Maple syrup urine disease: branched-chain amino acid concentrations and metabolism in cultured human lymphoblasts
| Autor: | J. Edwin Seegmiller, Stephen D. Skaper, Daniel P. Molden |
|---|---|
| Rok vydání: | 1976 |
| Předmět: |
Adult
Male Carboxy-Lyases Branched-chain amino acid Biology Biochemistry chemistry.chemical_compound Maple Syrup Urine Disease Valine Leucine Genetics medicine Humans Lymphocytes Amino Acids Isoleucine Molecular Biology Ecology Evolution Behavior and Systematics Cells Cultured chemistry.chemical_classification Maple syrup urine disease Lymphoblast General Medicine Metabolism medicine.disease Amino acid chemistry Cell Division |
| Zdroj: | Biochemical genetics. 14(7-8) |
| ISSN: | 0006-2928 |
| Popis: | The intracellular concentration of free leucine, isoleucine, and valine and their metabolism were studied in lymphoblast cultures established from peripheral blood of an individual with maple syrup urine disease (MSUD) and a control subject. Branched-chain alpha-keto acid decarboxylase activity in the MSUD cells was 10% or less of the control value as measured by the ability of the cells to release 14CO2 from the corresponding [1-14C]labeled branched-chain amino acid. The intracellular concentrations of free leucine and isoleucine were increased three-fold in MSUD lymphoblasts as compared to control cells. Free valine was present in only trace amounts of less than 0.1 mM in both cell lines. Exposure of normal and mutant cells to a 10 mM load of leucine, isoleucine, and valine revealed in a comparable concentration within cells after 24 hr. Concentrations returned to base values in normal cells 12 hr after removal of load, but leucine remained elevated in MSUD cells after 3 days. Leucine and its keto acid, alpha-ketoisocaproic acid, added to the culture medium gave significant growth inhibition of MSUD lymphoblasts but not of normal cells, in the millimolar range. Isoleucine, valine, and their keto acids had no effect. |
| Databáze: | OpenAIRE |
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