CaCl2-washing of O2-evolving PS II particles liberated 33, 24 and 16 kDa proteins concomitant with inactivation of O2 evolution, whereas almost all Mn remained associated with membranes [FEBS Lett. 164 (1983) 252-260], and the lost O2 evolution was significantly restored when 33 kDa protein rebound to the washed membranes [FEBS Lett. 166 (1984) 381-384]. Half of the Mn atoms retained in CaCl2-washed particles were unstably associated with the membrane, being gradually released during incubation in the absence of Ca2+, whereas in the presence of Ca2+ the release of Mn was suppressed concomitant with partial reactivation of O2 evolution. These results were interpreted as indicating that Ca2+ as well as 33 kDa protein maintains the conformation around the Mn-binding sites as required for O2 evolution. © 1984.
Ono, T. aki, & Inoue, Y. (1984). Ca2+-dependent restoration of O2-evolving activity in CaCl2-washed PS II particles depleted of 33, 24 and 16 kDa proteins. FEBS Letters, 168(2), 281–286. https://doi.org/10.1016/0014-5793(84)80263-X