Phosphoglyceric acid mutase activity without added 2,3-diphosphoglycerate in preparations purified from wheat germ.

The phosphoglyceric acid mutases from Baker’s yeast and rabbit skeletal muscle have been crystallized or highly purified in this laboratory, and a comparative study of the kinetic and molecular properties has been conducted (l-3). The phosphoglyceric acid mutases from these two sources as well as from many others (2, 4) are stimulated by catalytic amounts of 2,3-diphosphoglyceric acid, as was observed previously by Sutherland et al. (5). We found, however, that crude wheat germ extracts and partially purified preparations from these extracts (4) appear not to require 2,3-diphosphoglyceric acid for activity. Moreover, traces of activity at high concentrations of crystalline yeast mutase were observed in the absence of DPG (2).l These observations point towards possible differences in the active site(s) of the enzymes and make highly desirable the purification of the wheat germ mutase in order to conduct additional comparative studies. This paper presents a method for the extensive purification of the 3-phosphoglyceric mutase from wheat germ. A number of the properties of the enzyme are also described.