Pyrimidine degradation in tomato cell suspension cultures and in Euglena gracilis: localization of enzymes

摘要: Abstract 1. Subcellular location of dihydropyrimidinase and NCβA-amidohydrolase† was studied in a cell suspension culture tomato ( Lycopersicon esculentum cv. Lukullus) Euglena gracilis . 2. By differential centrifugation, crude extracts were separated into ten fractions. Activities both enzymes found mainly cytosolic fractions marked by EDH (tomato) glu-6-P-DH E. ). 3. A also 20–60% 17.5–30% sucrose density gradients. 4. Using mitochondrial marker such as fumarase, SDH, CS MDH, occurrence or their release from mitochondria can be excluded gradient centrifugations. This achieved using purified prepared cells two subsequent 5. possible vacuolar NCβA-amidohydrolase comparing activities isolated protoplasts vacuoles which characterized enzyme α-mannosidase. 6. nuclear and/or the nucleus during procedures used cannot excluded. 7. The results are discussed relation to subcellular other pyrimidine-metabolizing plant cells.