SITE-SPECIFIC INACTIVATION OF PHOTOPHOSPHORYLATION REACTIONS OF ANABAENA VARIABILIS

The photophosphorylation activities of chlorophyll-containing particles from Anabaena variabilis reflect the method of cell disruption. Lysozyme treatment followed by osmotic shock and differential centrifugation yields particle preparations active in both stoichiometric and cyclic phosphorylation. Sonic or mechanical disruption of the cells in 0.4 M sucrose gives particle preparations which are active only in cyclic phosphorylation. Further sonication of these particles in absence of sucrose removes protein essential for cyclic phosphorylation. Cyclic phosphorylation activity can be restored to the depleted particles by readdition of the extracted protein. The depleted particles can catalyze the light-dependent transfer of electrons from reduced indophenol dye to NADP+ only when supplemented with either plastocyanin or cytochrome C554, and the protein required for cyclic photophosphorylation has no effect on this activity. Conversely, plastocyanin and cytochrome C554 have no effect on the restoration of cyclic photophosphorylation. © 1969.