The association of glycolytic enzymes from yeast confers resistance against inhibition by trehalose.
During stress, many organisms accumulate compatible solutes. These solutes must be eliminated upon return to optimal conditions as they inhibit cell metabolism and growth. In contrast, enzyme interactions optimize metabolism through mechanisms such as channeling of substrates. It was decided to test the (compatible solute) trehalose-mediated inhibition of some yeast glycolytic pathway enzymes known to associate and whether inhibition is prevented when enzymes are allowed to associate. Trehalose inhibited the isolated glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and hexokinase (HXK), but not aldolase (ALD) nor phosphoglycerate kinase (PGK). When these enzymes were mixed in pairs, both GAPDH and HXK were protected by either ALD or PGK acquiring the inhibition behavior of the resistant enzyme. GAPDH was not protected by HXK, albumin or lactate dehydrogenase (LDH). Also, ALD did not protect glucose 6-phosphate dehydrogenase (G6PDH), suggesting that protection is specific. In yeast cell extracts, fermentation was resistant to trehalose inhibition, suggesting all enzymes involved in the glucose-dependent production of ethanol were stabilized. It is suggested that during the yeast stress response, enzyme association protects some metabolic pathways against trehalose-mediated inhibition.
Instituto de Fisiología Celular, UNAM, Mexico City, Mexico.
Daniela
D
Araiza-Olivera
José G
JG
Sampedro
Adela
A
Mújica
Antonio
A
Peña
Salvador
S
Uribe-Carvajal
D004791:Enzyme Inhibitors; D005634:Fructose-Bisphosphate Aldolase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D005954:Glucosephosphate Dehydrogenase / Q000037:antagonists & inhibitors / Q000378:metabolism; D024581:Glyceraldehyde-3-Phosphate Dehydrogenase (Phosphorylating) / Q000037:antagonists & inhibitors / Q000378:metabolism*; D006019:Glycolysis; D006593:Hexokinase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D007770:L-Lactate Dehydrogenase / Q000037:antagonists & inhibitors / Q000378:metabolism; D010735:Phosphoglycerate Kinase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000254:growth & development / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D014199:Trehalose / Q000378:metabolism* / Q000494:pharmacology
D004791:Enzyme Inhibitors; D029701:Saccharomyces cerevisiae Proteins; D014199:Trehalose; D007770:L-Lactate Dehydrogenase; D005954:Glucosephosphate Dehydrogenase; D024581:Glyceraldehyde-3-Phosphate Dehydrogenase (Phosphorylating); D006593:Hexokinase; D010735:Phosphoglycerate Kinase; D005634:Fructose-Bisphosphate Aldolase