Is thermostability of glucose-6-phosphatase indeed dependent on a stabilizing protein?

Partial purification of glucose-6-phosphatase from rat liver microsomes by solubilization of the membranes with the non-ionic detergent Triton X-114 at pH 6.5 and the removal of inactivating detergent by hydrophobic chromatography results in a thermostable enzyme protein which is not dependent on stabilizing phospholipids or proteins. The readdition of low amounts of detergent immediately causes a conversion into a thermo-unstable phosphohydrolase protein. Thus these findings present evidence that heat instability of partially purified glucose-6-phosphatase derives from traces of inactivating detergent changing the structural properties of the phosphohydrolase rather than from the absence of the postulated specific stabilizing protein.