Purification of Constitutive Isoenzymes of Succinate Dehydrogenase from Zea mays Scutellum in the Homogeneous State and the Study of Their Characteristics.

The use of a modified, four-stage purification scheme allowed us to obtain electrophoretically homogeneous preparations of constitutive forms of succinate dehydrogenase from maize (Zea mays L.) scutellum in the late stages of seed germination. It has been established that the isoenzymes differed significantly in their quaternary structure. Thus, succinate dehydrogenase 1 turned out to be a heterotetramer, and succinate dehydrogenase 2 turned out to be a heteroterodimer. It was found that their main catalytic and kinetic characteristics also differed, in particular, by their affinity to the substrate (succinate) and the value of pH optimum of the catalyzed reaction. Succinate dehydrogenase 2 was characterized by enhanced resistance to a specific inhibitor—malonate. [ABSTRACT FROM AUTHOR]