Immunological evidences for a localization of system I on the outside face and of system II on the inside face of the chloroplast lamella

Energy Conservation in Photosynthetic Electron Transport of Chloroplasts

“…Antibodies to photosystem II particles prepared by Briantais & Picaud (58) were less active in agglutinating intact chloro plast lamellae, and an antibody against an antigen on the surface of intact lamellae is not in the antiserum against photosystem II particles. From this the authors (58) supported the model of Arntzen et al (8), mentioned above. However, there is also evidence that the acceptor site of photosystem II is close to the surface of the thylakoid, though still in a lipophilic region and not in the hydrophilic environment (of the matrix).…”

“…Of the antibodies against two different photosystem I fractions, one inhibited photosystem I activity in intact lamellae while the other did so only after disrupture of the membrane, suggesting that one antibody was against the inside and the other against the outside of photosystem I. Briantais & Picaud (58) prepared antibodies against enriched photosystem I and photosystem II preparations as obtained after fractionation of chloroplast membranes with triton. They showed that the antibody against the photosystem I fraction would also react with and precipitate the isolated lamellar system, whereas the antibody against photosystem II would do so to a much lesser extent (57,58). They concluded that photosystem I is therefore accessible in the lamellar system.…”

“…The donor site of photosystem I need not necessarily be located on the inside. An orientation towards the inner fa ce is sufficient if only artificial electron donors antibody against fe rredoxin (123) antibody against S leth (37,238) antibodies against subchloroplast particles (58,176) DABS labeling (74,264) field formation (255,313,314) binary model (8,205) Acceptor precipitation of DAB oxidation product (218,299) no DABS labeling (74) field formation (255,313,314) H+ release inside (at plastohydroquinone) (152,240) PHOTOSYSTEM II proton pump and proton uptake via plastoquinone (152,240) photoreductions by photosystem II (96, 141, 226, 25 1, 287• 289) antibody against plastoquinone and antibody against chlorophyll (234,235,256) antibody against subchloroplast particles (58,176) Acceptor side field fo rmation (255,313,314) accessibility of cytochrome bSS9 (66) new version of binary model (8,205) DABS labeling (92,93) antibody against lutein (234) antibodies against photosystem II approach it from the inner fa ce and, as in the reoxidation of plastohydroquinone in the native chain, release hydrogens inside. The proton uptake from the outside in plastoquinone reduction may very well occur through a protein lipid layer cover ing up the lipophilic quinone from the hydrophilic matrix.…”

Primary Events and the Trapping of Energy

“…In addition, labeling studies using diazonium compounds (Dilley, Peters and Shaw, 1972) or antibodies (Briantais and Picaud, 1972) indicate that these faces differ in their activity, with access to photosystem 1 on the outside and photosystem 2 on the inside of the chloroplast thylakoids. …”