Purification of trehalose synthase from baker's yeast. Its temperature-dependent activation by fructose 6-phosphate and inhibition by phosphate.
A trehalose synthase purified from baker's yeast contained 56-kDa, 102-kDa and 123-kDa polypeptides as its main components. The 102-kDa polypeptide was isolated and shown to be a specific trehalose-6-phosphatase. The trehalose-6-phosphate synthase (Tre6P synthase) activator described by Londesborough and Vuorio [(1991) J. Gen. Microbiol. 137, 323-330] was shown to be phosphoglucoisomerase and to function entirely by generating fructose 6-phosphate. Below 35 degrees C, fructose 6-phosphate is a powerful activator of the Tre6P synthase activity of intact trehalose synthase, especially at physiological phosphate concentration, but does not affect its trehalose-6-phosphatase activity nor the Tre6P synthase activity of truncated trehalose synthase containing truncated versions of the 123-kDa polypeptide. At 50 degrees C, activation by fructose 6-phosphate and inhibition by phosphate are greatly decreased, resulting in an unusually high temperature-dependence for the Tre6P synthase activity at a physiological phosphate concentration (2 mM).
Londesborough
J
J
Research Laboratories, Alko Ltd, Helsinki, Finland.
Vuorio
O E
OE
D000595:Amino Acid Sequence; D015153:Blotting, Western; D002848:Chromatography, DEAE-Cellulose; D004591:Electrophoresis, Polyacrylamide Gel; D004789:Enzyme Activation; D005636:Fructosephosphates / Q000494:pharmacology*; D005956:Glucose-6-Phosphate Isomerase / Q000737:chemistry / Q000494:pharmacology; D005964:Glucosyltransferases / Q000037:antagonists & inhibitors / Q000302:isolation & purification* / Q000378:metabolism; D008969:Molecular Sequence Data; D010755:Organophosphates / Q000494:pharmacology*; D010449:Peptide Mapping; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D013696:Temperature
D005636:Fructosephosphates; D010755:Organophosphates; C027618:fructose-6-phosphate; D005964:Glucosyltransferases; C023180:trehalose-6-phosphate synthase; D005956:Glucose-6-Phosphate Isomerase