Preparation and Some Properties of Yeast Mitochondria

The biogenesis of mitochondria: 4. The differentiation of mitochondrial and cytoplasmic protein synthesizing systems in vitro by antibiotics

Vacuoles can be isolated by flotation from suspensions of lysed proto-plasts in the presence of Ficoll. The purity of the respective preparations is demonstrated by the complete absence of enzymes of the mitochondria and of the groundplasm, as well as by morphological observations. Hydrolytic enzymes (two acid proteases, p-nitrophenylacetate-esterase, RNase and leucylaminopeptidase) are present in high specific activities in isolated vacuoles. The vacuole therefore represents the lysosome of the yeast cell.

The vacuole as the lysosome of the yeast cell

The redundancy of ribosomal and transfer RNA genes in Saccharomyces cerevisiae.

Mitochondrial DNA. V. A 25 micron closed circular duplex DNA molecule in wild-type yeast mitochondria. Stucture and genetic complexity.

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

Sakae Inoue

Papers

Isolation and properties of intact mitochondria from spheroplasts of yeast