Spinach class II chloroplasts were trearted with purified potato galactolipase, and the effects on the photoactivities and the functional proteins were investigated.
A treatment of chloroplasts with the enzyme in the absence of bovine serum albumin caused a marked decrease in NADP photoreduction and a great increase in NADPH-diaphorase activity. This indicates that the ferredoxin-NADP reductase was released from the membranes by the enzyme action. The rate of the release by the lipolytic enzyme was much higher than those of release by sonication with or without Triton X-100. Other treatment with the enzyme in the presence of bovine serum albumin, followed by a separation by density gradient centrifugation, also caused a decrease in photosystem I activity, but the decrease was recovered with addition of plastocyanin. This indicates a release of plastocyanin by the enzyme.