Storage of Plant Mitochondria

Abstract

ONE of the difficulties encountered in the purification of many plant enzymes is their low concentration in the intact cell. When enzymes are contained in the mitochondria, considerable concentration of such enzymes can be achieved by using isolated mitochondria as the starting material for further purification. An example of this approach is the purification of the acetate-activating enzyme of beef heart¹. Millerd and Bonner² have pointed out that the difficulty in using this method in the case of plants is that no convenient sources exist for the isolation of large quantities of plant mitochondria. It has now been found that plant mitochondrial suspensions may be stored in the frozen state for at least thirty days. Although the activity of the mitochondria gradually decreases, the ability to store such suspensions makes possible the accumulation of relatively large quantities of material which can then be Used for the isolation of specific enzymes.