Regulation of enzymes and isoenzymes of carbohydrate metabolism in the yeast Saccharomyces cerevisiae.
Biochim Biophys Acta
; 799(2): 181-6, 1984 Jun 15.
Article
en En
| MEDLINE
| ID: mdl-6329315
ABSTRACT
An electrophoretic method has been devised to investigate the changes in the enzymes and isoenzymes of carbohydrate metabolism, upon adding glucose to derepressed yeast cells. (i) Of the glycolytic enzymes tested, enolase II, pyruvate kinase and pyruvate decarboxylase were markedly increased. This increase was accompanied by an overall increase in glycolytic activity and was prevented by cycloheximide, an inhibitor of protein synthesis. (ii) In contrast, respiratory activity decreased after adding glucose. This decrease was clearly shown to be the result of repression of respiratory enzymes. A rapid decrease within a few minutes of adding glucose, by analogy with the so-called ' Crabtree effect', was not observed in yeast. (iii) The gluconeogenic enzymes, fructose-1,6-bisphosphatase and malate dehydrogenase, which are inactivated after adding glucose, showed no significant changes in electrophoretic mobilities. Hence, there was no evidence of enzyme modifications, which were postulated as initiating degradation. However, it was possible to investigate cytoplasmic and mitochondrial malate dehydrogenase isoenzymes separately. Synthesis of the mitochondrial isoenzyme was repressed, whereas only cytoplasmic malate dehydrogenase was subject to glucose inactivation.
Buscar en Google
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Saccharomyces cerevisiae
/
Gluconeogénesis
/
Glucólisis
Idioma:
En
Revista:
Biochim Biophys Acta
Año:
1984
Tipo del documento:
Article