Heat inactivation of oxygen evolution by isolated Photosystem II particles was accelerated by Cl- depletion and exogenous Mn2+. Weak red light also accelerated heat inactivation. Heat treatment released the 33, 24 and 18 kDa proteins and Mn from the Photosystem II particles. The protein release was stimulated by Cl- depletion and exogenous Mn2+, and the Mn release was also stimulated by Cl- depletion. A 50% loss of Mn corresponded to full inactivation of oxygen evolution, whereas no direct correlation seemed to exist between the loss of any one protein and inactivation of oxygen evolution. Removal of the 24 and 18 kDa proteins from photosystem II particles only slightly decreased the heat stability of oxygen evolution.
ASJC Scopus subject areas
- Cell Biology