Distribution of glyoxylate-cycle enzymes between microbodies and mitochondria in Aspergillus tamarii.

The distribution of glyoxylate-cycle enzymes between microbodies and mitochondria was examined in ethanol-grown Aspergillus tamarii Kita. Particulate activities of catalase and the two glyoxylate by-pass enzymes, malate synthase and isocitrate lyase, were localized in the microbodies. The microbodies had a buoyant density of about 1.23 g cm(-3) after isopycnic centrifugation in linear sucrose gradients. Particulate activities of the other two glyoxycitrate synthase, together with that of succinate dehydrogenase were restricted to the mitochondria, which had a buoyant density of about 1.20 g cm(-3). Catalase also appeared to be localized in a second particle, perhaps the microbody inclusions or the Woronin bodies, having a buoyant density of about 1.26 g cm(-3).