Partial purification of the protein system controlling the breakdown of trehalose in baker's yeast

Abstract

The inactive form of trehalase as well as its activating protein have been partially purified from resting cells of baker's yeast using (NH 4) 2SO 4 fractionation and subsequent DEAE- and CM-cellulose column chromatography. For its activation by cyclic 3′,5′-AMP the system appeared to be dependent on the presence of ATP and a divalent cation such as Mg 2+, Mn 2+ or Co 2+. No sensitivity towards the pH was observed in the range 6.0 – 7.5. The amount of active trehalase formed was determined by the preincubation time and the concentration of the proteins involved. The activating protein partly lost its dependence on cyclic 3′,5′-AMP during purification. The results presented suggest that this protein may be a protein kinase and that activation of trehalase is associated with phosphorylation of the enzyme protein.