distribution and on the presence of the triosephosphate translocator (TPT). This translocator is a well studied Chromoplast membranes from Capsicum fruits were protein (Heldt and Sauer, 1971; Flü gge et al., 1989; fractionated by isopycnic continuous sucrose gradi-Schü nemann et al., 1996; Quick and Neuhaus, 1996) ents resulting in the separation of outer (d=1.08 which is involved in the ... [Show full abstract] phosphate transport across the g cm−3) and inner (d=1.11 g cm−3) envelopes. Both inner envelope membrane. membranes were characterized by marker enzymes In contrast, the outer envelope membrane is freely and with antibodies against the phosphate trans-permeable to molecules with a lower molecular weight, locator. This report is concerned with the location of owing to the presence of porins. The co-ordinated trans-a-tocopherol synthesis in these membranes. port across the plastid envelope is achieved by several transporter proteins located in the inner envelope mem-Key words: Capsicum fruits, chromoplasts, a-tocopherol brane (Cline et al., 1981). Using an antibody against the synthesis, compartmentation, envelope membranes. spinach chloroplast envelope polypeptide E30, the separa-tion of inner and outer envelopes of chromoplasts is demonstrated.