Thermostable amino acid dehydrogenases: applications and gene cloning

Over the last decade, amino acid dehydrogenases, and in particular leucine dehydrogenase (Leu DH), alanine dehydrogenase (Ala DH) and phenylalanine dehydrogenase (Phe DH) have been applied to the enantiomeric-specific synthesis and analysis of various amino acids. Amino acid dehydrogenases from thermophiles have received much attention because of their high thermostability. Now that the genes for thermostable amino acid dehydrogenases have been cloned into E. coli, enzyme productivity has been enhanced and purification facilitated. The thermostable enzymes are proving very useful as industrial and analytical biocatalysts.