Mitochondrial heterogeneity in Aspergillus nidulans: in vivo protein biosynthetic activities of the mitochondrial populations

Abstract

Two mitochondrial populations with cytochrome c oxidase activity, and densities of 1.07 and 1.08 g/ml have been separated by means of a dextran-sucrose gradient.The highest enzymatic specific activity appeared in the 1.07 g/ml band.The mitochondria assayed by their in vivo cycloheximide resistant leucine incorporation appeared at the 1.08 g/ml density band of the gradient.Some amount of activity of cytochrome c oxidase, and leucine incorporation appeared at the bottom of the gradient.The cytochrome spectra in liquid nitrogen of each band showed different proportion of cytochrome(s) a, b and c.The highest ratio of cytochrome a and cytochrome b in respect to cytochrome c appeared in the 1.08 g/ml band.