background and objectives: leucine dehydrogenase (leudh; ec 1.4.1.9) belongs to the amino acid dehydrogenase family and isused as a biocatalyst in medical and pharmaceutical industries (1). this study reported deals with the isolation and characterization of leudh from a thermophilic bacterium isolated from jask port in the province of hormozgan. materials and methods: aliquots of soil and wate...

BACKGROUND AND OBJECTIVES Leucine dehydrogenase (LeuDH; EC 1.4.1.9) belongs to the amino acid dehydrogenase family and isused as a biocatalyst in medical and pharmaceutical industries (1). This study reported deals with the isolation and characterization of LeuDH from a thermophilic bacterium isolated from Jask Port in the Province of Hormozgan. MATERIALS AND METHODS Aliquots of soil and wate...

Abstract Background Biosynthesis of l - tert -leucine ( -tle), a significant pharmaceutical intermediate, by cofactor regeneration system friendly and efficiently is worthful goal all the time. The leucine dehydrogenase (LeuDH) glucose (GDH) has showed great coupling catalytic efficiency in synthesis -tle, however multi-enzyme complex GDH LeuDH never been constructed successfully. Results In th...

On the basis of sequence comparison between NAD+-dependent leucine dehydrogenase (LeuDH) from Thermoactinomyces intermedius and NADP+-dependent dehydrogenases, a set of amino acid residues that are supposed to determine the coenzyme specificity of LeuDH were assigned. Systematic replacement of these amino acids by others was done with the aim to switch its natural coenzyme specificity to a new ...

Leucine and monomethyl succinate initiate insulin release, and glutamine potentiates leucine-induced insulin release. Alanine enhances and malate inhibits leucine plus glutamine-induced insulin release. The insulinotropic effect of leucine is at least in part secondary to its ability to activate glutamate oxidation by glutamate dehydrogenase (Sener, A., Malaisse-Lagae, F., and Malaisse, W. J. (...

A continuous procedure for the determination of leucine aminopeptidase is described. L-leucinamide is used as substrate and the liberated ammonia is determined with the glutamate dehydrogenase reaction. The enzyme is Mn2+-activated and 30 mumol/l MnCl2 is necessary for an optimal activity measurement. Influence of buffer type, buffer concentration and pH are reported together with the apparent ...

Amino acids, leucine in particular, are known to inhibit autophagy, at least in part by their ability to stimulate MTOR-mediated signaling. Evidence is presented showing that glutamate dehydrogenase, the central enzyme in amino acid catabolism, contributes to leucine sensing in the regulation of autophagy. The data suggest a dual mechanism by which glutamate dehydrogenase activity modulates aut...

Much evidence has accumulated to support the idea that leucine can stimulate insulin release by allosterically activating glutamate dehydrogenase thus enhancing glutamate metabolism. It is less clear how the metabolism of leucine itself contributes to the signal for insulin release. We recently found that culturing pancreatic islets for 1 day at low glucose (1 mM) suppressed glucose-induced ins...

We describe a simple method for enzymatic synthesis of L and D amino acids from a-keto acids with Escherichia coli cells which express heterologous genes. L-amino acids were produced with thermostable L-amino acid dehydrogenase and formate dehydrogenase (FDH) from a-keto acids and ammonium formate with only an intracellular pool of NAD for the regeneration of NADH. We constructed plasmids conta...