Purification, characterization, and cDNA cloning of lipoate-activating enzyme from bovine liver
| Autor: | Kazuko Fujiwara, Kazuko Okamura-Ikeda, Yutaro Motokawa, Shinji Takeuchi |
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| Rok vydání: | 2001 |
| Předmět: |
DNA
Complementary GTP' Molecular Sequence Data Dehydrogenase Biology medicine.disease_cause Biochemistry Substrate Specificity Adenosine Triphosphate Cytosol Complementary DNA medicine Animals Magnesium Cloning Molecular Molecular Biology Escherichia coli Peptide sequence chemistry.chemical_classification Mammals Chromatography Glycine cleavage system Polymorphism Genetic Sequence Homology Amino Acid Thioctic Acid Fatty acid Stereoisomerism Cell Biology Chromatography Ion Exchange Molecular biology Nucleotidyltransferases Recombinant Proteins Kinetics Enzyme Durapatite chemistry Amino Acid Substitution Liver Chromatography Gel Cattle Guanosine Triphosphate Sequence Alignment Acyltransferases |
| Zdroj: | The Journal of biological chemistry. 276(31) |
| ISSN: | 0021-9258 |
| Popis: | In mammals, lipoate-activating enzyme (LAE) catalyzes the activation of lipoate to lipoyl-nucleoside monophosphate. The lipoyl moiety is then transferred to the specific lysine residue of lipoate-dependent enzymes by the action of lipoyltransferase. We purified LAE from bovine liver mitochondria to apparent homogeneity. LAE activated lipoate with GTP at a 1000-fold higher rate than with ATP. The reaction absolutely required lipoate, GTP, and Mg(2+) ion, and the reaction product was lipoyl-GMP. LAE activated both (R)- and (S)-lipoate to the respective lipoyl-GMP, although a preference for (R)-lipoate was observed. Similarly, lipoyltransferase equally transferred both the (R)- and (S)-lipoyl moieties from the respectively activated lipoates to apoH-protein. Interestingly, however, only H-protein carrying (R)-lipoate was active in the glycine cleavage reaction. cDNA clones encoding a precursor LAE with a mitochondrial presequence were isolated. The predicted amino acid sequence of LAE is identical with that of xenobiotic-metabolizing/medium-chain fatty acid:CoA ligase-III, but an amino acid substitution due to a single nucleotide polymorphism was found. These results indicate that the medium-chain acyl-CoA synthetase in mitochondria has a novel function, the activation of lipoate with GTP. |
| Databáze: | OpenAIRE |
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