Charakterisierung der Phosphorylase aus Kartoffeln durch Ultrazentrifuge und Gelpermeationschromatographie

Characterization of Potato Phosphorylase by Ultracentrifugation and Gel Permeation Chromatography. Potato phosphorylase was characterized by ultracentrifugation and gel permeation chromatography. The sedimentation constant was determined by sedimentation transport measurements at protein concentrations of 2 to 20 mg/ml. Using the equation of Scholtan the molecular weight of phosphorylase was found to be 200 000. The same value was obtained by gel permeation chromatography. In all experiments the phosphorylase behaved as a homogeneous component, whereas the measurements of sedimentation equilibrium showed a concentration dependence of the molecular weight indicating dissoziation of the phosphorylase protein into two components with a molecular weight of each 90 000. As the dissoziation of the phosphorylase into two subunits didn't bring about either an inactivation or a change of the specific activity the existence of an enzymatically active protein with a molecular weight of 90 000 is to be assumed.