Intracellular Conversion of Malate and Localization of Enzymes Involved in the Metabolism of Malate in Photoautotrophic Cell Cultures of Chenopodium rubrum

Cells from photoautotrophic cultures o f Chenopodium rubrum were fractionated for the iso­ lation o f purified chloroplasts and mitochondria. The subcellular localization o f the enzymatic activities involved in the metabolism o f malic acid was investigated. Highly purified chloro­ plasts were obtained from the protoplasts, whereas peroxisomes were still present in the mito­ chondrial fraction. N A D and NADP-dependent malate dehydrogenase and malic enzyme activities were found in the mitochondrial and chloroplast fractions, respectively. Exogenously supplied [14C]labelled malate was metabolized by the photoautotrophic cell suspension, obviously to the greater part in mitochondria.