Although an X-ray model sequence of a leucine dehydrogenase from Bacillus sphaericus ATCC4525 was reported, the amino acid sequence of this enzyme has not been confirmed. In the current study, this leucine dehydrogenase gene was cloned, sequenced, and over-expressed in Escherichia coli, and the protein sequence has been clarified. This leucine dehydrogenase is not identical with that of B. sphaericus IFO3525 because there are 16 different amino acid residues between these two proteins. Since the information on the catalytic properties of leucine dehydrogenase from B. sphaericus ATCC4525 has been limited, the recombinant enzyme was purified as His-tagged protein and further studied. This enzyme showed activity toward aliphatic substrates for both oxidative deamination and reductive amination and is an effective catalyst for the asymmetric synthesis of alpha-amino acids from the corresponding alpha-ketoacids.
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http://dx.doi.org/10.1007/s12010-008-8304-2 | DOI Listing |
Molecules
December 2024
Department of Biochemistry and Molecular Biology, Graduate School of Medical Science, Yamagata University, Yamagata 990-9585, Japan.
Leucine, isoleucine, and valine are collectively known as branched chain amino acids (BCAAs) and are often discussed in the same physiological and pathological situations. The two consecutive initial reactions of BCAA catabolism are catalyzed by the common enzymes referred to as branched chain aminotransferase (BCAT) and branched chain α-keto acid dehydrogenase (BCKDH). BCAT transfers the amino group of BCAAs to 2-ketoglutarate, which results in corresponding branched chain 2-keto acids (BCKAs) and glutamate.
View Article and Find Full Text PDFNat Commun
January 2025
Institut de Recherche en Cancérologie de Montpellier (IRCM), INSERM U1194, Univ. Montpellier, Institut régional du Cancer de Montpellier (ICM), Montpellier, France.
Pyruvate metabolism defects lead to severe neuropathies such as the Leigh syndrome (LS) but the molecular mechanisms underlying neuronal cell death remain poorly understood. Here, we unravel a connection between pyruvate metabolism and the regulation of the epitranscriptome that plays an essential role during brain development. Using genetically engineered mouse model and primary neuronal cells, we identify the transcription factor E4F1 as a key coordinator of AcetylCoenzyme A (AcCoA) production by the pyruvate dehydrogenase complex (PDC) and its utilization as an essential co-factor by the Elongator complex to acetylate tRNAs at the wobble position uridine 34 (U).
View Article and Find Full Text PDFJIMD Rep
January 2025
Division of Genetics and Genomic Medicine, Department of Pediatrics Washington University School of Medicine St. Louis Missouri USA.
Maple syrup urine disease (MSUD) is an inborn error of metabolism characterized by the accumulation of branched-chain amino acids (leucine, isoleucine, and valine) caused by a defect in the branched-chain alpha-keto acid dehydrogenase complex. Liver transplant is an effective therapy for MSUD, and patients can usually tolerate a regular diet after transplant without symptomatic metabolic decompensation. Most post-transplant patients do not follow a sick-day diet.
View Article and Find Full Text PDFJ Clin Invest
December 2024
Center for Autoimmunity and Inflammation, La Jolla Institute for Immunology, La Jolla, United States of America.
Parkinson's disease (PD) is the second most prevalent neurodegenerative disorder. While there is no curative treatment, the immune system's involvement with autoimmune T cells that recognize the protein alpha-synuclein (α-syn) in a subset of individuals suggests new areas for therapeutic strategies. As not all patients with PD have T cells specific for α-syn, we explored additional autoantigenic targets of T cells in PD.
View Article and Find Full Text PDFNutrients
November 2024
College of Pharmacy, Sahmyook University, Seoul 01795, Republic of Korea.
Men experience Leydig cell and mitochondrial dysfunction due to the accumulation of reactive oxygen species during aging, leading to hormonal imbalances in the body. This results in symptoms of testosterone deficiency syndrome (TDS) as testosterone levels decline. Consequently, there is a growing need for alternative therapies, such as phytotherapy, to regulate testosterone secretion.
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