ISOLATION AND PROPERTIES OF INTACT MITOCHONDRIA FROM SPHEROPLASTS OF YEAST.

Duell, E. A. (Western Reserve University, Cleveland, Ohio), Sakae Inoue, and Merton F. Utter. Isolation and properties of intact mitochondria from spheroplasts of yeast. J. Bacteriol. 88:1762-1773. 1964.-Functionally intact mitochondria can be obtained in good yields by osmotic disruption of spheroplasts formed from yeast by treatment with an enzyme mixture from the snail digestive tract. The useful range of this method is extended greatly by pretreatment of the yeast cells with 2-mercaptoethylamine and ethylene-diaminetetraacetate. The concentration of the yeast suspension can be increased greatly, the incubation period can be shortened considerably, and the requirement for log-phase cells is obviated. Mitochondria prepared by this method have been compared with those obtained by mechanical disruption in terms of respiratory control, specific activity on a wide range of oxidizable substrates, heterogeneity during centrifugation, and structures observed by electron microscopy. In all cases, the mitochondria obtained from spheroplasts appear to be much less damaged by the preparative procedures.