title: Comparison of Different Effects of Chloroacetates on Electron Transports in PS II and in the Reaction Center of Rb. sphaeroides 601.
abstract: Chloroacetates displayed different effects on electron transports in the photosynthetic reaction center of purple bacteria (Rb.sphaeroides 601) and in the photosystem II (PS II) of higher plants. Decays of chlorophyII a fluorescence measured after actinic flashes show that chloroacetates inhibit the electron transport from Q(A)(-) to Q(B) (Q(B)(-)) and the equilibrium between Q(A)(-)Q(B) (Q(B)(-)) and Q(A)Q(B)(-) (Q(B)(2-)), acting on electron transport as well as proton transduction. The study on PSII electron transport indicates another inhibition site of chloroacetate at the oxidation side of PSII. Chloroacetates up to 500 mM have no inhibition on the DCPIPH(2) right curved arrow MV electron transport in the RS601's chromatophores. Dissociation constants of OP and trichloroacetates from RS601 reaction center were assessed to be 1.1x10(-3) M and from Dixon curve respectively. The differences on aspects of structures and functions between RS601 reaction center and PS II were discussed.
authors.affiliation: Shanghai Institute of Plant Physiology, the Chinese Academy of Sciences, Shanghai 200032, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Yu
authors.forename: Xiao-Hua
authors.initials: XH
authors.lastname: Zeng
authors.forename: Kun-Bao
authors.initials: KB
authors.lastname: Li
authors.forename: Hong-Yu
authors.initials: HY
authors.lastname: Song
authors.forename: Zhang-Yu
authors.initials: ZY
authors.lastname: Zhu
authors.forename: Chun-He
authors.initials: CH
authors.lastname: Xu
authors.lastname: Govindjee