RESUMO
The dependence of the flux in the alcohol-degrading pathway on the activity of alcohol dehydrogenase was investigated in Drosophila larvae. Third-instar larvae were supplied with [2-13C]ethanol as a dietary carbon source. Specific carbon enrichments in de novo synthesized fatty acids were determined in vitro by means of 13C nuclear magnetic resonance spectroscopy. Carbon fluxes deduced from these enrichment patterns were correlated with the in vitro alcohol dehydrogenase activities in three different Adh genotypes in seven different strains. The flux control coefficient for alcohol dehydrogenase was shown to be approximately 1.0. This indicates that the alcohol dehydrogenase gene-enzyme system in Drosophila larvae can be a major target of natural selection.
Assuntos
Álcool Desidrogenase/metabolismo , Drosophila/metabolismo , Etanol/metabolismo , Isoenzimas/metabolismo , Metabolismo dos Lipídeos , Álcool Desidrogenase/genética , Animais , Isótopos de Carbono , Drosophila/genética , Genótipo , Isoenzimas/genética , Cinética , Larva , Espectroscopia de Ressonância Magnética/métodosRESUMO
Both aldehyde dehydrogenase (ALDH, EC 1.2.1.3) and the aldehyde dehydrogenase activity of alcohol dehydrogenase (ADH, EC 1.1.1.1) were found to coexist in Drosophila melanogaster larvae. The enzymes, however, showed different inhibition patterns with respect to pyrazole, cyanamide and disulphiram. ALDH-1 and ALDH-2 isoenzymes were detected in larvae by electrophoretic methods. Nonetheless, in tracer studies in vivo, more than 75% of the acetaldehyde converted to acetate by the ADH ethanol-degrading pathway appeared to be also catalysed by the ADH enzyme. The larval fat body probably was the major site of this pathway.
Assuntos
Acetaldeído/metabolismo , Álcool Desidrogenase/metabolismo , Aldeído Desidrogenase/metabolismo , Drosophila melanogaster/enzimologia , Etanol/metabolismo , Animais , Eletroforese em Gel de Poliacrilamida , Isoenzimas/metabolismo , Larva/enzimologia , Espectroscopia de Ressonância Magnética , EspectrofotometriaRESUMO
Virgidivarine, C (15)H (26)N (2)O (2), is a new dipiperidine alkaloid, isolated from the South African Virgilia divaricata Leguminosae. Its systematic name is 3-carboxy-N-(4'-butenyl)-5-(2'-piperidyl) piperidine.