STUDIES OF GLUCONEOGENIC MITOCHONDRIAL ENZYMES .I. A NEW METHOD OF PREPARING BOVINE LIVER GLUTAMATE DEHYDROGENASE AND EFFECTS OF PURIFICATION METHODS ON PROPERTIES OF ENZYME

A new simple method of preparing bovine liver glutamate dehydrogenase in pure crystalline form is described. There are no detectable alterations of the properties of the enzyme prepared with this method. Advantages of this method are its simplicity; essentially identical procedures can be used to purify and crystallize the enzyme from livers of other animals, and other mitochondrial enzymes can be conveniently purified from the mitochondrial extract. Since glutamate dehydrogenase is an allosteric enzyme which is localized in the mitochondria, it seems possible that some of the properties of this enzyme could be altered by purification procedures, especially those used to solubilize the enzyme from the mitochondrial fraction. Therefore various methods were used to solubilize and prepare the enzyme. The properties of the solubilized enzyme were essentially the same regardless of which procedures were used. Therefore it seems that the enzyme is not altered by these procedures and that differences between the bovine and other animal glutamate dehydrogenases are due to differences in the primary structure. © 1969.