Trehalose-6-phosphate synthase/phosphatase complex from bakers' yeast: purification of a proteolytically activated form

J Gen Microbiol. 1991 Feb;137(2):323-30. doi: 10.1099/00221287-137-2-323.


A protein of about 800 kDa with trehalose-6-phosphate synthase (TPS) and trehalose-6-phosphate phosphatase (TPP) activity was purified from bakers' yeast. This TPS/P complex contained 57, 86 and 93 kDa polypeptides. The 86 and 93 kDa polypeptides both appeared to be derived from a polypeptide of at least 115 kDa in the native enzyme. A TPS-activator (a dimer of 58 kDa subunits) was also purified. It decreased the Michaelis constants for both UDP-glucose (three-fold) and glucose 6-phosphate (G6P) (4.5-fold), and increased TPS activity at 5 mM-UDP-glucose/10 mM-G6P about three-fold. It did not affect TPP activity. The purification of TPS/P included an endogenous proteolytic step that increased TPS activity about three-fold and abolished its requirement for TPS-activator, but did not change TPP activity. This activation was accompanied by a decrease of some 20 kDa in the molecular mass of a cluster of SDS-PAGE bands at about 115 kDa recognized by antiserum to pure TPS/P, but by no change in the 57 kDa band. Phosphate inhibited TPS activity (Ki about 5 mM), but increased TPP activity about six-fold (Ka about 4 mM). Phosphate (6 mM) stimulated the synthesis of trehalose from G6P and UDP-glucose and decreased the accumulation of trehalose 6-phosphate.

MeSH terms

  • Enzyme Activation
  • Glucose-6-Phosphate
  • Glucosephosphates / metabolism
  • Glucosyltransferases / isolation & purification*
  • Glucosyltransferases / metabolism
  • Kinetics
  • Multienzyme Complexes / isolation & purification*
  • Multienzyme Complexes / metabolism
  • Phosphates / pharmacology
  • Phosphoric Monoester Hydrolases / isolation & purification*
  • Phosphoric Monoester Hydrolases / metabolism
  • Saccharomyces cerevisiae / enzymology*
  • Trehalose / metabolism


  • Glucosephosphates
  • Multienzyme Complexes
  • Phosphates
  • Glucose-6-Phosphate
  • Trehalose
  • Glucosyltransferases
  • trehalose-6-phosphate synthase
  • N-acetylglucosaminyldiphosphoundecaprenol glucosyltransferase
  • trehalose-phosphatase
  • Phosphoric Monoester Hydrolases