precision of the method. l -Alanine is widely distributed in nature in the free state as well as a constituent of proteins. Therefore, a number of methods for its determination after preliminary chromatographic or electrophoretic separation are available. The color tests, like the gas chromatographic method, are, however, only suitable when amino acid mixtures from peptide or protein hydrolysates are to be analyzed. The chapter discusses a specific enzymatic method for l -alanine determination with glutamate-pyruvate transaminase (GPT) and lactate dehydrogenase (LDH). This method depends on the reaction of l -alanine with 2-oxoglutarate (OxoG) in the presence of (GPT), where the pyruvate formed is determined with the aid of lactate dehydrogenase. It is used in biochemistry and foodstuff chemistry. It can also be carried out fluorimetrically.