In vivo incorporation of lipoic acid enantiomers and homologues in the pyruvate dehydrogenase complex from Escherichia coli
| Autor: | Sabine Loeffelhardt, Harald Borbe, Mathias Locher, Hans Bisswanger |
|---|---|
| Rok vydání: | 1996 |
| Předmět: |
Pyruvate decarboxylation
Enzyme complex Pyruvate dehydrogenase kinase Biophysics Pyruvate Dehydrogenase Complex Biology Pyruvate dehydrogenase phosphatase Dihydrolipoyllysine-Residue Acetyltransferase Biochemistry chemistry.chemical_compound Acetyltransferases Structural Biology Escherichia coli Molecular Biology Binding Sites Thioctic Acid Stereoisomerism Pyruvate dehydrogenase complex Precipitin Tests Molecular biology Lipoic acid chemistry lipids (amino acids peptides and proteins) Branched-chain alpha-keto acid dehydrogenase complex Oxoglutarate dehydrogenase complex |
| Zdroj: | Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology. 1297:90-98 |
| ISSN: | 0167-4838 |
| DOI: | 10.1016/0167-4838(96)00104-5 |
| Popis: | The strain Escherichia coli JRG26, which has a defect in the lipoic acid biosynthesis, was cultivated in the presence of R-lipoic acid, S-lipoic acid, RS-dithiolane-3-caproic acid, RS-bisnorlipoic acid, and RS-tetranorlipoic acid, respectively. With the exception of the last compound the strain was able to grow with all these substances. R-lipoic acid was the most efficient factor, concentrations of 10 ng/l were sufficient to support growth of the cells, while 10(4)-fold to 10(7)-fold higher concentrations were necessary for the other compounds. The specific catalytic activity of the pyruvate dehydrogenase complex isolated from the cells grown on RS-dithiolane-3-caproic acid was only slightly lower than from cells grown on R-lipoic acid. With RS bisnorlipoic acid the specific activity was one third compared to that of the native enzyme complex. The incorporation of the RS-bisnorlipoic acid into the pyruvate dehydrogenase could directly be demonstrated by polyclonal antibodies directed against R-lipoic acid and RS-bisnorlipoic acid, both conjugated to BSA. Western blot analysis showed that the antibodies against the R-lipoic acid reacted specifically with the E2 component of pyruvate dehydrogenase complex purified from cells grown on this factor, while antibodies against RS-bisnorlipoic acid reacted with the enzyme complex isolated from cells grown in the presence of this compound. |
| Databáze: | OpenAIRE |
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